Evolution of Cooperative Breeding in Birds: A Long-Term Fieldwork with the Ground Tits Endemic to the Tibet Plateau as a Model System

Abstract

Cooperative breeding in birds has been interesting to behavioral and evolutionary biologists as many basic questions associated with the mysterious phenomenon remain unsolved. The wasteland and meadow on the Tibetan plateau represent extremely harsh environments in the world. Since 2004, we have studied cooperative breeding behaviors of the ground tits Parus humilis endemic to the plateau. After knowing the basic structure of this species society, we are accumulating data to analyze lifetime fitness of helpers vs. independent breeders to test the kin-selection theory, cooperative breeding in relation to climate conditions to explore the mechanisms underlying ecological constraints, the relationship between cooperative breeding and extra-pair paternity across populations to elucidate genetic monogamy as the driver of helping behavior, and environmental conditions as extrinsic factors together with social interaction as intrinsic factors to give insight into population dynamics of avian cooperative breeders. Life-long efforts of researchers are required to uncover the mysteries of the ground tit society.