Fishers With Personality?
Roland Kays, curator of mammals at the New York State Museum, writes from Albany, where he is comparing the behavior of fishers in urban and wild settings.
Friday, May 6
One of my favorite parts of doing science is coming up with a new idea and testing it out. Usually these fail, and that’s O.K. — I still learn something. Studying animals that run around on their own terms in nature is fraught with difficulty: The animals don’t keep appointments well, and mold grows all over your electronics.
My student Scott LaPoint and I are wrapping up the main part of our fieldwork with fishers, large members of the weasel family that have recently recolonized much of their historic habitat in the eastern United States, and are now thriving in the suburban forests at our study site in Albany. Over the last few months, Scott and I have been using GPS tracking collars to record the exact details of how these animals adapted to human-dominated landscapes. Now that spring has come, the females are denned up with young kits, and we have shut down our live traps to avoid impounding a young mother for the night. We still have a few animals “on the air,” with active GPS collars, but the most intensive part of our fieldwork is over for the season, and we have a bit of time to catch our breath and think about new crazy ideas.
One of these is to develop a personality test for fishers. Pet owners know that individual animals can have different personalities (or “temperaments,” for those who don’t want to anthropomorphize). Zoologists have recently shown that some wild animals also vary in their personalities, and that, not surprisingly, these differences can affect their survival and reproductive success. Scientists have described five major axes of personality variation: shyness-boldness, exploration-avoidance, activity, sociability and aggressiveness. Scott and I would like to see if there is a difference in the personality of fishers that have colonized suburban areas in comparison with those that live in more natural wilderness areas. We have been thinking a lot about the shyness-boldness axis as one that might be most meaningful for a species that was historically only in the wild, but recently colonized suburban areas. Maybe these suburban fishers are more likely to approach novel objects and potential food sources? Or maybe the suburban animals are actually more cautious of novel objects, and therefore better able to avoid conflict with people?
We decided to try a test where we put in the woods an object that would be totally new to fishers and monitor their behavior toward it with a camera trap. This object needs to look and smell generally as if it might be food, but be something they have never encountered. We decided to try a pink flamingo garden ornament doused in orange scent. This falls squarely into the “category of crazy idea that will probably never work, but if it did, would make a cool video and merit further research.” We had to try it. Ideally we’d see animals showing different reactions to the novel object, with some attacking it like prey, and others walking through the field of view but not approaching the flamingo. More likely, the fishers would be freaked out by the tacky lawn ornament and never walk in front of the cameras.
We didn’t want to interfere with our continuing tracking research with this experiment, so we went to a patch of woods in the country south of town, behind a friend’s house where fisher tracks had been seen in the snow all winter. We put out two flamingos at two different places and poured some orange extract on them. Like most other mammals, fishers have a good sense of smell, and this orange should help get their attention, while still being completely foreign to them. Likewise, the plastic flamingo does look generally like a bird, which fishers eat, but a very different type of bird from anything they could find in New York State. We set two camera traps at each experiment to get different angles on their behavior, then let them sit for two weeks.
A camera trap video of fishers interacting with a plastic flamingo doused with orange scent. The difference in the behavior of different fishers may reflect bold or shy personalities of individuals.
By None None on Publish Date May 6, 2011.
We were amazed to see a fisher in the very first picture we looked at after retrieving the memory cards from the camera traps. This animal walked right up to the flamingo, sniffed it, then walked over to check out the camera traps. This would score high on the boldness axis. The next few frames show some porcupines and deer walking by, avoiding the flamingo, then another fisher, and then another. One of these fishers walks slowly through the edge of the frame without approaching the flamingo (score that as avoidance behavior), while another is suddenly right on top of it in a bold, quick approach (attack?) on this new, odd food source. The second site showed a similar high rate of fisher attendance, with two animals actually biting the plastic flamingo! High fives all around the computer screen — this fisher personality test might actually work.
Scott and I will have to devise standard criteria to judge the behavior of each fisher that we film near a flamingo and score them along the shyness-boldness personality axis. Ideally this test could be conducted repeatedly on known individual animals. Unfortunately, we can’t tell individuals apart from the camera trap pictures, other than the larger males from the smaller females. However, we could run a set of new experiments that are spaced out such that each flamingo is in a different animal’s home range. If it all works, this would get us a population-level measure of the average personality for urban and wild fishers, and allow us to evaluate if this was part of the suite of adaptations that helped them colonize suburban forests. Most likely it won’t work — fishers won’t show up on our cameras enough, or there won’t be any consistent pattern in their behavior, or maybe black bears will destroy all our citrus flamingos. Regardless, it will be fun to try, and should get us some more ridiculous videos of wild animals interacting with delicious-smelling pink flamingos.