Dispersal, survival and causes of mortality in black grouse Tetrao tetrix in northern England

摘要: Between autumn 1998 and spring 2000, 70 black grouse Tetrao tetrix (48 poults 22 adults) were equipped with radio transmitters in the North Pennines, England. We recorded timing distances of dispersal, survival rates causes death. First-year differed between years, but each year highest late prior to when predation by stoats Mustela erminea raptors accounted for three-quarters deaths. was lower than that adult birds owing winter stoats. The annual rate 0.72 higher those found most other European studies. By contrast, breeding success low. Dispersal confined first-year hens, distinct dispersal periods (mean 10.3 km) again early 5.8 km). Natal resulted none hens within study area. Adults either sex cocks showed high site fidelity. This has practical repercussions considering prescriptive management aid species recovery range expansion relation habitat fragmentation at both local regional levels.