Has BCG gone batty?Diversity in a Piped System project update - 2 June 2006
The end of autumn signals the completion of a full year’s data collection and the winding down of the fieldwork component of the ‘Diversity in a Piped System’ project, aiming to evaluate from a biodiversity and practical farm management perspective the compatibility of various water delivery systems and water access points within the Wimmera and Mallee environment, for value to native fauna and habitat function.
A total of 544 fauna surveys have been completed over the 36 study sites. A limited amount of surveying will be carried out this winter, mainly of the wildlife trough sites and at channels and dams following the hoped-for channel release.
An Anabat bat detector has allowed another faunal group to be surveyed. The Anabat bat detector records the echolocation calls of bats, in other words the high frequency sound they use to find their food in the dark. Most bats emit an ultrasonic sound that is inaudible to the human ear, making them a tad difficult to identify unaided. This is where the bat detector earns its merit. A bat detector converts the ultrasonic echolocation call into an audible electronic signal which is then used to identify the bat species. The Anabat has been used to record dozens of calls from at least five bat species, and there are still a number of calls yet to be identified. Bats hibernate in late autumn in tree hollows, so no further Anabat work will be possible until they become active again in the spring.
Bats, particularly insectivorous bats, are rarely seen by humans yet they play an important role in the ecosystem. Most insectivorous bats consume up to 25% of their own body weight in insects per night, with some species catching and consuming up to 600 mosquitos in an hour. So take that, you pesky little blood suckers! Although bats may not always be heard or seen, they are good indicators of a healthy ecosystem and play a major role as nocturnal hunters keeping the night flying insect populations under control.
With a full year’s data collected, some very interesting differences between sites are emerging. The two major findings are the influence that the presence of water and the presence of trees have on bird species diversity and abundance. Sites with both trees and water had significantly more birds than sites with trees but no water. Also, sites with trees and water supported up to 12 times more birds than sites with water in open paddocks.
Perhaps the most important finding is that the experimental wildlife troughs are able to support comparable levels of bird species diversity and abundance to farm dams in trees. The reptile surveys support this finding, where species abundance for the wildlife trough sites was similar to that of dams in trees.
Although the wildlife troughs have only been in place for a year they are already showing that they are able to support high levels of species diversity and abundance, attract birds and other wildlife to a site and go some way towards maintaining biodiversity levels in a Mallee farming landscape.
For more information on this project contact Jonathan Starks, Project Officer, on 0428 922 787.
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