Dr Parrott’s work with dunnarts, Antechinus and other marsupial species introduced a different method. She showed that when a female was able to select her own partner, it took less time for the pair to begin reproducing, gave rise to a greater number of pregnancies, and all with decreased aggression between the female and the male. On the surface, this seems like an easy and more certain way of increasing the success of breeding programs. However, the limited resources of conservation strategies mean that every angle needs to be considered and every variable controlled to best create genetically fit and well-adjusted populations. If the female was allowed to choose her own mate from a group of genetically suitable suitors provided by zoo staff, what was the risk of her choosing a bad match?
The dilemma was a strong one. It’s been shown that mammals are more comfortable socialising with individuals they’ve met before, and particularly with family. Dr Parrott and her collaborators’ work with Tasmanian devils at Healesville Sanctuary showed that introducing young devils to one another – growing used to the smells, sounds, and personalities of new animals – led to greater interactions, more activity and increased denning with their conspecifics. While socialising young devils appears to produce more socially competent animals as adults, further research showed that their interest in novel or familiar animals was similar; a good outcome for breeding programs that introduce a variety of potential mates. However, could some females be selecting males that appear familiar, and risk all the complications of inbreeding?
No, it turns out. Not at all. In her 2015 paper, Dr Parrott shows that female Antechinus were perfectly capable of distinguishing between related and unrelated males, and acting accordingly. Her earlier research on the species shows that it largely comes down to scent – among other cues, with a possibility that the MHC produces chemical traces that change how a male smells to a female. Multiple tests showed that females are more interested in those who smell different to themselves, making more frequent and longer visits to males that were genetically dissimilar. Males that were genetically dissimilar to females secured more matings and sired the highest proportion of young. While it’s not yet clear which range of specific cues other than genetic dissimilarity are providing the information, the result is inarguable – the lady knows best. In a system where multiple matings almost always produce a litter with more than one father, offspring were found to have come from genetically distant males around 9 out of 10 times.
With the limited resources available to conservation programs, understanding how to best produce a robust population is crucial. Zoos Victoria’s Fighting Extinction plan has committed to a magnificent goal: that no Victorian terrestrial vertebrates will go extinct on their watch. Ever. This includes 20 high priority species, as well as a watchlist of other vulnerable animals. But the programs aren’t just about breeding and habitat monitoring – we come into them as well, in the small changes we can make to our daily lives. The fantastic Wipe for Wildlife campaign is one such example, calling for the simple change to recycled toilet paper - with its very own superhero. And there’s the Love Your Locals campaign – helping children and adults alike to discover who they’re sharing Victoria with, before we’re left alone.