RESIDENCY AND SITE FIDELITY OF MARKED POPULATIONS OF THE COMMON BLOSSOM BAT SYCONYCTERIS-AUSTRALIS IN RELATION TO THE AVAILABILITY OF BANKSIA-INFLORESCENCES IN NEW-SOUTH-WALES, AUSTRALIA

Residency and site fidelity of marked populations of the nectar-feedin g common blossom bat Syconycteris australis were monitored for three y ears in three areas of high food availability (density of Banksia inte grifolia inflorescences) and three of low food availability on the nor th coast of New South Wales, Australia. Resident bats were present in all sites; however, populations in areas with low food abundance were more likely to be resident (63% recaptured) over a six-month flowering season than populations in areas with high food abundance (20% recapt ured). Residents were more likely to be adult males, than females or j uveniles. Intruder pressure fluctuated throughout the year with food a bundance as the number of transients was correlated with the density o f inflorescences. This had a marked effect on bats in autumn, when a l ower percentage of residents than transients was reproductive in sites with high intruder pressure. Also, residents at sites with high intru der pressure were less likely to be reproductive and their body condit ion was lower than residents experiencing low intruder pressure. Thus intruder pressure was probably the most important factor reducing resi dency. Nectar and pollen was locally scarce after B. integrifolia fini shed flowering; however, many bats returned to the same site in the fo llowing year. Site fidelity between consecutive B. integrifolia flower ing seasons (years), was greater in low-food sites (28%) than areas of high food (12%). The proximity of non B. integrifolia food sources ma y contribute to the degree of site fidelity, but this is yet to be tes ted. One site was monitored for five consecutive years and at least 4% of those marked in the first year were site faithful after five years . Strong site attachment would increase the vulnerability of this spec ies to the effects of disturbance. These observations indicate that th e abundance and dispersion of food has an important influence on behav iour and population dynamics of S. australis over long periods.