PARIS (AFP) - Some animals are "shape-shifting" and have developed bigger tails, beaks and ears to regulate their body temperatures as the planet warms, according to a new study.

From Australian parrots to European rabbits, researchers found evidence that a host of warm-blooded animals have evolved bigger body parts, which could allow them to lose body heat more effectively.

Climate change is heaping "a whole lot of pressure" on animals, said Ms Sara Ryding of Deakin University in Australia, who led the study, in a press release.

"It's high time we recognised that animals also have to adapt to these changes, but this is occurring over a far shorter timescale than would have occurred through most of evolutionary time," she added.

The study, published on Tuesday (Sept 7) in the journal Trends in Ecology and Evolution, reviewed previous research "where climatic warming is a potential hidden explanatory variable for the occurrence of shape-shifting" and found trends particularly noticeable in birds.

The Australian parrot, for example, had shown an average 4 per cent to 10 per cent increase in the size of its bill since 1871 and the authors said this positively correlated with the summer temperature each year.

Other birds, such as the North American dark-eyed juncos, thrushes and Galapagos finches, also saw bill size increases.

Meanwhile, the wings of the great roundleaf bat grew, the ears of the European rabbit became bigger, and the tails and legs of masked shrews were found to be larger.

"Shape-shifting does not mean that animals are coping with climate change and that all is 'fine'," said Ms Ryding.

"It just means they are evolving to survive it - but we're not sure what the other ecological consequences of these changes are, or indeed that all species are capable of changing and surviving."