By Kyler Abernathy, National Geographic Remote Imaging
The Crittercam team recently joined up with Australian researchers for a pilot project on Tasmanian devils.
Working with Channing Hughes and Jean-François DuCroz from the University of Sydney, and Marissa Parrott and the devil team from Zoos Victoria, we first did some test deployments with captive devils at Healesville Sanctuary in Victoria to check the safety and performance of the setup, and then headed down to Tasmania to deploy on wild devils.
They are facing a mortal threat from a transmissible cancer (Devil Facial Tumor Disease) that is devastating the wild population. And it turns out that there’s a lot that’s not known about their daily behavior.
The Crittercam deployments were conducted in an area that is currently free of the cancer, in hope of gathering data on a “normal” wild population and learning more about wild devils in general. The researchers also hope that comparing what is recorded in wild devils to the video collected at Healesville Sanctuary will help the teams caring for the captive “insurance” populations to promote and maintain behaviors as near to their wild cousins as possible. These captive breeding programs could be the salvation of the species if the disease continues its current destructive course.
Devils are not particularly large animals, so we had to be careful with the size and weight of the Crittercam we could have them wear. We decided to use a 90-gram model, with a light-weight, 3D-printed housing that we had used previously with a feral cat study in Georgia (watch “Kittycam” video). We were a bit concerned that the devils might be rougher on them than the cats had been.
We also needed an automatic release so that the collars would drop off and we could recover them without having to recapture the devils. This time though our existing release mechanisms were too bulky. Fortunately we were able to modify one of our designs to reduce its size and weight. We also added a small infrared light source to the units so they could film the devils when they’re active at night.
I have to admit that at first the devils just looked sort of odd to me. A devil’s head seems big for its body and its overall form seems a bit awkward somehow. As I spent more time with them though, I began to find them really endearing.
The fur is a bit like dog fur, coarser than a cat’s, and thins out towards the back of the body, particularly as the animal gets older. The white markings on their chests and rumps are quite variable and are unique to individuals.
They have a bit of a distinct odor as well, particularly the ones that had “made a deposit” while in the trap and then done some interior decorating. The scent lingered on our coveralls, and combined with the aging bait for the traps made for an interesting aroma in the fieldwork vehicle. The traps themselves we were always scrubbing and disinfecting. Good hygiene is an important part of the trapping and handling procedure.
Tassie devils’ ferocious vocalizations and fights over food have helped create a misleading reputation (and they don’t spin around in cartoonish tornados, though they do seem to be in constant motion). In the wild they are actually pretty shy and retiring around humans, and the devils we worked with were quite mellow, tolerating the trapping and physical examinations with little resistance or protest.
Each animal was given a thorough health screening including a visual inspection for wounds, parasites, or possible signs of the DFTD cancer, and blood and tissue samples were taken for future dietary analysis. The wild animals were caught in a trap made of a large PVC tube and baited with a bit of meat from wallabies or pademelons, small kangaroo relatives common in Tasmania and likely a common food source for the devils there.
Interestingly, the captive devils we worked with at Healesville were much more of a handful to collar. Most needed to be anesthetized for the collaring to make it less stressful for them and safer for their handlers. It’s possible that the captive bred animals have lost–or rather never developed–a fear of people and so are more dominant and demonstrative of their feelings about being handled.
Even our first quick review of the Crittercam footage is showing us interesting things about these clever creatures.
At least one of the wild devils has developed a technique for successfully removing the bait from the traps without getting caught. Before Crittercam revealed the culprit, Channing and Jean-François weren’t sure why they kept finding traps sprung with neither bait nor devil inside.
We also saw a female covering the opening to her den as she set out for a night’s foraging. She likely had joeys in there that she was trying to protect.
We are all quite excited about the promise seen in this preliminary effort. Our research partners in Australia were a great pleasure to work with and we are looking forward to joining them down there again soon to continue this project.