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Temporal and spatial dynamics of willow grouse Lagopus lagopus

Hörnell-Willebrand, Maria (2005). Temporal and spatial dynamics of willow grouse Lagopus lagopus. Diss. (sammanfattning/summary) Umeå : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2005:53
ISBN 91-576-6952-X
[Doctoral thesis]

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This study is a first attempt to analyze large-scale willow grouse (Lagopus lagopus) population dynamics. In this thesis I studied the population dynamics of willow grouse in the Swedish mountain range. I estimated the scale of synchrony in both breeding success, and the adult segment between populations throughout the mountain range by using time-series of harvest data and population densities estimated from line transect counts. Little evidence of regular fluctuations/cycles in juveniles in autumn was found, and chick production in willow grouse appears to fluctuate more irregularly than was previously believed. Breeding success estimated as number of juveniles per two adults in autumn, showed a spatial correlation between sites up to 200 km apart, but there was no spatial correlation in the adult segment of the populations. When analyzing the presence and strength of time-lags in density dependent processes, a first order process was detected in the southernmost region, and a combination of weak first and second order processes in the northern part of the mountain range. There was a positive relationship between breeding success the previous year and the intrinsic rate of increase in the northernmost region where first and second order density dependence was weak and of equal strength. No such relationship was found in the southern region where density dependence was stronger and dominated by a first order process. Natal dispersal resulted in 80% of the juvenile females dispersing more than 5 km from their summer area, with a mean dispersal distance of 10.2 km, three times further than for juvenile males (3.4 km). Adult females were migratory between wintering areas used as a juvenile and their first breeding site. At landscape scales, only juvenile females and migratory adult females are important in exchange of individuals between populations. Hunters’ effort provided a useful relationship with harvest rate. Setting limits to the totally allowable effort within an area has a stronger potential for controlling harvest than daily bag limits or adjusting the length of the open season. Another simple harvest strategy would be to prohibit harvest in parts of the total area hunted. By setting aside a part of the total area as a buffer, and placing limits on the harvest effort in the open parts of the hunting area, it would be possible to achieve a cost-efficient system with a small risk of over-harvesting.

Authors/Creators:Hörnell-Willebrand, Maria
Title:Temporal and spatial dynamics of willow grouse Lagopus lagopus
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :May 2005
Number of Pages:36
ALLI. Willebrand, T. and Hörnell, M. 2001. Understanding the effects of harvesting willow ptarmigan Lagopus lagopus in Sweden. Wildlife Biology 7: 205-212. II. Hörnell-Willebrand, M., Marcström, V., Brittas, R. and Willebrand, T. 2005. Temporal and spatial correlation in chick production of willow grouse (Lagopus lagopus) in Sweden and Norway. (Provisionally accepted in Wildlife Biology). III. Hörnell-Willebrand, M. Spatial and temporal dynamics of willow grouse (Lagopus lagopus) revealed by line transects. (Manuscript). IV. Hörnell-Willebrand, M. and Smith, A.A. Dispersal and movement pattern of willow grouse (Lagopus lagopus). (Manuscript). V. Willebrand, T. and Hörnell-Willebrand, M. Harvest, effort and catchability of willow grouse (Lagopus lagopus). (Manuscript).
Place of Publication:Umeå
ISBN for printed version:91-576-6952-X
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L20 Animal ecology
Subjects:Not in use, please see Agris categories
Agrovoc terms:grouse, population dynamics, population density, animal migration, hunting, highlands, sweden
Keywords:Willow grouse, Lagopus lagopus, cycles, density dependence, natal dispersal, harvest, catch per unit effort
Permanent URL:
ID Code:850
Department:(S) > Institutionen för skoglig zooekologi
Deposited By: Maria Hörnell-Willebrand
Deposited On:13 May 2005 00:00
Metadata Last Modified:02 Dec 2014 10:07

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