Climate Change and Avian Diversity in the Mediterranean: Ecological
Niche Modeling and Demographic Shifts
Abstract
The Mediterranean Basin is a critical biodiversity hotspot hosting
numerous bird species that are likely to be sensitive to climatic
changes. This study integrates ecological niche modeling and Bayesian
skyline plot analyses to assess the historical, current, and future
geographic distributions, and population dynamics of 45 endemic bird
species in the region. Using occurrence data from the Global
Biodiversity Information Facility and climate scenarios ranging from the
Last Interglacial, Last Glacial Maximum, mid-Holocene, and present to
projections for 2050 and 2070 under representative concentration
pathways (RCPs) 2.6, 4.5, and 8.5, we modeled species geographic
distributions to characterize shifts in climatic suitability. Our
results reveal significant distributional changes corresponding to past
climatic fluctuations, with contractions during the Last Interglacial
and Last Glacial Maximum into refugial areas, and expansions during the
mid-Holocene. Current species richness maps align closely with known
biodiversity hotspots in the Mediterranean. Future projections indicate
a northward shift in species’ distributions, with potential losses in
habitat suitability in central Iberia under higher emissions scenarios.
BSP analyses demonstrate increases in effective population sizes
following the Last Glacial Maximum. These findings highlight the complex
interplay between climate change and avian population dynamics,
emphasizing the necessity of incorporating climatic factors into
conservation strategies to preserve the rich avian diversity of the
Mediterranean Basin.