Comparison of beak and feather disease virus prevalence and immunity-associated genetic diversity over time in an island population of red-crowned parakeets

摘要: Pathogen outbreaks in the wild can contribute to a population’s extinction risk. Concern over effects of pathogen wildlife is amplified small, threatened populations, where degradation genetic diversity may hinder natural selection for enhanced immunocompetence. Beak and feather disease virus (BFDV) was detected first time an island population red-crowned parakeets (Cyanoramphus novaezelandiae) 2008 on Little Barrier Island (Hauturu-o-Toi) New Zealand. By 2013, prevalence viral infection had significantly decreased within population. We tested whether showed selective response BFDV, using neutral microsatellite two immunity-associated markers, major histocompatibility complex (MHC) Toll-like receptors (TLRs). found evidence at viral-associated TLR3; however, ability TLR3 elicit immune presence BFDV warrants confirmation. Alternatively, because parakeet populations are prone fluctuations size, decrease be attributed dropping below density threshold maintenance. Our results highlight that processes such as adaptation immunocompetence and/or efficient mechanisms reducing threatened, isolated