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Abstract

Breeding at the right time is essential for animals in seasonal climates in order to ensure that the energy demands of reproduction, particularly the nutritional requirements of growing young, coincide with peak food availability. Global climate change is likely to cause shifts in the timing of peak food availability, and in order to adapt successfully to current and future climate change, animals need to be able to adjust the time at which they initiate breeding. Many animals use environmental cues available before the breeding season to predict the seasonal peak in food availability and adjust their phenology accordingly. We tested the hypothesis that regulation of breeding onset should reflect the scale at which organisms perceive their environment by comparing phenology of three seabird species at a North Sea colony. As predicted, the phenology of two dispersive species, black-legged kittiwake (Rissa tridactyla) and common guillemot (Uria aalge), correlated with a large-scale environmental cue (the North Atlantic Oscillation), whereas a resident species, European shag (Phalacrocorax aristotelis), was more affected by local conditions (sea surface temperature) around the colony. Annual mean breeding success was lower in late years for European shags, but not for the other two species. Since correlations among climate patterns at different scales are likely to change in the future, these findings have important implications for how migratory animals can respond to future climate change.

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... While identifying a set of candidate environmental conditions and spatial scales is relatively straightforward for ectotherms that respond directly to temperature (Visser & Both, 2005) and species that are rooted/sessile or have small year-round ranges (Lindestad, Wheat, Nylin, & Gotthard, 2018), species at higher trophic levels and that are wide-ranging present a much greater challenge. For instance, wideranging species may respond to cues or conditions in the area where they breed (Frederiksen et al., 2004), at their wintering areas (Dobson et al., 2017;Szostek, Bouwhuis, & Becker, 2015), or both (Harrison, Blount, Inger, Norris, & Bearhop, 2011). ...
... They can forage at great distances from the breeding site during the breeding season, and have some of the longest migrations known in the animal kingdom (Egevang et al., 2010). Although many seabird species winter far from their colonies, many also spend time at the breeding site before egg laying commences, such that conditions at both breeding (Frederiksen et al., 2004;Love et al., 2010) and wintering grounds (Dobson et al., 2017;Szostek et al., 2015) may affect breeding phenology. ...
... As kittiwakes are restricted to foraging on the water's surface, this may make them more responsive to environmental effects on local conditions than other species that can dive (Furness & Tasker, 2000). It is evident that kittiwakes may therefore be sensitive to environmental conditions across multiple spatial scales (Frederiksen et al., 2004). ...
Article
1. Timing of breeding, an important driver of fitness in many populations, is widely studied in the context of global change, yet despite considerable efforts to identify environmental drivers of seabird nesting phenology, for most populations we lack evidence of strong drivers. Here we adopt an alternative approach, examining the degree to which different populations positively covary in their annual phenology to infer whether phenological responses to environmental drivers are likely to be (i) shared across species at a range of spatial scales, (ii) shared across populations of a species, or (iii) idiosyncratic to populations. 2. We combined 51 long‐term datasets on breeding phenology spanning 50 years from nine seabird species across 29 North Atlantic sites and examined the extent to which different populations share early versus late breeding seasons depending on a hierarchy of spatial scales comprising breeding site, small‐scale region, large‐scale region and the whole North Atlantic. 3. In about a third of cases we found laying dates of populations of different species sharing the same breeding site or small‐scale breeding region were positively correlated, which is consistent with the hypothesis that they share phenological responses to the same environmental conditions. In comparison we found no evidence for positive phenological covariation among populations across species aggregated at larger spatial scales. 4. In general we found little evidence for positive phenological covariation between populations of a single species, and in many instances the inter‐year variation specific to a population was substantial, consistent with each population responding idiosyncratically to local environmental conditions. Black‐legged kittiwake (Rissa tridactyla) was the exception, with populations exhibiting positive covariation in laying dates that decayed with the distance between breeding sites, suggesting that populations may be responding to a similar driver. 5. Our approach sheds light on the potential factors that may drive phenology in our study species, thus furthering our understanding of the scales at which different seabirds interact with interannual variation in their environment. We also identify additional systems and phenological questions to which our inferential approach could be applied.
... Population counts of breeding pairs were available for each year, collected using standardised methods (Walsh et al., 1995). positively correlated with SST in the same time period (Frederiksen et al., 2004). We averaged the monthly records to obtain a mean late winter temperature for each year. ...
... At the population level, we found timing of breeding to be a negative correlate of fitness, which accords with previous studies (Clutton-Brock, 1988;Frederiksen et al., 2004). This result is in keeping with the MMH in the situation where the consumer is showing no response to temperature and marked inter-annual variation, as shown in Scenario A in Figure 1a. ...
... In this scenario, better matching of peak demands and availability of resources in earlier years has a positive effect on fitness. Improved synchrony may enable shags to lay more eggs on average, as has been found in populations on Sklinna and Røst, Norway (Lorentsen et al., 2015), or to have fewer losses during incubation or chick-rearing in comparison to late years, as has been found previously on the Isle of May (Daunt et al., 2007;Frederiksen et al., 2004). However, alternative explanations could produce the same inter-annual patterns. ...
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1. As temperatures rise, timing of reproduction is changing at different rates across trophic levels, potentially resulting in asynchrony between consumers and their resources. The match-mismatch hypothesis (MMH) suggests that trophic asyn-chrony will have negative impacts on average productivity of consumers. It is also thought to lead to selection on timing of breeding, as the most asynchronous individuals will show the greatest reductions in fitness. 2. Using a 30-year individual-level dataset of breeding phenology and success from a population of European shags on the Isle of May, Scotland, we tested a series of predictions consistent with the hypothesis that fitness impacts of trophic asyn-chrony are increasing. 3. These predictions quantified changes in average annual breeding success and strength of selection on timing of breeding, over time and in relation to rising sea surface temperature (SST) and diet composition. 4. Annual average (population) breeding success was negatively correlated with average lay date yet showed no trend over time, or in relation to increasing SST or the proportion of principal prey in the diet, as would be expected if trophic mismatch was increasing. At the individual level, we found evidence for stabilising selection and directional selection for earlier breeding, although the earliest birds were not the most productive. However, selection for earlier laying did not strengthen over time, or in relation to SST or slope of the seasonal shift in diet from principal to secondary prey. We found that the optimum lay date advanced by almost 4 weeks during the study, and that the population mean lay date tracked this shift. 5. Our results indicate that average performance correlates with absolute timing of breeding of the population, and there is selection for earlier laying at the individual level. However, we found no fitness signatures of a change in the impact of climate‐induced trophic mismatch, and evidence that shags are tracking long‐term shifts in optimum timing. This suggests that if asynchrony is present in this system, breeding success is not impacted. Our approach highlights the advantages of examining variation at both population and individual levels when assessing evidence for fitness impacts of trophic asynchrony.
... First, we tested whether the relationship between breeding productivity of black-legged kittiwakes Rissa tridactyla, sea surface temperature (SST) and fishery was consistent between colonies within a region. Breeding productivity (number of fledged chicks per nest built) of kittiwakes on the Isle of May, SE Scotland, is strongly negatively related to late winter SST in the previous year and to the presence of an industrial (fishmeal) fishery for lesser sandeels Ammodytes marinus, the main prey during the breeding season (Frederiksen et al. 2004). Kittiwake breeding productivity has also been monitored under the UK Seabird Monitoring Programme at 6 other colonies in the same region of the NW North Sea (E Scotland and NE England; Fig. 1), as defined by sandeel population structure and correlations between kittiwake breeding productivity time series (Frederiksen et al. 2005, Mavor et al. 2005. ...
... Kittiwake breeding productivity has also been monitored under the UK Seabird Monitoring Programme at 6 other colonies in the same region of the NW North Sea (E Scotland and NE England; Fig. 1), as defined by sandeel population structure and correlations between kittiwake breeding productivity time series (Frederiksen et al. 2005, Mavor et al. 2005. We repeated the analysis of Frederiksen et al. (2004) for the Isle of May and these other colonies, as well as for the mean breeding productivity in the region, based on data from 1986 to 2004. The fishery was scored as present in 1991 to 1998, and mean February/ March SSTs from this region were obtained from the German Bundesamt für Seeschifffahrt und Hydrographie (www.bsh.de). ...
... The positive trend since 1990 (Fig. 4) thus implies that, relative to the alcids, these 2 species have done better in recent years, even though kittiwake breeding productivity has declined over the study period when viewed in isolation (cf. Frederiksen et al. 2004). ...
... Georgia (Croxall and Prince 1980), Crozet (Jouventin et al. 1985) and Kerguelen Islands Conversely, this difference could be linked to the predictability of food resources in the vicinity of the breeding areas (Frederiksen et al. 2004). In south-eastern Australia and New Zealand, the locally abundant coastal krill Nyctiphanes australis (Young et al. 1993) is a key food source for CDP (Fromant et al. 2020a, Miskelly pers. ...
... However, this euphausiid undergoes extreme inter-annual variations in biomass and distribution, considerably affecting the reproductive success of various fish (Young et al. 1993) and seabird species (Mills et al. 2008, Manno et al. 2014). Populations spending a long period near the colony before the reproductive season are more likely to follow local environmental cues to adapt their phenology (Frederiksen et al. 2004), which may explain the significant delay in the breeding period observed between the years in the present study at Kanowna Island . In contrast, CDP at ...
Thesis
Exploring a species’ ecological niche entails investigating at multiple scales, as different environmental threats and niche constraints between intra-species levels may lead to important ecological and conservation consequences. However, the absence of precise information about small procellariiform species ecology has greatly limited ecological niche modelling studies, directly impacting our ability to delineate proper conservation planning. Technological advancements in the miniaturisation of data loggers have made it possible to collect ecological data of such species. In the present study, a multi-tooled approach was used to investigate the ecological niche of the common and the South-Georgian diving petrels. The primary objectives were to: 1) describe their foraging ecology during the breeding and non-breeding periods, and investigate their inter-annual variations; 2) determine the ecological differences between populations throughout the Southern Ocean; and 3) study the variations in their foraging ecology throughout the entire annual-cycle in the context of niche segregation between two sibling species. The results demonstrated that diving petrels exhibit remarkable flying abilities despite their high wing loading, foraging over large areas during the breeding season, and migrating several thousands of kilometres from their colony during the post-breeding period. These analyses revealed important ecological differences throughout the species distribution, particularly in terms of phenology and migration area. Collecting data over several years substantially strengthens results and provides valuable information to understand the variations and the limits of diving petrel ecological niches. Finally, a stage-dependent and context-dependent niche segregation analysis demonstrated the importance of a multi-tooled approach to better describe and understand the co-existence of ecologically similar species.
... Rubolini et al. 2005, Both & te Marvelte 2007, Maggini et al. 2020. Some species, like the Black-legged Kittiwake Rissa tridactyla and Common Guillemot Uria aalge, breeding in the North Sea area, indeed show tendencies towards later reproduction over time (Frederiksen et al. 2004). The authors correlated this trend with population size, as progressively later breeding of Black-legged Kittiwakes was associated with low population density (Frederiksen et al. 2004). ...
... Some species, like the Black-legged Kittiwake Rissa tridactyla and Common Guillemot Uria aalge, breeding in the North Sea area, indeed show tendencies towards later reproduction over time (Frederiksen et al. 2004). The authors correlated this trend with population size, as progressively later breeding of Black-legged Kittiwakes was associated with low population density (Frederiksen et al. 2004). An explanation that could apply to our declining Lanner Falcon population, but not to the stable/increasing Peregrine population. ...
... Links among sand lance, seabirds, and climate in the North Atlantic were obscure until very recently, and remain complex (Frederiksen et al. 2004;Wanless et al. 2007). Part of the apparent absence of such a link was due to the complicated effects that changing temperatures have had upon atmospheric and oceanic circulation in the North Atlantic (as compared, for example, with either the Antarctic or eastern Pacific). ...
... For example, fledging success of Atlantic Puffins in Norway was found to depend on availability of yearling Atlantic Herring, which in turn depends on sea temperature (Durant et al. 2003). Reproductive success of Black-legged Kittiwakes in the North Sea depends on the condition of sand lance eaten by kittiwakes just prior to breeding, and sand lance condition depends on sea temperature, mediated through phytoplankton and copepods (Frederiksen et al. 2004;Wanless et al. 2007). ...
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Summarizes the current and historical status of all seabirds nesting on the East Coast of the United States, including the Bay of Fundy
... Поскольку формирование яиц у розовых чаек происходит непосредственно на местах гнездования, на основе местных кормовых ресурсов, при низких температурах в предгнездовой сезон бóльшая часть полученной энергии идет на поддержания физиологических потребностей организма. Среди чайковых сходные закономерности были обнаружены у моевок (Rissa tridactyla) в арктических районах (Murphy et al., 1991;Gaston et al., 2005;Moe et al., 2009), хотя в умеренной зоне, например в Шотландии, эта тенденция уже не проявлялась (Frederiksen et al., 2004). ...
... Например, в Канаде у толстоклювой кайры (Uria lomvia) в низких широтах гнездовой сезон сдвигается в соответствии с изменением климата, а в высокоартических районах этого не происходит (Gaston et al., 2005(Gaston et al., , 2009. Ряд исследований показывают, что потепление климата ведет как к более раннему началу гнездования у некоторых видов (Catharacta maccormicki, Fratercula cirrhata, Sterna paradisaea, Uria lomvia), так и к его отсрочке на более поздние даты у других (Daption capense, Fulmarus glacialis, Pygoscelis adeliae, Rissa tridactyla, Uria aalge), или отсутствию выраженных изменений (Aptenodytes forsteri, Fratercula arctica, Fulmarus glacialis, Pagodroma nivea, Ptychoramphus aleuticus) (Gjerdrum et al., 2003;Abraham, Sydeman, 2004;Frederiksen et al., 2004;Durant et al., 2004;Gaston et al., 2005Gaston et al., , 2009Barbraud, Weimerskirch, 2006;Møller et al., 2006;Moe et al., 2009;Reed et al., 2009;Wanless et al., 2009). Разная реакция на современные климатические изменения у видов со сходной экологией может свидетельствовать о наличии во многих случаях более существенных факторов, помимо климатических. ...
Article
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Data on spring phenology and reproductive parameters of the Ross's Gull were collected in 1982–2013 on the delta of Lena River, northern Yakutia (71°42′–74° N, 120°–129°30′ E). During this period, significant changes in weather occurred, the mean annual temperature (F1,27 = 7.74, p < 0.04), the mean June temperature (F1,27 = 11.75, p < 0.002), the summer temperature (F1,27 = 9.13, p < 0.005) increased, and the mean daily air temperatures crossing 0°C shifted to earlier dates (F1,26 = 14.73, p < 0.001). However, the duration of the period with positive temperatures slightly increased (F1,26 = 3.53, p < 0.07). The arrival of Ross's Gulls to the Lena Delta depended by mean June temperatures (r = –0.48, p < 0.01), minimal June daily temperatures (r =–0.70, p < 0.001), and dates of snow melting (r = 0.62, p < 0.05). The maximum amplitude of fluctuations in eggs numbers among all arctic gulls was revealed for complete clutches of the Ross's Gull. In more northern regions, this amplitude was higher. The clutch size was negatively correlated with dates of clutch initiation, the females that began to nest earlier showing larger clutch sizes (r = –0.85, p < 0.002). The clutch size decreased in years with lower temperatures of the prenesting period, after gulls arrival and before the onset of breeding (F1,172 = 27.31, p < 0.00001), and after relatively colder June temperatures (F1,172 = 8.86, p < 0.003). The reproductive effort of the Ross's Gull depended negatively on the temperature of the prenesting period. In cold years, the dates of the onset of breeding shifted to later times (r = –0.75, p < 0.001), the clutch size declined (F1,172 = 27.31, p < 0.00001), and the egg volume was reduced (F1,226 = 23.4, p < 0.00001). Despite an increase in the nesting season temperatures in the Lena Delta since 1982 and the earlier arrival of Ross's Gull (F1,27 = 14.87, p < 0.001), no shift in the dates of nesting initiation was detected. In our opinion, this is because the amplitude of interannual changes has a wider range than the long-term trend. The patterns of variations in the dates of nesting initiation, in clutch sizes and eggs volume are due to the dynamics of environmental conditions, primarily air temperatures.
... Conversely, this difference could be linked to the predictability of food resources in the vicinity of the breeding areas [83]. In southeastern Australia and New Zealand, the locally abundant coastal krill Nyctiphanes australis [82] is a key food source for CDP [34] (C. ...
... However, this euphausiid undergoes extreme inter-annual variations in biomass and distribution, considerably affecting the reproductive success of various fish [82] and seabird species [84,85]. Populations spending a long period near the colony before the reproductive season are more likely to follow local environmental cues to adapt their phenology [83], which may explain the significant delay in the breeding period observed between the years in the present study at Kanowna Island [78]. ...
Article
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The non-breeding period plays a major role in seabird survival and population dynamics. However, our understanding of the migratory behaviour, moulting and feeding strategies of non-breeding seabirds is still very limited, especially for small-sized species. The present study investigated the post-breeding behaviour of three distant populations (Kerguelen Archipelago, south-eastern Australia, New Zealand) of the common diving petrel (Pelecanoides urinatrix), an abundant, widely distributed zooplanktivorous seabird breeding throughout the southern Atlantic, Indian and Pacific oceans. The timing, geographical destination and activity pattern of birds were quantified through geolocator deployments during the post-breeding migration, while moult pattern of body feathers was investigated using stable isotope analysis. Despite the high energetic cost of flapping flight, all the individuals quickly travelled long distances (> ~2500 km) after the end of the breeding season, targeting oceanic frontal systems. The three populations, however, clearly diverged spatially (migration pathways and destinations), and temporally (timing and duration) in their post-breeding movements, as well as in their period of moult. Philopatry to distantly separated breeding grounds, different breeding phenologies, and distinct post-breeding destinations suggest that the common diving petrel populations have a high potential for isolation, and hence, speciation. These results contribute to improving knowledge of ecological divergence and evolution between populations and inform the challenges of conserving migratory species.
... In the Arctic tundra ecosystem, a warming two to three times higher than the increase of the global mean surface temperature (IPCC 2013) has led to longer vegetative growing seasons (Oberbauer et al. 2013); and a 50% increase in the above ground vegetation biomass (Epstein et al. 2000). In response to these plant phenological changes, many animal species have shifted their timing of reproduction (bird: Visser et al. 1998;Frederiksen et al. 2004;Bourret et al. 2015;amphibian: Blaustein et al. 2001;fish: Asch 2015;mammal: Réale et al. 2003;Moyes et al. 2011;Lane et al. 2012; marine species: review by Poloczanska et al. 2013). However, there is increasing evidence of a mismatch, due to these phenological changes, between the peak of resource demands by reproducing animals and the peak of forage availability (Post and Forchhammer 2008). ...
... ). In stochastic environments, a plastic response of mating time to environmental change would thus allow species to optimize their recruitment rate under changing climatic conditions.The timing of reproduction of many taxa has changed over the past two to three decades in response to climate change (bird:Visser et al. 1998;Frederiksen et al. 2004, amphibian: Blaustein et al. 2001, fish: Asch 2015, mammal: Burthe et al. 2011 Moyes et al. 2011, marine species: review byPoloczanska et al. 2013). Such observed responses to climate change, however, ...
Thesis
The timing of reproduction in plant and animal species is a strong determinant of offspring viability and reproductive success. The large changes in climate reported the last decades could therefore have unprecedented consequences on population dynamics. The breeding time of many species have changed over the past two to three decades in response to climate change, and a developing trophic mismatch between the peak of energy demands by reproducing animals and the peak of forage availability has caused many species’ reproductive success to decrease. The main aim of this thesis was to determine how reproductive phenology of reindeer (Rangifer tarandus) responds to the changes in its environment and whether there could be resulting fitness consequences. Using long-term datasets of 45 years of birth dates, 13 years of mating behaviors and 14 years of copulation dates of a semi-domesticated reindeer population in Kaamanen, northern Finland, I showed that both the reindeer timing of mating and timing of calving have occurred earlier over time, in response to climate. Climatic variables at four key periods in the reproductive cycle of reindeer were identified as driving the changes in reindeer breeding phenology: winter, late winter/early spring, summer and autumn. Those phenological changes allowed reindeer to keep track of its changing environment, leading to an improvement in females’ reproductive success. I also found a “head-start” benefit with some females always doing better than others do. However, a later vegetative senescence in autumn negatively affected females’ physical condition in winter and the subsequent calf’s birth weight and calf’s first-summer survival. If climatic changes were to exacerbate, the population dynamics of several ungulate species will certainly be affected.
... Capelin are often far sparser during periods of warmer SST. These changes in the types and quantities of marine prey species available during any given breeding season are often reflected in BLKIs' reproductive success as top marine predators, ultimately suggesting that macroclimate influences food availability by shifting trophic interactions at a lower level within the food chain, which then influences at least a portion of variation in the reproductive success of BLKI (Frederiksen, Harris, Daunt, Rothery, and Wanless 2004;Hatch 2013;Grémillet and Boulinier 2009). ...
... Therefore, it is also possible that short-term exposure to nest site microclimate during the nest building and pre-laying period may influence these variables. Additionally, Frederiksen et al. (2004) suggested that if BLKI, which maintain widespread migration patterns and therefore often sense climatic shifts at a very large environmental scale (that of macroclimate), are unable to change the scale at which they process and respond to environmental variation, they may be very heavily impacted by climate change. However, they also suggested that BLKI may be able to sense the smaller scale environmental cues of their breeding site (microclimate) very soon upon arrival, and may be able to adjust the timing of their breeding and reproductive parameters accordingly. ...
... A positive NAO phase (larger pressure difference) is generally associated with an intensification of the westerly winds above the North Atlantic, while a negative NAO phase (smaller pressure difference) is generally associated with weaker westerlies, as well as differences in storm track, precipitation humidity, and temperature. Annual and seasonal NAO has been shown to influence seabird adult survival [30,31]; breeding phenology [32]; reproductive success and breeding propensity [33]; foraging behaviour [33,34]; and chick growth rates [34]. In the northwest Atlantic, positive NAO is associated with strong northwest winds, colder temperatures, less precipitation, higher ice cover, and increased storm activity [35][36][37]. ...
Article
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Background Homeothermic marine animals in Polar Regions face an energetic bottleneck in winter. The challenges of short days and cold temperatures are exacerbated for flying seabirds with small body size and limited fat stores. We use biologging approaches to examine how habitat, weather, and moon illumination influence behaviour and energetics of a marine bird species, thick-billed murres (Uria lomvia). Methods We used temperature-depth-light recorders to examine strategies murres use to survive winter in the Northwest Atlantic, where contrasting currents create two distinct marine habitats: cold (−0.1 ± 1.2 °C), shallower water along the Labrador Shelf and warmer (3.1 ± 0.3 °C), deep water in the Labrador Basin. Results In the cold shelf water, murres used a high-energy strategy, with more flying and less diving each day, resulting in high daily energy expenditure and also high apparent energy intake; this strategy was most evident in early winter when day lengths were shortest. By contrast, murres in warmer basin water employed a low-energy strategy, with less time flying and more time diving under low light conditions (nautical twilight and night). In warmer basin water, murres increased diving at night when the moon was more illuminated, likely taking advantage of diel vertically migrating prey. In warmer basin water, murres dove more at night and foraging efficiency increased under negative North Atlantic Oscillation (calmer ocean conditions). Conclusions The proximity of two distinct marine habitats in this region allows individuals from a single species to use dual (low-energy/high-energy) strategies to overcome winter energy bottlenecks.
... There is a vast amount of literature on intraspecific variation of breeding patterns in relation to environmental conditions, in particular latitude, altitude and climate. In the context of current climate change, many species in temperate regions have advanced their breeding time (e.g. Brown et al., 2016;Frederiksen et al., 2004;Møller, 2008), as a result of microevolutionary changes and/or of phenotypic plasticity (Charmantier & Gienapp, 2014). Most of these studies concern species with a single reproductive peak in the year, which has to match as precisely as possible a seasonal peak of resource availability in order to maximize reproductive success (e.g. ...
Article
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When environmental conditions are unpredictable, expressing alternative phenotypes spreads the risk of failure, a mixed strategy called bet-hedging. In the southern part of its range, the Parsley Frog Pelodytes punctatus breeds both in autumn and in spring. Our aim was to study the breeding phenology and reproductive success associated with the use of those two seasonal niches to understand how this breeding strategy can be maintained. Field surveys revealed that breeding phenology was typically bimodal with a higher breeding effort in autumn. More importantly, in spring, the survival rate of offspring was severely reduced by the presence of autumn tadpoles, indicating a clear priority effect. However, the autumn cohort often failed to survive over winter, in which case spring cohorts were often successful. Based on those results, we constructed a model in which females can allocate a variable portion of eggs to each season and added a priority effect. We conclude that the existence of the two breeding seasons may indeed constitute a bet-hedging strategy.
... The North Atlantic Oscillation (NAO) and the Southern Oscillation indices (SOI), for example, have been used in many studies as ecological predictors in both terrestrial and marine ecosystems (see [12,13] and references therein). In marine ecosystems, the winter NAO (hereafter wNAO) is known to influence demographic parameters, such as reproductive success and survival in long-lived and long-ranging top predators [14][15][16]. It is often assumed that the influence of these large-scale climatic indices occurs via their influence on local climatic variables (see [12,17] and references therein) and/or via the indirect effects on local food abundance (see [9,12,18] and references therein). ...
Article
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Large-scale climatic indices are extensively used as predictors of ecological processes, but the mechanisms and the spatio-temporal scales at which climatic indices influence these processes are often speculative. Here, we use long-term data to evaluate how a measure of individual breeding investment (the egg volume) of three long-lived and long-distance-migrating seabirds is influenced by i) a large-scale climatic index (the North Atlantic Oscillation) and ii) local-scale variables (food abundance, foraging conditions, and competition). Winter values of the North Atlantic Oscillation did not correlate with local-scale variables measured in spring, but surprisingly, both had a high predictive power of the temporal variability of the egg volume in the three study species, even though they have different life-history strategies. The importance of the winter North Atlantic Oscillation suggests carry-over effects of winter conditions on subsequent breeding investment. Interestingly, the most important local-scale variables measured in spring were associated with food detectability (foraging conditions) and the factors influencing its accessibility (foraging conditions and competition by density-dependence). Large-scale climatic indices may work better as pre-dictors of foraging conditions when organisms perform long distance migrations, while local-scale variables are more appropriate when foraging areas are more restricted (e.g. during the breeding season). Contrary to what is commonly assumed, food abundance does not directly translate into food intake and its detectability and accessibility should be considered in the study of food-related ecological processes.
... In some cases, different studies reported information on the same phenophase for the same species and location. Whenever the timespans of different studies did not fully overlap, we included in the database both pieces of information (e.g., Burthe et al., 2012;Frederiksen et al., 2004). Whenever the time series fully overlapped, we selected the longest one. ...
Article
The alteration of the timing of biological events is one of the best documented effects of climate change, with overwhelming evidence across taxa. Many studies have investigated the phenology of consumers, especially birds. However, most of these studies have focused on specific phenophases, while a global analysis of avian phenological trends during recent climate change across different phases of the circannual cycle is still lacking. Here, we performed a comprehensive meta‐analytic synthesis of the phenological responses (temporal shifts in days year‐1) of birds across different phenophases (pre‐breeding migration, breeding, and post‐breeding migration) by summarizing more than 5500 time series from 684 species from five continents during 1811‐2018. Our results confirm that avian taxa have advanced pre‐breeding migration and breeding by ca. 2‐3 days per decade, while no significant temporal changes in the timing of post‐breeding migration were documented. Advancement in timing of pre‐breeding migration and breeding strongly depended on migratory behaviour, with the advance being the weakest for long‐distance migrants and the strongest for resident species. Diet generalists and primary consumers tended to advance pre‐breeding migration timing more than species with different dietary specializations. Increasing body size resulted in a larger advancement in the onset (but not in the mean date) of pre‐breeding migration and breeding, while phenological advances were larger in the northern than in the southern hemisphere. Our synthesis, covering most of the world, highlighted previously unappreciated patterns in avian phenological shifts over time, suggesting that specific life‐history or ecological traits may drive different responses to climate change.
... There is a vast amount of literature on intraspecific variation of breeding patterns in relation to environmental conditions, in particular latitude, altitude and climate. In the context of current climate change, many species in temperate regions have advanced their breeding time (e.g. Brown et al., 2016;Frederiksen et al., 2004;Møller, 2008), as a result of microevolutionary changes and/or of phenotypic plasticity (Charmantier & Gienapp, 2014). Most of these studies concern species with a single reproductive peak in the year, which has to match as precisely as possible a seasonal peak of resource availability in order to maximize reproductive success (e.g. ...
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A bstract When environmental conditions are unpredictable, expressing alternative phenotypes spreads the risk of failure, a mixed strategy called bet-hedging. In the southern part of its range, the Parsley Frog Pelodytes punctatus breeds both in autumn and in spring. Our aim was to study the breeding phenology and reproductive success associated with the use of those two seasonal niches to understand how this breeding strategy can be maintained. Field surveys revealed that breeding phenology was typically bimodal with a higher breeding effort in autumn. More importantly, in spring, the survival rate of offspring was severely reduced by the presence of autumn tadpoles, indicating a clear priority effect. However, the autumn cohort often failed to survive over winter, in which case spring cohorts were often successful. Based on those results, we constructed a model in which females can allocate a variable portion of eggs to each season and added a priority effect. We conclude that the existence of the two breeding seasons may indeed constitute a bet-hedging strategy.
... Variations in climate, and consequent indirect effects on prey, can have broad impacts on species [3]. The outcome of such impacts can be the difference Birds 2022, 3 between 'good' and 'bad' breeding years, leading to either population growth or decline, respectively [4], and are likely to be exacerbated by predicted climate change [5]. ...
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Grey-faced Petrels (Pterodroma gouldi) are a colonial burrowing seabird predominantly nesting on offshore islands of the upper North Island of New Zealand. We studied their annual breeding biology and the impact of Southern Oscillation Index climatic effects by measuring colony productivity and chick growth rates from 2011 to 2015 on Te Hāwere-a-Maki as unfavorable warmer La Niña conditions changed to favorable cooler El Niño conditions. Across all five years, annual chick hatching consistently occurred within a one-week period at the end of August but fledging variably occurred over a three-week period following Christmas. Because ship rats are pest controlled on Te Hāwere-a-Maki, we found only a slight reduction in breeding success with nearby predator-free islands. However, chick growth and fledging rates were significantly higher under El Niño conditions occurring towards the end of our study, rather than La Niña conditions at the start of our study. Our regular handling of chicks for monitoring had no discernible impact compared to a set of control chicks. The combined impacts of annual variation in predation and climate mean the Grey-faced Petrel colony on Te Hāwere-a-Maki maintains a constant population size of around 100 burrows.
... Long-term studies of auk biology at colonies elsewhere, notably at the Isle of Man off Scotland (Frederiksen et al. 2004), Triangle Island off the British Columbia coast (Hipfner et al. 2020), and Hornøya in Norway (Barrett 2015), have recorded changes in breeding success and diet comparable to those that we have seen on MSI. This confirms the value of such work not only to seabird conservation but also towards a more holistic perspective on changes in the ocean ecosystem. ...
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This paper reviews some of the more obvious changes in the populations and diets of seabirds breeding on Machias Seal Island, at the junction of the Bay of Fundy and the Gulf of Maine, from 1995 through 2015. This is the largest seabird colony in this oceanic ecosystem, hosting colonies of cold-water species at the southern edge of their distribution. My lab's research over 20 years has been focused in two directions-exploring how several closely-related species persist in coexistence here, and interpreting changes in the birds' biology in terms of responses to environmental changes. Diet played a major role in ecological isolation, but has changed considerably in response to virtual disappearance of juvenile herring since the late 1990s and the recent appearance of juvenile haddock. Ocean warming since 2000 has accelerated, especially after a sudden decrease in water temperature and salinity around 2005, which had as much deleterious effect as the subsequent warming. A major finding has been that the three most abundant breeders-Atlantic Puffin, Razorbill, and Arctic Tern-exchange individuals with other colonies in the Gulf of Maine and so each constitutes a true meta-population. This study, with similar collaborative work on those colonies, provides a unique spatial perspective on marine seabird population dynamics in a rapidly-changing ecosystem. Two species (Razorbills and Common Murres) show wholly unexpected increases in numbers, despite declines in several demographic measures that bode ill for the long-term sustainability of this colony.
... Since the formation of eggs in Ross's gulls occurs directly at the nesting sites and is based on local food resources, low temperatures in the prenesting season lead to most of the energy received being used to maintain the physiological needs of the body. Among gulls, similar patterns were found in kittiwakes (Rissa tridactyla) in the Arctic regions (Murphy et al., 1991;Gaston et al., 2005;Moe et al., 2009), although this trend already did not take place in the temperate zone, for example, in Scotland (Frederiksen et al., 2004). ...
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Data on the spring phenology and reproductive parameters of Ross's Gull were collected during the period 1980-2013 on the delta of Lena River, northern Yakutia (71°42-74° N, 120°-129°30 E). During this period, significant changes in weather occurred. The mean annual temperature (F 1.27 = 7.74, p < 0.04), the mean June temperature (F 1.27 = 11.75, p < 0.002), and the summer temperature (F 1.27 = 9.13, p < 0.005) increased, and the mean daily air temperatures crossing 0°C shifted to earlier dates (F 1.26 = 14.73, p < 0.001). However, the duration of the period with positive temperatures increased only slightly (F 1.26 = 3.53, p < 0.07). The arrival of Ross's gulls to the Lena Delta depended on the dates of snow melting (r = 0.62, p < 0.05), the mean June temperatures (r =-0.48, p < 0.01), and the minimal June daily temperatures (r =-0.70, p < 0.001). The maximum amplitude of fluctuations in egg numbers among all arctic gulls was revealed for complete clutches of Ross's Gull. In the Lena Delta, this amplitude was higher than in more southerly regions, where the nesting ecology of the species was mainly studied. The clutch size was negatively correlated with the dates of clutch initiation, the females that began to nest earlier showing larger clutch sizes. The reproductive effort of the species depended negatively on the temperature of the prenesting period. In cold years, the dates of nesting initiation shifted to later times (r =-0.75, p < 0.001) and the clutch size declined (F 1,172 = 27.31, p < 0.00001). There was a tendency towards a decrease in the egg volume, which is the most noticeable from the dates of snow melting (F 1,226 = 33.4, p < 0.00001) and a decrease in the average temperature of the prenesting period (F 1,226 = 23.4, p < 0.00001). Despite an increase in the nesting season temperatures in the Lena Delta since 1982 and the earlier arrival of Ross's Gull (F 1.27 = 14.87, p < 0.001), no shift in the dates of nesting initiation was detected. In our opinion, this is because the amplitude of interannual changes has a wider range than the long-term trend. The patterns of variations in the dates of nesting initiation and in the clutch sizes and egg volume are due to the dynamics of environmental conditions, primarily air temperatures.
... During the study period, both FP and CDP exhibited delayed phenology and low breeding performance in two consecutive years (2018/19 and 2019/20). Overlap between timing of reproduction and the peak of prey availability is crucial for seabird breeding success [65], with the timing of laying having been shown to be influenced by oceanographic conditions and, ultimately, food availability [66]. In the present study, the late start of the breeding season for both species in 2018/19 and 2019/20 was followed by substantial incubation failure, lower chick growth and/or lower fledging success and, for CDP in 2019/20, complete breeding failure. ...
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Seabirds play a vital role in marine ecosystems and the long-term study of their responses to environmental variations can be used to monitor the effects of climate change on marine fauna. However, slight differences in similar seabird species result in a range of responses which complicates our understanding of the effects of environmental changes to marine ecosystems. The present study investigated inter-annual differences in the breeding biology (breeding phenology, chick growth rates and breeding success) and environmental conditions (seasonal sea surface temperatures) of important foraging areas in two sympatric small Procellariiform species, the fairy prion ( Pachyptila turtur ) and the common diving petrel ( Pelecanoides urinatrix ), over four reproductive seasons (2017–2020) in Bass Strait, south-eastern Australia. Marine heatwaves occurred during the years of 2018/19 and 2019/20 and coincided with years of delayed laying dates, slower chick growth and reduced breeding success, in both species. While fairy prions maintained a relatively high breeding success and broadly constant breeding phenology, common diving petrels delayed the start of the breeding season by up to 50 days and experienced dramatic collapses in breeding success in years of high marine heat wave occurrence. The difference in foraging ecology and physiological capacity (largely in the production of stomach oils and fasting abilities of adults and chicks) between both species are likely to influence the variability and phenology in the observed breeding seasons.
... While many seabirds exhibit high levels of behavioural flexibility to contend with the resultant variability in the location of their food in the oceans (Kowalczyk et al. 2015, Castillo-Guerrero et al. 2016, the degree of flexibility is reported to differ depending on large-scale biogeographical factors (Weimerskirch 2007). In temperate and polar regions, marked seasonal fluctuations in marine productivity cause seabirds to congregate and breed at specific times of the year, ensuring that the energy demands of reproduction coincide with peak food availability, usually driven by warmer summer sea surface temperatures and associated increased ocean productivity (Frederiksen et al. 2004). The typical foraging strategy that seabirds breeding in these regions adopt is to repeatedly visit similar locations at sea throughout a breeding season, usually associated with coastal and oceanic features which drive hotspots of productivity (Hamer et al. 2001, Kappes et al. 2011, Kotzerka et al. 2011, Wakefield et al. 2015. ...
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The archetypal foraging behaviour of tropical seabirds is generally accepted to differ from that of their temperate and polar breeding counterparts, with the former exhibiting less predictable foraging behaviour associated with the less predictable prey of the tropical marine environment. Similarly, temperate and polar species have predictable, annual breeding seasons, enabling them to profit during periods of the year when prey availability is highest, while tropical seabird species exhibit considerable variability in their breeding strategies. Until now, the reasons for such variation in breeding strategies between tropical seabirds are yet to be investigated. We hypothesise that while some tropical species breed asynchronously in response to unpredictable fluctuations in prey availability, others adopt a seasonal breeding strategy for the same reasons that temperate and polar species do. Consequently, the predictability of seabird foraging behaviour in the tropics may be related to breeding strategy, with populations that breed seasonally exhibiting more predictable foraging behaviour than those that breed aseasonally. To test these predictions, we used GPS tracking to examine the foraging behaviour of two closely related tropical seabird species that colonise the same island yet exhibit markedly different breeding strategies: the asynchronously breeding brown booby Sula leucogaster and the seasonal breeding masked booby Sula dactylatra. We obtained tracks for 251 birds over five years. We found that brown boobies forage less predictably than masked boobies, indicated by larger core foraging areas, lower levels of foraging area overlap between individuals and exhibit more variability between breeding periods. Our results challenge the view that the foraging behaviour of tropical seabirds is always less predictable than that of seabirds breeding in temperate and polar regions and highlight the considerable variability in the breeding and foraging strategies adopted by tropical seabirds which demand further exploration.
... The impact of climate on resource availability and accessibility is well documented in seabirds (Frederiksen et al. 2004, Barbraud et al. 2018). The climate system drives -through the interannual variations of the atmosphere or the hydrosphere and external limiting factors (i.e. ...
Article
Understanding the demographic responses of wild animal populations to different factors is fundamental to make reliable prediction of population dynamics. Both bottom-up processes and top-down regulation operate in terrestrial and marine ecosystems, but their relative contribution remains insufficiently known. In addition, direct weather effects on demographic rates have been overlooked in marine ecosystems and inferences on the demographic effects of environmental drivers were overwhelmingly made from single study sites. Here, we evaluate the relative effects of bottom-up, top-down and weather processes on four vital rates and on population growth rates of a long-lived seabird, the snow petrel Pagodroma nivea, within three different breeding colonies. We used multistate capture-recapture modelling and perturbation analyses from a matrix population model based on a 36-year-long (1981-2017) individual monitoring dataset to quantify the different drivers (predation, climatic and weather covariates) of probabilities of survival, breeding, hatching and fledging according to colony, sex and breeding status of individuals. Results show that bottom-up forces and local weather affected breeding parameters, and that survival was driven by top-down regulation pressure and bottom-up processes. Breeding parameters differed between colonies and survival was sex-specific. Sensitivity analysis revealed that population regulation was mainly driven by bottom-up processes and that top-down processes played a minor role. However, there were major differences between colonies about the importance of how local weather processes affected population growth rate. Our study brings new insights into the drivers of demographic processes in a marine meso-predator , and how these drivers vary according to colonies and individual characteristics. We emphasize the importance of considering multiple study sites to make robust inferences on the effects of environmental drivers on wildlife demography. More generally, robust conclusions about the importance of environmental drivers on demography rely on considering multiple causal effects at multiple sites, while accounting for individual characteristics.
... Seabird condition, breeding performance and foraging success are strongly linked to resource availability and abundance (e.g. Frederiksen et al., 2004;Durant et al., 2006;Price et al., 2020). There was intercolony variability in body mass and breeding participation among the four colonies. ...
Article
Biotic responses to large-scale climate processes are scale-dependant and can influence population trajectories of highly migratory species such as short-tailed shearwaters Ardenna tenuirostris. In this study, we quantified changes in climate, measured through large-scale climate indices (i.e. Northern Pacific Index, Pacific Decadal Oscillation, El Niño–Southern Oscillation and Southern Annular Mode) and local weather conditions (i.e. rainfall) on the breeding performance of short-tailed shearwaters at four of their breeding colonies within the Furneaux Island Group, Tasmania, Australia, from 2010 to 2018. There was inter-colony variability in adult body mass and breeding participation, which were influenced by climate conditions in the preceding year. In contrast, breeding success was influenced by climate conditions in the preceding three to four months and by local weather conditions at the time of breeding. These findings demonstrate that variation in the breeding performance of short-tailed shearwaters are explained both by large-scale climate indices and local environmental conditions. The outcomes of this study provide a better understanding of the environmental factors affecting short-tailed shearwaters.
... To date, the response of breeding phenology to environmental change has been most thoroughly studied in birds (e.g., Crick et al., 1997;Forchhammer et al., 1998;Frederiksen, Harris, Daunt, Rothery, & Wanless, 2004), amphibians (BeeBee, 1995;Forchhammer et al., 1998), and ungulates (Post & Stenseth, 1999). ...
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Change in breeding phenology is often a response to environmental forcing, but less is known of the mechanism underlying such changes and their fitness consequences. Here, we report on changes in the breeding phenology from a 27-year longitudinal study (1991-2017) of individually marked, known-aged grey seals (Halichoerus grypus) on Sable Island, Nova Scotia, Canada. We used generalized linear mixed models and a 3-step process to develop a model that includes interactions between intrinsic and extrinsic covariates and to test hypotheses about the influence of fixed factors (maternal age, parity, previous reproductive success, pup sex, colony density, Atlantic Multidecal Oscillation (AMO), North Atlantic Oscillation (NAO), and Sea Surface Temperature) and a random factor (female identity) on parturition dates. We also examined the consequences of the shift in birthdates on maternal energy allocation in offspring as measured by pup weaning mass. Birthdates were known for 2,768 pups of 660 known-age females. For 494 females with ≥2 parturition dates, repeatability as measured by the intraclass correlation was high (mean = 0.66). 87% of the variation in birthdates was explained by a mixed-effects model that included intrinsic and extrinsic fixed effects. Most of the explained variation was associated with the random effect of female identity. Parity was the most important intrinsic fixed effect, with inexperienced mothers giving birth later in the season than multiparous females. Over almost 3 decades, mean birthdates advanced by 15 days. The mixed model with intrinsic effects and population size, the detrended AMO from the previous year and mean NAO in the previous 3 years explained 80% of the variation with 21% of variation from the fixed effects. Both primiparous and multiparous individuals responded to the climate forcing, and there was strong evidence for heterogeneity in the response. Nevertheless, the shift in birthdates did not impact pup weaning mass.
... As preocupações relativas às mudanças climáticas dizem respeito ao potencial de intensificação dos impactos já existentes, bem como a interferências na fenologia (ou seja, nos fenômenos cíclicos) e relações ecológicas das espécies (Frederiksen et al., 2004;Daunt e Mitchell, 2013). Esses efeitos podem ser ainda mais severos para espécies que apresentam longa migração, principalmente para aquelas que dependem de áreas reprodutivas em ambientes de altas latitudes (Wauchope et al., 2016) e/ou que poderão sofrer com as perdas de áreas costeiras tropicais (Foden et al., 2013). ...
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As informações sobre as ocorrências de aves marinhas e costeiras ainda são restritas a algumas regiões e grupos taxonômicos. Para os litorais de Sergipe, norte da Bahia e sul de Alagoas, a avifauna marinha ainda é pouco conhecida. Aqui apresentamos os dados resultantes de projetos e programa conduzidos pela Petrobras, refletindo a contribuição para a caracterização das aves marinhas da região compreendida pela Bacia Sedimentar de Sergipe-Alagoas. A partir da execução desses projetos, entre os anos de 2010 e 2015, foi possível obter um total de 5.044 registros de aves, contemplando a ocorrência de 12 ordens, 23 famílias, 44 gêneros e 60 espécies. Entre as principais espécies registradas, destacam-se as cagarras (Calonectris spp.) e as pardela (Puffinus spp.), constituindo o grupo de aves com maior prevalência de encalhes no litoral amostrado, sendo o período de abril a junho os meses de maior incidência de aves mortas e/ou debilitadas na região. Os atobás (Sula dactylatra), tesourão (Fregata magnificens), trinta-réis (Sterna spp.) e mandriões (Stercorarius spp.) foram os táxons mais abundantes e mais comuns de serem observados utilizando a região marinha de Sergipe-Alagoas. Os resultados obtidos nos projetos PCR-SEAL, Biota e PRMEA contribuíram sobremaneira para ampliar os conhecimentos sobre a avifauna marinha do litoral de Alagoas, Sergipe e Bahia, evidenciando a necessidade de maior esforço para a condução de pesquisas direcionadas para o entendimento sobre a dinâmica populacional, uso de habitat e potenciais impactos e ameaças que podem estar associados às aves marinhas da região.
... Study years are highlighted as the most negative (2010 in blue) and most positive (2015 in red) phases of NAO index reported in recent decades ecological interpretation of the tracking results, corroborated with data on adult body condition and chick growth rates, gives support to the idea that species or populations breeding in neritic and oceanic areas of the eastern North Atlantic Ocean may adopt different strategies in response to climate extremes, as already documented for opposing areas of the Pacific Ocean in response to major ENSO events (Duffy 1990). That seabirds are able to respond to climate change by adjusting some of their key life-history traits is widely supported by the literature (Frederiksen et al. 2004;Moe et al. 2009;Weimerskirch et al. 2012;Jenouvrier et al. 2018). However, most previous studies have evaluated the effects of climate variability on breeding measures at the colony level and few tried to understand the interplay between these parameters and the individuals' at-sea behaviour or body condition. ...
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Climate projections predict increases in the frequency and severity of extreme climate events over the next decades. Hence, phases of extreme climatic indices are emerging as one of the most dangerous effects of climate change, though their impacts on wildlife populations are still poorly understood. Here, we studied the foraging behaviour, body condition and breeding performance of a neritic (Berlenga Island) and oceanic (Corvo Island) population of Cory’s shearwaters (Calonectris borealis) in the mid-North Atlantic, during the two most positive and negative phases of North Atlantic Oscillation (NAO) reported in recent decades. We showed that during an extreme negative NAO phase, birds from Berlenga spent less time foraging and provided less food to their chicks, which subsequently grew more slowly and were in poorer body condition. In contrast, the opposite pattern was found during the strong positive NAO phase in this population. Interestingly, during the same extreme negative NAO phase, birds from Corvo were more successful in terms of their foraging and breeding performance, taking advantage of the enhanced productivity associated with the cyclonic eddies (negative sea surface height anomalies) which occurred close to the colony. However, when anticyclonic eddies (positive sea surface height anomalies) were prevalent near the colony during the strong positive NAO phase, birds travelled longer distances, which negatively impacted their own body condition and that of their chicks. Our study shows that populations breeding in neritic and oceanic areas of the eastern North Atlantic Ocean make contrasting foraging behavioural decisions in response to climate extremes and highlights the importance of mesoscale eddies for oceanic populations of pelagic seabirds.
... Oceanographic properties are influenced by large-scale physical forcing that alters atmospheric conditions, sea level pressure and ocean temperature, which in turn affect bottom-up processes, such as changes in primary and secondary productivity (Zador et al. 2013, Cushing et al. 2018. Variations in oceano-graphic and climatic conditions can influence seabird nesting habitat, foraging grounds and resource availability, which could change their distribution, abundance, reproductive output and population growth (Frederiksen et al. 2004, Humphries & Möller 2017. ...
Article
ABSTRACT: Climate variability affects physical oceanographic systems and environmental conditions at multiple spatial and temporal scales. These changes can influence biological and ecological processes, from primary productivity to higher trophic levels. Short-tailed shearwaters Ardenna tenuirostris are transhemispheric migratory procellariiform seabirds that forage on secondary consumers such as fish (myctophids) and zooplankton (euphausiids). In this study, we investigated the breeding parameters of the short-tailed shearwater from a colony of 100 to 200 breeding pairs at Fisher Island, Tasmania, Australia, for the period 1950 to 2012, with the aim to quantify the relationship between breeding parameters with large-scale climate indices in the Northern (i.e. Northern Pacific Index and Pacific Decadal Oscillation) and Southern Hemispheres (i.e. El Niño-Southern Oscillation and Southern Annular Mode). Through the use of generalised linear models, we found that breeding participation among short-tailed shearwaters was affected by climate variability with a 12-mo temporal lag. Furthermore, breeding success decreased in years of increased rainfall at the colony. These findings demonstrate that both large-scale climate indices and local environmental conditions could explain some of the variability among breeding parameters of the short-tailed shearwater.
... Crick 2004;) and specific studies (e.g. Both and Visser 2001;Frederiksen et al. 2004;. These features make seabirds excellent candidate sentinel indicators of global change (e.g. ...
... Released from the obligation of incubation and care of dependent young, many seabirds disperse widely from colonies during the non-breeding winter period to access more favorable foraging locations. Conditions experienced during the winter can strongly impact the probability of survival to, and success during, the subsequent summer breeding season (Frederiksen et al. 2004, Pineda and Lobo 2009, Sydeman and Bograd 2009, Harding et al. 2011. Departures from climatological norms can result in reduced primary production and more severe storms during the winter, leading to a higher risk of mortality for seabirds through starvation and injury (Barbraud and Weimerskirch 2003, Harris et al. 2005, Genovart et al. 2013. ...
Article
Reduced prey abundance and severe weather can lead to a greater risk of mortality for seabirds during the non-breeding winter months. Resource patterns in some regions are shifting and becoming more variable in relation to past conditions, potentially further impacting survival and carryover to the breeding season. As animal tracking technologies and methods to analyze movement data have advanced, it has become increasingly feasible to draw fine-scale inference about how environmental variation affects foraging behavior and habitat use of seabirds during this critical period. Here, we used archival light-sensing tags to evaluate how inter-annual variation in oceanography affected the winter distribution of Cassin's auklets from Southeast Farallon Island, California. Thirty-five out of 93 geolocators deployed from 2015-2017 were recovered and successfully recorded light-level data, from which geographic positions were estimated. Step-selection functions were applied to identify environmental covariates that best explained winter movement decisions and habitat use, revealing Cassin's auklets dispersed farther from the colony during a winter with warm SST anomalies, but remained more centralized near the breeding colony during two average winters. Movement patterns were driven by avoidance of areas with higher sea surface temperatures and possible limits of dispersal from the breeding colony, and selection for areas with well-defined mesoscale fronts and cooler surface waters. Through multiple years of tagging and the application of step-selection functions, a robust and widely applied approach for analyzing animal movement in terrestrial species, we show how inter-annual differences in the movement patterns of a small seabird are driven by oceanographic variability across years. Understanding the winter habitat use of seabirds can help inform changes in population structure and measures of reproductive success, aiding managers in determining potential causes of breeding failures.
... Such patterns offer a glimpse into the potential resilience of seabirds to changes in parameters af fecting breeding success. Phenology, in particular, is changing for many kittiwake populations, with a trend toward later timing in the North Sea (Frederiksen et al. 2004a, Burthe et al. 2012) and earlier timing in the Bering Sea (Byrd et al. 2008), but no significant trend for kittiwakes in a European high Arctic colony (Moe et al. 2009). Our work, along with that of Renner et al. (2014) and Shultz et al. (2009), highlights the important association between phenology and kittiwake laying success. ...
Article
While we have a good understanding in many systems of the effects of single variable changes on organisms, we understand far less about how variables act in concert to affect living systems, where interactions among variables can lead to unanticipated results. We used mixed-effect models to evaluate the effects of multiple variables that we expected to play a role in the early reproductive stages of a North Pacific seabird, the black-legged kittiwake Rissa tridactyla, during 1992-2008 using data collected on known-aged individuals. Our work revealed the potential for contrasting stressor effects across successive stages of reproduction. Bird age, timing of egg laying, and winter ENSO conditions best explained individual laying success, such that laying success was greater when parents were older, the average winter ENSO index was positive (as occurs during El Niño episodes), and the median laying date for the colony was earlier. Age and salmon run timing (a proxy for predator presence at the colony) best explained hatching success, such that hatching success was greater when parents were older and when salmon runs were early. Identifying such differential effects of multiple stressors across consecutive reproductive stages can greatly enhance our ability to interpret trends and manage populations in the face of changes currently occurring in living systems.
... These migrations are often crucial a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 for recovering body condition and for replacement of flight and body feathers prior to the next breeding season [4]. Foraging success in non-breeding areas may, consequently, have carryover effects on breeding phenology and reproductive success in migratory birds [5,6,7]. For instance, Bogdanova and colleagues [8] linked breeding success or breeding failure of blacklegged kittiwakes (Rissa tridactyla) with contrasting geographical distributions in the nonbreeding season. ...
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We present the first study to examine the year-round distribution, activity patterns, and habitat use of one of New Zealand's most common seabirds, the fluttering shearwater (Puffinus gavia). Seven adults from Burgess Island, in the Hauraki Gulf, and one individual from Long Island, in the Marlborough Sounds, were successfully tracked with combined light-saltwater immersion loggers for one to three years. Our tracking data confirms that fluttering shearwaters employ different overwintering dispersal strategies, where three out of eight individuals, for at least one of the three years when they were being tracked, crossed the Tasman Sea to forage over coastal waters along eastern Tasmania and southeastern Australia. Resident birds stayed confined to waters of northern and central New Zealand year-round. Although birds frequently foraged over pelagic shelf waters, the majority of tracking locations were found over shallow waters close to the coast. All birds foraged predominantly in daylight and frequently visited the colony at night throughout the year. We found no significant inter-seasonal differences in the activity patterns, or between migratory and resident individuals. Although further studies of inter-colony variation in different age groups will be necessary, this study presents novel insights into year-round distribution, activity patterns and habitat use of the fluttering shearwater, which provide valuable baseline information for conservation as well as for further ecological studies.
... In the Arctic tundra ecosystem, a warming 2-3 times higher than the increase of the global mean surface temperature (IPCC 2013) has led to longer vegetative growing seasons ( Oberbauer et al. 2013); and a 50% increase in the above ground vegetation biomass (Epstein et al. 2000). In response to these plant phenological changes, many animal species have shifted their timing of reproduction (bird: Visser et al. 1998;Frederiksen et al. 2004;Bourret et al. 2015; amphibian: Blaustein et al. 2001; fish: Asch 2015; mammal: Réale et al. 2003;Moyes et al. 2011;Lane et al. 2012; marine species: review by Poloczanska et al. 2013). However, there is increasing evidence of a mismatch, due to these phenological changes, between the peak of resource demands by reproducing animals and the peak of forage availability (Post and Forchhammer 2008). ...
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A developing trophic mismatch between the peak of energy demands by reproducing animals and the peak of forage availability has caused many species’ reproductive success to decrease. The match–mismatch hypothesis (MMH) is an appealing concept that can be used to assess such fitness consequences. However, concerns have been raised on applying the MMH on capital breeders such as reindeer because the reliance on maternal capita rather than dietary income may mitigate negative effects of changing phenologies. Using a long-term dataset of reindeer calving dates recorded since 1970 in a semidomesticated reindeer population in Finnish Lapland and proxies of plant phenology; we tested the main hypothesis that the time lag between calving date and the plant phenology in autumn when females store nutrient reserves to finance reproduction would lead to consequences on reproductive success, as the time lag with spring conditions would. As predicted, the reproductive success of females of the Kutuharju reindeer population was affected by both the onset of spring green-up and vegetative senescence in autumn as calves were born heavier and with a higher first-summer survival when the onset of the vegetation growth was earlier and the end of the thermal growing season the previous year was earlier as well. Our results demonstrated that longer plant growing seasons might be detrimental to reindeer’s reproductive success if a later end is accompanied by a reduced abundance of mushrooms.
... The Laysan albatross, like many other seabird species, is considered a sentinel of environmental change [32,33]. The at-sea distribution of this seabird is influenced by factors like ocean circulation, wind patterns, sea surface temperatures, habitat quality, and prey availability [28,[34][35][36][37][38][39][40][41]. More specifically, the Laysan (P. ...
Article
We evaluated the existence of sexual dimorphism in Laysan albatross from Guadalupe Island. Males were larger than females across all the morphological variables analyzed. We created a sex predictor model for Laysan albatross individuals that requires a minimum number of input variables and will considerably reduce the handling times and field costs of future studies. Laysan albatross foraging trips were recorded during their breeding season over multiple years and no significant di�erences were found between the distances travelled by males versus females.
... The Laysan albatross, like many other seabird species, is considered a sentinel of environmental change [32,33]. The at-sea distribution of this seabird is influenced by factors like ocean circulation, wind patterns, sea surface temperatures, habitat quality, and prey availability [28,[34][35][36][37][38][39][40][41]. More specifically, the Laysan (P. ...
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Sexual dimorphism in the Laysan albatross (Phoebastria immutabilis) on Guadalupe Island was evaluated during the breeding seasons of 2015–2018 by measuring and comparing 10 morphological attributes: cranial length, bill length, nostril length, cranial width, bill height, bill width, tarsus length, closed wing length, opened wing length, and wingspan length in reproductive adults (n = 135). Males were larger than females across all traits (Student’s t-test, p < 0.05, p < 0.05). We created a logistic model using stepwise regression to predict sex based on morphological variables. This model indicated four significant morphological predictor variables (z < 0.05) and was able to successfully predict the sex of P. immutabilis individuals in more than 90% of the cases. Based on these predictor variables, a web app was developed to determine the sex of the Laysan albatross in the field, providing a non-invasive method for rapid data collection that reduces costs and handling times while improving conservation efforts. We tracked Laysan albatross (n = 36) during breeding seasons and found no significant differences between females and males for either trip length (GLMM, F = 0.017, DF = 1, 1, p = 0.917 > 0.05) or maximum trip distance (GLMM, F = 0.374, DF = 1, 1, p = 0.651 > 0.05). Our results suggest that both sexes show a strong preference to travel to highly productive coastal waters northeast of the breeding colony that are influenced by the California Current. The present research will serve to establish a baseline to protect this species on Guadalupe Island and highlights the importance of understanding sexual dimorphism in at-risk seabird species.
... This may be because indices of global climate processes integrate multiple components of climate parameters (Namias and Cayan 1981), and populations are affected by the interaction of many weather variables (Stenseth et al. 2003). However, more recent work in seabird populations indicate that local sea surface temperature outperforms indices of global climate processes in explaining variation in a number of parameters associated with breeding (Frederiksen et al. 2004), including nestling mass and survival (Oro et al. 2010;Ancona et al. 2011). Comparatively, little is known about whether the same pattern holds true for terrestrial avian species. ...
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The El Niño Southern Oscillation (ENSO) is a global phenomenon that influences climate variation and, in turn, the ecological processes affecting the abundance and distribution of populations across taxa. For example, the ENSO can profoundly influence the development and survival of pelagic species, but the extent to which the ENSO affects offspring of terrestrial species is less well known. We used piecewise structural equation modeling to investigate the direct and indirect relationship between the ENSO and offspring development and survival in a terrestrial tropical passerine, the lance-tailed manakin (Chiroxiphia lanceolata). The Oceanic Niño Index (ONI), a measure of the ENSO, was negatively related to individual growth rate, maximum number of lesion developed by nestlings, and hatching day-of-year; which in turn mediated indirect effects on fledging success and recruitment. Further the ONI was a better predictor of nestling development compared to local temperature and rainfall. Our study establishes a link between the ENSO and the development and survival of young of a terrestrial species and underscores the need to better understand how offspring cope with global climate variation.
... A reliable long-term monitoring method must be robust to shifts in breeding phenology. For burrow nesting seabirds, surveys are traditionally timed to coincide with assumed periods of high colony attendance (Ratcliffe et al., 2010), yet seabird breeding phenology is known to shift due to changing environmental conditions (Gjerdrum et al., 2003;Frederiksen et al., 2004). This consideration is certainly pertinent for the Oregon coast, as recent oceanographic conditions-a marine heatwave (Bond et al., 2015), are unprecedented (Frölicher & Laufkötter, 2018). ...
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Seabirds are integral components of marine ecosystems and, with many populations globally threatened, there is a critical need for effective and scalable seabird monitoring strategies. Many seabird species nest in burrows, which can make traditional monitoring methods costly, infeasible, or damaging to nesting habitats. Traditional burrow occupancy surveys, where possible, can occur infrequently and therefore lead to an incomplete understanding of population trends. For example, in Oregon, during the last three decades there have been large changes in the abundance of Leach's storm-petrels (Hydrobates leucorhoa), which included drastic declines at some colonies. Unfortunately, traditional monitoring failed to capture the timing and magnitude of change, limiting managers' ability to determine causes of the decline and curtailing management options. New, easily repeatable methods of quantifying relative abundance are needed. For this study, we tested three methods of remote monitoring: passive acoustic monitoring, time-lapse cameras, and radar. Abundance indices derived from acoustics and imagery: call rates, acoustic energy, and counts were significantly related to traditional estimates of burrow occupancy of Leach's storm-petrels. Due to sampling limitations, we were unable to compare radar to burrow occupancy. Image counts were significantly correlated with all other indices, including radar, while indices derived from acoustics and radar were not correlated. Acoustic data likely reflect different aspects of the population and hold the potential for the further development of indices to disentangle phenology, attendance of breeding birds, and reproductive success. We found that image counts are comparable with standard methods (e.g., radar) in producing annual abundance indices. We recommend that managers consider a sampling scheme that incorporates both acoustics and imaging, but for sites inaccessible How to cite this article Orben RA, Fleishman AB, Borker AL, Bridgeland W, Gladics AJ, Porquez J, Sanzenbacher P, Stephensen SW, Swift R, McKown MW, Suryan RM. 2019. Comparing imaging, acoustics, and radar to monitor Leach's storm-petrel colonies. PeerJ 7:e6721 http://doi.org/10.7717/peerj.6721 to humans, radar remains the sole option. Implementation of acoustic and camera based monitoring programs will provide much needed information for a vulnerable group of seabirds.
... This further emphasizes the significance of saithe as the most important prey species for shags in this colony. Close correlations between prey availability and population size , Elliott et al. 2015, Velarde et al. 2015, Sandvik et al. 2016) and breeding success (Frederiksen et al. 2004, Cury et al. 2011) have been found in many seabird studies. In this context, this study provides novel insight by combining a multi-year data set on diet and foraging behavior and concurrent data on reproductive success and breeding numbers. ...
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Seabird populations have declined worldwide, and several of the potential threats are of anthropogenic origin. To understand how changes in seabird populations relate to environmental conditions it is important to know the functional relationships between prey availability and foraging behaviour, prey choice and breeding performance over several years. This was studied by linking breeding success of European shag Phalacrocorax aristotelis to variation in diet composition, and investigating the underlaying mechanism driving this variation, primarily based on be - havioural costs associated with foraging, such as foraging range and diving effort. We obtained demographic data and foraging trip metrics (using GPS-loggers and time−depth recorders) from a shag colony at Sklinna, Central Norway, during the 2011−2016 breeding seasons. Breeding population size was closely and positively correlated with breeding success, which in turn was positively correlated with the proportion of saithe Pollachius virens in the diet. When the dietary proportion of uncommon prey species increased, breeding success decreased. Breeding success was negatively influenced by increasing distance travelled and accumulated dive depths on an annual basis. Summed dive depths were greatest when prey species other than saithe dominated the diet. We found that in years with low availability of saithe fewer shags bred, and those that did had lower breeding success. This indicates that in years with poor feeding conditions, there might not be sufficient resources in the foraging area to support the whole breeding population of shags.
... Seabirds are directly affected by environmental variability (Barbraud et al., 2012;Meier et al., 2017;Watanuki & Ito, 2012;Wolf et al., 2009) and therefore could be sentinels of changes occurring at larger-scales (Barbraud et al., 2012). For instance, oceanographic conditions influence prey availability with direct effects on seabird population dynamics (Frederiksen, Daunt, Harris, & Wanless, 2008;Frederiksen, Harris, Daunt, Rothery, & Wanless, 2004;Furness & Tasker, 2000). Pelagic ecosystems are dominated by few abundant midtrophic species, usually pelagic schooling fish (Batten et al., 2006;Rice, 1995). ...
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During the breeding season, seabird foraging trips are constrained by nest attendance schedule and are necessarily colony centred. Oceanographic cues play a major role in the choice of foraging areas to minimize the time spent away from the nest. Here, we analysed the foraging tracks of Black‐vented Shearwaters Puffinus opisthomelas during the incubation and chick‐rearing periods of 2016 and 2017 at Isla Natividad (Mexico). We applied expectation‐maximization binary clustering to track data to clusterize different behaviour patterns during foraging flights. We then applied binary generalized linear mixed models to characterize of foraging areas based on of environmental variables. We finally used kernel estimation techniques to describe main foraging areas. In 2016, breeding shearwaters used two core areas for foraging and resting on the water; the core area delineated by males was located northward from the colony in the Vizcaino Bay and the core area for females was located southward from the colony at the entrance of San Ignacio Lagoon. In 2017, males and females used the same areas with no evident segregation. Our study provided the first information on Black‐vented Shearwater foraging areas during the breeding season and indicated that sexual segregation within coastal waters off the central Baja California Peninsula might be a foraging strategy during years of warmer ocean, likely less productive regimes. Factors including ocean‐climate‐mediated sexual segregation at sea, leading to interannual variation in foraging areas, should be considered when evaluating management actions intended to protect critical foraging habitats for Black‐vented Shearwaters.
... 34,35 ). The NAO index seems to be particularly well suited to studying the population dynamics of migrants that rely on climatic clues 36 . As an example, survival of little auks breeding in Spitsbergen was linked to winter NAO with a time lag of 2 years, with negative effects on the birds being possibly mediated through varying intakes of little auk prey 23 . ...
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Ongoing global changes apply drastic environmental forcing onto Arctic marine ecosystems, particularly through ocean warming, sea-ice shrinkage and enhanced pollution. To test impacts on arctic marine ecological functioning, we used a 12-year integrative study of little auks (Alle alle), the most abundant seabird in the Atlantic Arctic. We monitored the foraging ecology, reproduction, survival and body condition of breeding birds, and we tested linkages between these biological variables and a set of environmental parameters including sea-ice concentration (SIC) and mercury contamination. Little auks showed substantial plasticity in response to SIC, with deeper and longer dives but less time spent underwater and more time flying when SIC decreased. Their diet also contained less lipid-rich ice-associated prey when SIC decreased. Further, in contrast to former studies conducted at the annual scale, little auk fitness proxies were impacted by environmental changes: Adult body condition and chick growth rate were negatively linked to SIC and mercury contamination. However, no trend was found for adult survival despite high inter-annual variability. Our results suggest that potential benefits of milder climatic conditions in East Greenland may be offset by increasing pollution in the Arctic. Overall, our study stresses the importance of long-term studies integrating ecology and ecotoxicology.
... We predicted rainfall would positively affect the vital rates, temperature would negatively affect the vital rates and that high variation in rainfall and temperature would negatively affect these rates. Depending on the species biology and the environment, survival and recruitment rates of some species are strongly influenced by large-scale climatic phenomena, such as North Atlantic Oscillation (e.g., black-legged kittiwake Rissa tridactyla : Frederiksen, Harris, Daunt, Rothery, & Wanless, 2004; Soay sheep Ovis aries: Coulson et al., 2001) or El Niño events (e.g., Darwin's finches Geospiza spp.: Grant & Grant, 1993). However, small mammals typically have restricted movement and are adapted to respond rapidly to small-scale changes in rainfall and temperature (Bradley et al., 2006;Madsen & Shine, 1999;Previtali et al., 2009;Southgate & Masters, 1996). ...
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Highly variable patterns in temperature and rainfall events can have pronounced consequences for small mammals in resource‐restricted environments. Climatic factors can therefore play a crucial role in determining the fates of small mammal populations. We applied Pradel's temporal symmetry model to a 21‐year capture–recapture dataset to study population dynamics of the pinyon mouse (Peromyscus truei) in a semi‐arid mixed oak woodland in California, USA. We examined time‐, season‐ and sex‐specific variation in realized population growth rate (λ) and its constituent vital rates, apparent survival and recruitment. We also tested the influence of climatic factors on these rates. Overall monthly apparent survival was 0.81 ± 0.004 (estimate ± SE). Survival was generally higher during wetter months (October–May) but varied over time. Monthly recruitment rate was 0.18 ± 0.01, ranging from 0.07 ± 0.01 to 0.63 ± 0.07. Although population growth rate (λ) was highly variable, overall monthly growth rate was close to 1.0, indicating a stable population during the study period (λ ± SE = 0.99 ± 0.01). Average temperature and its variability negatively affected survival, whereas rainfall positively influenced survival and recruitment rates, and thus the population growth rate. Our results suggest that seasonal rainfall and variation in temperature at the local scale, rather than regional climatic patterns, more strongly affected vital rates in this population. Discerning such linkages between species' population dynamics and environmental variability are critical for understanding local and regional impacts of global climate change, and for gauging viability and resilience of populations in resource‐restricted environments.
Chapter
Mostly indirectly, but also through direct mechanisms, climate change is becoming an increasingly significant threat to seabird populations globally. Marine ecosystems and associated trophic linkages are being influenced by changing climatic conditions, while breeding colonies are being subjected to an increasing frequency of heat waves, storms, and unusual precipitation events. We provide an overview of the different responses of seabirds to climate change, including examples of distributional, phenological, demographic, and dietary changes that have been observed. Climate change is largely impacting predator-prey dynamics, and we elaborate on mechanisms and examples of how seabirds are being affected by changes in the distribution and biomass of their prey. Different life history stages vary in their vulnerability to climate change, and we discuss these different stages independently, highlighting the need for a stronger research focus on nonbreeding seabirds, both adults outside the breeding season and juveniles. We discuss factors such as life history traits and geographic distribution that influence vulnerabilities of different species to climate change before elaborating on challenges in understanding and predicting the influence of climate change on seabirds. Particularly noteworthy is the inconsistency between seabird species, even within the same regions, in terms of their responses to climate change. A better understanding of the intrinsic and extrinsic factors giving rise to species-specific vulnerabilities to climate change, and the interaction with other threats associated with biodiversity loss, is needed for improved seabird conservation management.
Chapter
Marine birds form a vital part of marine ecosystems and are among the few species groups (all secondary marine forms) that transcend the boundaries of air and water, bridging terrestrial and marine environments. They are also among the most threatened group of vertebrates worldwide, with up to 70% of the 368 species experiencing population declines and up to a third imminently threatened with extinction. Seabirds have been dramatically impacted by human activities. In their terrestrial breeding habitat, resource extraction, commercial harvest, introductions of invasive species, and anthropogenically influenced increases in predator populations have significant negative impacts. In their marine feeding habitat, fisheries, pollutants, resource extraction, and direct and indirect effects associated with climate change negatively impact their populations. This chapter presents an overview of seabirds, with a focus on breeding and feeding ecology, the associated life history characteristics that make seabirds distinct and unique, and how these traits influence their susceptibility to threats and inform conservation strategies. Other comprehensive references on seabirds include “Biology of Marine Birds” by Schreiber and Burger and “Seabirds: A Natural History” by Anthony Gaston.
Thesis
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Recent policies on the ban of fishing discards and the closure of open-air landfills are expected to reduce amount of predictable anthropogenic food subsidies (PAFS) for seabirds. To forecast the ecological consequences of these policies, it is necessary to understand the influence that each of these resources has on ecological parameters and how this can be mediated by density-dependent mechanisms. Besides, for those species exploiting both types of resources, it is important to consider whether or not their effects act synergistically. Finally, it is also important to understand how the ecological interactions between seabirds and PAFS can be influenced by other potentially important environmental factors, such as for example, the abundance of natural prey or the one of foraging conditions. In the first chapter of this thesis, I reviewed the current knowledge on the ecological interactions between seabirds and fishery discards, with the aim of identifying the main knowledge gaps and to propose new challenges to improve our understanding of the ecological role of PAFS availability to seabirds. In the second chapter, I assessed the relative role of fishery discards and open-air landfills in the breeding investment of a generalist seabird, investigating the possible interplay with density-dependent mechanisms. In the third chapter I collaborated to investigate the role of PAFS in buffering environmental stochasticity and disrupting the natural synchronous dynamics between two seabirds. Finally, in the last chapter, I assessed the importance of several environmental factors in the breeding investment of three seabirds with contrasting life-history strategies. In particular, I considered local environmental variables (food abundance, competition and sea state) during breeding as well as the influence of winter conditions summarized by a large-scale climatic index, the North Atlantic Oscillation (NAO). Considering these variables simultaneously allowed me to assess the relative importance of natural and anthropogenic food resources, intra- and inter-specific competition and foraging conditions in the form of detectability and accessibility of food. This thesis shows that the main knowledge gaps on seabird-discard ecological interactions are related to survival, dispersal and reproduction, the resilience of their populations against perturbations and the role of individual specialization in the foraging process. Results showed that both fishery discards and open-air landfills can significantly increase seabirds’ breeding investment. However, the landfill effect was weaker than the effect of fishing discards, probably due to the lower quality of waste as food resource. It is also shown that these effects can be masked by density-dependence processes. In addition, the thesis highlights the importance of considering the possible influence of socio-economic factors on the availability of these PAFS depending on the geographic area considered. I showed that PAFS can alter natural stochasticity, increasing the breeding investment of generalist species, which in turn, may alter the community structure. Finally, this thesis makes evident that foraging conditions in the form of detectability and accessibility of food can play a very important role in key demographic parameters such as breeding investment. This implies that in contrast to what is commonly assumed, food abundance does not directly translate into food intake. Finally, the results also suggest that the influence that the winter North Atlantic Oscillation has on breeding investment in some seabirds is limited to winter months and acts in spring as a ‘carry-over’ effect of winter conditions.
Thesis
L’impact du changement climatique sur la glace de mer et les écosystèmes polaires qui en dépendent est reconnu depuis plusieurs décennies. Cependant, ces milieux sont généralement difficiles à étudier en raison de leur climat extrême, de leur isolement et des difficultés logistiques associées. Le manque de connaissances concernant les mécanismes reliant les traits d’histoire de vie des organismes polaires et la variation de la glace de mer est particulièrement préjudiciable à notre compréhension des conséquences du changement climatique sur les espèces longévives comme les oiseaux marins polaires. Ces derniers, généralement situés au sommet des réseaux trophiques, pourraient cependant constituer des espèces sentinelles des écosystèmes liés à la glace de mer. L’objectif de cette thèse est d’améliorer les connaissances sur les processus impliqués dans les réponses des populations de prédateurs marins polaires aux variations environnementales, et principalement les mécanismes liés à la glace de mer. Pour répondre à cet objectif nous nous sommes basés sur le suivi individuel à long terme de deux espèces d’oiseaux marins polaires, le pétrel des neiges (Pagodroma nivea) et le damier du Cap (Daption capense). Les deux espèces se reproduisent en milieu polaire. L’une est particulièrement dépendante de la glace de mer pour s’alimenter (le pétrel des neiges) tandis que l’autre préfère un habitat libre de glace (le damier du Cap). Au cours de ce travail, nous avons estimé l’influence de facteurs extrinsèques (forçages ascendants, descendants, météorologie locale) et intrinsèques (âge, expérience de reproduction, sexe, colonie) sur les réponses démographiques des espèces à l’aide de modèles multi-états de capture-marquage-recapture. Nous avons également testé l’influence des facteurs environnementaux sur les traits phénotypiques (condition corporelle et phénologie de reproduction) du pétrel des neiges. Chez les damiers du Cap nous montrons une diminution du succès reproducteur ainsi que l’influence de plusieurs paramètres extrinsèques (température de surface de l’eau de mer, prédation, météorologie locale) sur celui-ci. En parallèle nous montrons une augmentation de la survie des adultes et une corrélation de celle-ci avec l’oscillation Antarctique. Chez le pétrel des neiges, nous avons mis en évidence l’influence de la glace de mer et d’autres facteurs extrinsèques (prédation, oscillation Antarctique, météorologie locale) et intrinsèques (sexe, colonie, expérience de reproduction) sur de multiples traits démographiques. Nous avons également montré un décalage (retard) dans la phénologie de reproduction des pétrels des neiges en réponse à des changements environnementaux (concentration de glace de mer, vents) et nous avons constaté que la reproduction retardée avait un impact négatif sur la probabilité d'envol des poussins. Enfin nous avons aussi montré que la concentration de glace de mer et l’oscillation Antarctique ont une influence négative sur la survie et la condition corporelle des juvéniles de pétrel des neiges. Cette thèse permet d’apporter de nouvelles connaissances sur les liens entre glace de mer et les traits d’histoire de vie d’une espèce pagophilique, le pétrel des neiges et d’une espèce moins associée à la glace, le damier du Cap. Ces connaissances permettent de mieux appréhender les conséquences du changement climatique sur les oiseaux marins polaires et les écosystèmes polaires en général, et apporte une contribution à la compréhension de la dynamique des populations concernant les variations démographiques intra spécifiques à fine échelle spatiale.
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Seabirds play a vital role in marine ecosystems and are determinant sentinels of the productivity of their environments. The long-term study of their breeding biology and their responses to environmental variations can be used to monitor the effects of climate change on marine fauna. However, the ecological and physiological differences among seabirds induce a large range of responses complicating our understanding of the effects of environmental changes on marine ecosystems. The present study investigated the impact of environmental variability on breeding biology in two sympatric small Procellariiform species, the fairy prion ( Pachyptila turtur ) ) and the common diving petrel ( Pelecanoides urinatrix ), over four reproductive seasons (2017-2020) in Bass Strait, south-eastern Australia. Marine heatwaves had a negative effect on chick growth, breeding success, and induced a delay in laying dates in both species. While fairy prions maintained a relatively high breeding success and broadly constant breeding phenology, common diving petrels delayed the start of the breeding season by up to 50 days and experienced dramatic collapses in breeding success in years of high marine heat wave occurrence. The high wing loading and absence of stomach oils in the common diving petrel are likely to have limited the capacity of this species to increase foraging effort in years of low food availability.
Thesis
Seabirds have frequently been proposed to serve as valuable indicators of change in marine ecosystems. In this study I compiled, analysed and presented 10 years of monitoring data from ecological studies of the clupeid-consuming seabird Common guillemot (Uria aalge) at Stora Karlsö in central Baltic Sea. To investigate how seabirds respond to ecosystem changes, external parameters (prey and climate) were also compiled and their effects on the Common guillemot parameters analysed. Fish stock trends used in the analysis was based on scientific survey data only, avoiding modelled stock data possibly biased by commercial misreporting. To increase resolution of the relationship between the seabirds and the Baltic Sea food web, stomach content of 107 Common guillemot chicks was analysed through otolith sampling. This increases general knowledge of prey species composition, and makes modelled parameters (e.g. prey size) more precise. All time series data was analysed by Principal Component Analysis (PCA) and evaluated to distinguish the most prominent parameters and their relationships. The results included relationships contradicting previous reporting on the effect of prey on the Baltic Sea Common guillemot chicks: Sprat (Sprattus sprattus) general abundance rather than individual Sprat weight was shown to influence chick fledging weight positively. Also, contrary to previous chick diet accounts, a large proportion of Herring was found in the chick diet additional to the Sprat, effecting future prey response models. All monitored Common guillemot parameters showed to be interacting internally, while also directly or indirectly being effected by changing external conditions such as fish stocks and climate. The usefulness and potential of seabirds capturing larger and smaller ecosystem changes in the Baltic Sea is already established but also holds promise for the future, suggesting the Baltic Sea Common guillemot to be included in national marine ecosystem monitoring programs.
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Population decline and the threat of extinction are realities currently facing many species. Yet, in most cases, the detailed demographic data necessary to identify causes of population decline are unavailable. Using 43 years (1975−2017) of data from a box-nesting population of tree swallows (Tachycineta bicolor), we identified reduced survival of offspring as a probable demographic cause of population decline. Poor fledging success was associated with increased predation and poor weather conditions during early nestling development. Low juvenile survival and subsequent recruitment was linked to poor weather conditions during the post-fledging period and may also be linked to conditions on the wintering grounds. Regional weather conditions during critical stages of breeding (early nestling and post-fledging) have become progressively worse over the 43-year study period. None of the other factors linked to offspring survival have similarly deteriorated. Overall, our results suggest tree swallows should be added to the growing list of species challenged by climate change, and that other species of aerial insect specialists may face similar impacts of climate change.
Preprint
Seabirds are globally threatened. In the face of multiple threats, it is critical to understand how conservation strategies that mitigate one threat intersect with others to impact population viability. Marine threats, including pollution, climate change, and fisheries could derail gains to seabird populations resulting from arduous predator eradication efforts. However, this potentially negative effect is yet to be evaluated. We test whether mortality from marine threats can subvert the on-going recovery of 17 seabird species from 37 colonies on islands worldwide where predators were removed. We use demographic modelling to estimate potential adult mortality from fisheries, plastic ingestion, and climate change. For 82% of the species we examine, marine threats do not impede recovery following predator eradication. However, for six colonies of three species, Calonectris diomedea, C. borealis, and Ardenna carneipes, mortality from multiple marine threats may interrupt their recovery. Combining our demographic approach with comparative phylogenetic methods, we explore whether foraging niche, range, and morphometric traits inform the vulnerability to marine threats using an expanded dataset of 81 seabird species. Our analyses reveal surface filtering and pursuit diving species, and species with smaller at-sea distributions to be most vulnerable to declines due to multiple threats. However, these traits do not necessarily predict species vulnerability to marine threats in the absence of predators at nesting colonies, suggesting that shared traits may not be useful to infer vulnerability to multiple marine threats. Post-eradication monitoring to determine whether species require additional conservation management following predator eradication are essential in the face of intensifying pressures in the marine environment.
Article
Seabirds are key marine top predator species that are often used as indicators of the environmental quality of the oceans. Their breeding phenology has been studied extensively, but their pelagic habits mean less is known about the phenology of other events during the non‐breeding period. Here, we used miniaturized saltwater immersion light‐based geolocators (GLS) to investigate moult phenology in individuals with known breeding histories in a population of Northern Fulmar Fulmarus glacialis in Orkney, Scotland. As seabirds spend more time on the water during moult, moulting periods can be identified from patterns of variation in the amount of time that birds are in contact with saltwater. Estimates of daily variation in this behaviour during the non‐breeding period were based upon wet/dry sensors and then modelled to characterize the timing of the moult. Light‐based geolocation provided information on the areas used by each individual during its moult period. Inter‐individual variability in moult timing was investigated in relation to sex and breeding success in the previous summer. We found a sex difference in the location of the moult, but not in its timing. However, the timing of moult did differ between individuals that had succeeded or failed in their previous breeding attempt, with successful breeders moulting the latest. In contrast, the duration of moult did not depend on prior reproductive success, but there was evidence of inter‐annual variation in moult duration. GLS studies have provided a step change in our understanding of the at‐sea distribution of pelagic seabirds. Our work highlights how activity data from these devices can add value to such studies by identifying key phases of the annual cycle, and locations at these times, when seabirds may be at particular risk. Furthermore, our findings indicate that individual and inter‐annual variation in breeding success may influence phenological patterns in other phases of the Northern Fulmar annual cycle.
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The lesser sandeel Ammodytes marinus is a key prey species for many marine birds in the North Sea. This fish is currently the target of the largest single species fishery in the area, and this has led to concern about the potential impact of the fishery on seabirds. There are 2 critical issues: does the breeding success of seabirds depend on sandeel availability and does the fishery reduce sandeel availability to a level at which avian reproductive output is affected? This paper investigates the first question in detail and briefly touches on the second by testing for correlations between productivity, breeding effort and diet in 3 species of seabird with contrasting foraging and dietary characteristics (common guillemot Uria aalge, black-legged kittiwake Rissa tridactyla, and European shag Phalacrocorax aristotelis) and an index of availability of 1 group and older sandeels derived from catch per unit effort statistics from the Danish sandeel fishery. Breeding success in all 3 species was significantly reduced when sandeel availability to the fishery in June was low. There was also evidence that the timing of peak sandeel availability influenced reproductive output such that success was lower when availability peaked early. We speculate that these effects are linked to annual variations in sandeel Life history events and, in particular, to the onset of burying behaviour of 1+ group fish and the arrival of 0 group sandeels on the seabirds' feeding grounds. Although the timing of these events is unlikely to be directly influenced by the sandeel fishery, since most catches are taken in June, it is possible that the fishery could exacerbate a difficult situation for seabirds by further reducing the biomass of available 1+ group fish. We suggest that this may have occurred in one of the years of the study.
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The lesser sandeel Ammodytes marinus is a key prey species for many avian predators in the North Sea, and is the target of the largest single species fishery in the area. This has led to concern about the potential impact of the fishery on seabirds. The most vulnerable predatory species are small and surface-feeding, characteristics that are exemplified by the black-legged kittiwake Rissa tridactyla. This paper reports on the first assessment of seasonal changes in prey composition and prey size for the kittiwake in the North Sea during 4 breeding seasons (1997 to 2000) in which breeding success varied dramatically. Kittiwake diet showed little inter-annual variation, with a well-defined seasonal change from planktonic crustacea in early spring, to 1+ group sandeels in April and May, to 0 group sandeels in June and July. However, there was evidence that temporal differences in sandeel life history events were well reflected in both kittiwake diet and breeding success. Thus, the most successful year (2000) was characterised by the earliest appearance of 0 group sandeels, while the least successful season had the latest appearance. There was also a link between annual variations in breeding success and sandeel size such that success was lower when 0 group sandeels were smaller and hence of lower energy value. Our study included 3 seasons (1997, 1998, 1999) during which the industrial fishery was operating within 50 km of the study colony and 1 (2000) in which the fishing grounds were closed. The higher breeding success in 2000 than in the other years suggests that the closure of the fishery might have had an immediate and positive effect on kittiwake productivity. However, as the dietary data indicated, the earlier appearance and rapid growth rates of 0 group sandeels in 2000 suggests that the enhanced breeding success was more likely to have been a response to environmental factors influencing the growth and timing of life history transitions of this prey.
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Changes in the timing, composition, and intensity of freshwater phytoplankton blooms are known to have an impact on water quality and aquatic ecosystem functions. Factors provoking these changes are, therefore, of major importance. In Lake Erken in southeastern Sweden considerable changes in the timing and large variations in the composition of phytoplankton spring peaks have been observed during the past 45 yr. Here we show that long-term changes and variations in Lake Erken are strongly related to a single global parameter - the North Atlantic Oscillation (NAO). Even regional parameters that are known to have most influence on the spring development of phytoplankton such as ice break-up and nutrient concentrations could not provide a more conclusive explanation of the observed changes in spring phytoplankton, making the NAO a very powerful and simple tool in determining the timing and composition of phytoplankton spring peaks in a temperate lake.
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The increase in spring temperatures in temperate regions over the last two decades has led to an advancing spring phenology, and most resident birds have responded to it by advancing their onset of breeding. The pied flycatcher (Ficedula hypoleuca) is a long-distance migrant bird with a relatively late onset of breeding with respect to both resident birds and spring phenology in Europe. In the present correlational study, we show that some fitness components of pied flycatchers are suffering from climate change in two of the southernmost European breeding populations. In both montane study areas, temperature during May increased between 1980 and 2000 and an advancement of oak leafing was detected by using the normalized difference vegetation index (NDVI) to assess tree phenology. This might result in an advancement of the peak in availability of caterpillars, the main prey during the nestling stage. Over the past 18 yr, the time of egg laying and clutch size of pied flycatchers were not affected by the increase in spring temperatures in these Mediterranean populations. However, this increase seems to have an adverse effect on the reproductive output of pied flycatchers over the same period. Our data suggest that the mismatch between the timing of peak food supply and nestling demand caused by recent climate change might result in a reduction of parental energy expenditure that is reflected in a reduction of nestling growth and survival of fledged young in our study populations. The data seem to indicate that the breeding season has not shifted and it is the environment that has shifted away from the timing of the pied flycatcher breeding season. Mediterranean pied flycatchers were not able to advance their onset of breeding, probably, because they are constrained by their late arrival date and their restricted high altitude breeding habitat selection near the southern border of their range.
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We integrated experimental and natural gradient field methods to investigate effects of climate change and variability on flowering phenology of 11 subalpine meadow shrub, forb, and graminoid species in Gunnison County, Colorado (USA). At a subalpine meadow site, overhead electric radiant heaters advanced snowmelt date by 16 d and warmed and dried soil during the growing season. At three additional sites, a snow removal ma-nipulation advanced snowmelt date by 7 d without altering growing season soil microcli-mate. We compared phenological responses to experimental climate change with responses to natural microclimate variability across spatial gradients at small and landscape scales, as well as across a temporal gradient from a separate study. Both manipulations significantly advanced timing of flowering for the group of species and for most species individually, closely paralleling responses of timing to natural spatial and temporal variability in snowmelt date. Snowmelt date singularly explained observed shifts in timing only in the earliest flowering species, Claytonia lanceolata. Among all other species except Artemisia tridentata var. vaseyana, the latest flowering species, a consistent combination of temperature-related microclimate factors (earlier snowmelt date, warmer soil temperatures, and decreased soil degree-days) substantially explained earlier timing. Both manipulations also extended flowering duration for the group of species, similar to species' responses to natural snowmelt variability at small spatial scales. However, only early flowering species displayed consistent, significant changes in duration, with extended duration related to earlier snowmelt or warmer spring soil temperatures. Soil moisture was generally not a significant explanatory factor for either timing or duration of flowering. Best-fit microclimate models explained an average of 82% of variation in timing but only 38% of variation in duration across species. Our research demonstrates the value of comparing and synthesizing results of multiple field methods within a single study. This integrated approach makes it easier to identify robust community-wide trends, as well as species-specific responses of phenology to climate change. The predicted short-term flowering phenology responses to temperature-related aspects of climate change may lead to longer term asynchronies in interspecific interactions, potentially altering population and evolutionary dynamics, community structure, and eco-system functioning.
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The North Atlantic Oscillation (NAO) is one of the most prominent and recurrent patterns of atmospheric circulation variability. It dictates climate variability from the eastern seaboard of the United States to Siberia and from the Arctic to the subtropical Atlantic, especially during boreal winter, so variations in the NAO are important to society and for the environment. Understanding the processes that govern this variability is, therefore, of high priority, especially in the context of global climate change. This review, aimed at a scientifically diverse audience, provides general background material for the other chapters in the monograph, and it synthesizes some of their central points. It begins with a description of the spatial structure of climate and climate variability, including how the NAO relates to other prominent patterns of atmospheric circulation variability. There is no unique way to define the spatial structure of the NAO, or thus its temporal evolution, but several common approaches are illustrated. The relationship between the NAO and variations in surface temperature, storms and precipitation, and thus the economy, as well as the ocean and ecosystem responses to NAO variability, are described. Although the NAO is a mode of variability internal to the atmosphere, indices of it exhibit decadal variability and trends. That not all of its variability can be attributed to intraseasonal stochastic atmospheric processes points to a role for external forcings and, perhaps, a small but useful amount of predictability. The surface, stratospheric and anthropogenic processes that may influence the phase and amplitude of the NAO are reviewed.
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Climatologists tell us that Earth's climate is changing (1): It currently seems clear that a warmer climate is developing in the northern hemisphere, and that the weather will become more variable (2, 3). As part of this global change, seasonal patterns are being altered to make spring conditions occur earlier in the year in the north (4), without necessarily corresponding changes in more southern latitudes (5).
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Chapter
Although a considerable amount of evidence suggesting endogenous annual clocks in plants and animals was accumulated during the first half of this century, their existence was not demonstrated before the early 1960’s. The most compelling evidence then was provided by the work of Pengelley and Fisher (1957, 1963) with golden-mantled ground spuirrels (Spermophilus lateralis). Figure 2.1 shows the seasonal changes in body weight and food consumption, as well as the occurrence of hibernation, in two ground squirrels maintained for about 2 years under a constant LD 12:12 and constant temperature conditions. Both animals continued to hibernate about once a year, and each period of hibernation was preceded by a dramatic increase in body weight and food consumption. The general pattern of these seasonal functions was rather similar to that in free-living squirrels with an obvious difference that can be seen particularly clearly in the squirrel maintained in 0 °C. In the first year of the experiment this animal entered hibernation in late October, but in the second the onset of hibernation had shifted forward to mid-August and in the third to early April. In other words, the period measured between onsets of hibernation was shorter than 12 months.
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The aim of this paper is to demonstrate the effect of climate change on different migratory processes: Spring arrival, migratory take-off, spring and autumnal en route migration. The analysis of arrival dates of 128 bird species registered in Zuvintas and 48 species registered in Vilnius showed that, under the effect of global warming, spring arrival became markedly earlier both for short- and long-distance migrants. The difference between these arrival dates is more pronounced at the beginning of the arrival season, and it is less at the end of the season for short-distance migrants but more constant for long-distance migrants. We tried to explain the effect of climate change upon species specificity of bird migration, mechanisms controlling migratory movements. The article presents material confirming the impact of the global climate change on different breeding bird species and populations, changes of their ranges and population state. It was established that the impact of global warming upon birds of terrestrial and wetland complexes is more evident than upon waterfowl. We also attempted to explain changes in bird staging and wintering concentrations areas due to climate change. Attention is focussed on the aspects of the effect of climate change upon birds in environmental protection, aviation flight safety and other branches of economy.
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Changes in the timing, composition, and intensity of freshwater phytoplankton blooms are known to have an impact on water quality and aquatic ecosystem functions. Factors provoking these changes are, therefore, of major importance. In Lake Erken in southeastern Sweden considerable changes in the timing and large variations in the composition of phytoplankton spring peaks have been observed during the past 45 yr. Here we show that long-term changes and variations in Lake Erken are strongly related to a single global parameter-the North Atlantic Oscillation (NAO). Even regional parameters that are known to have most influence on the spring development of phytoplankton such as ice break-up and nutrient concentrations could not provide a more conclusive explanation of the observed changes in spring phytoplankton, making the NAO a very powerful and simple tool in determining the timing and composition of phytoplankton spring peaks in a temperate lake.
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(1) Between 1974 and 1976, the numbers of shags breeding on the Isle of May, S.E. Scotland, crashed from 1076 to 497 pairs. Before 1974, the colony had been increasing steadily at an average annual rate of 15.6%. (2) Sustained ringing of both adults and young since 1962 made possible a retrospective investigation, in 1982, of the population dynamics of the colony. (3) The adult annual mortality rate remained unchanged over the critical period; it was apparently greater in old birds. Emigration was low (nil in 1974-76); immigration was negligible. The crash was due to extensive non-breeding by experienced adult shags: simulation showed that the proportion of adult non-breeders was 0-30% in 1974, and 25-60% in both 1975 and 1976. Pesticides, heavy metal poisoning and paralytic shellfish poisoning were not implicated. (4) Egg-laying was abnormally late in 1974-76 and annual young production dropped from 1.16 to 0.77 fledglings per pair. The first-year survival rate was 56% in normal years and 17% in crash years, when the peak in first-year mortality shifted from late winter to the autumn. (5) Climate and the abundance of food accounted independently for 68% of the variation in annual laying date. March was colder than average in 1974-76, herring and sandeel stocks were unusually low. Failure of the food supply was probably the main reason for poor breeding in those years.
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Egg production does not impose a major food need in the Shag Phalacrocorax aristotelis because the eggs are small, are formed slowly and are laid at 3-day intervals. I used dye-dosing of females, laying time and, after fixing and staining the yolk, daily ring counts to estimate the amounts of protein and energy needed each day to produce a clutch of three eggs. Maximum daily nutrient needs during egg formation were only 1.15 g per day additional protein and 34 kJ per day energy. Yolk formation times of 40 eggs were 13.5 (±1.2 s.d.) days. Based on yolk-ring counts and laying dates of 15 eggs that contained dye, the lag period between yolk completion and laying was 3.1 ± 0.06 days. The distinct light and dark rings of the stained yolk resulted from differences in the transparency of the yolk spheres. In the dark rings, the spheres were relatively clear, so more depth of stained yolk could be seen than in the light rings, which reflected the incident light.
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Regurgitated food and pellets were collected from Shags on the Isle of May, Scotland. Young Shags were fed almost exclusively lesser sandeels. The relative contributions of 0-group and older sandeels varied markedly between years. Fish were the predominant prey of full grown birds which consumed a wider spectrum of fish than were fed to chicks. Otoliths from at least 14 species were identified but sandeels dominated the diet and were present in 93% of all pellets and accounted for 97% of otoliths. There was no evidence that clupeids were ever an important prey. Although most published data suggest that lesser sandeels spend most of the winter buried in the sand they were obviously still available to Shags during this time and their otoliths occurred in >90% of pellets and accounted for >90% of otoliths. The availability of sandeels, specifically when the fish emerge from the sand in spring is probably a major determinant of the timing of breeding of Shags on the Isle of May.