Patch choice of avian herbivores along a migration trajectory:From temperate to arctic

Migratory waterfowl species seem to track temporal and spatial pulses of optimal forage availability on their way from temperate wintering to arctic breeding sites. In order to unravel the relative contribution of forage quality and forage biomass to foraging choices in avian herbivores, we experime...

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Bibliographic Details
Published in:Basic and Applied Ecology
Main Authors: van der Graaf, A.J., Stahl, J., Veen, G.F., Havinga, R.M., Drent, R.H.
Format: Article in Journal/Newspaper
Language:English
Published: 2007
Subjects:
barnacle goose
Branta leucopsis
flyway
forage quality
grazing experiment
plant biomass
ptant-herbivore interactions
salt marsh
GEESE BRANTA-LEUCOPSIS
BARNACLE GEESE
BRENT GEESE
BODY-SIZE
FORAGING BEHAVIOR
GOOSE POPULATION
KOLOKOLKOVA BAY
FOOD QUALITY
B-BERNICLA
SNOW GEESE
Arctic
Barnacle goose
brent geese
Online Access:https://hdl.handle.net/11370/a3cc63bb-f203-4101-9277-ac03c85e9663
https://research.rug.nl/en/publications/a3cc63bb-f203-4101-9277-ac03c85e9663
https://doi.org/10.1016/j.baae.2006.07.001
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Summary:Migratory waterfowl species seem to track temporal and spatial pulses of optimal forage availability on their way from temperate wintering to arctic breeding sites. In order to unravel the relative contribution of forage quality and forage biomass to foraging choices in avian herbivores, we experimentally manipulated biomass and quality of main forage plants through fertilisation and grazing exclusion at three sites along the flyway of barnacle geese, Branta leucopsis. Fertilisation increased the nitrogen content of the forage and grazing exclusion increased biomass levels. Manipulated plots were offered to wild geese in a random block experimental design and goose visitation was measured through dropping counts. At all sites there was a trend towards a higher preference of plots with increased quality and average biomass above plots with an average quality and increased biomass. Generally, geese preferred plots with highest standing crop of nitrogen. The numerical response of the geese to forage changes was supported by behavioural observations at the Baltic site. We conclude that for migrating barnacle geese the bottlenecks in the standing crop of nitrogen appear to tie in the limited biomass availability at the Baltic stopover site and the limited nutrient content of food in the Arctic breeding site, restricting the potential nutrient intake on these sites. (C) 2006 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.

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