Dr Scott Carver
You know, wombats put those cube poos in all sorts of kind of curious places and they seem to like stick them around things, but nobody had really done much research on like on what they kind of use them for and or really any research. And so it’s just a really fun opportunity to be able to look into that. Kate was a really fantastic student who did really great work on that. And I mean, essentially, our hypothesis was that they live in this kind of olfactory world of smells that is much more complex than what we understand. And so that’s what Kate was spending her honours doing.

Helen Shield
Right, Kate, I always thought the cube poos were just to stop them rolling away.

Kate McMahon
Yeah, it’s definitely possible that that plays a role in helping them stay aggregated at these shared latrine sites. But there’s a whole other world to it as well. We really dived into the chemical components of these scats and that opens a whole can of worms of what they may be communicating, as well as we took a really multifaceted approach at looking at any potential reception structures and looking at behavioural responses when we introduce new scents to their landscape as well.

Helen Shield
Right. So you learnt more about the smell-o-vision experience that wombats are having around the cube poos they leave all over the place.

Kate McMahon
Yeah, absolutely. That was our goal.

Helen Shield
Dr Carver, did you find out more about the complexity of what wombats are capable of smelling?

Dr Scott Carver
Yeah, we did. So we did an experiment that’s called basically gas chromatography and mass spectrometry, which is like a really long name for basically trying to figure out what are all the kind of like chemicals that can get aerosolised from wombat scats. And so Kate basically went around and collected groups of scats from individual wombats that we were able to identify. We knew that this came from one wombat over here and this one came from a different wombat over there. And we were then able to like characterise what are the sort of chemical mixtures. And you might think of this as like, you know, if you, you know, one person smells a little bit one way and then another person smells a little bit differently to that. Those basically, those different odours that people have are like their chemical signatures. And so by like characterising these chemicals, essentially we were like figuring out what were individual wombats odours and they were all like individually distinct. You could kind of tell one individual wombat from another based on that chemical mixture.

Helen Shield
Wow. What sort of variety did you find in the chemicals, Kate?

Kate McMahon
Well we identified 44 compounds in total. And this was a combination of those which were likely plant derived, like from their diet and some which were endogenous to the wombats themselves. And I think it was approximately eight of those compounds have been identified in other mammalian species to be associated with importance in chemical signalling. So it was really exciting to identify like a range in that they were individually distinct and also opening avenues for further research on perhaps those compounds which may be saying more.

Helen Shield
Right. Because that could be a message about their availability to mate or…About, you know, they share their burrows, don’t they, in dry conditions. They’ll let other creatures come in and drink from, you know, if they’re burrowed down to the water table. Could they be sending messages about stuff like that?

Kate McMahon
It’s shown in other species that they often communicate, yeah, reproductive state. Like you said, that’s a really important message to communicate in the animal world, as well as sex, age, a whole range of things.

Helen Shield
That’s very interesting. Scott Carver, you won an Ig Nobel Prize for an earlier stage of this research. How hopeful are you that cube poo smell-o-vision might mean you can back that up?

Dr Scott Carver
That would be fun. And you know, they call people who win two of these prizes double eggs. But you know, they get like 10,000 nominations a year for the Ig Nobel Prizes and they get about 10. So just objectively, I think our chances are low, but I’ll certainly be sharing the research with the people that run the Ig Nobel Prizes, which I’m sure that they will get some enjoyment out of regardless. And in fact, I was at a, I happened to be in Boston earlier this year and I got the opportunity to go to a sort of, not the main Ig Nobel ceremony, but an associated one. And so I got to give a one minute talk about wombats and their cube poos to people over there, which was a lot of fun.

Helen Shield
Kate, is it like when you take your dog for a walk and they check their P-mails around the neighbourhood and the messages they’re leaving and getting from each other? Is it kind of like that, but the wombat version?

Kate McMahon
Yeah, absolutely. And wombats also exhibit flehmen behaviour, which you will often see in cats and horses where they curl up their lip and make that funny face. That’s them facilitating the transfer of chemical signals to associated olfactory organs. So you see this in your pets at home.

Helen Shield
Next level smelling. This is not just like the way we smell. What else is going on in their noses?

Kate McMahon
So in the nasal cavity, there’s a vomeronasal organ and this actually made part of our study as well. We undertook some gross anatomy studies looking in the nasal cavity of wombats to try and identify whether or not they did in fact have this vomeronasal organ, which plays a central but not exclusive role in pheromone detection.

Helen Shield
Do you love that it’s called a gross anatomy study and it’s also about smelling poo?

Kate McMahon
Yeah, I have had lots of jokes about that.

Helen Shield
Quality science pun. Yeah. Quality. So what else would you like to know about them, Kate, about the messages some wombats are leaving in their cubed poos?

Kate McMahon
I would love to see so much more research come out of this, specifically really getting into the chemical components of their scats as well. I feel like there’s a lot of work that could be done in that space, particularly perhaps in captive populations where you’re working with individuals of known age and sex. So working with wild populations, it was an amazing opportunity being over on Maria Island, but for people who are familiar with wombats, it’s really hard to tell their age or whether they’re male or female just because they all look gorgeous, brown, round little fluffy guys. It would be amazing to take that further.

Helen Shield
But how did you go catching them?

Kate McMahon
I didn’t get to catch them.

Helen Shield
You didn’t have to get the big butterfly net out?

Kate McMahon
No, no. It was all setting up camera traps and watching their behavioural responses to us introducing new scents to their landscape. Right.

Helen Shield
Dr Scott Carver, what did you make of the variation of the scent compounds that turned up in these scats?

Dr Scott Carver
You know, there had been basically nothing done on wombat communication prior to this. So for us, it was all new knowledge, right? So it was all discoveries. And that was one of the great things about this project was that we got to do lots of little studies to kind of get a broad understanding of what’s going on with wombats and their communication and that kind of lays the groundwork for further research. And one of the cool things about wombats is it’s often really hard to study communication in mammals in particular because they kind of avoid people and it’s just kind of challenging. But I think the wombats, particularly the ones on Maria, are a really great system to be able to do it because they’re basically relatively habituated to people. You can watch them kind of doing their thing without being too disturbed by us being present. And their behaviours are relatively obvious to see. So you can actually do quite a lot with them and learn quite a lot about communication in mammals more generally. So I think it’s just a really wonderful system.

Helen Shield
How tough was it for you, Dr. Carver, being the remote scientist on this project and having somebody else out with the wombats from the team on your behalf?

Dr Scott Carver
Well, I do miss my wombats a lot. And the good part was Kate started her project before I left Tasmania. So I got to spend a good pile of time running around with her in the field and counting poos. I think both of us have counted more poos than we care to name. But that was a lot of fun. And my last picture of fieldwork in Australia before I left and moved to the US was of a couple of wombats on Maria while doing fieldwork with Kate. So that’s a great one to have.

Helen Shield
I just wouldn’t have known you could get this much variation in a cube of digested grass, Kate. That is surprising.

Kate McMahon
Absolutely. Yeah, it’s pretty cool.