Koalas: Floating Research Station
Posted at 9:38 am May 1, 2009 by Bill Ellis
It has been a busy month for the St. Bees Island koala project, not that you would know it from the number of koala bellows we are recording on the island. (See previous blog, Koalas of St. Bees Use Cell Phones.) As usual, when the koalas over at the San Diego Zoo are getting their vocal chords warmed up, those at St. Bees are being quiet. I have just stepped off a boat that has been my home for the last few weeks, having finished a survey of the other islands that lie close to St. Bees, off the coast of Queensland, Australia.
Thanks to our close relationship with the Queensland Parks and Wildlife Service (QPWS) rangers, I was fortunate enough to travel aboard the Tamoya, a 43-foot (13-meter) catamaran that is operated by the Mackay Marine Parks team to conduct their island infrastructure maintenance and compliance work. This boat became our home as we stopped in at a few of the other islands that are home to koalas in the Whitsunday region of Australia.
First stop was Newry Island, then Rabbit Island, then across to Brampton, and finally, St. Bees. Newry and Rabbit Islands are very close to the mainland and we suspected that koalas from these islands got across the mudflats to visit their coastal counterparts. To check on this, we put a Global Positioning System collar on the only koala (named Nigel) we found on Newry Island last year. We found him on the current trip and downloaded his GPS data. Nigel never left Newry Island, although his GPS data revealed that he had traversed the whole island while we were away. I wonder how he got to the island, if he doesn’t ever leave?
After finding five more koalas on these close islands, we floated off to Brampton, where we found more koalas, even a small koala (named Inky) that Fred Bercovitch and I had found in October last year. It seems that this population of koalas is larger than anyone had predicted. The koalas on Brampton Island are also quite healthy, and judging by the number of young koalas we are finding, they aren’t having any problems finding one another in the rain forests.
Finally, to St. Bees, where we renewed acquaintances with all the regulars. Koala Elizabeth was looking very well and has a two-month-old pouch young, so she bred later than usual this year. I even found The Hurricane, a big male who has evaded us since he broke his collar two years ago. I hope to bring him back into the “collared crew” on a later trip this year.
I was very lucky to be able to travel with the QPWS crew for this trip, but we are already planning for another trip with the rangers in the future. Since part of their job is looking after all the wildlife on all of the islands, they too are interested in the koalas of St. Bees.
Bill Ellis is a Conservation Research postdoctoral fellow for the San Diego Zoo.
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May 1st, 2009 at 6:55 pm
It’s a fascinating mystery how they get to these islands. I don’t think they swim, so could it be extra low tides ??? It’s good they weren’t affected by the horrendous wildfires that ravaged the Koalas in the more southern area of the mainland. I hope you will eventually find and re-collar The Hurricane (what a great name for a cuddly-looking but very LOUD, aggressive male koala!). Keep up the good work you are doing, and thanks for all of it!
May 2nd, 2009 at 1:30 pm
Has anyone done a genetic study on these island koalas to see or how closely they might be related?
May 4th, 2009 at 3:49 pm
Hi Shirley,
Yes, it is really interesting to see the koalas on the islands, but koalas do swim, so perhaps that is how they got to the islands that are close to the mainland. However, since Nigel has not crossed to Rabbit Island from his home on Newry Island, perhaps they only swim if they really need to. It is also interesting that no koalas have ever swum from St. Bees to Keswick Island, even though it is only about a quarter of a mile.
I hope we catch up with The Hurricane soon too, although he’s a bit of a handful to deal with!
Cheers
Bill
May 4th, 2009 at 3:59 pm
That is a really good question njr_sd, and that is what we are doing at the moment. We have been gathering the DNA fingerprints of all the koalas on St Bees Island and are using this information to examine their breeding behavior. We have also found some interesting results when comparing the DNA of the koalas from each of the islands we have looked at. I’ll be presenting some of this information when I visit the Beckman Centre in July, and we will have it written up by the end of the year. So far, we have found that the St Bees Island koalas are genetically quite diverse – more so than most Victorian populations for example, and more so than the only naturally occurring Queensland Island population. It looks like the koalas on the other islands came from the same source population as St Bees, but we are still not 100% sure about that. So, you’ve hit on one of our “hot topics” there!
Cheers
Bill