Applying opportunistic observations to model current and future suitability of the Kopet Dagh Mountains for a Near Threatened avian scavenger

Abstract

Many avian species are in danger of extinction due to anthropogenic activities and climate change. Human activities have led to eradication of many natural habitats and climate change has altered species distribution especially in mountainous habitats. In the present study, we used distribution records of a Near Threatened avian scavenger, bearded vulture ( Gypaetus barbatus) that were collected through 9 years of opportunistic observations and modeled its distribution in the Khorasane-Razavi Province in Iran. We also assessed the impacts of future climate change on the distribution of this species. Our results show that most suitable habitats for Bearded vultures are in the northern regions of the Khorasan-e-Razavi province. The most important variables affecting the distribution of the bearded vulture were the annual precipitation (37.5% contribution), landcover (22% contribution), and distance to road (16.2% contribution). Our results also showed that around 80% to 91% of the species’ suitable habitats will decrease due to climate change in the future. Suitable habitats of the species that are predicted to remain suitable in the future should be prioritized for conservation. Human activities like road expansion should be avoided in areas with high suitability for this species. This study stresses the need for action to conserve this vulture in the Khorasan-e-Razavi province, and beyond its borders.

Modeling global habitat suitability and environmental predictor of distribution of a Near Threatened avian scavenger at a high spatial resolution

“…Confirming previous findings, our results show that species responses to environmental factors such as climate, topography, vegetation, and anthropogenic factors are speciesspecific and depend on the scale of studies (Roland and Taylor, 1997;Holland et al, 2004;McGarigal et al, 2016). We showed that while topography shaped the species' global distribution range, precipitation was the most important determinant of the species distribution in the Kopet Dagh Mountains in Asia (Sheykhi Ilanloo et al, 2020), and food availability was the most important variable in explaining habitat suitability of bearded vulture in the Swiss Alpine range. In comparison with other vulture species, Panthi et al (2021) modeled the global habitat suitability of the Egyptian vulture (Neophron percnopterus) and found that climate is the most important determinant of the species' global habitat suitability.…”

“…Despite we were expecting that climate will outperform other variables in predicting the species' global habitat suitability, the results showed that topography was the most influential factor. Topographic heterogeneity is an indicator of habitat diversity and species diversity (Stein et al, 2014;Badgley et al, 2017), which, in turn, influences food resources availability to bearded vultures (Sheykhi Ilanloo et al, 2020). Vignali et al (2021) built several habitat suitability maps with respect to bearded vulture age class (immature and adult) and season (warm and cold) in the Swiss Alpine range.…”

“…The precipitation of the driest month was the second most important predictor of the species distribution range showing the importance of precipitation for the species' habitat suitability. Sheykhi Ilanloo et al (2020) modeled the habitat suitability of the bearded vulture in the Kopet Dagh Mountains in Asia and found that the precipitation was the most influential predictor of the species' suitable habitat in the area. Surprisingly, results of variable importance revealed that the human footprint index did not play an important role in shaping the species distribution showing that at least at a global scale, the species' suitable habitat is not affected by human activities.…”

“…There has been a major decline in the distribution range of the habitat specialists' avian scavengers such as bearded vulture, Gypaetus barbatus (Acharya et al, 2010;Safford et al, 2019). As one of the most well-known vulture species, the bearded vulture has experienced a severe population decline in many of its distribution regions and may soon become endangered or reach the status of local extinction (Green et al, 2004;Sheykhi Ilanloo et al, 2020). However, population trends varied significantly throughout the species range; while the European population species has increased since 1980, some other local populations experienced a decline of 89.3% in Nepal (BirdLife International, 2022).…”

Global habitat suitability modeling reveals insufficient habitat protection for mangrove crabs

“…In this regard, Species Distribution Models (SDMs) are practical tools as they are frequently being applied in studying species biogeography, ecology and conservation [24][25][26] .Species Distribution Models need species occurrence records and environmental variables to estimate target species probability of presence in a user defined geographic region 24,27 . These models are used in predicting species distribution [28][29][30][31][32][33] , identifying environmental derivers of species distribution 28,[32][33][34] assessing protected area effectiveness in conservation of species [35][36][37] and quantifying the impacts of future climatic changes on species distribution [38][39][40][41][42][43][44][45] . For instance, Luan et al 28 applied SDMs and modeled the spatial distribution of three portunid crabs (Charybdis bimaculata, Charybdis japonica and Portunus trituberculatus) in China.…”