A University of Queensland PhD student is searching for answers to 'pointed questions' about the unusual hibernation habits of one of Australia's best-loved but least understood mammals, the enigmatic echidna.
Louise Kuchel wants to know why echidnas disappear underground in March and April when there is neither a shortage of food nor a need to escape from severe cold, unlike the behaviour of hibernating animals in the northern hemisphere.
Although found throughout Australia and in widely differing climates, adult echidnas emerge from their burrows in July-August to run around and breed. The echidnas hatch a single egg in September-October. Echidnas that do not breed in a particular year appear to remain in hibernation until October.
Ms Kuchel is also hoping to discover why they experience sudden metabolic changes during their annual sleep-in.
At times their body temperature drops to only 5 degrees, while in other 24-hour periods it can rise from 5 degrees to the normal active temperature of 32 degrees.
'No one knows how they manage to warm their bodies up again, or why their temperature fluctuates so much,' Ms Kuchel said.
Extensive fieldwork in an echidna habitat near Stanthorpe will include the use of implanted transmitters to provide accurate information on body temperature and heart rate.
It will be the first time new technology for monitoring heart rate has been used outside laboratory conditions.
Also under consideration is setting up a 'burrow cam' to give Ms Kuchel a first-hand look at the home life of the secretive egg-laying mammal, whose closest Australian relative is the platypus.
The remainder of the studies will be at the University's zoology department laboratory and animal research centre.
Ms Kuchel, who studied the physiology of saltwater crocodiles to receive honours in zoology from the University last year, is five months through what she expects to be a three-year echidna project.
'When you consider how much of an Australian icon the echidna is, it is still a bit of a mystery,' Ms Kuchel said.
'While this study is mainly looking at hibernation, so little is known about things such as their breeding habits that any information will be valuable.'
One theory about echidna hibernation being considered by Ms Kuchel is that it is an energy-saving device to ready them for the breeding season and the rigours of raising their youngster after it hatches around October and November each year.
'It may be part of a cycle where they eat and get fat in summer, then sleep until the breeding cycle begins,' she said.
'The reason for animals hibernating is taken for granted everywhere around the world, but the echidna doesn't fit in to the usual pattern at all because they come out at the coldest time of the year to breed.
'Saying that animals hibernate to avoid the cold and because there is no food available may be an easy answer and it may be appropriate in the northern hemisphere, but it may not be appropriate here in the southern hemisphere.'
For more information contact Ms Kuchel (telephone 07 3365 1391)
