Jaime A Ramos

University of Coimbra | UC · Department of Life Sciences

The recent decline of Mediterranean oak woodlands in SW Iberian Peninsula is related to insect pests which affect both cork oak (Quercus suber) and holm oak (Quercus rotundifolia). We identified twenty-six bird species as potential regular predators of twenty major pests by reviewing the diet of breeding, wintering and resident species in this ecos...

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 co...

The effects of growing urbanization have caused an increase in human-wildlife interactions in urban areas. Human-gull conflicts have been particularly studied during the breeding season when gulls cause an obvious nuisance in urban areas. However, with many gulls being present in urban areas throughout the year, stakeholders need knowledge of seaso...

The availability of anthropogenic food subsidies has promoted an increase in generalist opportunistic gull species, which currently breed and forage on predictable anthropogenic resources (e.g. landfills). Here we investigated whether marine resources are still important to urban-dwelling gulls. We studied 4 natural and 2 urban yellow-legged gull L...

Gulls are highly opportunistic seabirds, and the exploitation of fishery discards led to many population increases worldwide. We investigated the importance of fish in the diet of yellow-legged and Audouin’s gulls and assessed the influence of fishery discards in their feeding ecology. We collected pellets in four islands along the western Iberian...

Chemical pollution is currently one of the main environmental threats resulting from anthropogenic activities. The presence and accumulation of chemical elements in organisms is often linked to their specific environment and diet, and their concentration tend to accumulate in food webs via bioaccumulation and biomagnification processes. Apex predat...

Hole-nesting birds, such as the great tit (Parus major), have been used as a model species to study adaptation to changing environments due to being ubiquitous, widespread and easy to study. Their breeding phenology responses to climate change have been recorded in long-term studies but most of these populations are located in central/northern Euro...

In recent decades, the breeding populations of the yellow-legged gull Larus michahellis (YLG) have increased significantly, primarily due to the increase in open refuse dumps and discards from fisheries. Portugal’s largest YLG breeding colony is located on Berlenga Island, where population numbers have been monitored since 1974. The population grew...

The utility of fresh green material in avian nests is still not fully understood. Potential explanations include the effects of plants’ volatile compounds on parasite reduction (nest protection hypothesis) or direct beneficial effects on nestling condition (drug hypothesis). We used correlative data collected during 2020 and 2021 in a Mediterranean...

Marine protected areas (MPAs) are widely used tools for conservation and management. Their correct delimitation is challenging, especially when the target species are small, elusive and inconspicuous, as little data are generally available to adequately assess their distribution at sea. Therefore, currently designated MPAs may not effectively cover...

Varias especies de aves colocan en sus nidos trozos de plantas aromáticas, caracterizadas por la emisión de metabolitos secundarios. Estas plantas no suelen encontrarse en las inmediaciones del nido, sino que componen una fracción no aleatoria de todas las plantas presentes en un área. Debido a que estas aves emplean tiempo y esfuerzo en su búsqued...

Las poblaciones de aves se encuentran en un declive generalizado, por lo que las técnicas de monitoreo eficientes, rápidas y no invasivas pueden ayudar a la conservación de las aves al predecir el éxito reproductivo a corto plazo. Sin embargo, estas técnicas suelen consumir tiempo, ser costosas o tener efectos negativos en el éxito reproductivo de...

The Eurasian Spoonbill Platalea leucorodia is currently experiencing an increasing population trend in Western Europe and colonising areas in its breeding range. In this study we assessed the diet and trophic ecology of spoonbill chicks in Portuguese colonies (Ria Formosa and Tagus Estuary) occupied at different years during the population expansio...

Oceans have been considered as an unlimited supply of goods and services, but resource extraction and waste disposal became ubiquitous and have been damaging the health of marine ecosystems. Finding suitable sentinel species of the human impacts on the oceans is thus imperative, since they may work as early warnings of disruptive situations. In thi...

Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are h...

Conservation guidance—an authoritative source of information and recommendations explicitly supporting decision-making and action regarding nature conservation—represents an important tool to communicate evidence-based advice to conservation actors. Given the rapidly increasing pressure that climate change poses to biodiversity, producing accessibl...

Seabirds have evolved several life-history characteristics to help buffer environmental stochasticity. However, particularly during the breeding season, seabirds may be affected by reductions in prey availability and localised oceanographic conditions caused by variations in the environment. The increase in sea surface temperature, triggered by acc...

Climate change affects timing of reproduction in many bird species, but few studies have investigated its influence on annual reproductive output. Here, we assess changes in the annual production of young by female breeders in 201 populations of 104 bird species (N = 745,962 clutches) covering all continents between 1970 and 2019. Overall, average...

Background: Marine pollution, caused by anthropogenic debris, is a significant environmental issue that has detrimental effects on marine ecosystems [1]. Finding suitable sentinel species of the human impacts on the oceans, is imperative. As top predators, seabirds are considered sentinels of the marine environment [2]. Objective: To provide quanti...

The establishment of large populations of yellow-legged gull Larus michahellis in coastal and urban areas can lead to strong changes in vegetation cover and composition through creating physical disturbance in the vegetation and impacting the soil quality through defecation. In this study, we evaluated the effects of breeding yellow-legged gull pop...

Avian growth has been traditionally examined using logistic, Gompertz or von Bertalanffy non-linear equations. Although many studies have analysed nestling mass increase and the factors affecting growth rates, there is little information on nestling growth curves for several avian groups, such as Nuthatches (Sittidae). Moreover, the breeding biolog...

Predator-prey interactions provide key information on the role of each species in the community and an overall assessment of the stability of food webs. DNA metabarcoding has the potential to provide highly informative data which substantially enhance trophic interactions analysis, by providing higher taxonomic detail compared to earlier methods. H...

Animal tracking has afforded insights into patterns of space use in numerous species and thereby informed area-based conservation planning. A crucial consideration when estimating spatial distributions from tracking data is whether the sample of tracked animals is representative of the wider population. However, it may also be important to track an...

Overfishing has been drastically changing food webs in marine ecosystems, and it is pivotal to quantify these changes at the ecosystem level. This is especially important for ecosystems with a high diversity of top predators such as the Eastern Atlantic marine region. In this work we used high-throughput sequencing methods to describe the diet of t...

According to the principles of community ecology, sympatric species may suffer a selective pressure to decrease their niche overlap through mechanisms of niche partitioning. However, there is still a gap in knowledge of the main drivers influencing niche differentiation, particularly in communities composed by small-sized and inconspicuous species....

Mercury (Hg) is a highly toxic metal that adversely impacts human and wildlife health. The amount of Hg released globally in the environment has increased steadily since the Industrial Revolution, resulting in growing contamination in biota. Seabirds have been extensively studied to monitor Hg contamination in the world's oceans. Multidecadal incre...

Amidst unprecedented anthropogenic pressure on marine ecosystems, seabirds can serve as sentinels for shifts in marine prey availability. We examined the diet and foraging ecology of two sympatric Procellariiformes, the Cape Verde shearwater (Calonectris edwardsii) and Bulwer’s petrel (Bulweria bulwerii), during their breeding period in Cabo Verde,...

Studies on sex-specific segregation in foraging behaviour and trophic niche have been focussed on large and dimorphic seabirds, with less information on small monomorphic species. Here, we used mini-GPS loggers, habitat suitability models, and stable isotopes to assess sex differences in the foraging movements, spatial distribution, and trophic eco...

The overall speed of bird migration is limited by the amount of fuel stores acquired during the initial phases of migration. The ability to mobilize fat is crucial for migratory birds that can exhibit different migratory strategies. Birds mobilize triglycerides during nocturnal flight thus increasing circulating fatty acids and glycerol to meet the...

Seabirds breeding at tropical latitudes suffer an increased pressure to forage efficiently, because oligotrophic waters have less abundant and more patchily distributed prey. In related species living in sympatry, trophic or spatial niche partitioning may emerge as a strategy to mitigate increased competition. However, studies using molecular metho...

Taxonomic identification of food is a key component to the correct implementation of traceability pipelines during fish processing. Genetic methods have increased exponentially our discrimination power at the species level. In this context, sustainable management of tuna fisheries can clearly profit from the implementation of this kind of quality c...

Despite the widely recognized value of wetlands in providing vital ecosystem services, these are presently being degraded and ultimately destroyed, leading to a decrease in the biodiversity associated with these areas. Some species inextricably linked to wetlands, however, have been increasing and (re)colonizing areas across their range; a notable...

The use of fresh green material in avian nests has been reported for several species, but its utility is still not fully understood. Potential explanations include the effects of plants’ volatile compounds on parasite reduction (“nest protection hypothesis”) or the direct beneficial effects on the nestling condition (e.g., through the stimulation o...

A detailed analysis of fatty acid (FA) profiles and their properties relating to fuelling strategy can improve understanding of avian migration. The study aimed to understand whether and how FA composition differs among several passerine species which migrate using different fuelling strategies (constant fuelling, gradual fuelling, early fuelling,...

Gull populations, as largely flexible opportunistic individuals, have been increasingly breeding in many cities around the world, but is still unclear whether urban habitats are of equal or higher quality than the traditional natural habitats; or if they represent an ecological trap with immediate reproductive benefits, but with longer‐term detrime...

Fisheries ecosystem-based management is an important tool for sustainable harvesting of fisheries worldwide. Knowledge of trophic interactions is crucial as changes in trophic balances can induce severe changes in the structure of marine communities. While advocated for deep-sea fisheries, a lack of studies in benthopelagic area persist. The Antarc...

Mixed-species broods appear to be an uncommon phenomenon in altricial birds. In secondary hole-nesting birds, such as tits (Paridae), mixed-species clutches occur as a consequence of facultative interspecific brood parasitism or as a byproduct of nest takeover. Here, we report a case of a mixed-species brood composed of one Coal Tit Periparus ater...

Foraging spatial segregation is frequent in central-place foragers during the breeding season, but very few studies have investigated foraging spatial segregation between adjacent sub-colonies. Here, we assessed for within-colony differences in the at-sea distribution, habitat use, trophic ecology and chick growth data of two Calonectris colonies d...

Although studying the diet of threatened species is crucial in terms of conservation, the diet of the Madeiran Storm Petrel (Hydrobates castro) and the vulnerable, Azores-endemic Monteiro's Storm Petrel (H. monteiroi) is mostly unknown. The only information available to date comes from anecdotal observations, analysis of mercury levels and stable i...

The moon cycle has long been recognized as a driving factor of animals' behavioural patterns. However, its influence on seabirds' nocturnal behaviour remains poorly understood. Using a long-term GPS tracking dataset from Cory's and Cape Verde shearwaters (Calonectris borealis and Calonectris edwardsii, respectively) in the Berlengas, Azores, Madeir...

Studies on sex-specific segregation in foraging and trophic niche have been focused on large and dimorphic seabirds, with less information on small monomorphic species. Here, we used mini-GPS loggers, habitat suitability models, and stable isotopes to assess the foraging movements, at-sea spatial distribution, and trophic ecology of male and female...

Urban habitats offer spatially and temporally predictable anthropogenic food sources for opportunistic species, such as several species of gulls that are known to exploit urban areas and take advantage of accessible and diverse food sources, reducing foraging time and energy expenditure. However, human-derived food may have a poorer nutritional qua...

Biological invasions are a major threat to global biodiversity with particularly deleteri-ous consequences on oceanic islands. The introduction of large terrestrial animals-generally absent on islands-can disrupt important ecosystem functions, such as the dispersal of native seeds. However, while the consequences of plant invasions received much at...

Exposure to environmental stressors, an increasingly recurring event in natural communities due to anthropogenic-induced environmental change, profoundly impacts disease emergence and spread. One mechanism through which this occurs is through stress-induced immunosuppression increasing disease susceptibility, prevalence, intensity and reactivation...

The effects of growing urbanization have caused an increase in human-wildlife interactions in urban areas. Human-gull conflicts have been particularly studied during the breeding season when gulls cause an obvious nuisance in urban areas. However, with many gulls being present in urban areas throughout the year, stakeholders need knowledge of seaso...

Seabirds are among the most threatened birds as a result of acute exposure to many anthropogenic threats. Their effective conservation requires a detailed understanding of how seabirds use marine habitats. Recently, one of the largest no-take marine reserves in the Atlantic was designated in tropical waters surrounding Ascension Island, on which th...

The assessment of contaminant exposure in marine organisms often focuses on the most toxic chemical elements from upper trophic level species. Information on mid-trophic level species and particularly on potentially less harmful elements is lacking. Additionally, microplastics have been considered emergent contaminants in aquatic environments which...

The use of plastics has been increasing dramatically in the last decades, and consequently plastics and microplastics have been considered emergent contaminants in aquatic environments. The occurrence of microplastics has been reported in several marine species worldwide, however species from mid-trophic chains have not been extensively studied. Th...

Multidisciplinary approaches are essential to diligently assess environmental health status of ecosystems. In this study, year-round chemical elements’ exposure and impacts were assessed on the wide-ranging Cory’s shearwater Calonectris borealis breeding in Berlenga Island, offshore Portugal, North Atlantic Ocean. The aim was to identify potential...

The conservation of migratory marine species, including pelagic seabirds, is challenging because their movements span vast distances frequently beyond national jurisdictions. Here, we aim to identify important aggregations of seabirds in the North Atlantic to inform ongoing regional conservation efforts. Using tracking, phenology, and population da...

In the oligotrophic tropical marine environment resources are usually more patchily distributed and less abundant to top predators. Thus, spatial and trophic competition can emerge, especially between related seabird species belonging to the same ecological guild. Here we studied the foraging ecology of two sympatric species–brown booby (BRBO) Sula...

Cephalopods are an important component of Southern Ocean food webs but studies analysing their habitat and trophic ecology are scarce. Here, we use the Antarctic toothfish Dissostichus mawsoni as a biological sampler of the Southern Ocean's cephalopods in the Ross, Amundsen, and D'Urville Seas. Ten cephalopod taxa were identified in the diet of the...

Multidisciplinary approaches are essential to diligently assess environmental health status of ecosystems. In this study, year-round chemical elements' exposure and impacts were assessed on the wide-ranging Cory's shearwater Calonectris borealis breeding in Berlenga Island, offshore Portugal, North Atlantic Ocean. The aim was to identify potential...

Pollution is a global concern, increasing rapidly throughout marine and terrestrial ecosystems, and affecting many species. Urbanization enhances waste production, leading to the opening of landfills that constitute a spatially and temporally predictable food source for opportunistic species. Several species of gulls are known to exploit and breed...

Phenotypic variation may be due to genetic and/or environmental causes. Many ecologists consider that phenotypic plasticity, which is the change in the phenotype expressed by a single genotype subjected to different environments, is an evolutionary strategy for adapting to variable environments. Also, it has been hypothesized that plasticity is hig...

The availability of anthropogenic food subsidies has promoted an increase in gener- alist opportunistic gull species, which currently breed and forage on predictable anthropogenic resources (e.g. landfills). Here we investigated whether marine resources are still important to urban-dwelling gulls. We studied 4 natural and 2 urban yellow-legged gull...

Within the same population, nesting green turtles (Chelonia mydas) might exploit different niches by exhibiting polymorphic foraging strategies and/or inhabiting geographically distinct foraging areas. This is crucial information for the conservation of this species. Here, we used stable carbon and nitrogen isotope ratios (δ13C and δ15N) to test fo...

Fisheries have impacted seabird populations worldwide, either via bycatch mortality or resource depletion. Understanding the overlap between seabird distributions and fisheries is an important element for bycatch risk assessment, though the drivers of variation in seabird–fishery overlap are not well understood for some seabird populations. Here, w...

Riparian galleries are among the most vulnerable habitats in the world and are well known for their importance to the most specialized riparian bird species. In this study, we analyzed songbird composition, songbird diet, trophic ecology and seed dispersal in riparian galleries and adjacent Montado matrices in southern Portugal to address the impor...

Anthropogenic materials are a persistent pressure on ecosystems, affecting many species. Seabirds can collect these materials to construct their nests, which may modify nest characteristics and cause entanglement of chicks and adults, with possible consequences on breeding success. The incorporation of anthropogenic materials in nests of seabird sp...

Metal pollution is currently a major issue in marine ecosystems, as organisms, and particularly seabirds, are exposed and accumulating increased levels from several anthropogenic sources. A set of 13 metals were quantified in two gull species breeding in sympatry, and in two distinct colonies separated by ca. 400 km. Oxidative stress was measured,...

Pelagic seabirds exhibit plasticity in foraging characteristics in relation to oceanographic conditions. This should be particularly relevant in tropical marine environments where food resources are naturally more unpredictable. We studied how inter-annual variations (2013-2018) in tropical oceanographic conditions (driver of oceanic productivity)...

Pelagic seabird populations have declined strongly worldwide. In the North Atlantic there was a huge reduction in seabird populations following the European colonization of the Azores, Madeira and Canary archipelagos but information on seabird status and distribution for the subtropical region of Cabo Verde is scarce, unavailable or dispersed in gr...

Seabirds are marine predators known to forage in association with fisheries, however detailed knowledge on seabird-fishery interactions remains scarce in several regions of the world. We quantified seabird-fishery interactions and bycatch in central Portuguese coastal waters (NE Atlantic) between 2016 and 2018 in four gears: purse-seines, longlines...

Oceans are extremely dynamic environments, which poses challenges for top-predators such as seabirds to find food resources. Yet, seabirds evolved sensorial abilities (olfactory senses) along with complex behaviours (social information transfer through local enhancement) to improve foraging efficiency. Using the Cory’s shearwater (Calonectris borea...