Greetings again from St. Bees Island, Australia. It’s raining less often and the temperature is going up, so spring is definitely here. This signals the start of a busy season for the koalas, not to mention the researchers.

I recently wrote that we used the growth data from the San Diego Zoo’s koala population to predict when most births would occur on St. Bees (see Zoo Data Key to Planning Koala Field Season). I said that this sort of planning was a key to success in the field. What I forgot to mention was how having a good team of field workers could also have a huge impact on the success of the field program.

Last year, Fred Bercovitch and I trialled some GPS (global positioning system) radio collars on the koalas on St. Bees Island. These collars were bought with money donated to us by the Ocelots program at the San Diego Zoo. We hope these collars will enable us to follow the koalas on the island much more closely so that we can see if individual koalas are avoiding, or are attracted to, other koalas. Thanks to another wonderful donation of money through the San Diego Zoo, we were able to buy 10 more of these collars this year, and my plan for my recent field trip was to deploy as many of these as I could before the koalas started breeding this year.

My colleague, Sean FitzGibbon, and two volunteers (Ben and Jay) met me in Mackay for the trip to the island. The weather was too rough for our planned boat trip, so we flew by small plane to a nearby island and then took a quick dash in a “tinnie” (that is Australian for a small aluminium boat with an outboard motor on it) across the channel to St. Bees.

The four of us spent over a week on St. Bees Island, looking for koalas to catch and collar in the area where I am doing most of my radio-tracking studies. In that time we caught 18 individuals, including some big males that had been avoiding me for some time. We caught “Digger,” a big male that the crew from the San Diego Zoo had watched bellowing last year, but who had previously proved too clever for our catch teams (see blog, Koala Field Project: A Koala Chorus). We also caught “Trotsky,” a big male that seems to have moved into Jackaroo’s old range (see blog, Jackaroo’s Journey). We have now deployed all 10 GPS collars (5 on males and 5 on females) and are collecting locations from these koalas every 2 hours, every day of the week.

I was really happy with the trip; it was beyond my expectations to get all the collars out, let alone collar 5 males and 5 females. There are still koalas in my study area without collars, but I am now sure that we have caught all the koalas that regularly use the area this year. In a few weeks I will be back on the island watching and listening to the koalas, and then in November I hope to begin downloading data from the GPS collars and replacing the batteries to cover the summer period.

I am very interested in the spatial dynamics of this group of animals, but the information we are collecting is also useful for presenting new questions to us and, hopefully, answering them. For example, the results from our trial collars last year were very interesting: the koalas were much more active during the day than we thought they would be. However, it seems that this activity might depend on the type of trees that the koalas use. The koalas that use rain forest trees seem to move less within the trees than do the koalas using the eucalypts. We think this is because the rain forest trees provide better shade, so the koalas remain shaded regardless of the sun’s position in the sky.

I will be interested to know how much difference there is between males and females in terms of daily travels. It will be interesting to see if some males move further than others, or whether the smaller males stay away from the big ones, or stay close to them (maybe in the hope of encountering females).

There seems to be no end to the planning and preparation that goes into the field work we do. Sometimes things just don’t work out, the weather can be bad and the koalas can seem to be too clever to be caught. I am sure I will be complaining at some stage in the future, but right now everything is going right to plan. I am keeping my fingers crossed that the collars are doing their bit, because if they do, I am sure I will have some fascinating results to talk about before too long.

Bill Ellis is a Conservation Research Postdoctoral Fellow in the Behavioral Biology Division at CRES.

Posted in Default, Conservation, Field Studies, CRES (Conservation and Research for Endangered Species), General | Link to this post

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