Gibt es tatsächlich einen Weibchenüberschuß bei überwinternden Kampfläufern Philomachus pugnax in Afrika?

Publication Type:Journal Article
Year of Publication:1996
Journal:Journal of Ornithology
Volume:137
Issue:1
Date Published:1996
ISBN Number:2193-7192
Keywords:Africa, Cameroon, Chad, Mali, Niger, Philomachus, Philomachus pugnax, Scolopacidae, Senegal, South Africa, Sudan
Abstract:Four ringing expeditions were carried out in Senegal in the winter periods from 1984 to 1988. Another expedition visited the Lake Chad basin in January/February 1991. Totally 1,989 Ruffs were caught in Senegal and 105 at Lake Chad in northern Cameroon. Age proportions varied only between different ringing sites in the same year. But sex ratios of adult birds could vary both between different sites and at the same site in different nights. Possible reasons for the changing results are discussed. Totally in the Senegal 35.1% of all birds were males, in adult birds 37.7% and in first-year birds 27.6%. The proportion of males was about 46% at Lake Chad. The wintering population in the Senegal delta was estimated at about 80–200,000 birds and at Lake Chad in Cameroon at somewhere between 250–350,000 birds. In these two very important winter areas males are much more numerous than reported from East and South Africa. So the sex ratio seems to be more balanced than supposed up to now. But because there is a lack of information from other important areas, like the innundation zone of the river Niger in Mali or southern Sudan, sex ratio of the total African wintering population cannot be investigated finally. Proportion of first-year birds varied in the Senegal between 24 and 31% and was about 40% at Lake Chad.
URL:http://dx.doi.org/10.1007/BF01651501
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith