Science plays matchmaker to boost bandicoot breeding

A new breeding program is combining what happens in the wild with what happens in the lab to give the endangered Eastern Barred Bandicoot the best chance of avoiding extinction.

A team from the University of Melbourne and Zoos Victoria is trialling a breeding technique known as ‘mate choice’ where bandicoots can choose their own mates, from potential partners allocated for their compatible genetic backgrounds.

In other species, the method can result in females becoming pregnant sooner, producing larger litters and having offspring with greater survival and reproductive success – extremely important in species you plan to return to the wild. 

Zoology student Chris Hartnett is trying to understand more about bandicoot breeding behaviour as part of her Masters of Science at the University of Melbourne, supervised by Associate Professor Raoul Mulder at the University and Dr Michael Magrath from Zoos Victoria.

“In the wild, a female bandicoot would choose a mate for herself, likely based on the male’s smell which may indicate the best age, size or genetics to produce the strongest offspring for her,” Ms Hartnett said.

“Because bandicoots are usually solitary animals, we first need to establish what behaviour indicates a female has chosen a mate, for example spending more time with one male and displaying certain grooming habits.”

At a special facility at the Werribee Open Range Zoo, the team has created ‘encounter screens’ which separately house one female and two male bandicoots, all chosen as good genetic matches.

The female is able to visit and smell her potential partners, but she can’t interact directly to mate.

This allows Ms Hartnett to observe what behaviour indicates a mate choice and the team can then pair those animals together in the hope that they breed successfully.

Once widespread across Western Victoria, the species is now technically extinct in the wild, leaving the smaller, managed populations to breed within themselves.

This has become a problem for animals like the endangered Tasmanian devil where smaller isolated populations lose the diversity in their genetic make-up, known as a ‘bottleneck’.

Scientists think this has resulted in a reduced range of immune system genes to fight off the facial tumour disease that is ravaging the species.

With this in mind, the bandicoot mate choice project begins with males and females that are genetically suitable, says Dr Marissa Parrott, Reproductive Biologist and co-ordinator of Zoos Victoria’s bandicoot breeding program.

“A successful bandicoot breeding program, based on pedigree and genetic analyses, has been run by Zoos Victoria since 1991 producing over 650 offspring. So we want to compare the current program with a new program that allows the female to choose a mate, in the hope that it will give a further boost to the population,” Dr Parrott said.

Dr Parrott first showed that mate choice was successful for the breeding of other marsupials, including antechinus, and dunnarts during her PhD and post-doctoral research at the University of Melbourne.

“Because mate choice has been successful for other marsupials, we are very hopeful that this program will produce a larger and stronger population of bandicoots at Werribee Open Range Zoo that can be returned to the wild.

“Ideally, Eastern Barred Bandicoot populations would recover to such a level that we would not need a breeding program at all, because they are safe in the wild.”

The project is expected to take a number of years in order to follow the success of the offspring. It has been supported by the Hermon Slade Foundation, Zoos Victoria and the University of Melbourne.

This research is part of a wider recovery program with the Department of Environment and Primary Industries, Parks Victoria, Conservation Volunteers Australia, Mt Rothwell Conservation and Research Centre and private landowners and stakeholders. 

www.zoology.unimelb.edu.au

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