Conrad Hoskin is an Australian based tropical biologist. He has a vast amount of knowledge about local Australian species and evolution. Recently he came to wider recognition worldwide, due to his exploration of a previously undiscovered area of rainforest in Northern Australia, called Cape Melville. He was kind enough to take time out of his busy schedule to share the tales of his adventures with us…
Hi Conrad, Ross Glacken here, how are you?
Yeah good, thank you. How are you?
Good too, thanks. Maybe to begin the interview you could tell me a little about your background? Were you always interested in and involved with nature?
Sure. So yeah, when I was a kid, I was very much interested in nature. It’s pretty much all I’ve ever been interested in. And I can attribute that to my parents. We always lived in out-of-the-way, you know, bushland areas, and they had a real interest in nature. Even though neither of them works specifically in biology or anything, my parents were really interested in nature. So we all grew up as kids very interested in nature. And we always lived in good places for nature. So I got right into it when I was young. And then, when I went to high school I knew I wanted to do something with animals but I didn’t realise until fairly late on that you could do biology research. But once I found that out, it was all I wanted to do. So then I went through an undergrad in biology. And along the way I became more and more interested in biodiversity and evolution and stuff like that. So then once I finished my undergrad I then sort of pursued an avenue in understanding the diversity that’s out there and the ways in which it forms. And that’s kind of just been my career since. You know, looking at diversity, what’s out there and how it forms.
And was it always with a focus on Australian nature and Australian animals, or was it global?
Yeah, I’m interested in everything globally. But in terms of my research, it’s mostly been in Australia. Especially with reptiles and frogs. Just because they’ve turned out to be particularly big groups for the questions I’m interested in. In terms of global diversity, I’m interested in most things.
I’d seen that you have an interest in other aspects of science like tropical biology and evolution and even conservation. So I thought it was interesting to have a diverse knowledge across multiple areas…
Yeah, as I’ve gone along I’ve started to research more and more different things. So, nowadays I also do a fair bit of conservation style research. For example, I do a bit of invasive species research now, their impact and how we can manage them. Yeah, just a variety of research projects have become interesting to me. I try to deal with it as it comes up. A lot of my work now is exploring tropical biology.
Can you tell me a little about your focus on population divergence? Is that a case when there is type of species and it changes itself over time?
Yeah. A lot of my work sort of generally focuses on how you can get variation between population. Sort of that first step on the way to adaptation to different environments. So, I study a lot of scales. One scale is between, you know, populations that have been isolated for even hundreds of thousands, or millions of years. So the historically isolated populations and habitats, for example bits of rainforest up in the north of Australia all the way through to something like the Asia Pacific, where you can find more differences between populations and degrees by which things can change and adapt. And it’s also a much more recent timeframe than the historic changes.
And is that kind of evolution generally a result of climate change or is there random cross breeding, or what are the main reasons behind it?
Yeah! I work on all those things actually. The more historic differences of population… some of those are because of climate change. So natural changes over time, that have isolated… for example, the rainforest in Eastern Australia has contracted towards the east and up into the mountains. So anything that can’t move around very easily, and is dependent on rainforest, over millions of years becomes completely isolated. So that might be an example of becoming isolated due to historic climate change. But those changes occurring more recently, for example to do with the house geckos, that’s more… there’s more avenues into the habitat so…. We don’t really know what causes it, or what determines it, but it’s definitely not climate change.
And in regard to the Australian rainforest, it’s amazing that there are still some places like that which haven’t really been explored. That must have been a great adventure for you?
Yeah. Cape Melville, that trip was fantastic. Yeah so, probably a decade ago I drove out to… you can actually get out to Cape Melville on a rough bit of road… it takes a long time but you get to the base of the rainforest. You can look up at the rainforest. Massive boulders everywhere. But you can see at the top there is a little patch of green. I realised that that must be totally isolated. And then if it’s hard to get up there it’s probably been isolated for a long time. And then, the beginning of last year the opportunity arose to get up there… and over a couple of surveys… I did one actually last November, just a couple of months ago. The place turned out to be incredible. Species found nowhere else. As you said, it’s exciting being somewhere like that, right here in Australia. That there’s still a place like that… Yeah, so that whole thing has been super exciting.
Were you expecting to discover new species before you actually went there?
Yeah, I thought that if that rainforest was a significant amount of rainforest as we thought and it had persisted through time…so closed off… I suspected that there should be new species up there. Just that area of isolation. Really rocky bouldery rainforest. So it’s quite different to other normal rainforests. So, I thought if things could be persisting there over hundreds of thousands or millions of years, and in this unusual habitat… I thought it would be in the range of vertebrates. I really hoped there’d be some new vertebrates. And as it turns out that was exactly the case.
And how do you choose the team to bring with you? It must be a highly sought after opportunity?
Yeah, everyone’s keen. Especially because it involved helicopter rides and that sort of thing. And it’s so wildly remote that it’s exciting for a biologist. …… And so, the first time I went in, I went in to the upper area. But we couldn’t get into the uplands. There was too much cloud cover so we couldn’t get in by helicopter. But what was interesting was that we found the blotched boulder frog. It was just as we were leaving. And then when I got back, this opportunity arose for me to team up with Tim Laman from National Geographic. And then we went in together on a joint expedition. And that time, that was March. And although that was a bad time to get in because it’s the wet season, we got lucky and were able to get into the uplands and we spent a few days up there exploring. Yeah, it was fantastic!
And what was your reaction when you saw that first skink scuttle past?
Very exciting. Because, in Australia particularly, we just don’t wander into a place now and find something really obviously brand new that you just look at in a second and see that it is new. So… it happened quite quickly to find that skink too. We were walking along this rocky region and it just basically ran right past me on the rocks. And the second I saw it I just knew. It was extremely exciting. And then that evening we found the frog that I found on the previous trip under the rocks. That was exciting again. And then on the walkout from there we found the big fantastic leaf-tailed gecko. Leaf tailed geckos are a spectacular species. We found all of them in this tiny area of rainforest.
Really cool. And in regards to the blotched boulder frog it must be interesting from an evolutionary perspective, how it hides under the moist rocks and lays it’s eggs outside of water, in comparison to normal frog behaviour?
Yeah! It’s hard to describe how amazing Cape Melville is unless you’ve seen it. You’ve got to picture a massive upper mountain range, where each rock is the size of, you know, a car. Or probably more like the size of a house. Millions of them piled up this mountain range that goes up to six-hundred meters elevation. Just an immense pile of black granite boulders. And the water just drains straight through it. There are some creaks, but basically it just drains away. There’s not a lot of opportunity up there for a frog just to be doing the classic breeding or anything like that. And also it is an interesting place, Cape Melville… very very wet during the wet season but then very very dry for the rest of the year. So what this frog does, is through the dry season it lives deep down in the boulders. There’s potentially hundreds of them down there. The rock caverns just go and go and go. Where it’s cool and moist. And then in the summer wet season it comes to the surface and… what the frogs do is they lay their eggs in little moist rock cracks. And then say over a month or two the little tadpoles develop. They don’t need any water to develop. Everything up there has adapted to the environment.
The whole experience sounds reminiscent of the story Journey to the Center of the Earth!
Yeah, right. Because as a human you are not particularly well suited to it. You get in there and most of the gaps are quite nasty and there’s big drops everywhere, so it’s quite dangerous and you have to be really careful. It’s not the sort of place you can really use ropes or anything. Because there’s nothing to attach to. So really you are just climbing down, and then you go a little way down and it just gets darker and you see all the caverns disappear. And you just get to the point where you think, “Oh, I’ll leave it at that, it’s a bit dangerous”. We basically had to go at the time when the creatures come to the surface because we can’t get down there in the other parts of the year.
And the leaf-tailed gecko, that’s something that you had hoped might exist up there, right? That Cape Melville might have been the perfect environment to find it in?
Yeah, so the leaf-tailed… if there was one thing I was really hoping for that we would find at Cape Melville, it was the leaf-tailed gecko. But I worried that the… the area of the rainforest is really quite small, and potentially it is even smaller in dry times of year. So, I thought maybe there is a chance… there may have been one some time in the past but it disappeared out over time. So, I was worried that the area of rainforest at the top was not large enough for the leaf-tailed which is rain forest dependent. So really that was the highlight of the trip. To find one of them was incredible. And it’s a really distinctive looking one too. Long lanky limbs and big eyes and all these other adaptations you’d expect for a creature that lives a lot of its life deep down in the rocks. Yeah, it was fantastic to find a new one, and not just that but a really exciting and unusual looking one. And these things really help complete the picture of rainforest history down the east coast of Australia. We got the really well known wet tropics area around the Cairns region, and we’ve got the Cape York rainforest, and the New Guinea connection. Cape Melville was only known to have a few interesting things, but now finding more shows that even these tiny little areas of rainforest have been persistent over millions of years… really unique environments, beside the fact that they might only be three kilometers wide or something like that… incredible. Amazing.
And what was the reactions of the animals themselves? Do they scuttle away, seeing you as a threat? It’s probably the first time they have come across this type of contact also?
Ah yeh. They would never have seen humans before. Yeah, so the leaf-tails, all leaf-tails are very… they don’t run away. They’re incredibly well camouflaged and they rely on that camouflage. They think that even when you’re standing a foot away from them that you can’t see them. And then when you pick them up they are remarkably calm animals. The skink… skinks are always fast and active. The frog was remarkably calm too. Yeah, I think most of the areas I go into are fairly remote anyway so the animals, most of them haven’t seen humans before, so this is fairly typical.
I actually read your ‘zootaxa’ article about the gecko (http://biotaxa.org/Zootaxa/article/view/3169) and found it fascinating. Not just the discovery of the gecko but also how descriptive the report is and how everything is noted about the creature physically and behaviorally.
Yeah, I love writing those descriptions. I always put a lot of detail in… one of the reasons for the detail is that… well firstly, the animal is not likely to be seen or documented again for some time just because it is so remote… we really want to get down everything we know about it now. It also helps in the future, if you want to know whether it has declined or adapted, just to have a quick record of it at one point in time. The reason that those descriptions are so detailed is that you need to be able to be able to distinguish that animal from everything that is known in the past and in the future. So if someone else, say in five years time, found another leaf-tail in a mountain range somewhere, that was similar to this one… without needing to go back and deal with the Cape Melville ones again you need to be able to assess if it’s the same or different. So, it’s just a way of putting down everything you know, in a very detailed way, about a species. So you can always compare to that record.
Sure. And it’s so fascinating to read back on it, even from a regular person’s perspective.
Yeah, and it’s also about habitats and what we can see from the few days we’re up there and how the animal lives, and… I mean, a lot of that stuff will help us understand general ecological information about the animal. We won’t really have to think about it. You know, change in species, climate change or whatever. I mean, the truth is we don’t know much about an animal when we are only up there for three days.
Sure. Are you planning to head back to Cape Melville again soon?
Yeah, so, I did a trip in December, a few months ago… We looked at vertebrates and are now looking at some other groups too. We looked at some mammals up there. You know there’s a lot of diversity… Australia is always thought of as a place of marsupials, you know, kangaroos and koalas and all that. So we have a lot of placental mammals too, like the rest of the world. So, we’ve got a lot of native rats and other small notable animals. And they are quite diverse. Areas like Cape Melville could potentially have unique species of those. We also did a thorough bird survey, and we looked at some of the plants. And some invertebrate groups. So, it’s just a way of… We looked at some of the vertebrates and now surveying across other groups to see what else is unique up there. We’re planning to go back. In May I hope to go back to a different site and survey there too.
Brilliant. Did you find that there was a lot of bird life there?
Yeah, a lot of bird life. Not especially high diversity, though that is mainly because it is such a small and isolated patch of rainforest. But the stuff that is there is interesting. I mean, no new species. That would be extremely unlikely for birds over such a small area of rainforest, because birds move around so much. But the rodents could be interesting… we caught a few different rodents and we’ll analyse their genetic make up and see how all that works out.
Is there something unusual about a particular type of snail there, or something like that?
Yeah, yeah we got a snail up there on one of the first trips. And then saw it again this last trip. It’s an interesting looking snail as it’s a highly distinctive species. Just like the gecko and the frog, it is highly distinct. And snails are another group in Australia with so many native species. We always hoped that there’d be unique snails up there. Finding this one means there is bound to be others up there too. This is a particularly interesting one.
Do you think there are many other places in Australia or around the world that are equally as undiscovered as Cape Melville?
Yeah, for sure. I don’t think we have that many places left in Australia that are unexplored. But in the Amazon there are some areas for sure. Many places that will be as diverse or more diverse, and undiscovered will be in places like New Guinea, South America… but particularly New Guinea. New Guinea sits right north of us, but it’s a very different environment to Australia. Much more diverse. But yeah, yeah there are definitely other places than just Cape Melville waiting to be discovered and explored.
One of the other interesting discoveries I read about recently, was about a new tiny spider in the Amazon that builds a cocoon for it’s eggs and a defence like garden fence around it. I found it so fascinating that even though an area can be so highly explored, that new creatures continue to emerge.
Oh yeah, it’s incredible. Absolutely incredible. Such a vast area, and so complex so that one spot is different from the next spot. Yeah, there seem to have been some amazing discoveries there over the last decade, even new mammals.
I was wondering if you might have any advice for would-be scientist explorers? Would you recommend studying something in particular detail and then find grants to pursue deeper research?
Yeah, I would definitely recommend… the best thing to do is focus on what your interests are in. Whether it is vertebrates, or a particular invertebrate group… or plants are a group that we know very poorly and there is always a lot of work for people who are very good at plants. But the thing is to get really good at something, become an expert and then just follow your interests and become the expert at the thing you are interested in. And then you’ll have much more success by establishing yourself as an expert and then going after and getting grants to go to places you think are particularly exciting. I guess the simplest pathway is to do a bachelor of science and along the way focus on the type of group and the research you’re interested in and then go from there.
Sure. It’s funny that you mention plants, because recently I interviewed a top paliobotanist (C. Kevin Boyce) and he said that one of the reasons he got into that field was because he felt that if he didn’t do it, nobody else would. And because of that he has gone on to become one of the very top guys in his field.
Yeah, it’s amazing. There is so much incredible plant diversity around us, and really there is only a handful of people that know it very well. And most students coming through in science, or interested in biology tend to focus on animals. And really there’s a wealth of plant diversity out there. Plants are often the best group to answer big questions. But really there are not a lot people who know them well. So anyone who is keen on botany should go for it, because there’s some great work out there.
When you were coming up as a scientist yourself you won the Eureka prize, is that right?
Yes. That was for a species discovery. In part for finding various species, new species, and also for uncovering some of the mechanisms for how species formed. I do a lot of work on hydrazones. So, areas where different genetic types meet and overlap in their ranges. And there’s often some amount of hybridization. People don’t realise, I think, how much hybridization goes on in nature. Particularly in plants actually! Funny that we mentioned them. But in animals too. A lot of ranges overlap between similar things and they hybridize. There’s various evolutionary processes that can happen in a hydrazone that can actually enhance speciation in those areas of overlap. So that’s one area of study I’ve done a fair bit in. And I continue to study hydrazones. Yeah, so that prize was both for species discovery and finding things in addressing the ways that species form, kind of way.
Awesome! That’s interesting because I was also going to ask about the process of analysing the evolution of species. I was wondering if it is paleo-modelling, or is it genetic analysis on existing species, or how does it work?
Yeah, there are many different ways. One approach that I use is to use a whole lot of different data types. For example you could compare a bunch of populations within a species to genetics. So, how long and historically isolated have they been and the course of gene flow. You can look at morphology. So, traits about the animals that relate to how they utilise their environment. All these different types of body shape and size measurements. Also, I often go after mating traits, because you know, speciation is a lot to do with reproductive isolation between populations. So the thing that sort of cuts down gene flow between them. That in large part is due to the animals choice of mate. So finding the traits that they use to choose mates is an important part of understanding divergence between populations. So, in frogs it could be the frog call. So I’ll often study frog calls within and between populations to assess how much they interbreed with each other. The other one is yes, as you mentioned, paleo-modelling, so taking their current distributions and habitat use and tracking that backwards through time, so we can understand the connectivity through habitats over time. There’s other ways to do it too. If you have some organism… so you can actually do experimental evolution. You can put them through different experiments and tests through time and monitor changes in various traits, for example pheromones in their mating traits. Increasingly there are very detailed genetic techniques too, for understanding the history of populations, and you know, current levels of interbreeding between them, and that sort of thing. So really, addressing speciation is a huge question that has been happening obviously for… there’s been a lot of interest in it since Darwin’s time, and obviously before that too. It continues in many different forms and it’s one of those big questions that we learn a lot about every year, via many different techniques.
Okay! Really interesting. And having studied animals and science in such great detail, has it taught you any interesting lessons about humans?
Ah….. oh….. …. no! Not really (laughing). No, my focus has been very much on the natural world. Understanding how we’ve come to be. You know, the thing that really fascinates me is the diversity that’s out there and how it’s formed. And I also think more and more these days about the future of that diversity. So some of my research involves questions to do with conservation and management of populations through time. And that’s probably the area that most obviously overlaps with us humans. But no, I wouldn’t say I’ve learnt a lot about humans.
Okay, sure. And one final question: I was wondering what for you are the most exciting things on the horizon, or even the most concerning?
I have a deep concern for the future in relation to biodiversity and the natural world. It is that the scale of human growth and development is clearly unsustainable, both here in Australia and globally, and I see no solution to this. The impacts to biodiversity and the health of the planet will continue to be severe and irreparable (in terms of diversity loss). So, that’s my biggest concern. And the things that most excite me are things like upcoming expeditions to new places and also amazingly even really detailed stuff in the lab. You might have these populations that you’re interested in and then you have these various samples that you’re going to run through in the lab and suddenly you go from knowing so little to knowing a whole lot. Suddenly you have a whole of new information. There’s lots of exciting things coming up to do.
That’s awesome that you enjoy the lab work as much as the field work.
Yeah! I like it all. I like the lab work, the field work, I like writing papers. All of it. It’s hard work, because there’s so many bits to it. And also with my job you have to do lecturing and various other commitments. So, it ends up being a busy job and it touches onto your personal life. But I like everything really.
Great! Thanks a million for taking the time to chat with me, Conrad. It’s been a real thrill.
Yeah, no worries. Thanks a lot.
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