Poster Session # 20: Predator - Prey / Mutualism - Parasitism Ecology.

Thursday, August 7 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.

Spatio-temporal niche partitioning among three sympatric predator species in a single-prey system.

Garneau, Danielle*,1, Post, Eric2, 1 The Pennsylvania State University, University Park, PA, USA2 The Pennsylvania State University, University Park, PA, USA

ABSTRACT- Terrestrial investigations of multiple predators sharing one prey are rare in natural systems. This study offers an explanation as to how sympatric black bears, grizzly bears and gray wolves coexist on a seasonally limiting prey item, specifically moose calves. Spatial and temporal separation within a shared niche dimension has classically been offered as an explanation for sympatric species coexistence. Niche partitioning, resulting from differential hunting behaviors among members of the predator guild, is often used as a means of capitalizing on a common resource. Our findings suggest that black bears and grizzly bears temporally separate hunting during moose parturition, due to their spatial overlap in habitat. Similarly during periods of increased inter-predatory competition, black bears and gray wolves exhibit temporal overlap in hunting bouts; therefore, they must spatially segregate within different hunting habitats. Consequently, findings from this study indicate the need to consider each member of the predator guild individually, complete with its own suite of behavioral, physiological and foraging strategies.

Key words: coexistence, predator-prey, niche complementarity, spatio-temporal partitioning