Suchergebnisse

The efficacy of spotlighting as a field survey technique for detecting the
greater glider (Petauroides volans) was assessed by
comparing the precise location of radio-tracked animals with locations
determined simultaneously from spotlighting searches. Radio-collars were
fitted to 20 greater gliders in three eucalypt patches embedded within an
extensive radiata pine (Pinus radiata) plantation near
Tumut in south-eastern New South Wales. Our success rate for detecting
collared animals was low, even when survey effort was increased. These
findings suggest that spotlighting underestimates actual population size. A
further, properly designed study, in different forest types is needed to
provide precise estimates of the magnitude of the bias in counts of
P. volans obtained by spotlighting.

We compare detection rates of different species of mammals by three types of
hairtubes in both the mountain ash forests of the central highlands of
Victoria and a range of wet forest types at Tumut in southern New South Wales.
The types of hairtubes were a small-diameter PVC pipe, a large-diameter PVC
pipe and a newly constructed tapered hair funnel. Data were analysed for brown
antechinus (Antechinus stuartii), bush rat
(Rattus fuscipes), common wombat
(Vombatus ursinus), swamp wallaby
(Wallabia bicolor) and common and mountain brushtail
possums (Trichosurus vulpecula and
T. caninus). The most effective hairtube type (i.e. the
one yielding the highest number of detections) varied between species: small
hairtubes forR. fuscipes, hair funnels for
Trichosurus spp., and large hairtubes for
V. ursinus and W. bicolor. For
A. stuartii, the most effective hairtube type differed
between the two study regions (hair funnels in Victoria and small hairtubes at
Tumut). Detection by more than one hairtube type at a given plot was uncommon.
Our findings have important implications for field surveys and how data
gathered from such studies are interpreted. For example, if the aim of field
survey is to detect a wide range of species then several types of hairtubes
may need to be deployed.