Differential selection of North American and Scandinavian conifer browse by northwestern moose (Alces alces andersoni) in winter

Abstract

Scandinavian moose (Alces alces) eat Scots pine (Pinus sylvestris) in winter. Although North American moose are known to eat conifers such as true firs (Abies spp.) in winter, substantial consumption of pine by moose in North America has not been documented. Here, we document short-term winter preferences of human-habituated northwestern moose (Alces alces andersoni) for branches of mature North American and European conifer species as determined by a cafeteria-style feeding trial. Moose selected for species such as Douglas fir (Pseudotsuga menziesii; from which they took the smallest bite diameters) while avoiding species such as lodgepole pine (Pinus contorta; from which they took the largest bites) and hybrid white spruce (Picea glauca × engelmanii). The amount of species-specific biomass consumed by moose was negatively correlated with bite diameters taken from branches of those species and did not appear to be significantly influenced by differences in twig morphology between species. Our trial suggests that northwestern moose readily consume conifers in winter and, from the species we tested, prefer Douglas fir. While no clear preference existed between Scots pine and lodgepole pine, moose avoided lodgepole pine, but not Scots pine, relative to Douglas fir. Our trial suggests that northwestern moose are more likely to feed on the branches of Douglas fir than pine, which may be of interest to foresters managing conifers within the North American range of moose, particularly where Scots pine are being considered for planting.