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Cheating crabs

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Males in some species of fiddler crab might deceive rivals and potential mates by growing back a "cheap" but convincing facsimile of their large claw after losing the appendage in fights or during moulting, according to research at the Australian National University.

Patricia Backwell, a senior lecturer in the School of Botany and Zoology, says the replacement claw in most species is identical to the original. But in some species, it is weaker, more delicate and lacks teeth. But it grows to full length more quickly and convinces competitors and potential mates.

She is investigating the possibility that the cheap claws are a case of deceptive signaling - cheating evolved because it confers an advantage on the individual. The crabs sacrifice real power in the claws in order to look fit.

Educated in South Africa, Backwell, a behavioural ecologist, has been studying fiddler crabs for several years. Her fieldwork has taken her to Mozambique, Japan and Central America to study the strange habits of the small, colourful tropical crabs which form about 100 species world wide. She is now focusing on some of the 20 Australian species, conducting her fieldwork in Darwin.

"I love being out in the environment observing animal behaviour," she says. "Some people are suited to working in the lab. Some people are suited to being in the field - in the natural environment - and you can make a career out of what I call the fun part of biology."

"In BoZo, there is an amazing mix of technical, laboratory- based staff and field-based staff collaborating."
Fieldwork figures prominently in undergraduate biology courses at ANU. "Students get to do lots of hands-on research from very early on."

And ANU's BSc program is flexible. "It has the most amazing freedom of choice," says Backwell. "Students are able to do a huge variety of courses, and they are free to change their choices at any time." Fieldwork is also central to postgraduate research, and Backwell supervises several PhD students.



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