科研之友
微信
新浪微博
Facebook
分享链接
摘要
The population of the Black-winged Pratincole Glareola nordmanni has declined significantly during the Course Of the 20(th) century, resulting in a classification as 'Near Threatened' and 'Endangered' in the Global and European Red Data Books, respectively. Reasons for the decline are largely unknown due to a lack of information on the breeding ecology of the species. We studied breeding performance and habitat use of the Black-winged Pratincole in two areas in Kazakhstan and evaluated a new world population estimate. Colony size ranged from two to 180 pairs and differed significantly between the study areas. Mean breeding success was 1.30 /- 0.16 (mean /- SE) fledged chicks per breeding pair in Central Kazakhstan, and 0.59 /- 0.13 (mean /- SE) fledged chicks per breeding pair in NE Kazakhstan. Habitat types preferred were intensively grazed natural steppe, abandoned and fallow fields, shores of freshwater and brackish lakes and solonchaks (salt pans). Factors influencing habitat selection were quantified the first time for this species: the probability Of Occurrence of breeding colonies was highest near human settlements, within 3km of open water and where sward heights were low or intermediate, indicating a reliance on heavy grazing and water. Using data from six surveys across the whole breeding range, we calculated a new world Population estimate Of 76,000-95,000 breeding pairs, which is substantially higher than previous estimates. We discuss colony size, habitat use and population trends in the light of changing landscape conditions in the steppe zone and suggest an increase in habitat available to Black-winged Pratincole due to an increase in the area of fallow fields and a change in grazing regimes since the collapse of the Soviet Union in 1991.
- 出版日期2009-6
