Diversity of passerine birds and mammals was estimated in well-drained areas located at proximity of the hydroelectric reservoir La Grande-3, where natural fire regime still prevails in the absence of forest exploitation. Forest stands were divided up into four post-fire stages: (i) recent burns (4 years old), (ii) shrubs (25 years old), (iii) young forests (50 years old), and (iv) mature forests (≥71 years old). Richness and species diversity were highest in middle stages, in shrubs and young forests. The degree of opening seems to have affected more the composition of bird communities than stand age. Some bird species, typical of shrub stands, in particular white-crowned sparrow (Zonotrichialeucophrys Forster), Lincoln's sparrow (Melospizalincolnii Audubon), and alder flycatcher (Empidonaxalnorum Brewster), appeared after the falling of dead trees, ≈15 years after fire, and disappeared progressively as forests matured. Deer mice (Peromyscusmaniculatus Wagner), moose (Alcesalces L.), and black bears (Ursusamericanus Pallas) were more common at the beginning of succession, whereas northern red-backed voles (Clethrionomysgapperi Vigors) and caribou (Rangifertarandus L.) were typical of late stages. Mammal presence was mostly associated to their feeding requirements. Fire creates a mosaic of forest stands through periodic killing of trees in the north of the boreal forest, which contributes to maintain regional wildlife diversity; its suppression would reduce biodiversity.
We developed an innovative method for estimating human impacts on animal species by measuring changes in feeding behaviour. We illustrate our approach with a study of the effect of vegetation control in a power-line right-of-way (ROW) passing through essential winter habitat of white-tailed deer ( Odocoileus virginianus (Zimmermann, 1780)) at the northern limit of their range. We used giving-up densitiy (GUD; i.e., the amount of food left behind when an animal stops foraging in a patch) to evaluate, in one deer yard, if the loss of forest shelter caused by the power-line installation had a greater effect on deer than the gain of food regenerated in the cleared area. We used GUDs to compare deer estimate of habitat quality in the ROW and in the forest. Our results suggest that the ROW had a negative impact on deer. GUDs were lower in the forest compared with the ROW. Either increased metabolic costs or increased predation risk in the ROW, apparently the latter, lead deer to abandon more food in the ROW than elsewhere. Higher GUDs were strongly correlated with greater snow depth in the ROW. Deer preferred habitats at the edge of the ROW where food and cover were both available.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.