The likely impact of the honeybee on a native pollination system was examined by studying the effectiveness of honeybees (Apis mellifera) as pollen vectors of Grevillea × gaudichaudii, near Bargo, New South Wales. Honeybees were the most frequent visitors to Grevillea inflorescences at the study site. Bees were found to be specific in their foraging, because only one pollen type was represented in the corbicula of each bee returning to a hive but the Grevillea was not present in these pollen loads. Bees were observed foraging for nectar on Grevillea plants in the study area, but had no Grevillea pollen on their bodies and failed to transfer pollen to stigmas of 500 flowers during two hours of observations over two days. It is concluded that bees harvested nectar from this plant species without effecting pollination, and would therefore make the plants less attractive to native pollinators without compensating for any consequent reduction in reproductive success.
Fragmentation of extensive natural ecosystems by roads, railways and other barriers poses major threats to populations of native animals. Attempts have been made to reduce the magnitude of these threats by constructing "underpasses" designed to permit exchange of animals. We compared mammal use of long-established drainage culverts and newly constructed tunnels under the Maldon-Dombarton rail line, near Wollongong, New South Wales. Small mammals used the established culverts, but use of the new tunnels was predominantly by feral predators. We predict that frequent use by small, native mammals will not occur until native vegetation regenerates around the tunnel entrances, establishing a connection between undisturbed vegetation on the two sides of the track. We also argue that follow-up studies such as this one should be an integral part of the environmental impact study of a proposed development.