Snowshoe Hares: From Winter to Spring, the importance of the right coat (credit: National Geographic)
Photograph credit: Randy Beacham, National Geographic
DISCUSSION: Have you started your spring cleaning? Taken off your warm winter coat, and put it in the back of the closet as spring sets in? For humans, shedding our winter coats is a one-minute, one-hanger task. As it turns out, not all animals are so capable.
Snowshoe hares are one such animal. This precocious hare species lives in the mountain ranges of North America, and dons a pure white coat during the winter time to match the snowy surroundings and to help avoid predators. While their name refers to their bright white winter camouflage, the snowshoe hare sheds it winter coat for a darker brown fur color to match the dirt and leaves after the snow melts in the spring. Sounds like a great way to avoid predators, right?
Unfortunately, snowshoe hares are showing up in concerning reports by research and field scientists, because they are actually showing up. Researchers are finding more and more stark white hares in the middle of a brown habitat, where the snow has already melted away and they no longer blend in. This is an issue for the hares, as they are more easily seen by predators, giving them a “mismatch” problem. The snowshoe hare times the coat change in spring from white to brown based off of the change in day length, not by the temperature or the presence of snow in their habitat. In the current climate, the snow is melting a week on average before the change in day length signals the change in coat color, leaving the snowshoe hare exposed to predators.
The real concern begins when scientists begin looking at how the warming climate will impact the hare’s mismatched timing. Some projections put them in up to 8 weeks of a white coat in a brown, snowless habitat by the end of this century. This timeline could spell doom for their populations, as the predators will have nearly 2 months of easily spotting these winter-camo hares. The snowshoe hare population is already showing signs of the impact of losing snow earlier in the year before the day length changes. Scientists have found that the hares no longer live in North Carolina, where the snow begins to melt earlier in the year due to climate change.
There is hope, however for these color-morphing bunnies, as scientists have found that some hares are already adapting and changing coats sooner than others. Researchers have found areas with snowshoe hares ranging in color from white to brown in the same place, meaning the timing of the coat change is a variable trait that can be influenced by the environment. Because snowshoe hares reproduce quickly, if the color change timing is passed down from parents to offspring then it is possible for these populations of bunnies to adapt to shorter seasons of winter, and change coats accordingly. By protecting areas with variable bunnies, we can give snowshoe hares the opportunity to pass on their genes for darker coats and the chance to adapt to the changing climate.
To learn more about snowshoe hares and other species with winter coats impacted by climate change, be sure to click here!
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© 2018 Biologist McKensie Daugherty
Credit: Liz Langley & Emma Maris, National Geographic