Dispersal patterns in a harvested willow ptarmigan population
نویسندگان
چکیده
منابع مشابه
Free-living Willow Ptarmigan Are Determinate Egg-layers
Egg-laying behavior of free-living Willow Ptarmigan (Lagopus lagopus) was studied at Chilkat Pass, B.C. to learn if females were indeterminate egg-layers in natural conditions. Eggs were removed from clutches of experimental birds during laying, usually beginning with the third egg. All birds were determinate egg-layers and there was no difference in the number of eggs laid by control (K = 8.11...
متن کاملThe effect of manipulated brood size on parental defence in a precocial bird, the Willow Ptarmigan
Offspring number was manipulated in Willow Ptarmigan Lrzgopus lagopus to determine the effect of brood size on parental effort in defence of young. Three chicks were added (n = 8), exchanged (n = 10) or removed (n = 12) among broods of females that had laid 7-9 eggs. If parents based effort on the value of the brood, it was predicted that defence should increase with offspring number because pt...
متن کاملDensity-dependent dispersal and population aggregation patterns.
We have derived reaction-dispersal-aggregation equations from Markovian reaction-random walks with density-dependent jump rate or density-dependent dispersal kernels. From the corresponding diffusion limit we recover well-known reaction-diffusion-aggregation and reaction-diffusion-advection-aggregation equations. It is found that the ratio between the reaction and jump rates controls the onset ...
متن کاملThe effect of renesting ability and nesting attempt on egg-size variation in willow ptarmigan
SANDERCOCK, B.K., and PEDERSEN, H.C. 1994. The effect of renesting ability and nesting attempt on egg-size variation in willow ptarmigan. Can. J. Zool . 72: 2252 2255. Interclutch variation in the size of free-living willow ptarmigan (Lagopus lagopus alexandrae) eggs was examined at Chilkat Pass, British Columbia. Egg volume (19.9 f 0.1 cm3; mean f 1 SE) fell within the range reported for other...
متن کاملPatterns of willow seed dispersal, seed entrapment, and seedling establishment in a heavily browsed montane riparian ecosystem
Declines in riparian willow (Salix spp.) communities in Rocky Mountain National Park, Colorado, USA , coincident with a large increase in elk (Cervus elaphus L.) populations, has raised concerns about the future of willow communities. To identify possible constraints on willow establishment in two heavily browsed riparian areas, in 2000 and 2001, we examined seed dispersal phenology, germinabil...
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ژورنال
عنوان ژورنال: Journal of Applied Ecology
سال: 2005
ISSN: 0021-8901
DOI: 10.1111/j.1365-2664.2005.01031.x