Do sulphur-crested cockatoos (Cacatua galerita) call the weather?

Abstract

Storms can have significant impacts on wildlife and many animals, including birds, can predict a storm’s arrival and change their behaviour accordingly. Storms are often associated with changes in environmental variables, particularly with a fall in barometric pressure. Social animals may collectively detect and advertise the potential onset of inclement weather to facilitate group responses. The present study tested the hypothesis that the sulphur-crested cockatoo uses environmental cues to predict the onset of storms and communicates this to conspecifics by emitting a specific ‘rain call’. Field observations were made over a four-month period at four locations in greater Sydney. Cockatoo calls were recorded, along with multiple environmental variables: barometric pressure, relative humidity, rainfall and temperature. We also noted the time of day relative to sunrise and sunset. We found that rain calls occurred throughout the day but were most prominent at dawn and were far more common at two of the four study sites. Rain calls were more likely to occur at slightly lower temperatures, during periods of high humidity and if it was currently raining. We found no evidence that the calls were prompted by current atmospheric pressure, but the observation period did not contain many storms.