Keeping track

Young cassowary chicks have a low chance of survival after the premature death of a parent, so chicks are regularly brought into care at the Garner’s Beach rehabilitation facility where they are hand-reared by DERM staff until ready for release into the wild.

Until recently, nothing was known about the fate of the released birds, but a new research project is changing that.

Dr Hamish Campbell and Dr Ross Dwyer from the University of Queensland, are working with staff from DERM, Ella Bay Ltd., and CRT member Graham Lauridsen of Tully Vet surgery, to track the movements of rehabilitated birds using GPS-based technology.

A small cuff, incorporating a remote sensing device and radio transmitter, is attached to the young cassowary’s leg before release. The GPS device is programmed to record the bird’s location every 30 minutes between 3am and 9pm for 180 days, and the VHF radio transmitter emits a signal 7am to 5pm two days a week. The radio signal enables researchers to relocate the bird regularly and to recover the device, which drops off after six months or if the bird is stationary for 48 hours (which suggests it has died).

Of the five cassowaries initially fitted with remote sensing devices, three devices have so far been recovered. One device remains attached to a cassowary in the hills around Flying Fish point (detachment scheduled for February 2012) and the fifth unit attached to a male released at Cape Tribulation has yet to be recovered despite searches of the area. It is thought this bird might Encouragingly, it seems as though all five birds survived following their release.have moved beyond the range in which researchers can pick up the radio signal. Encouragingly, it seems as though all five birds survived following their release.

One of the devices, attached to a female named “Dooley” released at Jarra Creek in the Tully hills, unfortunately dropped off after only 28 days. GPS tracks show that she, and another female “Annabelle” released at Cape Tribulation, quickly established a relatively small home range. The male released at Cape Tribulation moved back and forth between the release site and the Bloomfield River, 12km away, covering four times the distance travelled by Annabelle. The recovered devices are being rehabilitated for future releases.

The information gained through this research will help us better understand cassowary ecology (including how far juvenile cassowaries disperse, and when and where they establish a permanent home-range), and will also provide valuable information for the management of the rehabilitation and release programme. We’ll keep you posted!