Predicting origins of passerines migrating through Canadian migration monitoring stations using stable-hydrogen isotope analyses of feathers: a new tool for bird conservation

• Published in: Avian conservation and ecology 2015-06, Vol.10 (1), p.3, Article art3
• Main Authors: Hobson, Keith A., Van Wilgenburg, Steve L., Dunn, Erica H., Hussell, David J. T., Taylor, Philip D., Collister, Douglas M.
• Format: Article
• Language: English
• Subjects: Aves; catchment areas; CMMN; feathers; migration monitoring; population trends; stable isotopes
• ISSN: 1712-6568; 1712-6568
• DOI: 10.5751/ACE-00719-100103

The Canadian Migration Monitoring Network (CMMN) consists of standardized observation and migration count stations located largely along Canada's southern border. A major purpose of CMMN is to detect population trends of migratory passerines that breed primarily in the boreal forest and are otherwise poorly monitored by the North American Breeding Bird Survey (BBS). A primary limitation of this approach to monitoring is that it is currently not clear which geographic regions of the boreal forest are represented by the trends generated for each bird species at each station or group of stations. Such information on "catchment areas" for CMMN will greatly enhance their value in contributing to understanding causes of population trends, as well as facilitating joint trend analysis for stations with similar catchments. It is now well established that naturally occurring concentrations of deuterium in feathers grown in North America can provide information on their approximate geographic origins, especially latitude. We used stable hydrogen isotope analyses of feathers ([delta] super(2)H sub(f)) from 15 species intercepted at 22 CMMN stations to assign approximate origins to populations moving through stations or groups of stations. We further constrained the potential catchment areas using prior information on potential longitudinal origins based upon bird migration trajectories predicted from band recovery data and known breeding distributions. We detected several cases of differences in catchment area of species passing through sites, and between seasons within species. We discuss the importance of our findings, and future directions for using this approach to assist conservation of migratory birds at continental scales.Original Abstract: Le Reseau canadien de surveillance des migrations (RCSM) est compose de stations de denombrement d'oiseaux en migration dont les observations sont standardisees; ces stations sont surtout situees le long de la frontiere sud du Canada. Un des objectifs principaux du RCSM est de detecter la tendance des populations de passereaux migrateurs qui nichent principalement dans la foret boreale et qui sont moins bien suivis par le Releve des oiseaux nicheurs (BBS) d'Amerique du Nord. Une des lacunes principales de cette approche de suivi est qu'on ne connait pas clairement de quelle region geographique de la foret boreale est issue la tendance generee pour chaque espece a chaque station ou groupe de stations. L'information relative a