An uncertain future for the endemic Galliformes of the Caucasus

Abstract

Impacts of climate change are already evident in ecosystems worldwide. High-latitude and altitude regions are at greatest risk because the effects of climate change are greater in these regions, and species from these areas have limited ability to track their climate envelopes. The Caucasian snowcock (Tetraogallus caucasicus) and the Caucasian grouse (Lyrurus mlokosiewiczi) are both high-altitude specialists that are endemic to a restricted range in the Caucasus mountains of Europe. Little research has been performed to determine the status of the populations or the potential impacts of climate change. We investigated how climate and land use change may impact both species in future and determined whether their life history traits may increase their vulnerability using a combined exposure and trait-based index. We compared several climate models, and in all instances, both species showed drastic range contractions although the extent of the contraction varied with each model. Traits like habitat specialism, ground nesting and incubation period meant that both species may be considered "most vulnerable" in the exposure and trait-based index. Given that both species already occur near the maximum elevations of the Caucasus, and that they lack any dispersal capabilities due to the isolation from alternative mountainous areas, research efforts need to be prioritized to improve our knowledge about their population status, to monitor future trends and to begin developing species action plans that conserve these endemic and iconic species of Europe. Both species are flagship and umbrella species and may serve as indicator species, their protection may therefore benefit a whole range of other species inhabiting this vulnerable Alpine ecosystem. Especially the Caucasian grouse has a high aesthetic value and is favoured by hunters in the region. The potential demise of this species may therefore also be negative for local communities.

Meta‐analyzing the likely cross‐species responses to climate change

“…have shown that mountain bird species will lose a greater range of occurrence than other species (e.g., La Sorte & Jetz, 2010;Freeman, Scholer, Ruiz-Gutierez, & Fitzpatrick, 2018; see also a meta-analysis by Scridel et al, 2018). A possible reason for the difference between our results and those from other studies is that our data- Finally, had we assumed dispersal limitation in our ENMs, our estimates of range shift would be even greater (depicting a more pessimistic scenario) because dispersal limitation would make it difficult for species to track their optimal conditions in space (Hof & Allen, 2019;Wang, He, Thompson, Spetich, & Fraser, 2018). One could also argue that our estimates of potential geographic range loss would be lower after allowing for adaptation.…”

“…In general, our results suggest that the choice of AOGCMs is also an important aspect to be considered in studies searching for correlates of range shift.Finally, had we assumed dispersal limitation in our ENMs, our estimates of range shift would be even greater (depicting a more pessimistic scenario) because dispersal limitation would make it difficult for species to track their optimal conditions in space(Hof & Allen, 2019;Wang, He, Thompson, Spetich, & Fraser, 2018). A possible reason for the difference between our results and those from other studies is that our dataset included only 30 species (2.5% from all bird species we considered) with distributions restricted to high altitudes (following the classification proposed by Stotz, Fitzpatrick, Parker, & Moskovits, 1996; e.g., Accipter striatus Vieillot, 1808, Microcerculus ustulatus Salvin & Godman, 1883, Roraimia adusta (Salvin & Godman, 1884),and Trogon personatus Gould, 1842).…”

Rear‐edge populations are important for understanding climate change risk and adaptation potential of threatened species

“…Together, these considerations highlight that particularly the migration of individuals from the rear-edge populations of Caucasian grouse toward its core distribution might hold important potential for the species to cope with climate change. However, several ecological characteristics of the Caucasian grouse make this questionable, such as naturally low densities, often small and declining population size (BirdLife International, 2016; Gokhelashvili, Kerry, & Gavashelishvili, 2003) and a limited dispersal capability (Hof & Allen, 2019). Together, this suggests that the species is in growing need of conservation attention and active management to foster its survival in the Caucasus.…”

Central Asian wild tulip conservation requires a regional approach, especially in the face of climate change

“…MaxEnt has been used frequently in conservation to model species distributions primarily because it is highly accurate with small sample sizes (Elith et al 2011;Qin et al 2017), characteristic of Threatened species. This software also models distributions under future climate change scenarios, allowing this threat to be assessed (Qin et al 2017;Hof and Allen 2019). MaxEnt's inferences are correlative, with the software using a regression framework to produce predictions of occurrence.…”

“…Two climate models were selected for comparison, Community Climate System Model version 4 (CCSM4 GCM) and Model for Interdisciplinary Research on Climate (Miroc ESM), to allow us to assess the reliability of our results across models. We selected these as they have both been used in previous studies to assess changes in habitat suitability linked to climate change (Rej and Joyner 2018;Hof and Allen 2019). We also selected two climate change scenarios to model, RCP 2.6 which represents a best-case scenario (BC) where emissions peak in 2020, and RCP 8.5 which is a worst-case scenario and similar to business as usual (BU).…”