Counting cassowaries: what does cassowary sign reveal about their abundance?
In: Wildlife research, Band 26, Heft 1, S. 61
ISSN: 1448-5494, 1035-3712
The use of surveys of sign (e.g. dung, tracks and sightings) to estimate
abundance is a method in common usage with a variety of vertebrates,
especially forest species and those with cryptic habits. Particularly for
endangered species, such as the southern cassowary,
Casuarius casuarius, the resulting abundance estimates,
at both regional and local scales, can be fundamental to management and
conservation decisions. Current estimates of regional cassowary abundance in
North Queensland are based on the results of surveys that documented
indicators of cassowary activity across the Wet Tropics Region. When applied
to population abundance estimation this approach assumes (i) that cassowary
sign is as likely to be encountered on trails as it is in the forest
generally, and (ii) that there is a relationship between the amount of
cassowary sign encountered and the number of birds using a trail. These
assumptions were tested in a project conducted in Wooroonooran National Park,
north Queensland. In failing to support either assumption, the fieldwork
identified the need for the improvement of large-scale survey techniques for
cassowaries, and for caution in the application of this method and the
interpretation of its results more generally. In the case of cassowaries,
improvements to the current method could be achieved by incorporating multiple
surveys at each site, assessment of local use of trails by cassowaries and of
fruit abundance at the time of surveying.