Foraging habitat selection in the last Ortolan Bunting Emberiza hortulana population in Switzerland: Final lessons before extinction

Menz, Myles H. M., Mosimann-Kampe, Paul and Arlettaz, Raphaël (2009) Foraging habitat selection in the last Ortolan Bunting Emberiza hortulana population in Switzerland: Final lessons before extinction. Ardea, 97 3: 323-333. doi:10.5253/078.097.0308


Author Menz, Myles H. M.
Mosimann-Kampe, Paul
Arlettaz, Raphaël
Title Foraging habitat selection in the last Ortolan Bunting Emberiza hortulana population in Switzerland: Final lessons before extinction
Formatted title
Foraging habitat selection in the last Ortolan Bunting Emberiza hortulana population in Switzerland: Final lessons before extinction
Journal name Ardea   Check publisher's open access policy
ISSN 0373-2266
Publication date 2009-10-01
Sub-type Article (original research)
DOI 10.5253/078.097.0308
Open Access Status Not yet assessed
Volume 97
Issue 3
Start page 323
End page 333
Total pages 11
Place of publication Den Burg, Netherlands
Publisher Nederlandse Ornithologische Unie [Netherlands Ornithologists' Union]
Language eng
Formatted abstract
The Ortolan Bunting Emberiza hortulana has suffered a general decline across much of Western Europe in recent decades. In Switzerland, only one population remains in sub-Mediterranean shrub-steppe on the south-facing slopes of the Rhône Valley (Valais). We aimed to collect data on foraging ecology of the last Swiss Ortolan Buntings during reproduction. However, this population underwent a considerable decline, with no breeding confirmed in Switzerland in 2007. We investigated foraging habitat selection of four unpaired males at the habitat and microhabitat scales, and compared patterns of foraging habitat use with patterns of terrestrial invertebrate abundance. All radio-tracked birds foraged exclusively on the plain. The adjacent slope, which harboured the former breeding grounds, was used only for territorial song displays. All males showed a disproportionate use of conventional maize fields that had been treated with herbicides, while also exhibiting an avoidance of meadows and riparian vegetation. These observed patterns of habitat use may be driven by unavailability of optimal foraging habitat, with birds being forced to use the best of a poor set of options. Structurally, it was shown that birds foraged in areas with a high proportion of bare ground, as well as moderately dense overhead vegetation. These areas did not support higher arthropod abundance, suggesting that food accessibility (and/or cover) rather than food abundance dictated habitat selection. It remains to be seen whether these patterns of microhabitat use also apply to breeding Ortolan Buntings. Further work in southern European breeding grounds should be envisioned to gain crucial information about the ecological requirements of Ortolan Buntings in Mediterranean and sub-Mediterranean habitats. Additionally, effort needs to be focused on identifying factors affecting the species on the wintering grounds, which may assist in explaining the observed declines in the breeding areas.
Keyword Habitat selection
Generalised linear mixed models
Prey availability
Population decline
Species conservation
Farmland bird populations
Endangered population
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collection: Ecology Centre Publications
 
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Citation counts: TR Web of Science Citation Count  Cited 11 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 14 times in Scopus Article | Citations
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Created: Sun, 20 Dec 2009, 10:05:18 EST