The Birds of the Western Palearctic
... The study of magpies was conducted in gardens in farmland. In northern Europe, magpies defend all-purpose territories with a size of about 5−7 ha [4,39]. The species is sedentary [40] and adult survival rate is high. ...
... The trials were conducted in the breeding season and thus presumably when most of the older territorial ravens were present in their nesting area. Therefore, most ravens were probably non-breeding yearlings and 2 year-old birds because ravens do not breed until they are (2)−3 years old [39]; in accordance with the birds that we could age from the photos, yearling ravens having a browner plumage colour than older birds [39]. During the present study, pieces of plastic and metal, including spoons, were common at the landfill. ...
... The trials were conducted in the breeding season and thus presumably when most of the older territorial ravens were present in their nesting area. Therefore, most ravens were probably non-breeding yearlings and 2 year-old birds because ravens do not breed until they are (2)−3 years old [39]; in accordance with the birds that we could age from the photos, yearling ravens having a browner plumage colour than older birds [39]. During the present study, pieces of plastic and metal, including spoons, were common at the landfill. ...
Many birds suffer heavily from nest predation, selecting several behaviours to avoid the risk. Corvids are among the most serious nest predators. However, they are also among the most neophobic of any birds. We suggest that nesting birds may take advantage of this fear by decorating the nest with anthropogenic materials that are novel to the predators (termed the Neophobia Hypothesis). They may also add large, conspicuous feathers that may indicate a site where a bird has recently been killed. In a study in the field, we found that territorial Eurasian magpies Pica pica waited for a longer period to remove eggs from artificial nests decorated with a shiny metal teaspoon, or with large, white feathers compared to adjacent artificial control nests with no decoration. On a landfill, where the birds had become more habituated to forage among anthropogenic material, common ravens Corvus corax also avoided nests decorated with a teaspoon or with feathers. The study supports the hypothesis that birds may suffer less nest predation by corvids if they decorate the nest with anthropogenic material or with large feathers.
... Breeding individuals commonly cluster in colonies, with nests rarely found in natural environments, in cavities in trees or rock cliffs, and much more commonly in the cavities of man-made buildings. Each cavity contains only one nest, because swifts are extremely territorial and defend their cavity from intruders (Cramp, 1985). ...
... During each inspection all chicks were ringed, and breeding adults were captured and ringed when present. The laying date (Julian date, i.e., days elapsed from January 1st) for each nest was estimated by backdating based on nest content, considering 20 days for egg incubation (Cramp, 1985) and adding the estimated age of the chicks based on growth curves (Tigges, 2008;Sicurella et al., 2015). When the inspections were too far apart to allow backdating of the laying date, we only estimated the fortnight (15-day period) during which laying occurred. ...
... Local rainfall was not found to be significantly related with the laying date, probably because rainwater has a double contrasting effect on environmental conditions for swifts at our study site latitude, reducing the flying invertebrates that are food for these aerial feeders during the rainfall hours, but increasing the growth of vegetation and the number of insects which consume vegetal substances after rainfall events (Cocu et al., 2005;Bourhis et al., 2021). The breeding success in our study area was similar to those reported in other portions of the breeding range (Lack, 1956;Weitnauer, 1980;Cramp, 1985;Meyer, 2019;Knaus et al., 2022), with small differences between colonies. In our long-term study, we did not notice a decline in the breeding success, similarly to a long-term study in Scotland (Thomson et al., 1996), while in Bohemia, a decline of productivity was found (Rajchard et al., 2006). ...
... Within the Nature Park, the Tawny Owl is ubiquitous, indicating that the entire area is suitable for this species. Primarily residing in forests and along forest edges, the Tawny Owl can also adapt to more open habitats, provided there are scattered trees to perch and hunt from (Cramp 1985). The non-forested habitats in the Park, occupying slightly less than a quarter of the total area, consist of small-sized patches of traditionally managed agricultural mosaics that are suitable for the Tawny Owl. ...
... ests, woodlands, and various types of scrub, they are found only on the very edges of larger woods and forests; most breed in small woodland patches surrounded by open meadows and fields (Mikkola 1983). They typically hunt in a slow, steady, searching flight over open ground (Cramp 1985). The detection of Long-eared Owls at seven out of twelve survey stations suggests that the proportion of open habitats within larger patches of traditionally managed agricultural mosaics in the Park, despite being partly in a state of succession, was still sufficient for the Long-eared Owl. ...
... Both the Little Owl and the Barn Owl are primarily lowland species. In Central Europe, the Little Owl is seldom found at elevations above 600 meters (Glutz von Blotzheim & Bauer 1980, Cramp 1985, Juillard 1985. In neighbouring Slovenia, it predominantly occupies areas below 400 meters (Tome 1996). ...
... In Romania, after the flying out of the juveniles, no more Isabelline Wheatears were observed in the breeding area after 15 June [15]. Although most individuals are leaving by rule at the start of autumn, some individuals are delaying until mid-October [43]. ...
... The Isabelline Wheatear spends its winter in sub-Saharan Africa from Senegal to Ethiopia across the Sahel ( [43,44]). Populations from the eastern part of the range winter in the Arabian Peninsula [42] and the Indian subcontinent. Usually, the birds are present in the wintering grounds until the start of March, although migration movements may start from early January [43]. ...
... Populations from the eastern part of the range winter in the Arabian Peninsula [42] and the Indian subcontinent. Usually, the birds are present in the wintering grounds until the start of March, although migration movements may start from early January [43]. ...
Increasing temperatures due to climate change can favor more thermophilic species, allowing them to expand their territories northward. For the Isabelline Wheatear (Oenanthe isabellina), climate change may facilitate further range expansion as higher temperatures and changing precipitation patterns create more favorable conditions in new areas. The Isabelline Wheatear is a small passerine bird belonging to the Old-World flycatchers. This species’ breeding range extends from temperate southeastern Europe and Asia Minor across arid desert and steppe regions to subtropical northern areas. Its habitat preference includes arid environments characterized by high temperatures, low precipitation, and open spaces. Field observations were collected over four breeding seasons (2021–2024) through the Common Bird Monitoring scheme and occasional observations. Prediction models also incorporated observations from scientific literature and online databases for covering neighboring areas in Ukraine and Romania. Using Maxent species distribution models (SDMs) and all presence locations and bioclimatic variables, predicted modes were built to identify new suitable areas for the Isabelline Wheatear. Most of the predicted range lies close to the Black Sea coast, in southeastern and southwestern Moldova. According to available data, the Isabelline Wheatear inhabits the southern third of Moldova. Fifteen locations have been identified as hosting breeding populations in proper habitats. Until 2021, the Isabelline Wheatear was considered a recent cryptic or overlooked breeding species in Moldova. This is likely due to several factors, including its recent entry into the country’s territory, potentially from two different directions at different times. The new data and predictive models provide valuable insights into the current distribution and future expansion potential of this species, underscoring the dynamic nature of avian responses to climate change.
... Their songs are variable in the number of notes, frequency, and duration, but species can be easily identified by their vocalizations. In the literature, songs and calls of the species in the focal community are well described and can be clearly differentiated (Fig. I.3;Catchpole and Slater 2003;Cramp et al. 2004). ...
... We broadcast alarms of 14 species in the local community, one species per trial (Table S2.1). In all 14 species, alarm calls were clearly differentiated from songs and other calls (see references in Table S2.1, and Cramp et al. 2004) and elicited different kinds of responses in the local community (Rossetto and Laiolo 2004). The broadcast stimuli were obtained from recordings downloaded from the xeno-canto repository (https://xeno-canto.org/) by selecting alarm recordings with low background noise that were of high quality (when possible, graded as quality 'A' in xenocanto) and recorded close to our study area (see Rossetto and Laiolo 2024 for the reliability of this source of tracks). ...
... After selecting and downloading the recordings, tracks were prepared using Avisoft-SASLab Pro (Specht 2002). Half of the tracks broadcast were composed by "narrow-sense" alarms, which are the sounds most commonly used by each species known to warn of predator threats (sensu Cramp et al. 2004) and another half of the tracks were composed by the most commonly used alarm (narrow-sense alarms) plus other types of alarms, such as the high frequency 'seet' calls used for some predators that are deaf to high frequency calls (Table S2.1; Cramp et al. 2004;Suzuki 2020). In any event, all types of alarm calls broadcast are used under an antipredator context (Cramp et al. 2004). ...
The acquisition of information from the environment plays a central role in the decision making of individuals. Information can be obtained from the abiotic component of the environment, but also from the biotic component of the environment. A specific case of the latter is when information is obtained from other species of the community: information may link heterospecifics to one another, generating interactions. Interactions are of paramount importance in building up and maintaining biodiversity. Thus, understanding the nature of interactions generating information transfer, as well as the ecological consequences of making informed decisions, may have a relevant reach in ecology. The transfer of information among heterospecifics can occur through acoustic signals. Even if acoustic signals are emitted towards a receiver to which the signal is intended, co-occurring heterospecifics can gather information by eavesdropping these inadvertent cues, for example to be informed on predator presence or resources availability. This would represent a type of positive interaction among species, potentially generating a network of information transfer connecting different species that can be benefited from it or, in other terms, a facilitation network. In animal communities, special attention has been traditionally given to negative interactions – especially among the members of the same guild – while little is known about whether and how positive interactions – such as facilitation – are originated, and their ecological consequences on community dynamics.
The present doctoral thesis aims to disclose the occurrence and the underlying mechanisms of acoustic interactions among members of the same community, and its emerging ecological consequences at the community level. More specifically, interspecific information transfer and interactions through bird song and alarm call are assessed and the structure of the resulting network is investigated at the community level.
Passive acoustic monitoring and playback experiments in an avian assemblage revealed that birds were acoustically stimulated by heterospecific acoustic signals. Specifically, birds tended to sing after the songs of other species that are more dissimilar from their own songs. One possible explication is that the singing activity of community members may indicate safe conditions for displaying (because of low predation risk or diluted attacks from predators), thus being a generally positive stimulation for community members. Acoustic stimulation occurred through alarm calls as well, and the responses of species were associated with low predation risk: the species that responded most to heterospecifics calls were the less vulnerable. Alarming in response to heterospecifics may serve to warn conspecifics of danger but only in low-risk conditions for the signalling individual. Thus, both interactions though songs and alarms might be potentially facilitative, and this idea is strengthened by the fact that the occurrence and abundance of species eliciting greater acoustic stimulation in heterospecifics was associated with high species richness, as expected for facilitative interactions promoting species coexistence. Some groups of species interacted through songs more frequently with subsets of species, thus the song network is modular, while alarming tend to better connect all community members. Finally, a new methodology to disclose the occurrence of acoustic interactions in communities based on soundscape analyses is proposed, analyzing its pros and cons. These analyses should be restricted to low-noise conditions and networks that are far from acoustic saturation (low background and biotic noise).
Overall, this thesis suggests a novel role of acoustic behavior in generating interactions and facilitation in animal communities, and as a mechanism shaping community assembly.
... The distribution of the Eurasian scops owl during breeding season is based on occurrence data from 20 April to 30 June, in order to minimize the accounts of migrating individuals in the analysis (Cramp, 1985). To map the distribution of the Little owl we used data collected during and after the breeding season from 2016 onward (Ignatov & Popgeorgiev, 2021). ...
... The Barn owl is associated with open habitats of agricultural landscape that is dominating the Upper Thracian Lowland (Cramp, 1985). Furthermore, the population density and distribution as noted in other studies from southern Bulgaria seems to be around the average for Europe (5 breeding pairs/100 km 2 ) which can also explain the number of UTM squares where the species has been confirmed (Daskalova et al., 2019;Milchev & Gruychev, 2014). ...
... During the non-breeding season, the species was recorded in seven UTM squares, all of which different from the squares where the species was confirmed or newly recorded during breeding (Fig. 6b). However, some of those might be breeding sites too as the species is mainly sedentary (Cramp, 1985). ...
Here we aim to present the recent breeding distribution of the owl species from the Upper Thracian Lowland, Bulgaria, and to compare it with previous studies to highlight distribution changes in the species. Moreover, as a second objective we aim to present the non-breeding distribution (during winter or migration) of the studied species for the first time. The most common species, widely distributed in the study area were the Little owl, the Eurasian Scops owl, the Long-eared owl and the Barn owl. We found new localities for the Short-eared owl and the Eagle owl that are rare breeding species in the study area. The Tawny owl is also rare in the Upper Thracian Lowland and mostly occurs in old preserved forest patches along the Maritsa river valley.
... Phylloscopus sibilatrix and P. bonelli are sister species that diverged from each other ca. 4 million years ago (Alström et al. 2018). They co-occur during their breeding season in parts of central Europe (Bezzel 1977;Cramp 1992), and the area of sympatry appears to be extending due to the northward expansion and increased abundance of P. bonelli in Europe (Keller et al. 2020). Given their sister-species status, it is unsurprising that the ecological niches of P. bonelli and P. sibilatrix apparently overlap in various dimensions. ...
... Furthermore, the high similarities in morphology and dietary niches of P. bonelli and P. sibilatrix (both insectivorous species, foraging with similar tactics in the tree canopy, Glutz von Blotzheim and Bauer 1991) may result in competition for food during the breeding season, when food demand is very high. Finally, anecdotal evidence from our own fieldwork and natural history accounts (Schneider 1969;Cramp 1992;Riedinger 1995) indicates that aggression between P. sibilatrix and P. bonelli occurs in the form of chases and even physical fights (either species can be the aggressor). Thus, it seems plausible that producing a song that resembles the song of P. bonelli could enhance the ability of P. sibilatrix to establish and maintain territories among P. bonelli, which on average, occur at densities 11 times higher than P. sibilatrix (Table S1). ...
... Phylloscopus bonelli and P. sibilatrix are small, migratory passerines (~8 and 9 g, respectively, see Table S2 for detailed biometrics) that over-winter in sub-Saharan Africa. The breeding range of P. sibilatrix extends across much of Europe into Russia, whereas P. bonelli is restricted to more mountainous areas throughout the Mediterranean, western and central Europe (Cramp 1992). In our study sites, males of both species begin arriving in mid-April and sing intensively to attract females (females are not known to sing). ...
In this era of rapid global change, understanding the mechanisms that enable or prevent species from co-occurring has assumed new urgency. The convergent agonistic character displacement (CACD) hypothesis posits that signal similarity enables co-occurrence of ecological competitors by promoting aggressive interactions that reduce interspecific territory overlap and hence, exploitative competition. In northwestern Switzerland, ca. 10% of Phylloscopus sibilatrix produce songs containing syllables that are typical of their co-occurring sister species, P. bonelli (“mixed singers”). To examine whether the consequences of P. sibilatrix mixed singing are consistent with CACD, we combined a playback experiment and an analysis of interspecific territory overlap. Although P. bonelli reacted more aggressively to playback of mixed P. sibilatrix song than to playback of typical P. sibilatrix song, interspecific territory overlap was not reduced for mixed singers. Thus, the CACD hypothesis was not supported, which stresses the importance of distinguishing between interspecific aggressive interactions and their presumed spatial consequences.
... We sampled a total of 157 Eurasian hoopoes in two study areas located in southeast Spain: Guadix (37°18ʹN-3°04ʹW), a semi-arid high plateau that combines irrigated crops, almond and olive groves, isolated holm oak trees, and pine forest patches; and Plasencia (40°10ʹN-6°07ʹW), a dehesa, the typical Mediterranean open forest characterised by a mix of pastureland and dispersed oak trees (mainly holm and cork oaks), and livestock grazing. Both populations are located in the southernmost part of the Eurasian hoopoe breeding range (Cramp 1985) and have the highest abundance of individuals wintering in the Iberian Peninsula (SEO/BirdLife 2012). The two sampling areas are 400 km apart from each other and are considered to be two different breeding populations. ...
... We collected 455 feather samples from 91 individuals, targeting five different areas that are considered important for determining the moult pattern of the species: the fourth primary, the seventh secondary, their respective coverts, and the breast (Cramp 1985, Demongin 2016. We obtained deuterium values ( 2 H) from all feather samples using the comparative equilibrium method, which determines the non-exchangeable hydrogen composition of organic tissues by comparison with homogenised standards (Wassenaar and Hobson 2003). ...
Ecophysiology has enhanced our understanding of avian migration, yet many aspects of how these processes interrelate are still unclear. Partially migratory populations provide an ideal framework for its study in the wild, since resident and migratory individuals coexist temporarily in the same area and face similar selection pressures. We focused on two Iberian populations of Eurasian hoopoe Upupa epops, a trans‐Saharan long‐distance migrant, to explore the links between the immune system and migratory behaviour. We determined the migratory status of individual hoopoes using stable isotope analysis of deuterium (²H) and measured a number of immunological parameters, including estimates of innate and adaptive immunity, as well as body condition, and muscle and fat stores. Our results indicate that resident hoopoes had higher IgY levels and higher muscle and fat stores compared to migrants during the breeding season. Moreover, we found seasonal variation in leukocyte profiles of resident birds, with higher heterophil/lymphocyte (H/L) ratios in winter than during the breeding season. We observed significantly higher H/L ratios and complement activity in resident males than in resident females, but not within migratory birds. Overall, we show differences in immune response linked to migratory behaviour in partial migratory populations. This study contributes to unraveling the associations between physiological status and migratory behaviour and ultimately helps to understand how different migratory strategies are maintained in partially migratory populations.
... Below: the values of the univariate diversity metrics at the community level: normalized richness (Margalef index; Dm), Shannon-Wiener diversity (H ′ ) and evenness (J). To assign species to different ecological guilds, we refer to [45][46][47][48][49]. To calculate the biomass values, the mean body mass values were obtained from [45][46][47][48][49]. When available, we used biomass data available for an area immediately surrounding (4 km away; Villa Pamphili urban park; [50]), and (iii) the relative frequencies were calculated both for density (fr D , as D/N, where N is the total species density) and for biomass (fr Cb , expressed as the ratio of specific Cb/total Cb). ...
... Below: the values of the univariate diversity metrics at the community level: normalized richness (Margalef index; Dm), Shannon-Wiener diversity (H ′ ) and evenness (J). To assign species to different ecological guilds, we refer to [45][46][47][48][49]. To calculate the biomass values, the mean body mass values were obtained from [45][46][47][48][49]. When available, we used biomass data available for an area immediately surrounding (4 km away; Villa Pamphili urban park; [50]), and (iii) the relative frequencies were calculated both for density (fr D , as D/N, where N is the total species density) and for biomass (fr Cb , expressed as the ratio of specific Cb/total Cb). ...
When we compared breeding bird communities in cork oak patches located before and after a fire event, we did not observe any significant changes in the density of territorial pairs or in the diversity metrics. This counterintuitive response may be due to the characteristics of cork oak (Quercus suber), a sclerophilous tree that is very resilient to fires and able to recover foliage in the following spring season, thus allowing rapid bird recolonization. Abstract: Forest fires are disturbance events that can impact biological assemblages at multiple scales. In this study, the structures of breeding bird communities in cork oak patches located in an agro-mosaic suburban landscape of central Italy (Rome) were compared at the local scale with a fine-grained mapping method before (2018) and after (2023) a fire event occurred in July 2022. The analyses did not reveal any significant changes in the density of territorial pairs or in the diversity metrics, both univariate (Shannon-Wiener index, evenness, Margalef normalized richness) and bivariate (Whittaker and k-dominance plots, abundance/biomass curves) of diversity. Even when the guilds of strictly forest-related species were compared, no differences emerged before and after the fire. This counterintuitive phenomenon may be due to the characteristics of the dominant tree, the cork oak (Quercus suber), a sclerophilous tree that is very resilient to fires and able to recover foliage in the following spring season, thus allowing rapid bird recolonization. However, other small-scale phenomena (e.g., the 'crowding effect' and local dispersal of territorial pairs from remnant wood patches not affected by fire) may explain this lack of change in breeding bird density and diversity. Further studies should be carried out at larger spatial and temporal scales and at different levels of fire frequency and intensity to confirm these responses at the guild/community level in suburban cork oak wood patches.
... The species is distributed in relatively small, isolated populations across numerous Algerian wetlands. This fragmented distribution likely increases its vulnerability to anthropogenic pressures, such as habitat loss, pollution, and human disturbances, which can have a disproportionate impact on smaller, less connected populations [22,28]. Most studies on these species have been conducted over short periods and have not assessed the impact of climate change on their population fluctuations. ...
Understanding the impact of climate change on waterbirds, particularly those of conservation concern, is essential for their long-term management and effective conservation. In arid regions such as North Africa, wetlands of international importance have been affected by severe drought events, but their impact on waterbirds is still not well understood. Here, we assess the population dynamics of four emblematic resident species (Aythya nyroca, Marmaronetta angustirostris, Oxyura leucocephala, and Porphyrio porphyrio porphyrio) in a North African Ramsar site (Garaet Hadj Tahar marsh, Northeast Algeria), and determine the climatic variables (temperature, precipitation, and drought index) that best predict the change in abundance in wintering and breeding seasons. We used a long-term survey of regular counts during the wintering and breeding seasons of 2002–2019. The temporal trend of waterbird abundance differed between species and seasons. Species showed different sensitivities to different climatic variables at different time windows preceding the wintering and breeding seasons. We found that the population dynamics of the endangered O. leucocephala in the wintering and breeding seasons were best predicted with the drought index, whereas those of P. p. porphyrio were best correlated with maximum temperature. Population dynamics during the wintering and breeding season of the two other species were best explained with either maximum temperature, precipitation, average temperature, or drought. Species responded differently to warming and drought. The most endangered species (O. leucocephala) showed population declines in drier years, whereas less threatened species (A. nyroca, M. angustirostris, and P. p. porphyrio) exhibited either positive or negative correlations. The observed temporal increase in vegetation cover was positively correlated with the wintering population size of O. leucocephala, as well as the breeding population size of P. p. porphyrio and M. angustirostris. These findings highlight the urgent need for climate-adaptive conservation strategies to sustain wetland biodiversity and ecosystem resilience in the face of increasing climate stressors, aligning with the global sustainability goals for biodiversity conservation and ecosystem management. Our results suggest that future increases in temperatures and drought severity might threaten endangered waterbirds and benefit more common species in the region.
... Moreover, we found no differences in apparent survival between sexes for either Moustached or Reed Warblers, which agrees with previous research (Castany 2003, López-Iborra et al. 2006, Thaxter et al. 2006. This was expected since males and females in both species contribute similarly during incubation and the parental care of the chicks (Cramp 1992). ...
The Spanish population of the vulnerable Moustached Warbler Acrocephalus melanopogon, which has undergone a continuous decline in recent decades, is the most important in Western Europe. It coexists with the widespread Reed Warbler Acrocephalus scirpaceus, whose population has increased. Differences in breeding productivity have been identified as a factor behind these diverging trends. We investigated these warblers’ apparent adult survival rates to assess if this demographic parameter might also influence these different trends. Additionally, we tested to see whether there were any sex-related differences in survival and whether the different migration strategies of these two species (short-distance vs. long-distance migrant) might influence survival. To do so, we ringed both species intensively at 10 ringing stations located in El Marjal de Pego-Oliva Natural Park (Eastern Spain) in 2011–2015. In total, we ringed 502 Moustached Warblers and 459 Reed Warblers and built sex-known encounter histories for 396 (223 males and 173 females) and 394 (255 males and 139 females), respectively. We found that transient male Reed Warblers represented 35% of the population and that apparent survival rates did not differ between these two warblers, being 0.486 ± 0.050 (mean ± SE) for both male and female Moustached Warblers, 0.475 ± 0.105 for male and 0.471 ± 0.171 for female Reed Warblers. Our results indicate that there were no significant sex-related differences in survival in either species, as expected in species that exhibit bi-parental care behaviour. This study should encourage conservation managers and bird ringers alike to study survival as a means of improving knowledge of avian population dynamics.
... The Bluethroat Luscinia svecica has a wide breeding range across the Palearctic and migrates during the boreal winter to Southern Europe, Northern and Sahelian Africa, the Arabian Peninsula, the Indian subcontinent and South-East Asia (Bird-Life International and Handbook of the Birds of the World 2023, Fig. 1). Ten subspecies are known to date (Cramp 1988), but little is known on population-specific migration. Bluethroats breeding in Spain (Luscinia svecica azuricollis) have been tracked to wintering areas in Mauritania and Mali (Vega et al. 2019). ...
The Red-spotted Bluethroat ( Luscinia svecica svecica ) has a large breeding range in northern Eurasia and populations are known to migrate along the Indo-European or the East Asian flyway towards wintering areas in South and South-East Asia. The migration routes of birds breeding in Western and Central Siberia, where a migratory divide is expected, remain largely unknown. In this study, we tracked a Red-spotted Bluethroat with light-level geolocation from its breeding site in Central Siberia to its wintering area in the border region between north-western India and Pakistan. The bird followed the Central Asian flyway, with possible stopovers near the Tien Shan mountains during autumn as well as north and south of the Central Asian mountain ranges and in north-eastern Kazakhstan during spring migration. Our findings suggest a potential migratory divide for Red-spotted Bluethroats east of the Yenisei River, supported by contrasting migration patterns between Central and north-eastern Siberian populations. Further tracking and genomic studies are needed to explore the origins and migratory connectivity of Bluethroats across Siberia and to locate the migratory divide.
... Nightjars' mating and territorial behaviour suggests that white markings in males' wings and tail convey information for rivals and potential mates. During their display, male Nightjars glide over their territory, with fanned wings and tail, exhibiting their white markings [39,65] (see also Figure 1). When male Nightjars are not displaying, the innermost markings are partially covered by outer feathers, which may, in addition to concealing the visibility of conspicuous markings to predators [23,25], aid in resisting degradation better compared to the rest of the markings [15,66,67]. ...
Secondary sexual traits, such as specific body parts or colouration, play an important role in mating interactions. It has been proposed that they function as quality indicators driven by sexual selection. In birds, much attention has been paid to the study of feather pigmentation, especially in diurnal passerines. However, recent research demonstrates that structural achromatic colours are likely to be of similar importance for communication, especially for species inhabiting poorly lit environments and that are active at night. Using 15 years of capture–recapture data from a long-term study on adult European Nightjars (Caprimulgus europaeus), we investigated the role of males’ white tail and wing markings as secondary sexual traits. We show that the inter-individual variation in marking size exceeds that of the other morphometric variables, suggesting that wing and tail markings could be subject to sexual selection. Older males, individuals with a higher body condition index, and long-term territory holders had larger markings, while these effects were particularly pronounced in terminal tail feather markings. The importance of markings for signalling is likely related to their observed use in social displays. Pronounced site differences in tail marking sizes and annual variation suggest environmental factors acting on the ornaments that remain to be further examined.
... Large owls, such as the GGO, require large numbers of prey to feed on. It is estimated that the GGO requires about 1400 voles per year [54], and the incubating female needs 60-80 g of prey per day [86]. Having enough preferred prey, owls do not prey on less preferred species [40-43, 45, 64]. ...
... The rapid increase in the Eurasian magpie population observed in the second half of the 20th century was evident in many European cities [2,16]. Among the factors responsible for this phenomenon were changes in urban green spaces, particularly the planting of fastgrowing tree species [13]. ...
This study investigates the changes in population size, distribution, and habitat preferences of the Eurasian magpie Pica pica in Zielona Góra over 23 years, emphasising the effects of urbanisation and habitat transformation. A comprehensive survey conducted in 2022 identified 953 magpie pairs, with an average density of 8.8 pairs/km² across the current administrative boundaries of Zielona Góra (without forests), and 27.7 pairs/km² in strictly urbanised zones. The highest densities were observed in the old town (36.5 pairs/km²) and residential blocks (34.5 pairs/km²), while peripheral areas, like allotment gardens and industrial zones, showed significantly lower densities. The nests were predominantly located in coniferous trees, especially spruces, marking a shift from the previously favoured poplars. The mean nest height was 11.8 m, varying by habitat type, with the highest nests found in the old town and parks. Environmental factors, such as proximity to trash bins, water sources, and tall trees, were significant predictors of nest density and placement. These findings underscore the magpie’s adaptability to urban environments, influenced by the availability of anthropogenic resources, habitat structure, and surrounding urban features.
... This difference could have several explanations. First, males may have started body molt while remaining on the breeding grounds attending their young and dropped their tags before departure 45 . Second, females and males may differ in their preference for either coastal or oceanic migratory routes. ...
Understanding movement ecology of long-distance migrants is essential for effective conservation. We showed that West Atlantic Flyway Whimbrels (Numenius phaeopus) depart their breeding grounds at different times based on breeding latitude, sex, and nest fate. Whimbrel may exhibit sex-specific preferences in migration, with males favoring oceanic routes, or molt strategies, with males losing glued-on tags earlier than females. We radio-tracked 45 birds from two study sites 710 km apart, with 30 detected after departure. The northern population departed significantly later than the southern population. Successful males in the north tended to depart later than the other groups. Detection probability declined with time after departure, and males were less likely to be detected than females. Seven females, but no males, were detected in one location for more than 1 day. Birds detected in the Maritime Provinces were not detected farther south, while all other birds were detected farther south along the Western Atlantic coast. This suggests that birds detected in the Maritimes may continue with overwater flights to their wintering areas. Our results are the first to suggest that there may be sex-specific preferences for migration routes, or molt strategies in Whimbrel, implying the need for more complex conservation actions.
Invasive, non-native species are recognised as a global problem, and their dispersal and introduction are controversial topics. However, a source of particular interest is that of human–nature interactions and consequent perceptions of natives and non-natives, an issue complicated by misunderstandings of history and sometimes of science. Furthermore, there are only few studies on the perceptions of exotic species by people living in a region subject to invasion. The research compared local stakeholder responses to a non-native invasive bird (ring-necked parakeet Psittacula krameri Scopoli) in two areas with contrasting scenarios regarding the history of establishment, their spread, and their current status. In both locations, parakeets were considered by respondents to be attractive, but where long-established, they were also viewed as a nuisance. Desire for or tolerance of active control measures also increased in areas with a well-established population in comparison to where parakeets were still viewed as a novelty. Increased encounters between native birds and invasive parakeets influenced attitudes towards possible controls. An online survey gathered stakeholder responses, and long-term citizen science and action research were combined with data from Local Environmental Records Centres and ornithological recording groups for each region.
The study of bird assemblages recovered from archaeological sites provides palaeoclimatic and environ-mental information, as well as data on the formation processes assemblages and the agents that have acted upon them. In this paper, we present the results of palaeontological and taphonomic analysis of seven avian assemblages recovered from two sites located in the north-eastern Iberian Peninsula: Galls Carboners (GC; 31,380–31,170 cal. BP) and Cudó (CU; CU107 31,245–24,404 cal. BP and CU105 15,585–10,199 cal. BP). GC has yielded four different assemblages (GC105, GC106, GC107, GC108) corre-sponding to the Heinrich event 3, with only three different taxa, dominated by the presence of Columba. Most of these remains belong to immature individuals. At CU, we studied two assemblages (CU107– CU105) corresponding to Heinrich 3, Heinrich 2 and the Last Glacial Maximum with a similar taxonomic diversity to GC. Assemblage CU105 exhibits the greatest diversity, and small Passeriformes are the most abundant taxa recorded. Of particular interest is the presence of cf. Pinicola enucleator in CU107, today absent in the area and present in boreal areas. Taphonomic results suggest that the origin of accumula-tions for both sites (GC and CU) was natural death. In addition, different agents modified these accumu-lations: small carnivorous mammals and nocturnal raptors affected GC’s assemblages, while nocturnal and diurnal raptors would have been the main predators of the birds documented at the CU site. Despite the differences between the accumulations, Heinrich 3 assemblages from GC and CU show a sim-ilar low degree of diversity, dominated by rock-dwelling taxa. This may be related to the harsh environ-ment of the area during Heinrich event 3, and not to a taphonomic bias. The more diverse assemblage of CU105 points to an ecosystem recovery after the LGM.
The application of high-tech methods for tracking birds, primarily satellite telemetry, has made it possible in a relatively short time to reveal real migratory routes and wintering areas for many bird species. In the Common cuckoo, whose breeding range extends over a vast territory from Portugal to Kamchatka, the migratory routes and wintering grounds have been well studied for a number of European populations, while the migration of Asian populations of this species is still not so well studied. In this work, we analyze satellite telemetry data obtained from four adult males of the Common cuckoo caught in early June 2017 during the nesting period on the Kamchatka Peninsula near the town of Yelizovo. The autumn migration of these birds started in August to early September. They crossed the Sea of Okhotsk (more than 1 000 km) and, without staying for a long time in the Khabarovsk Region, stopped in China (Sichuan, Hebei, Heilongjiang provinces), where they remained for a long time, from 32 to 52 days, moving around this country until October to November. In southern China, all three surviving males changed their SW direction of migration to almost western and flew crossing Myanmar and Bangladesh to India, where they stopped over for 24–34 days until November 10th or 29th. Then the birds crossed the Arabian Sea in 2–3 days overcoming the huge body of water of about 3 000 km in width without stop to land on the African continent (Somalia). Further migration of Kamchatka cuckoos passed through the countries of East Africa such as Ethiopia, Kenya, Tanzania, Malawi, Zambia or Zimbabwe, where they stayed from 2 to 11 days. Finally, all three individuals reached wintering areas in December, first in Botswana, then in Namibia. Thus, the duration of autumn migration of Kamchatka cuckoos varied from 106 to 123 days. During this time, they overcame a record distance of 17,340 km for land birds. The spring migration of two birds started on April 19th or 26th next year. They flew back using a similar route as in autumn. One individual crossed the Arabian Sea in early May, the other from May 20th to 22nd. Having reached India, one bird almost the same day arrived to Bangladesh and then to China. The other one stayed on the Hindustan Peninsula for 11 days, this being much shorter than in autumn. Unfortunately, only one male reached the nesting area in Kamchatka (May 31st). Apparently, the other one either died or lost the transmitter in China. The survived male returned to its former nesting area with high accuracy, its transmitter emitted signals until July 10th. The spring migration took the birds much less time (42 days) than in autumn (106–123 days). Thus, we recorded an ultra-long total distance of autumn and spring migration for a land bird species of almost 34,000 km from Kamchatka to Namibia and back.
Seed dispersal is crucial for ecosystem persistence, especially in fragmented landscapes, such as those common in Europe. Ongoing defaunation might compromise effective seed dispersal, but the conservation status of pairwise interactions remains unknown. With a literature review, we reconstructed the first European-wide seed dispersal network and evaluated the conservation status of interactions by assessing each interacting partner’s IUCN (International Union for Conservation of Nature) conservation status and population trends. We found that a third of the disperser species and interactions face potential extinction and that 30% of the plant species have most of their dispersers threatened or declining. Our study reveals a developing seed dispersal crisis in Europe and highlights large knowledge gaps regarding the dispersers and conservation status of zoochorous plants, urging further scrutiny and action to conserve the seed dispersal service.
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