Tag Archives: koala

10,000 Hours Listening For Screaming Koalas

Image Credit: sandid, Pixabay licence, Image Cropped

Mini-acoustic sensors reveal occupancy and threats to koalas Phascolarctos cinereus in private native forests (2021) Law et al., Journal of Applied Ecology, https://doi.org/10.1111/1365-2664.14099

The Crux

Forests that lie on privately owned land make up a huge percentage of Australia’s native forests – over 23%. That’s 164 million hectares, a massive swathe of territory for Australia’s amazing endemic species to call home.

The problem is that because it’s private, it’s often difficult to survey. Which means there’s a huge chunk of an ecosystem that we have very little knowledge about. Sometimes this frustrates, but other times it breeds novel approaches to conservation.

This week’s authors wanted to survey native Australian forests, with one species in mind – the charismatic and oft-threatened koala. They took an approach which brought land-owners on board, and sent them audio recording equipment to register the presence of koalas, in an effort to figure out how many koalas made use of private forests.

What They Did

Spread across Australia’s privately owned forests, the researchers found just under a million hectares worth of land that they estimated to be suitable for koalas. They contacted the owners of said land and explained the project and its significance. Once the owners understood the concept and the work involved, they were sent ‘Audiomoths’ – small recording devices that can be attached to trees in koala habitat and record male koalas bellows during mating season (September to December).

Recording koala bellows isn’t that straightforward though, and many recordings had to be removed from the final results as heavy wind and rain made it difficult to determine what was making what noise.

Once koalas were identified, their presence was modelled against a range of different human impacts, including nearby roads and land clearance, and environmental variables like extent of vegetation and local fire severity.

Did You Know: Koala Extinction

Koalas are notoriously picky eaters, and many people know that they will only eat eucalyptus leaves. Yet it goes further, with some koalas only eating leaves from certain species of eucalyptus tree, having grown so accustomed to these species that their gut bacteria can’t tolerate anything else. It means that relocating koalas can be almost impossible, and that preserving their natural habitat is of the utmost importance (and benefits a huge range of other species).

Read More: What Being Functionally Extinct Means, Why Koalas Aren’t, and Why Things Are Still Pretty Dire

What They Found

The survey resulted in almost 10,000 hours of recordings across 128 properties and three years. Over 1,600 bellows were recorded across 41% of all the sites surveyed.

The only variables which had an affect on koala presence were the proximity of sealed (paved) roads and the vegetation cover. The closer by a sealed road was, the less likely koalas were to show up. Heavily forested areas were also less likely to house koalas, whereas forest that was more fragmented by grassland and open woodland were better suited for them.

Problems

The study mentions early on that there are often differences between private and public forest, yet there’s no comparison here between the two. Using Audiomoths in public nature reserves would have made for a great comparison, particularly to check whether the environmental and human variables affected koalas in the same way. However the constraints here are financial ones, and I think the authors would agree that it’s more interesting the double the data for this particular experiment rather than double the Audiomoth budget and make a comparative study.

So What?

The environmental results here aren’t particularly interesting – koala’s habitat preferences are relatively well studied. What is a real positive is the success of the technique used, that of bringing private landowners on side and getting a wealth of data in return. An added bonus of a project like that is that as well as collecting data, you get the opportunity to share scientific knowledge and teach a group of the public about local wildlife.


Dr. Sam Perrin is a freshwater ecologist who completed his PhD at the Norwegian University of Science and Technology and is currently working as a climate data analyst at Ducky AS. You can read more about his research and the rest of the Ecology for the Masses writers here, see more of his work at Ecology for the Masses here, or follow him on Twitter here.

Mermaid Sex, Evil Spirit Birds and More Weird Ecology Search Terms

Image Credit: Ray Bilcliff, Pexels licence, Image Cropped

We get a lot of fun and strange search terms which lead people to Ecology for the Masses. So inspired by Captain Awkward’s segment ‘It Came From the Search Terms‘, let’s have a look at some of the weirder questions that led people to this site and see if we can provide some answers. Spelling mistakes have been corrected.

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What Being Functionally Extinct Means, Why Koalas Aren’t, and Why Things Are Still Pretty Dire

Image Credit: Swallowtail Grass Seeds, Public Domain Mark 1.0, Image Cropped

There has been a lot of recent (and well deserved) press surrounding the bush fires in Australia. Because of these fires countless animal and plant life has been lost, and the most visible example of that are the koalas. You probably saw the video of a woman running into a burning area to save a koala from the fire*. Unfortunately, most of the koalas didn’t have people around to save them and over 1,000 are estimated to have died. Because of this a group has claimed that koalas are now “functionally extinct”, and the press has run with this claim. While it is unfortunate that this misinformation spread so quickly and so widely, the good news is that koalas are in fact NOT functionally extinct. Great! But what does being “functionally extinct” mean? 

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Dragon Guts in the City

Image Credit: Aravindhanp, CC BY-SA 3.0, Image Cropped

City life alters the gut microbiome and stable isotope profiling of the eastern water dragon (Intellagama lesueuriii) (2019) Littleford-Colquhoun, Weyrich, Kent & Frere, Molecular Ecology, https://doi.org/10.1111/mec.15240

The Crux

It’s a pretty fair call to assume that if you build a city on a species’ habitat, it might be a little miffed. Yet as human settlements expand worldwide, many species are showing that they’re able to make rapid changes to their biology to adapt to living around humans.

This includes their diet, of course. As diets shift, many other aspects of a species’ biology follows, including the microbes that live in a species’ gut. And gut microbes influence a huge range of factors, including immunology, development, and general health. The response of a gut microbe community (the gut microbiome) to a new diet can in turn affect an animal’s ability to adapt to that environment.

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Celine Frere: Working With Charismatic Species

Charismatic species like the bottlenose dolphin are generally easier to find funding for. So what's it like to work with them as a scientist. I spoke to evolutionary biologist Celine Frere to find out

Charismatic species like the bottlenose dolphin are generally easier to find funding for. So what’s it like to work with them as a scientist. I spoke to evolutionary biologist Celine Frere to find out (Image Credit: Jason Pratt, CC BY 2.0, Image Cropped)

We’ve talked at length about charismatic species on Ecology for the Masses. They’re the ones that draw in the public, whether they’re cute and fluffy, majestic, or dangerous. They’re generally easier to procure funding for. So what’s it like to work with them?

During a recent visit to the University of the Sunshine Coast, I sat down with Doctor Celine Frere to find out. Celine works with two of Australia’s most charismatic species, the koala and the bottlenose dolphin. We talked about the pros and cons of charismatic species, getting the public interested in them, and the future of global conservation.

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Kath Handasyde: Charisma, Culling and Conservation

Koalas are gorgeous, no doubt. But does their overwhelming charisma mean that we forget about other species?

Koalas are gorgeous, no doubt. But does their overwhelming charisma mean that we forget about other species? (Image Credit: Erik Veland, CC BY-SA 3.0, Image Cropped)

Australia plays host to a wonderful range of very endearing species. Tourists come from the world over to get up close with kangaroos or koalas. But the charisma of these animals can often lead to issues, whether it’s prioritisation of resources for them over other more endangered species, or even to the detriment of the species themselves.

Doctor Kath Handasyde of Melbourne University has been working with Australian field wildlife for almost 40 years, and is perhaps the most charismatic teacher I had during my Bachelor’s at the same institute. During my time in Melbourne, I had the chance to talk to Kath about the sometimes problematic role of charismatic species in Australian wildlife conservation.

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