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A 300-day science experiment by an Avondale College lecturer has helped explain how animals cope with seasonal changes in weather.

Dr Terry Annable used a detector on the end of a wire to measure temperature one metre below ground. A logger recorded data every four hours each day for 300 days. "I would have preferred 365," says Dr Annable, "but the limit of the logger was only 300."

Temperature on the surface averaged 19.9 degrees Celsius but ranged from a minimum of 13.1 degrees Celsius in winter to a maximum of 25.2 degrees Celsius in summer. It increased by an average of 1.7 degrees Celsius a month in spring and decreased by 2.7 degrees Celsius a month in autumn. However, at one metre below the surface, daily variation in temperature is undetectable.

"While we find the shade of a tree on a summer's day or the warmth of a fire on a winter's night a relief," says Dr Annable, "animals and plants must adapt to such variation in temperature. This may help explain how."

Dr Annable hopes the experiment will help biologists discover how animals such as goannas know when to begin and to end their hibernation. "Generally, they don't emerge on warm days in winter, but you can just about set your watch by the days small species of lizards emerge." He is concerned about how animals will adapt to the long-term changes in weather brought about by global warming. "We can be certain extinction rates will increase."

The experiment by Dr Annable, a recently retired senior lecturer in the Faculty of Science and Mathematics, is an extension of others by ecophysiology students at Avondale. Led by Dr Annable, the students have measured how humidity, soil composition and colour and vegetation cover contribute to micro-environmental temperatures.