The secret life of phascogales

00:00 Eliza Herbert: Bush Heritage acknowledges the Traditional Owners of the places in which this podcast was recorded and in which we live, work and play. We recognise the enduring relationships they have with their lands and waters and pay our deepest respects to elders past and present.

00:15 Angela Sanders: We need the ladder, a kit, and net and the data sheet. OK, and wool you've got yours, Rhiannon? That's it. Well, we've got everything and Jeff's got the ladder.

00:31 Eliza Herbert: It is dawn on Wagyl Kaip and Southern Noongar country in the wheat belt of WA. The air is crisp with the first stirring of bird calls, marking a new day. A team of ecologists, volunteers and staff have arrived at a 392-hectare nature reserve called Kojonup. They're there to look for some very special animals. And to find them, they're going to have to climb some trees.

00:59 Angela Sanders: So, we're going to try these to see if they will block the holes, so the animals can't get out.

01:05 Eliza Herbert: These researchers are looking for phascogales, Red-tailed Phascogales.

01:11 Angela Sanders: You could say for people that know squirrels, they look a little bit like a squirrel, except they don't have the really big back legs.

01:20 Eliza Herbert: Arboreal marsupials, so small, they can fit in the palm of your hand. And so charismatic with big ears that poke out of their head like satellite dishes and a big-eyed look, they will melt your heart.

01:33 Angela Sanders: And they have a long brushy tail and right at the base of the tail, it's a very beautiful rufous red colour. It's not bright red, but it's a nice rufousy red.

01:45 Eliza Herbert: Known as kenngoor to Noongar people, they might not be as popular as kangaroos or koalas, but like other small mammals found across Australia, they are a fundamental part of our ecosystem. But this population we are looking for today is special for another reason. It hasn't always been here. Over 11 years ago, with the species in decline, a small group of Red-tailed Phascogales were captured, bundled up carefully and driven about 100 km for their new home, Kojonup Reserve, in what would be the first wild to wild translocation for the species. Today on Big Sky Country, a podcast by Bush Heritage Australia, we tell you their story.

02:30 Angela Sanders: OK, there's no phascogale in here, but there's a beautiful nest. So, we've got feathers, leaves, and casuarina needles. That's about it in here and a little bit of alpaca wool.

02:45 Eliza Herbert: That's Angela Sanders, an ecologist who has been working with Bush Heritage for over 15 years. She was there when the very first phascogales were released.

02:54 Angela Sanders: So back in the, you know, 2010 when we were first thinking about this translocation. The phascogales were present in in less than 5% of their known range. So, they had been found right across the south of Australia right into Victoria, South Australia through the deserts and right through the south west of Western Australia and a little bit further north. But they disappeared from almost all of their range.

03:23 Eliza Herbert: As is the case with most small to medium sized mammals, the decline of Red-tailed Phascogales coincided with the arrival of foxes and feral cats in Australia, coupled with widespread land clearing. Now the wheat belt of Western Australia is the phascogale’s last remaining stronghold. But even there, less than 10% of native vegetation remains.

03:44 Angela Sanders: So, the Department of Conservation in WA at the time were looking for areas where they could translocate Red-tailed Phascogales to, you know, secure their population. So, at that stage, they were only found in a few wheat belt reserves further north than Kojonup, and they wanted to move them a little bit further south to get a little bit more rainfall in the areas and to move them because of, you know, the threat of climate change.

04:13 Eliza Herbert: Kojonup Reserve fit the bill perfectly. This small patch of remnant bushland is prime phascogale habitat being one of the largest protected areas of Wandoo Woodlands in the region, since Bush Heritage purchased the land in 1996.

04:27 Angela Sanders: Those trees are, I suppose, nature's boarding houses, and they have lots of hollows in them. They have lots of loose bark. They have lots of dead limbs and lots of places for animals to live. Not just vertebrates but also invertebrates. So, there's a lot of food in those trees and there are a lot of places for animals to hide. So, in this nest, we've got scats, we've got feathers. We've got leaves, She-oak and lichen...
Rhiannon:  A fresh nest?
Angela Sanders:  It's a fresh nest. Yep. So, if you come up and just put your fingers down into the nest, you'll see how deep and soft it is on the inside. It took a while to get the translocation project approved through Bush Heritage and through the department. And once it was approved, the animals were moved in May 2010, and then again, more were moved in May 2011.

05:33 Eliza Herbert: If you're wondering what a translocation is, in conservation terms, it is when a species, habitat or ecological material is moved from one location to another to help them settle in. An initial twenty nest boxes were erected in the woodlands.

05:48 Angela Sanders: So, we'd let them go in, in at dusk and we put them in the boxes and then they would, we'd leave them alone, and then they would find their own way out and find other individuals and they get to know each other that way. It was a good way of doing it rather than just letting them go into the environment without having anywhere secure for them to, you know, to hide if they were attacked by predators.

06:19 Eliza Herbert: As the population grew and the animals spread out, the team installed more nest boxes and now there are over 60. Every year they go out to check those boxes and monitor the population, and every year they learn a little bit more about them, like some of the peculiar items that feature on their menu.

06:38 Angela Sanders: And often you don't, you know, you don't see them because they're in their nest, but this particular box had nothing else in it but a half-eaten frog. And this was a big frog. It would fit in the palm of a hand. And what had happened is the phascogale had caught the frog, carried it up the tree, and pushed it into the small, you know, 30 millimetre diameter entrance hole, and it had eaten the frog’s head and one of its legs and left it there.

07:10 Eliza Herbert: But one of the most peculiar things about the phascogales, their mating habits.

07:16 Angela Sanders: Oh yeah, the males. Yeah. So, the reason that we only do the surveys in May to June every year is that they've got a fairly regular sort of breeding cycle. And what happens is the males only live for about 11 months and they've got a fast and furious life.

07:35 Eliza Herbert: So fast and furious that at nine months old, they embark on a deadly mission. To mate with as many females as they can.

07:44 Angela Sanders: And then very soon after that, they die from stress related, I suppose breakdown of their body.

07:52 Eliza Herbert: Yes, we are talking about two months of non-stop sex.

07:57 Michelle Hall: It's been called suicidal mating cause males basically just have one breeding season in their life and they put they're all into it.

08:06 Eliza Herbert: That's Bush heritage ecologist Dr Michelle Hall, who works closely with Angela.

08:10 Michelle Hall: Females can live for a bit longer. Yeah, so we've captured, recaptured females, you know, a year later that are still around, so they can live for longer and maybe breed for two seasons in their life. But yeah, it's a pretty unusual mating system and especially for a mammal.

08:25 Angela Sanders: We think it's because they're living in a fairly, I guess, limited resource habitat that having the males around for two or three years is going to take up a lot of resources, so they've evolved not to survive in fact.

08:44 Eliza Herbert: So, there's a lot of sex and a lot of death, which seems counterproductive. So, what does it mean for the survival of their species?

08:52 Tony Friend: The female can produce eight young a year. So, she has eight nipples and there's generally eight babies attached after the birth.

09:01 Eliza Herbert: That's research associate, Doctor Tony Friend, who, until recently, was a Principal Research Scientist with the Department of Biodiversity, Conservation and Attractions in WA, the group who first proposed the translocation. Tony selected the phascogale source sites for the Kojonup translocation and helped move the animals in 2010. Oh, and those babies he mentioned can be as small as a tic tac.

09:24 Tony Friend: In a good year, when there's lots of food everywhere, say there's been, you know, lots of rain and lots of seeding and flowering and lots of insects for the phascogales to eat, a lot of those young will survive and where there were two phascogales, suddenly there's nine phascogales.

09:40 Eliza Herbert: But what happens in a bad year?

09:42 Tony Friend: On the sort of downside, I guess it means that for a period every year there are no males in the population. If you get a really bad year, when there's no food around, it's possible that the population would die out. And I guess it also makes you think about how cheap life is in that scenario. Lots of young are produced just so that a few get through.

10:10 Eliza Herbert: This means that from year to year, there can be huge fluctuations in phascogale populations. So, to really understand how they are tracking, you need to be able to monitor the population over decades, not years.

Rhiannon: Why are you wanting to be able to know which individual they are?
10:26 Angela Sanders: Well, because if we come back in May, it's really interesting to see where they are. So, where we recatch them? Yeah.
10:34 Michelle Hall: And survival data.
10:37 Angela Sanders: Yeah. And it might give us an idea. We might be able to do something with population size, maybe. Yeah. Because it's like mark and recapture.
10:44 Michelle Hall: Yeah, it was, yeah.
0:45 Eliza Herbert: Now, more than a decade on, the Kojonup population is thriving and even expanding onto neighbouring properties. But to ensure its survival long term, genetic diversity is going to be key.

10:57 Angela Sanders: So, we've got tissue from the original animals that were translocated in 2010 and 2011 and that's been stored. And what we're doing now is collecting more tissue to have a look at how many of the foundation animals are represented genetically in the animals that are on the reserve at the moment.

11:18 Eliza Herbert: They are hoping that the DNA will be varied and that they will have a strong genetic pool.

11:23 Angela Sanders: If that's not the case, if we're finding that the animals that are there now are only related to one or two or three or four of the original individuals, we'll be looking at another translocation to, you know, increase the gene pool of that population at Kojonup.

11:43 Eliza Herbert: This is important. Say if a disease goes through the population, if all the animals have the same genetic makeup, then they are all going to be equally susceptible to the disease. But if there is enough genetic diversity, then hopefully some of those animals will survive and the population won't be wiped out.

12:00 Angela Sanders: I suppose through the whole process, I've learned that it takes time. It needs good planning, and it certainly needs monitoring and you need to go back and find out, what's happening and be able to respond to anything untoward that you're finding. So it's really not about moving animals and then walking away.

12:27 Eliza Herbert: So clearly there's a lot of thought, research and work that goes into keeping this population stable, and it raises some bigger questions around the value and ethics of translocations more broadly.

12:38 Angela Sanders: I've seen a lot of translocations done where animals have just been moved into areas where there's already a local population of a certain animal. And of course they will fight and be territorial and we have no real knowledge of if those animals have survived or which ones have survived and how the animals that already were in place, how they've survived.

13:03 Tony Friend: And of course, one of the things is that you may be putting some of those animals at risk. So, it’s a matter of stating that and weighing it up against other risks like if you don't do it for instance. I guess that the really pertinent point here in my life experience has been with the Gilbert’s potoroo, which was rediscovered in 1994, only one population, and that's all that was left. About 30 animals. We tried for a long time breeding in captivity and then, but in the end, put some on an island which they hadn't been recorded on before. Turned out that island Bald Island was fabulous for the potoroos and that population rose to be the largest population of about 70 animals. We also put them into a fenced area on the mainland, about 35 animals.

14:07 Eliza Herbert: In 2015, a lightning strike started a bush fire at the original site where the Gilbert’s Potoroos were rediscovered in 1994, wiping out that population. If Tony and his team hadn't successfully carried out those two translocations, the Gilbert’s potoroo might not exist today.

14:24 Tony Friend: That's the risk I think you see there. There's a risk of not doing anything. Of just perhaps being so timid and not wanting to put any animals at risk, that you lose your whole species.

14:35 Eliza Herbert: On the flip side, there's also the risk that we pin too much on translocations without addressing the bigger issues.

14:42 Angela Sanders: So, I think sometimes we can appease our sense of guilt or our wanting to do something and help. because an area is going to be cleared of vegetation. So let's move some of the animals and I think we need to get to the stage where when we make these decisions to clear a patch of native vegetation, we need to face up to the fact that thousands of animals are going to die and that's what's going to happen. That's the truth of it.

15:15 Michelle Hall: Yeah. I mean, translocation is really, it's not the last resort, but it's really only done for species that are really in extreme circumstances.

15:25 Angela Sanders: So, translocating just a few bandicoots or possums or whatever is not the answer, and I think we need to look at the bigger picture and look at why are we still clearing native vegetation in Australia? That's my biggest question. We just should not be doing any more clearing. When you look at the satellite images of the more arable areas of Australia, just about all of it is cleared of its native vegetation. So You know by looking after these small remnants, we are just holding back the tide really because there are still a lot of ongoing effects that we see from that fragmentation that still hasn't fully played out.

16:18 Tony Friend: You know, we've caused this situation. So, in my mind, it's our duty to actually ameliorate it and try and stop the loss, because, I mean, you know, if you look at the wheat belt from space, there are not many trees left there, not much bush and that's really put most of the wildlife into very perilous situation.

16:59 Eliza Herbert: And of course, aside from clearing, there's another big issue facing species like the Red-tailed Phascogale. Climate change modelling shows that the wheatbelt region is likely to experience lower rainfall, hotter, drier conditions, and more frequent and severe bushfires.

17:17 Angela Sanders: I think climate change is going to be the biggest threat to them. So, when the woodlands start to decline, which has been happening right across Australia, so that's going to have a big impact on them.

17:29 Eliza Herbert: Aside from losing their homes, isolated populations such as this are also at risk of being wiped out by bushfires, as Tony's story about the Gilbert’s Potoroo demonstrates, though thankfully, there's a lot of people actively managing Kojonup and the surrounding area to keep the fires at Bay.

17:45 Angela Sanders: That certainly would have a catastrophic effect on the Red-tailed Phascogales, but we're, you know, we're well aware of that and we're we've got all that in our fire planning. To do what we can to keep, you know, catastrophic wildfire out of that reserve.

18:05 Eliza Herbert: So, for now, the Red-tailed Phascogales are safe at Kojonup thanks to people like Angela, Michelle and Tony, and the many people who have supported their journey along the way. And while some uncertainty remains, the future is looking bright with a solid plan in place to keep these adorable marsupials safe in their trees.

18:25 Angela Sanders: You've got a closed trap. You know, they're still there and they're still in other parts of the wheat belt too. So, it's, you know, it. It's as bright as it can be in the face of climate change and fragmentation, yeah, it's not all good news, but it's we're aware of what's going on and we can do something about it. That's the main thing.

18:56 Eliza Herbert: Big Sky Country is a podcast by Bush Heritage Australia. A conservation not-for-profit, that buys and manages land and partners with Aboriginal people to protect our irreplaceable landscapes and magnificent native species forever.

To learn more about our work, follow us on social media or sign up to our newsletter via the link in the show notes. Special thanks to Angela, Tony, and Michelle for their contributions, Duncan for recording audio on the ground in WA and donors Peter and Maxine Wilshaw, who funded the genetics project to Kojonup. This episode was produced by Amelia Caddy and myself, Eliza Herbert, with advice from Liz Keene. The theme music is “Invertebrate City” by the Orb Weavers and audio was mixed and mastered by Mitch Ansell.