People are often surprised when a wild koala shows up suddenly, in a place where no koalas have been seen for years (1, 2, 3).
It’s a bit like Doctor Who popping by, in the Tardis. One minute he’s not there, the next minute he is.
But koalas are not Time Lords. They don’t magically appear out of space. They were always there, living quietly, unseen and unknown.
Here’s the story of an amazing female koala named Mear. She appeared, disappeared, and appeared again. But where did she go?
Mear lives in the You Yangs, near Melbourne. Her home range is part of Echidna Walkabout’s wild koala research area. She has lived there since 2012 at least, and is still going strong in 2020.
She is a big, healthy female who has had two joeys in the time we’ve known her. But she’s always been shy – she was inclined to freeze when we were present. Many of the photos show her leaning back, slowly moving to hide herself behind a branch.
Experienced Koala researchers with keen eyes have been walking through and past Mear’s home range +/-310 days a year since 2012.
The first year, 2012, we saw her 7 times. That increased to 19 times in 2013, 31 times in 2014, 15 times in 2015 and 10 times in 2016.
Normally sightings of a koala increase with time, as we get to know their home range better, and as they get to know us better. Often as they get older they slow down a bit too. But not Mear.
Mear was only seen 4 times in 2017, and not seen at all in 2018.
At this point we started to think that she might have moved away, or died.
So it was a big surprise to see her once in 2019, and even better to see her 6 times in 2020.
Of course it is possible that she did move away for a time. But there’s no reason to think that – sightings of her still occur in the same area as in 2015. An absence of sightings does not equal an absence of koala.
How did we know it was Mear? Read how we identify koalas by their nose patterns.
Koalas can live in low densities for many years and not be sighted by anyone. Partly because they are cryptic – hard to see. Even if you are experienced at looking for them you don’t necessarily see them. A recent study (4) by Dr Ryan Witt & a University of Newcastle team compared drones to visual spotlighting (nighttime) surveys by experts, and found that drones found 84% of koalas, and spotlighting only found 39% of koalas. Daytime visual surveys achieve even poorer results than nighttime spotlighting.
It’s likely that Mear was living quietly beside us the whole time. She probably watched us go past many times. I bet she froze, or hid behind a leafy branch.
Koalas mostly move around at night, not in the daytime. Human eyes are programmed to spot movement, and most of us are active in the daytime. So if you’re a farmer or outdoor worker, working during the day, you might pass right by a koala and not see it. They won’t move, so they won’t attract your attention.
The difference between our researchers and other outdoor workers is that we are actively looking for koalas. Our researchers know the home ranges of many koalas, know their behaviour, and are very experienced. So our chances of seeing a quiet, unmoving koala are much higher. But we don’t find all the koalas present.
Koalas can be noisy, especially in breeding season. Often people who live near koala habitat hear them more often that they see them. But female koalas are not as noisy as males. A female koala can live very quietly a long way from other koalas for most of the year. She only needs company when she is ready to mate, and she might leave her home range and walk kilometres to find a male.
If you live in an area that was once koala habitat, but no koala has been seen there recently, don’t stop trying. They might be gone, but they might not. A conservation group in Eurobodalla, southern NSW, are working with the community to protect and replant koala habitat even though koalas have been almost extinct in the area for some years. Recently, locals have been “astonished” to see two koalas in different parts of the shire.
“People thought I was mad when I told them,” said Bede Cooper, East Lynne.
There’s no doubt that the future is pretty bleak for koalas if current levels of habitat destruction continue, and as climate change effects escalate. But it’s not over yet.
I like to think wild koalas are not far away, and that by planting trees for them in suitable places, they may return. Like Mear did. She’s not Doctor Who, but she is long-lived and a bit magical.
NOTES & REFERENCES:
(1) First koala seen at Yourka, north Queensland in 13 years:
(2) Rare koala sighting on far south coast of NSW:
(3) Two new sightings of koalas in Eurobodalla, NSW:
(4) Witt RR, Beranek CT, Howell LG, Ryan SA, Clulow J, Jordan NR, et al. (2020) Real-time drone derived thermal imagery outperforms traditional survey methods for an arboreal forest mammal. PLoS ONE 15(11): e0242204. https://doi.org/10.1371/journal.pone.0242204
Sydney Morning Herald: “How good were koalas?” https://www.smh.com.au/national/how-good-were-koalas-a-national-treasure-in-peril-20201203-p56kac.html