Fréquentation des habitats par la paruline à calotte noire (Wilsonia Pusilla) en sapinière boréale humide

Authors: Tardif, Jacinthe
Advisor: Desrochers, André
Abstract: Many bird species breeding in North America require long term tracking because of their unknown or declining population status. Of those, an important proportion is represented by species associated with open habitats. Open habitats are created every year by clear-cutting in boreal forest but they have been decreasing since last two decades in deciduous and mixed forests of Eastern North America. Due to the important media coverage with conservation NGOs accusing clear-cutting and other types of timber harvest for the loss of old forest and associated species, perception of perturbation of forest made by man is mostly negative. However, clear-cuts, as open habitats, may be important to wildlife. To understand their conservation value, it is necessary to better understand their use by wildlife. The present study focused on a species dependent on open areas, Wilson’s Warbler (Wilsonia pusilla). Populations of this species have been declining importantly since the last 40 years. We evaluated species occurrence in 43 alder sites and 90 clear-cut sites, at the Forêt Montmorency, Québec. We also measured 5 physical traits of captured males (weight, rectrix length, beak length, cap length and wing length) in order to establish if there is a difference between birds found in the two different habitats. Finally, we evaluated which factors of the landscape affected the occurrence of bird in a site, at four different radii (50, 100, 200 and 400 m). We found an equal proportion of Wilson’s Warbler in both habitats and no phenotypic difference was found. Percentage of open area around site was strongly associated with the presence of Wilson’s Warblers, at each radius. Presence of patchy alder and percentage of regeneration between 2 and 4 m high were also associated with the species’ occurrence. Those results throw new light on the habitat of Wilson’s Warblers and highlight the potential role of clear-cuts for the maintenance of its populations. However, the role of clear-cuts will need to addressed with data on reproduction.
Document Type: Mémoire de maîtrise
Issue Date: 2004
Open Access Date: 11 April 2018
Permalink: http://hdl.handle.net/20.500.11794/17887
Grantor: Université Laval
Collection:Thèses et mémoires

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