Its easy to assume that wild koalas have small, reliable home ranges. After all, you don’t see them moving about much do you?
If we’ve learnt one thing over 17 years of wild koala research, its that koalas move! A lot!
We first met Cruiz in November 2008 in the Turntable region of the You Yangs. He looked big, strong and healthy. We assumed he was mature – at least 4 or 5 years old. It was exciting to have a new male on the block.
But then he disappeared. Sadly, we filed his photos and nose pattern diagram under the “Koalas once seen, never to be seen again” file.
You should never give up on a koala, though. Out of the blue in December 2011 he re-appeared in the turntable area. He’s back, we thought. “Don’t be hasty” he thought.
We didn’t see Cruiz once in 2012. Not once. Back into The File he went.
So when he showed up three times in 2013 and three times in 2014, we had learnt our lesson. We didn’t get excited. Maybe he’s a nomad. Maybe he’s in protracted negotiations with dominant male Anzac, and other residents Vincent, Zack, Kenny and Rocky.
But 2015 was a good year for Cruiz. Already we have seen him 12 times. He’s been all over the place – turntable, branding yard 2 km to the east, Branch Rd. If we simply join the dots of all his locations this year, his home range would be around 117 hectares!
Interestingly, too, he isn’t migrating steadily from one area to another – he is regularly traversing that entire area. One day he’ll be in Branding Yard, a week later he’ll be back in Turntable.
He’s not young either – we estimate he is at least 12 years old. That’s a really good age for a wild male these days.
Every single wild koala is different. Cruiz is a special fellow.
We become very fond of our Koala friends in the You Yangs. Every one is so individual, with special idiosyncrasies that will never be seen in another koala. So it’s heartbreaking when a familiar old fella is displaced from his home by a new, virile stud. It’s nature, of course, and we have to accept that it is necessary to the health of the species. But sometimes there is a silver lining to the cloud!
Vegemite was dominant male at Big Rock track for 3 years. At first he didn’t like our attention one bit, but over time he came to tolerate us, in a rather grudging way. He would look down his aristocratic nose at us, flare his nostrils and return to sleep. He shared his home with gorgeous females Mary, Cloud and Aris. Life was good.
But it never lasts…. Along came Anzac in May 2009. He was young, very fit and looking for a palace big enough to fit his ambitions. He checked out Merle’s home on three occasions in Autumn 2009, and either rejected it, or was escorted out by big-boy Merle. Next stop was Vegemite’s house, and this he liked.
Over three months Anzac moved in on Vegemite. We don’t know whether they fought, or battled by bluff, but by August 2009 Vegemite had had enough. He left Big Rock Track and returned to the area he had occupied in 2006 before he took Big Rock Track off Tim Tam, the previous dominant male.
But Vegemite couldn’t let go of his hard-won home, and returned in early October. Maybe he was missing Mary, his beautiful partner of 3 years. Maybe he had one last try at beating Anzac. But, after one last visit on 25 October 2009, he left the area entirely, and was next found 3.5km away to the east, outside of the You Yangs Park. He was carrying a few new scars.
We thought it was the last time we would see our old friend.
A year later – 11 November 2010 – we rediscovered Vegemite on East Boundary Track in the eastern portion of the You Yangs Park. At first we couldn’t believe it. But when you know somebody that well, their face is imprinted on your memory. His nose pattern (our method of identifying individuals) is still the same. He has even more scars, but he is looking very well. We’ve since seen him three more times, so we think he has made this area his new home. He has a few lovely ladies hanging around too!
We have always wondered what happens to males after they’ve been displaced. Some probably die from fight injuries, others might travel long distances looking for a home. Some possibly stay nearby, but in sub-optimal habitat. The strong ones, like Vegemite, may succeed in becoming dominant male a second time in another area. He is just one example, but what a great opportunity to monitor one male’s ongoing progress!
We first met Karen in May 2006 in a poor-looking habitat that had been badly burnt in the 1985 fire, and had barely recovered. Large, indigenous eucalypts were few but there were lots of small, skinny Golden Wattles and many Brown Mallets, a few Yellow Gums and Red Ironbarks, and a couple of fairly big Blue Gums. As a home for koalas, it was a bit of a mess really.
Karen was a small female, and probably about 6 years old when we met her. She was nervous, and we got the feeling she hadn’t had much contact with people. We took it slowly, staying well away, and she relaxed over time. There were a lot of other female koalas around the area at that time – Eureka, Emma, Rosa and Raini all used Karen’s home range at times, and nearby lived Smoky with baby Pat, Maya, Mary and Zelda. So maybe this poor little patch of habitat was the best Karen could manage.
Towards the end of 2006 Karen started moving out of that poor area. She appeared near the Valley Picnic Ground next to young male Merle. She must have been impressed by him, as soon after she showed up in Red Gum Gully, the home of Merle. Little did we know then, but a beautiful “friendship” was forming! On her next visit to Red Gum Gully we think Merle made advances towards her. They were sharing a tree, we heard a scuffle, and next thing we knew Merle was racing away at high speed across the ground. Most koala romance sounds more like a scuffle than a lovesong. So we don’t know if it was love or a fight! It may have even been a successful mating.
Through most of 2007 Karen stayed in her “new” home range of Red Gum Gully. She was only once seen back up in her 2006 range. Then summer came along, and guess what? Karen went wandering again! She appeared to the east, then, a week later, all the way up in Lower Picnic Ground. That’s a move of at least 500metres from her normal home range. It was breeding season again, so was she checking out Merle’s northern rival, Ngallo?
We don’t know what she thought of Ngallo, but she quickly returned to Red Gum Gully and spent all of 2008 there. Her special relationship with Merle continued to grow – in the next two years they were seen sharing trees on five occasions, three times in breeding season, but twice outside of the season! In the same period, resident females in the same home range were only seen sharing tree with Merle once (Smoky), and never (Pat).
On one occasion I found Merle and Karen sharing a tree – she high, he low. After some time he started to climb down the tree. He bellowed as he left, and Karen bellowed as well! As he reached the ground he continued to speak, and she to answer. I really don’t know what they were saying to each other. I have recorded it on YouTube – search Echidna Walkabout channel or go to: http://www.youtube.com/watch?v=7PPxGlhTbkk
In September 2009 Mary, the dominant female at Big Rock track, died, leaving her home range vacant. For 3 months the area remained essentially unused by koalas. But it was Karen, the mobile koala, who took the opportunity in both hands and tried the new place. She appeared on Big Rock track (where she had never been seen before) on 7th Jan 2010. Then on 9th Jan she was back in her normal area of Red Gum Gully. For the rest of January she was found in her normal area. Then again in early Feb she was back at Big Rock track. For the next four months she was back and forth, new home, old home, but the trend was towards Big Rock track. By the end of May 2010 she was permanently found at Big Rock track.
And what of her boyfriend, Merle? Well, he followed her a little bit. On two occasions he was seen closer to Big Rock track than his normal range extends.
Sadly, on 13th September 2010 Karen was found on the ground, not looking well. She had been looking thin for some time. Upon examination she was found to have worn teeth (particularly the upper incisors), but more importantly, a prolapsed cervix (her inside was outside). Veterinary advice suggested that this can happen with chronic cystitis or reproductive tract disease, or diarrhoea. She didn’t have diarrhoea, so we can rule that out. Some underlying problem had been wearing her down for some time. Her age was judged to be 10 – 12 years, and her condition not considered robust enough for surgery so she was euthanased.
What does all this suggest? That some adult females do move their home range from time to time. In Karen’s case it didn’t happen quickly, though, it took months for a complete shift, with initial exploratory forays followed by longer stints in the new area. The initial exploration, both times, happened in summer – we wonder if it is connected with breeding behaviour and looking for a mate. We have noticed other female koalas moving long distances during early summer, then returning to their normal home range.
We wonder too, if declining health might cause a koala to search for better food. We’ve seen it before – Calvin, Zelda, Mary all moved around a lot just before they died. And was it significant that the resident female at Big Rock track had died, therefore opening an opportunity? Or would Karen have moved anyway? We just don’t know.
Karen has taught us a lot, and burst apart some of our preconceptions about koala behaviour. A special lady!
Special thanks to Mary and the bushwalkers on 13/9/10 who found Karen; Donna, Marilyn & Gordon at Beremboke Wildlife Shelter for caring for her, and Dr Anne Fowler at Healesville Sanctuary Wildlife Hospital for her diagnosis. The beautiful picture of Karen shown here was taken by wildlife photographer Mark Helle, and very kindly given to us.