Genetic changes influence behavioral shifts of brown bears in response to human-dominated landscapes in Eastern Türkiye

Abstract

Abstract Large carnivores are known for altering their life-history strategies in response to environmental change. One such shift was recently discovered in Eurasian brown bears (Ursus arctos arctos) in Sarıkamış, Eastern Türkiye where an open city garbage dump has led to the emergence of two distinct life strategists: sedentary bears that use the city dump as a primary food source and migratory bears that avoid the dump and migrate in search of food. Understanding the genetic processes that have led to the establishment of these strategies is vital for predicting the overall impact of anthropogenic pressures on brown bears forced to live in human-dominated landscapes. To this end, we determined the amounts of genetic and adaptive variation associated with these two life-history strategies using genome-wide data obtained from 31 bears fitted with satellite collars and tracked for an average of one year. We found that the Eastern Türkiye brown bear population is genetically highly differentiated and isolated from other world populations but nevertheless contains high genetic diversity and mixed ancestry. We identified genomic regions and distinct genotypes associated with sedentary and migratory behavior and high differentiation between behavioral groups at these loci. Outlier loci were associated with several genes related to transcriptional modification, including a key SNP within the first exon of CCRL2 that regulates immune response. Collectively, our results present the first test of the genetic basis of behavioral shifts that may be playing an important role in the ongoing adaptation of Eastern Türkiye brown bears to human-dominated landscapes, emphasizing the importance of evolutionary genomics for understanding how species survive and adapt to global change.