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Soortgroepen => Vogels => Topic gestart door: HPM op augustus 29, 2010, 12:28:53 pm

Titel: Nederlandse Grutto's in Afrika
Bericht door: HPM op augustus 29, 2010, 12:28:53 pm
Net gepubliceerd:

Kleijn, D., J. van der Kamp, H. Monteiro, I. Ndiaye, E. Wymenga & L. Zwarts (2010)
Black-tailed Godwits in West African winter staging areas. Habitat use and hunting related mortality
Alterra Rapport 2058 (http://nl.sitestat.com/wur/alterra/s?AlterraRapport2058&ns_type=pdf&ns_url=http://content.alterra.wur.nl/Webdocs/PDFFiles/Alterrarapporten/AlterraRapport2058.pdf) (pdf 32 pp, 3.3 mb.)


Summary
"The reproductive success of Black-tailed Godwits is currently extremely low and the main driver of its population decline. The persistence of the Dutch Black-tailed Godwit population seems to depend to a large extent on the high adult survival and the longevity of adult birds. Adult survival may be influenced by hunting pressure and land use change in the West African coastal zone, the key wintering area of the Black-tailed Godwit.

In this study we examined how severe hunting pressure on Black-tailed Godwits is in West African rice-growing areas and what types of habitats are being used by godwits during the course of the wintering period. We examined hunting pressure in Casamance and Guinea-Bissau using farmer questionnaires. We examined godwit distribution and habitat use at the beginning of the wintering season by means of an aerial survey. Finally, between August 2008 and January 2009 we used monthly ground surveys to examine godwit phenology and changes in habitat use at different times of the winter season.

The Black-tailed Godwit is exposed to hunting throughout the core wintering area in West Africa, but hunting related mortality doesn’t seem to be severe enough to substantially influence its population dynamics. Between August and January, peak numbers of Black-tailed Godwits move between different parts of their wintering range. These movements seem to be governed by the availability of their preferred habitat: (man-made) bare wet soil which is consecutively available in different parts of West Africa throughout the entire wintering period.

Our results suggest that effective conservation probably should target the continuation of the traditional extensive rice cultivation systems throughout the core wintering area of the Black-tailed Godwit, with the rice growing areas in Guinea-Bissau being of particular importance as this is the only East-Atlantic area that provides suitable habitat in November-December. Important potential threats to Black-tailed Godwits are changes in land use such as the abandonment of the labour-intensive traditional rice cultivation system or large scale irrigation works. A good second is increased access to rifles and/or cheap ammunition which might increase hunting related mortality."

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Groeten, Herman van der Meer