Migratory connectivity in a declining bird species: using feather isotopes to inform demographic modelling
| Autor: | Michael Schaub, Keith A. Hobson, Dirk Tolkmitt, Leonard I. Wassenaar, Detlef Becker, Thomas S. Reichlin, Raphaël Arlettaz, Lukas Jenni |
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| Rok vydání: | 2010 |
| Předmět: |
education.field_of_study
animal structures Jynx torquilla Ecology Population Endangered species Biodiversity Biology biology.organism_classification Feather visual_art visual_art.visual_art_medium Wildlife management education Moulting Ecology Evolution Behavior and Systematics Wildlife conservation |
| Zdroj: | Diversity and Distributions. 16:643-654 |
| ISSN: | 1472-4642 1366-9516 |
| DOI: | 10.1111/j.1472-4642.2010.00664.x |
| Popis: | Aim Conservation programmes for endangered migratory species or populations require locating and evaluating breeding, stopover and wintering areas. We used multiple stable isotopes in two endangered European populations of wrynecks, Jynx torquilla L., to locate wintering regions and assess the degree of migratory connectivity between breeding and wintering populations. Location Switzerland and Germany. Methods We analysed stable nitrogen (d 15 N), carbon (d 13 C) and hydrogen (dD) isotopes from wing feathers from two populations of wrynecks to infer their wintering origins and to assess the strength of migratory connectivity. We tested whether variation in feather isotopic values within the Swiss population was affected by bird age and collection year and then considered differences in isotopic values between the two breeding populations. We used isotopic values of summer- and winter-grown feathers to estimate seasonal distributions. Finally, we calculated a species-specific dD discrimination factor between feathers and mean annual dD values to assign winter-grown feathers to origin. Results Bird age and collection year caused substantial isotopic variation in winter-grown feathers, which may be because of annually variable weather conditions, movements of birds among wintering sites and/or reflect asynchronous moulting or selection pressure. The large isotopic variance in winter-grown feathers nevertheless suggested low migratory connectivity for each breeding population, with partially overlapping wintering regions for the two populations. Main conclusions Isotopic variance in winter-grown feathers of two breeding populations of wrynecks and their geographical assignment point to defined, albeit overlapping, wintering areas, suggesting both leapfrog migration and low migratory connectivity. On this basis, integrative demographic models can be built looking at seasonal survival patterns with links to local environmental conditions on both breeding and wintering grounds, which may elucidate causes of declines in migratory bird species. |
| Databáze: | OpenAIRE |
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