PARENT SESSION
Oral Session # 78: Predator - Prey Ecology II: Terrestrial II.
Presiding: M Wolf
Thursday, August 7. 1:30 PM to 5:00 PM, SITCC Meeting Room 103.
Rodent seed predators may offset benefits of corridors for bird-dispersed plants.
Orrock, John*,1, Damschen, Ellen2, 1 Ecology and Evolutionary Biology Interdepartmental Program, Ames, IA2 Department of Zoology, Raleigh, NC
ABSTRACT- Some of the detrimental effects of habitat fragmentation may be offset by corridors, strips of habitat that promote movement of individuals and propagules among patches. However, most work in corridors has neglected how corridors may impact predator-prey interactions. We demonstrate that corridors affect seed predation, resulting in negative effects on seeds of a bird-dispersed tree, black cherry (Prunus serotina). In fall 2002, we placed 20 seeds of P. serotina in each of 80 experimental exclosures located within a large-scale, replicated landscape with connected and unconnected patches. After four weeks, seeds were collected and the experiment was repeated. Seed predation by arthropods was negligible, as arthropods removed < 1 % of P. serotina seeds. Conversely, rodents were significant agents of seed predation, removing 54% of P. serotina seeds in unconnected patches and 84% of P. serotina seeds in connected patches. The significant difference in seed predation between connected and unconnected patches suggests that, although bird-dispersed seeds may experience increased dispersal when corridors are present, this benefit may be offset by corridor-mediated changes in seed predation.
Key words: granivory, corridors, rodents, predator-prey