Adaptive Shifts in Migratory Routes of Birds in Response to Habitat Loss, Climate Change, and Anthropogenic Pressures

Abstract

It is worth noting that migratory birds are instrumental in preserving the ecological equilibrium through seed dispersal, pollination, nutrient recycling, and pest regulation, but changing migratory behaviors and routes due to habitat destruction, climate change, and human disturbances are becoming increasingly common. The current study aimed to investigate changes in migratory routes of some species within migratory corridors characterized by different land uses, including wetlands, forests, grasslands, and urban areas, using satellite tracking data, Geographic Information System (GIS)-based environmental assessment, climatic variables, and on-ground observations. The results found that about 68% of the studied migratory routes showed moderate-to-high spatial shifts when compared with their historic migratory pathways. For instance, migratory paths of the Siberian Crane and Greater Flamingo had the highest shifts at 12.6% and 12.5%, respectively, as a result of wetland destruction and urban expansion. Environmental evaluation indicated that there was considerable environmental deterioration with regard to the Coastal Migratory Corridor, as 42% of the wetlands and 31% of urbanization took place in the region. Besides, there was a temperature rise of 2.1°C accompanied by a 28% increase in heatwaves and 19% increase in drought occurrences. Additionally, there were statistically significant, strong positive correlations between environmental threats and alterations in the migratory path due to the rise in temperature (r=0.81) and wetland reduction (r=0.76). In order to adapt to the changing environment, migratory birds showed behavior changes such as being able to use flexible routes (68%) during their flight, migration timing adaptation (61%), and using alternative habitats (54%). Thus, this study suggests that combined conservation actions should be taken to preserve the migratory birds' population.