Population Dynamics and Monitoring
One would imagine that a bird as large as a Cassowary would be relatively easy to find and count, however this elusive creature presents quite a challenge for several reasons.
- Cassowary live predominantly in rainforest which remains one of the most difficult forest types to traverse.
- Each individual Cassowary ranges over quite a large patch of forest
- Cassowary tend to forage alone except for a brief mating period
All of these issues have caused researchers and land managers to be frustrated by a lack of reliable data on population trends and numbers.
In the Daintree lowlands, population surveys were conducted in the early and mid 90’s using a method of transects, sightings and scat (poo) counts in an attempt to determine the population status. Crome and Moore put the figure at approximately 63 adults. Since then little follow up work has been undertaken and the reliability of using scat placement as a basis for population estimation has been questioned.
Over the last twenty years population estimates have varied alarmingly from hopeful beliefs that around 4,500 Cassowary existed in Australia to perhaps a more realistic number of as few as 1,000 birds.
Recent DNA sampling of fresh scats in the Mission Beach area has demonstrated that unless you know which bird is responsible for the dropping your data can be dangerously skewed.
Much hope is now placed on perfecting the process of obtaining DNA samples from fresh scats and using that knowledge to identify individual birds. This will enable researchers to either build up population knowledge of all the birds in a given area or use the data to statistically determine the approximate populations.