Selective herbivory by red-necked pademelon Thylogale thetis at rainforestmargins: factors affecting predation rates

We examined browsing by red-necked pademelons (Thylogale thetis) on shoots of rainforest plants at areas of rainforest-grassland interface in the Lami ngton Plateau of southeast Queensland. Terminal shoots from nine species (t hree each of vines, trees and shrubs) were compared. The effects of five fa ctors (plant species, site, distance from forest edge, habitat (grassland o r forest) and time (trip) at two levels of exposure (caged or uncaged)) wer e also compared. Among the uncaged shoots, 98% showed signs of damage compa red with 18% of the caged shoots. In general, shoot predation was higher in the grassland than in the forest and decreased with increasing distance aw ay from the forest edge in both habitats. The three vine species were more heavily browsed than all other species. Browsing by red-necked pademelons i s likely to influence regeneration near forest edges through direct death o f seedlings as a result of predation and through altered competitive intera ctions resulting from selective herbivory. This effect, however, would be l ower on seedlings within the forest habitat and would also reduce as seedli ngs establish themselves further from the forest edge into grassland habita t.