Assessment of climate change impacts on geographic distribution of Merops orientalis in southern Iran: a case study in Fars province

Climate change is a major driver of species extinction, shifts in species’ phenology, distribution and morphology. Considering global warming impacts on different aspects of bird’s biology, especially on resident species living in lowland and warm areas, in this study, contemporary distribution points of Green Bee-eater in Fars province were combined with climate variables. Models were constructed using the maximum entropy algorithm implemented in MaxEnt 3.3.3 software. We evaluated the impacts of climate change using the General circulation model CCSM4 along with the concentration pathways RCP 2.6, RCP 4.5, RCP 6.0, RCP 8.5 from the IPCC Assessment Report 5. Climate suitability maps were constructed based on the average of ten replications by cross validation method. Modelling shows the distribution of this species is restricted to the lowlands of southern, central and western parts of Fars province and there are relatively large climatic potential areas in the southern half. Estimates of relative contributions of the climate variables to the Maxent models show that min temperature of coldest month is the most important variable, and areas with very cold winters are apparently not favorable for this species. To estimate the potential impacts of climate change on the species, the predicted potential areas in the future scenarios were compared with the current potential areas. Results predicted decline in climate suitability but no poleward range expansion. Therefore the responses of each species to future climate change is different and depends on various factors.