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

Abstract

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

Autumn Dispersal and Winter Residency Do Not Confer Reproductive Advantages on Female Spruce Grouse

“…ruffed grouse Bonasa umbellus (Small & Rusch 1989, Rusch et al 2000, spruce grouse Falcipennis canadensis (Boag & Schroeder 1992, Keppie 2004, blue grouse Dendragapus obscurus (Hines 1986, Zwickel 1992, and black grouse Tetrao tetrix (Warren & Baines 2002, Caizergues & Ellison 2002) and our data are consistent with this. Similarly, cock grouse are usually found to be more philopatric than hens.…”

Genetic variation in Black Grouse populations with different lekking systems in the Czech Republic

“…This genetic differentiation is likely to be caused by an almost complete lack of male natal dispersal. While females disperse approximately 20 km in their first year, males are often recruited to the lek where their male parent displayed (Caizergues and Ellison 2002;Warren and Baines 2002;Willebrandt 1988). Negative changes of environmental conditions are expected to lower population fitness including male survival and lead to a decrease of numbers of displaying males in leks.…”

Demography of Female Greater Prairie-Chickens in Unfragmented Grasslands in Kansas

“…Predator numbers are inversely correlated with breeding success of Red Grouse (Lagopus lagopus scoticus) and Greater Sage-Grouse (Centrocercus urophasianus; Coates andDelehanty 2010, Fletcher et al 2010), and predation is often the main cause of nest failure ). Predation by raptors or mammals also accounts for a majority of mortality of adult grouse (Schroeder and Baydack 2001, Warren and Baines 2002, Bowker et al 2007). …”