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Abstract Migratory animals rely on multiple sites during their annual cycles. Deteriorating conditions at any site can have population-level consequences, with long-distance migrants seen as especially susceptible to such changes. Reduced adult survival caused by persecution at non-breeding sites has been suggested a major reason for the catastrophic decline of a formerly abundant, long-distance migratory songbird, the Yellow-breasted Bunting Emberiza aureola. However, it is unknown whether the ongoing extinction of this Eurasian species especially in the west of its range could be related to differences in survival or migration routes. We investigated survival rates of populations from both western and eastern parts of the breeding range and successfully tracked the migration of individuals from two eastern populations with light-level geolocators. We found moderate apparent local survival rates in eastern populations, but observed no returning birds in western populations. Our tracking data highlights (1) a joint migration corridor of eastern populations through eastern China, (2) long autumn stopovers likely used for moult and re-fuelling, and (3) very long occurrences at wintering sites. These areas should be given priority for future conservation measures. We call for an increased monitoring of adult survival and breeding output in multiple populations (including western ones) of this critically endangered species to determine (1) the causes for the observed differences in apparent local survival and (2) whether the current survival rates are sufficient to sustain viable breeding populations.

Abstract Basic information on the ecology of species is key for their conservation. Here we study the ecology of the little‐known yellow‐throated bunting Emberiza elegans based on a multi‐year study on its breeding grounds in the Russian Far East. For the first time in this species, we quantified breeding habitat parameters, calculated sex‐specific apparent survival, and determined individual nonbreeding locations using light‐level geolocation. We found that the habitat around song posts of male yellow‐throated buntings is characterized by tree and shrub layers on richly littered moist ground. Habitat use overlaps with co‐occurring Tristram's Buntings Emberiza tristrami and Black‐faced Buntings E. spodocephala, but territories differ especially in tree cover and litter cover. Based on 4 years of color‐ringing data of 72 individuals, we calculated an apparent survival rate of 36%, with higher survival estimates for male than for female yellow‐throated buntings. We found no effect of carrying a geolocator on survival. We retrieved six geolocators from males. All birds migrated south‐westward during autumn and spent the nonbreeding season at locations in China 700–1700 km away from their breeding sites. At least two individuals spent the boreal winter outside of the known range in northern or central China. Birds left the breeding area between early October and early November and returned between mid‐March and mid‐April. Our data on habitat use, survival rate, and migratory connectivity will help to assess threats to the populations of this enigmatic species, which might include habitat loss due to forest fires on the breeding grounds, and unsustainable harvest for consumption during the nonbreeding season.

Abstract The population of the Yellow‐breasted Bunting Emberiza aureola, a formerly widely distributed and abundant songbird of northern Eurasia, suffered a catastrophic decline and a strong range contraction between 1980 and 2013. There is evidence that the decline was driven by illegal trapping during migration, but potential contributions of other factors to the decline, such as land‐use change, have not yet been evaluated. Before the effects of land‐use change can be evaluated, a basic understanding of the ecological requirements of the species is needed. We therefore compared habitat use in ten remaining breeding regions across the range, from European Russia to Japan and the Russian Far East. We also assessed large‐scale variation in habitat parameters across the breeding range. We found large variation in habitat use, within and between populations. Differences were related to the cover and height of trees and shrubs at Yellow‐breasted Bunting territories. In many regions, Yellow‐breasted Buntings occupied early successional stages, including anthropogenic habitats characterized by mowing, grazing, or fire regimes. We found that the probability of presence can be best predicted with the cover of shrubs, herbs, and grasses. Highest probabilities were found at shrub cover values of 40%–70%. Differences in habitat use along a longitudinal gradient were small, but we found strong differences across latitudes, possibly related to habitat availability. We conclude that the remaining Yellow‐breasted Bunting populations are not limited to specific habitat types. Our results provide important baseline information to model the range‐wide distribution of this critically endangered species and to guide targeted conservation measures.