Abstract
Movements of the endangered giant barred river frog (Mixophyes iteratus) were followed over 2 to 5 day periods using radio-transmitters and nylon spools. This species was historically found from the mountains west of Sydney to the Conondale ranges NW of Brisbane, Australia; since the 1970s it appears to have suffered a large decline, and is now extinct in the most southern parts of its range and has suffered serious population reductions elsewhere. Tracking studies were conducted along four permanent streams (3-7 m wide) on the Dorrigo escarpment, New South Wales: 2 streams are within Eucalyptus grandis plantations; one in wet sclerophyll forest dominated by E. grandis and E. saligna; and one coastal stream occurs in a mixed environment. Thirty-one nights of data were obtained from 10 radio-tracked frogs, and 45 nights from 22 frogs using spool-tracking. Nightly movements varied from 0 to over 100 m, with a mean of 8.3 m for radio-tracked frogs and 13.2 m for spool tracked frogs. Individuals were found to occupy two distinct daytime shelter positions, namely (1) inactive beneath leaf litter, or (2) alert but sheltered under vegetation where frogs could avoid predators by jumping away. All frogs were captured and recorded moving within a 20-m wide band either side of the streams. Unlogged buffer zones 30 m in width along each side of streams are currently used to protect the breeding habitat of this species from the possible effects of logging operations. The study data indicate that these buffer zones should be effective in protecting the habitat generally used by giant barred river frogs. However, further studies are recommended, to determine whether the over-wintering habitat used differs from the spring-autumn patterns observed in this study.
For further details log on website :
http://cabdirect.cab.semcs.net/abstracts/20000616155.html?start=56900
No comments:
Post a Comment