Investigating potential modifiers of the timing of hares’ coat color molts

Now that the spring molt is wrapping up I wanted to give you guys an update on the part of the project that I am working on. One aspect of the project focuses on variables that might influence the rate of change of the molt. A paper by Scott, Marketa and colleagues that documented the molt was just published in PNAS. Amongst other things this paper demonstrated that the initiation date of fall and spring molts were fixed across the three years of the study but they found a significant degree of plasticity in the spring rate of change. This means that hares were actually able to partially adjust their molt to match their environment in the spring! They molted from white to brown faster when there was less snow and it was warmer and slower when there was more snow and the temperatures were colder allowing them to better match their surroundings. I find that pretty cool. So now the next step is to ask how do they do it?

This is where the part of the project that I am working on picks up. Hares show considerable individual variation in the rate of the molts and we want to try and link local temperature and/or snow cover to the rate of change of the molt of individual hares. To do this we will be taking temperature and snow cover readings at the spots that we track hares to. Then when we go to analyze the data we will try and figure out whether either variable, or both, or their interaction influences the rate of change of their molt. Pretty exciting stuff especially when you consider not much information is known on the regulation of these molts and 10 different mammalian species also molt from brown to white and we don’t know much about any of their molts either so this research could be applicable to them as well.

Other aspects of the project that I am working on include examining the potential seasonality of hare use of larch stands and examining the effects of larch restoration on snowshoe hare vital rates. More on that to come!

– Alex Kumar (MS student)