Defining spring foraging habitat and prioritization of conservation sites for Tricolored Blackbirds in California, USA

摘要: The Tricolored Blackbird (Agelaius tricolor) is a range-restricted, colonial-nesting species in decline. Colonies include tens of thousands individuals that forage the surrounding landscape, at times commuting miles between nesting and foraging grounds. We explored role landscape composition on colony occupancy mapped core potential spring habitat California, USA. used observations colonies from 2008, 2011, 2014 characterized changes during an extended drought. Then, we constructed occurrence abundance models order to map across 4 ecoregions California. Finally, simulated land cover identify under restoration scenarios. Across 3 survey years, surface water declined over time unoccupied locations but remained stable occupied locations, confirming permanent was critical feature persistent colonies. Average percent nearly all types suitable for foraging, as well frequency dairies median NDVI, were higher current or historical sites than elsewhere. proportion alfalfa, grasslands, elements best able predict early breeding season presence size. Core covered 6 million acres study region, only 18% 2014. This result suggests need additional factors determining persistence, such connectivity, distributions substrates, risk predators. vast majority (93.1%) occurred private land; therefore, saving will require engagement partnership with landowners.