Expansion into an Herbivorous Niche by a Customary Carnivore: Black-Tailed Godwits Feeding on Rhizomes of ZOSTERA at a Newly Established Wintering Site
Robin, F.; Piersma, T.; Meunier, F.; Bocher, P. (2013). Expansion into an Herbivorous Niche by a Customary Carnivore: Black-Tailed Godwits Feeding on Rhizomes of ZOSTERA at a Newly Established Wintering Site. Condor 115(2): 340-347. dx.doi.org/10.1525/cond.2013.120053
In: The Condor: an international journal of avian biology. Cooper Ornithological Society: Santa Clara, Calif.. ISSN 0010-5422; e-ISSN 1938-5129, more
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| Author keywords |
behavioral plasticity; buffer effect; herbivory; seagrass; intertidalflats; shorebirds; stable isotopes |
| Authors | | Top |
- Robin, F.
- Piersma, T., more
- Meunier, F.
- Bocher, P.
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| Abstract |
In expanding populations, individuals may increasingly be forced to use sites of relatively low quality. This process, named the "buffer effect," was previously described for the Black-tailed Godwit (Limosa limosa islandica) in its use of nonbreeding sites in Great Britain and of breeding areas in Iceland. On the basis of diet analyses from droppings and stable isotopes, we describe a new case for the expanding French wintering population of the Black-tailed Godwit, an expansion accompanied by a drastic change in feeding strategy. In the 1990s, Black-tailed Godwits started using intertidal mudflats at Ile de Re, where they eat the rhizomes of seagrass (Zostera noltii) rather than the customary shellfish (Macoma balthica) eaten at both the preferred (initial) site (Aiguillon Bay) and the area occupied last (Yves to Marennes-Oleron bays). Individually color-marked godwits appeared faithful to both diet type and site, suggesting a cost of a change of strategy. This represents a first case of rhizome-feeding in shorebirds, and it exemplifies a case of carnivorous birds occupying a new site shifting to herbivory. |
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