Competition and habitat use in native Australian Rattus: is competition intense, or important?

摘要: This study investigates patterns of habitat use and competition in sympatric populations the bush rat, Rattus fuscipes, swamp R. lutreolus, Blue Mountains National Park, New South Wales, Australia. Radiotracking showed that home ranges fuscipes tended to occupy woodland more than those whereas heath sedgeland by both species was equal. Home range overlaps were less between two individuals lutreolus. Trap-captures used structurally complex microhabitats, but also occupied relatively drier sites with denser leaf litter taller canopy In a field enclosure containing equal parts dense sedge woodland, spent most time sedge. lutreolus frequently initiated agonistic behaviour dominated its smaller congener; subordinate fled or vocalized loudly. To test whether observed resulted from selection experiment carried out which latter removed maintained controls. Following removal, capture rate increased some 6.5-fold had been formerly while rates control remained unchanged. The rapidity shift implicates current intense competition, mediated interference. Although interference is costly process, it may benefit dominant allowing priority access preferred moist habitats important food shelter resources. Conversely, tolerate if benefits even temporary habitats, can reliably detect avoid prior encounters, has areas under-used species. We suggest finally extensive gene flow preclude adaptive shifts preferences local are thus reducing importance maintaining intensity over time.