Lynx and Snowshoe Hare: The Color of Survival

Climate change is impacting wildlife and their habitats across the globe. Canada lynx, the threatened mysterious cat of northern climes, is not immune to such impacts. Numerous studies predict lynx habitat and populations will decline with increased temperatures and reduced snow levels, as lynx require deep, fluffy snow in order to have a competitive advantage over other predators that cannot move across such terrain. Not only are lynx faced with reduced amount and quality of habitat in the future – but their primary prey, the snowshoe hare, may also be challenged by climate change.

Canada lynx (© Timothy J. Catton/USFS)

Lynx are specialized hunters that focus almost entirely on snowshoe hares – in fact, lynx can only sustain populations where there are adequate snowshoe hare populations. Snowshoe hares are a prey species and thus have evolved ways to avoid predators. Each year, their fur changes color from brown in the summer to all white in the winter (and back again come springtime) in order to camouflage themselves and match their surrounding habitat. This color-changing molt begins based on day length; as we’re all aware, in the northern regions days shorten throughout the fall into winter, and lengthen into spring. It is this changing photoperiod caused by the Earth’s rotation that triggers the molt, rather than the actual amount of snow on the ground. There have always been those awkward time periods between seasons with sudden snowfalls and rapid melting snow that leave snowshoe hares embarrassingly (and possibly threateningly) mismatched from their surroundings. But as climate change alters these landscapes with snow arriving later and melting earlier, hares will continue to start turning white at the same time each year based on photoperiod. Hares will fall increasingly out of sync with these new seasonal cycles. When they are mismatched, they are more likely to be noticed by predators, and hare populations could get into trouble. Reduced numbers of hares would then of course impact lynx populations that rely almost completely on the hares.

This snowshoe hare is part of the way through its yearly molt. (© D. Sikes/Flickr)

However, it may not all be complete doom and gloom. While photoperiod changes set off the start of the color-changing molt, ongoing research is shedding light onto whether hares can adjust the pace at which their coat changes once it has started. Hares may be able to seek warmer or cooler places to speed or slow their change. The speed at which their coats change seems to partially vary from year to year depending on snow conditions. Yet, the shorter winters of the present and future due to climate change may stretch this variation beyond its limit.

Defenders’ Rockies and Plains program has a local partner in Missoula, Montana that is helping researchers investigate the coat color change of snowshoe hares and whether they will be able to adapt to climate change. MPG Ranch is a privately-owned conservation property that promotes conservation through restoration, research, education and information sharing. They are kicking off a contest that will help support Defenders’ Rockies and Plains work to conserve lynx, wolverines and fishers! MPG has an extensive wildlife camera network and you can view it on their website.

The contest involves two parts, and you can participate in either or both:

1 – Guess when the first all-white hare will appear on MPG North’s camera network
In Montana, hares begin to change color in mid-October and appear all white by early December. Guess the date when the first all-white hare will appear on the camera network and enter to win a $300 donation in your name to Defenders’ work on wolverines, fishers, and lynx, and receive MPG and Defenders’ t-shirts for yourself. Go to MPG’s Contact Us page to submit your guess. Submissions for this part of the contest will be accepted until midnight on Monday, November 4.

2 – Find the first all-white hare!
Go to the image galleries from MPG’s live cams and check them as often as you like. When you see the first all-white hare, note the date and time stamped on the image and be the first to send them to us right away using the Contact Us page as described above. Win a $700 donation in your name to Defenders, and receive MPG and Defenders’ t-shirts and hats for yourself.

Thanks for participating, and good luck!

Kylie Paul is Defenders’ Rockies & Plains Representative