Does foraging in Teal Anas crecca depend on season and disturbance by predators?
2006 (English)In: Integrating science and duck management: the 4th North American Duck Symposium and Workshop, 2006, 131- p.Conference paper, Abstract (Refereed)
To ensure wise management of migratory species it is crucial to know their energy requirements throughout their biological cycle, especially during periods like spring migration, that might affect future breeding success. Surprisingly, this period has seldom been studied. To start filling this gap for dabbling ducks and especially Eurasian Teal Anas crecca, we studied their foraging time and foraging methods along their Western European flyway from wintering to breeding grounds. Differences in foraging activity between sexes, species, years, seasons, sites and diel patterns were checked, as well as potential effects of disturbances by potential predators. Ducks of both sexes presented a fairly constant nocturnal foraging along the flyway, whereas diurnal foraging increased at periods of high requirements (spring, breeding, moulting). Ducks might thus not only be income breeders, but also income migrators (relying on the food they encounter along their flyway to fuel their travel). Moreover, Teal foraging depth increased along the flyway when disturbance due to potential predators decreased. This probably reflects their diet switch (from granivorous to carnivorous). The decrease in predator pressure probably makes it possible for teals to use riskiest behaviors (greater depths associated to eyes underwater and less prevention of predators).We thus highlight the need for adequate management of staging wetlands all along the flyway, since ducks have to fulfill high energy requirements there. Water level control may be useful to provide more shallow foraging habitats in which they can use less risky foraging techniques at times when nutrient needs increases and predation risk is relatively high.
Place, publisher, year, edition, pages
2006. 131- p.
IdentifiersURN: urn:nbn:se:hkr:diva-15956OAI: oai:DiVA.org:hkr-15956DiVA: diva2:967647
The 4th North American Duck Symposium and Workshop, Bismarck N.D., August 23-26, 2006