Black Bears (Ursus Americanus) as Possible Vectors of Bi-directional Nutrient Transfer in Marine and Terrestrial Systems Inferred from their Late Summer Diets

Abstract

American black bears (Ursus americanus) are highly opportunistic omnivores and tend to forage selectively depending on the seasonal abundance of food items. We collected and analyzed 22 scats from various beaches and forests near Bamfield B.C. and determined that in late summer, bears in the area rely heavily on Gaultheria shallon berries. Hemigrapsus spp., Talitrid amphipods and seaweeds were also fed on by black bears in the area in late August. Marine-derived organisms were found in scats collected in the forest, and terrestrial-derived organisms were found in scats collected on beaches, suggesting that there is a bi-directional transfer of marine and terrestrial nutrients and biomass.