Roosting and foraging ecology of the golden-tipped bat (Kerivoula papuensis) on the south coast of New South Wales

Abstract

The roosting and foraging ecology of the golden-tipped bat (Kerivoula papuensis) was studied by radio-tracking on the south coast of New South Wales. Despite a previous scarcity of records, 16 bats were harp-trapped during spring and summer, of which 11 were radio-tracked. Roost types (n = 33 roosts over 48 roost days) were the suspended nests of yellow-throated scrubwrens (Sericornis citreogularis) (50%), nests of brown gerygone (Gerygone mouki) (27%), beneath hanging moss on tree trunks (21%) and in foliage (2%). All roosts were located in rainforest and close to creek lines (mean = 6 m). Yellow-throated scrubwren nests were more common in rainforest on small, first- and second-order streams (4.6 nests km^–1 – 5.2 km searched) than on larger, third-order streams (1.1 nests km^–1 – 2.7 km searched). Colonies were small (<10 bats) and usually comprised a mix of sexes. Maternity roosts in summer were located in both yellow-throated scrubwren nests (n = 8) and brown gerygone nests (n = 3). Foraging bats were recorded flying a maximum of 2.1 km and were regularly recorded (43% of monitored time) on upper slopes away from rainforest. Plots (5 × 5 m) were used to compare prey densities (small web-building spiders) between rainforest and sclerophyll forest and different topographies (creeks, riparian vegetation and upper slopes). Although spider numbers were patchy, upper-slope sclerophyll forest supported the greatest number of spiders, the number being significantly greater in upper-sclerophyll forest than in sclerophyll creeks and rainforest on upper slopes. A forward step-wise multiple regression showed that spider numbers per plot were positively related to the density of understorey stems. Management implications from this research are that riparian rainforest provides the key roosting habitat for K. papuensis. Recent management prescriptions in New South Wales' forests available for logging have correctly targeted the protection of this environment. However, the extent of foraging in sclerophyll forest on upper slopes was previously unknown. Attention needs to be given to management actions that maintain a mosaic of dense patches of understorey on upper slopes, where the numbers of web-building spiders are high. Further research is required to determine the effectiveness of using buffered protection zones within logged areas for K. papuensis.