Biology subjects

Sekercioglu, C. H.

Publications and source records attributed to Sekercioglu, C. H..

8 recordsLinked to original sources

bioRxiv2025

Bird species with color polymorphism have greater ecological success

The explanation of the variation in ecological success of species is one of the key challenges in ecology, evolutionary biology and conservation biology. Here, we discuss the function of polymorphism in body color which is one of the most conspicuous features of organisms strongly affecting the performance of species. We applied a phylogenetic comparative approach to assess whether body color polymorphisms contribute to species success in birds, reflected in distributional ranges, extinction risk, and current population trends. We compiled and analyzed a comprehensive global dataset that included the distribution, phylogeny, ecology and morphological traits of all extant bird species. Species with body color polymorphism showed larger distributional ranges, larger environmental ranges, lower risk of extinction, and more stable population trends. Our analyses suggest that the presence of color polymorphism contributes to avian species success at the global scale, especially reflected in lower extinction likelihood and better population trends.

ecology↗

bioRxiv2025

Impacts of high pathogenicity avian influenza H5N1 2.3.4.4b south of the Antarctic Circle

High pathogenicity avian influenza (HPAI) H5N1 2.3.4.4b poses a substantial conservation threat to ecosystems, populations, and species globally, with its continued spread into new regions increasing concern for potential ecological consequences. During surveys in February - March 2025, we confirmed the viruss presence at the southern extent of its known range along the Western Antarctic Peninsula, with recorded mortalities in South Polar Skuas Stercorarius maccormicki on distinct islands in Marguerite Bay, as well as one confirmed and one suspected case in Kelp Gulls Larus dominicanus. At the time of sampling, no evidence of infection was observed in other seabird or mammal species. Consistent with previous global reports, skuas - here, South Polar Skuas - appear particularly vulnerable, yet broader impacts on the local seabird and mammal community remain unclear. Additionally, our use of rapid antigen tests (VDRG(R) AIV Ag Rapid kit 2.0 - Median Diagnostics) in the field demonstrated their potential utility for real-time surveillance, though false negatives (10%) highlight limitations in test sensitivity. These findings contribute to a growing understanding of the impacts of HPAI H5N1 2.3.4.4b outbreaks on Antarctic species and populations, and will inform continued monitoring, conservation strategies, and biosecurity measures in response to the viruss ongoing spread.

ecology↗

bioRxiv2023

Solar Bird Banding: Notes on Changes in Avian Behavior While Mist-netting During an Eclipse

Solar eclipses present rare celestial events that can elicit unique behavioral responses in animals, yet comprehensive studies on these phenomena, particularly concerning bird behavior, remain limited. This study, conducted at the Red Butte Canyon Research Natural Area in Utah during the annular solar eclipse on October 14, 2023, aimed to document and analyze avian activity using bird banding data. Leveraging 11 years of banding records, we observed a surprising positive peak in bird captures, indicating increased activity during the eclipse, challenging conventional expectations of decreased activity during peak totality. The unexpected, record-breaking captures on the eclipse day at this location, which also surpassed the average trend in captures over time for 18 other banding days in mid-October, highlights the complexity of bird behavior during celestial events. This study marks the first known published effort to conduct bird banding during a solar eclipse. Quantitative analyses, including species composition and capture trends, contribute to a nuanced understanding of avian responses to the eclipse. This study underscores the importance of empirical research in unraveling the intricacies of how birds navigate and adapt to unique environmental conditions created by solar eclipses.

zoology↗

bioRxiv2023

Human-brown bear conflicts in Turkey are driven by increased human presence around protected areas

Human-wildlife conflict is increasing steadily worldwide and is rapidly becoming an important challenge for the success of conservation programs. Brown bears, which suffer from reduced habitat suitability and quality globally, frequently conflict with humans. These animals need large home ranges to fulfill their habitat requirements. When space and food are restricted, brown bears frequently shift towards human-dominated landscapes that offer reliable food sources. As a country where most of the landscape and habitats are human-dominated, human-brown bear conflict events (HBCs) are frequent in Turkiye. However, there has been no formal analysis of the nature and scope of these conflicts at the country level. Here, using HBC data from 2017 to 2022, we determined the spatial and temporal dynamics of HBC events and generated a risk probability map based on anthropogenic predictors and geographic profiling, to determine the factors driving HBC across Turkiye. HBC events did not show any annual or seasonal trends but varied considerably across biogeographic regions, with most conflicts occurring along the Black Sea coast and Eastern Anatolia. Sixty percent of all conflicts were due to bear foraging behavior in human settlements while twelve percent were the result of human activity in forests, with 57% of all conflict events resulting in direct injury to either humans or bears. We found that distance to villages, distance to protected areas, distance to farmland and human footprint to be the most important factors contributing to conflict risk. Consequently, 21% of the country was found to be under human-bear conflict risk, with 43% of the risks occurring within a 10 km radius from the centers of protected areas. Our analyses indicate that the high occurrence of HBCs is mainly the result of limited natural areas and resources available to brown bears and the increasing human encroachment in and around core bear habitats.

ecology↗

bioRxiv2022

What is an urban bird? Trait-based predictions of urban tolerance for the world's birds are modulated by latitude and human population density

As human density increases, biodiversity must increasingly co-exist with urbanization or face local extinction. Tolerance of urban areas has been linked to numerous functional traits, yet few globally-consistent patterns have emerged to explain variation in urban tolerance, which stymies attempts at a generalizable predictive framework. Here, we calculate an Urban Association Index (UAI) for 3768 bird species in 137 cities across all permanently inhabited continents. We then assess how UAI varies as a function of ten species-specific traits and further test whether the strength of trait relationships vary as a function of three city-specific variables. Of the ten species traits, nine were significantly associated with urban tolerance. Urban-associated species tend to be smaller, less territorial, have greater dispersal ability, broader dietary and habitat niches, larger clutch sizes, greater longevity, and have lower elevational limits. Only bill shape showed no global association with urban tolerance. Additionally, the strength of several trait relationships varied across cities as a function of latitude and/or human population density. For example, the effects of body mass and diet breadth are more pronounced at higher latitudes, while the effects of territoriality and longevity were reduced in cities with higher population density. Thus, the importance of trait filters in birds varies predictably across cities, indicating biogeographic variation in selection for urban tolerance that could explain prior challenges in the search for global patterns. A globally-informed framework that predicts urban tolerance will be integral to conservation as increasing proportions of the worlds biodiversity are impacted by urbanization.

ecology↗

bioRxiv2021

Mismatch between bird species sensitivity and the protection of intact habitats across the Americas

Protected areas, the most prevalent international policy mechanism for biodiversity conservation, are highly heterogeneous in their effectiveness at buffering ecosystems and species habitats from human pressure. Protected areas with intense human pressure cannot protect species that are highly sensitive to human activities. Here, we use 60 million bird observations from the eBird citizen science platform to estimate the sensitivity to human pressure of each bird species breeding in the Americas (Nearctic and Neotropical regions). We find that high-sensitivity species, while found in all ecoregions, are concentrated in the tropical biomes. Ecoregions with large proportions of high-sensitivity species do not have more intact protected habitat, resulting in a low coverage of intact protected habitat for many high-sensitivity species. What is more, 139 high-sensitivity species have little or no intact protected habitat within their distributions while being threatened with extinction. Finally, we show that protected area intactness is decreasing faster in ecoregions with many high-sensitivity species. Our results highlight a major mismatch between species conservation needs and the coverage of intact protected habitats, and will likely hamper the long-term effectiveness of protected areas at retaining species. We highlight ecoregions where the protection and management of intact habitats, complemented by the restoration of degraded ones, is urgently needed to avoid extinctions.

ecology↗

bioRxiv2019

Succession of bacterial communities on carrion is independent of vertebrate scavengers

The decomposition of carrion is carried out by a suite of macro- and micro-organisms who interact with each other in a variety of ecological contexts. The ultimate result of carrion decomposition is the recycling of carbon and nutrients from the carrion back into the ecosystem. Exploring these ecological interactions among animals and microbes is a critical aspect of understanding the nutrient cycling of an ecosystem. Here we investigate the potential impacts that vertebrate scavenging may have on the microbial community of carrion. In this study, we placed seven juvenile domestic cow carcasses in the Grassy Mountain region of Utah, USA and collected tissue samples at periodic intervals. Using high-depth environmental sequencing of the 16S rRNA gene and camera trap data, we documented the microbial community shifts associated with decomposition and with vertebrate scavenger visitation. The remarkable scarcity of animals at our study site enabled us to examine natural carrion decomposition in the near absence of animal scavengers. Our results indicate that the microbial communities of carcasses that experienced large amounts of scavenging activity were not significantly different than those carcasses that observed very little scavenging activity. Rather, the microbial community shifts reflected changes in the stage of decomposition similar to other studies documenting the successional changes of carrion microbial communities. Our study suggests that microbial community succession on carrion follows consistent patterns that are largely unaffected by scavenging.

microbiology↗

bioRxiv2017

The Use of Biogeographical Patterns to Assess Key Adaptations in Two Families of Birds

Adaptations can be thought of as evolutionary technologies which allow an organism to exploit environments. Among convergent taxa, adaptations may be largely equivalent with the taxa operating in a similar set of environmental conditions, divergent with the taxa operating in different sets of environmental conditions, or superior with one taxon operating within an extended range of environmental conditions than the other. With this framework in mind, we sought to characterize the adaptations of two convergent nectarivorous bird families, the New World hummingbirds (Trochilidae) and Old World sunbirds (Nectariniidae), by comparing their biogeography. Looking at their elevational and latitudinal gradients, hummingbirds not only extend into but also maintain species richness in more extreme environments. We suspect that hummingbirds have a superior key adaptation that sunbirds lack, namely a musculoskeletal architecture that allows for hovering. Through biogeographic comparisons, we have been able to assess and understand adaptations as evolutionary technologies among two convergent bird families, a process that should work for most taxa.

ecology↗