How does a harsh winter affect wildlife?
This story comes from Mother Nature Network. We can finally see the ground in parts of New England, and my mind has officially transitioned into spring. But will the aftermath of this winter have lingering effects on our wildlife?
By Tom Oder
Freezing temperatures and record amounts of snow in New England have been tough on humans this winter. They’ve also made life difficult for many forms of wildlife. For some, including salmon and an endangered mussel, the worst may still be ahead because quickly melting snow could lead to heavy spring floods.
But the news isn’t all bad for wildlife. Deep snows have given biologists a special opportunity to study some species such as the rare New England cottontail. Scientists are watching other creatures, such as the snowshoe hare, migratory birds and wild turkeys, to determine what impact the winter might have on their populations.
New England cottontail: The deep and lingering snow has had varying affects on a rare rabbit, the New England cottontail across its range, according to Maine Department of Inland Fisheries and Wildlife biologist Walter Jakubas. The snow, for example has helped biologists and volunteers find and study the rabbits in Rhode Island. Radio-collared rabbits there have been surviving the winter.
However, in Maine and New Hampshire deeper and longer lasting snow has made it more difficult to find rabbits because they move less and burrow under the snow. The past hard winters have been associated with a 60 percent reduction in the number of New England cottontail sites in Maine, Jakubas said. This year in New Hampshire all the radio-collared rabbits died after the heavy snows, he added.
Bobcats and lynx: One of the snowshoes hare’s predators, the bobcat can have a tough time during severe winters. For at least 25 years, Maine’s bobcat management system has considered heavy snows with a sinking depth of more than 10 inches to be a high mortality factor for bobcats. Some biologists have suggested that bobcats at the northern edge of their range did poorly in the deep snow during the harsh winters of 2008 and 2009 and then recovered after subsequent mild winters. It’s too early to know how this winter’s snows will impact populations, Jabukas said.
The severity and length of the winter, though, can provide opportunities for the Canada lynx. This lynx is typically dominated by bobcats and consequently relegated to snowier parts where their exceptionally large feet allow them to seemingly float on the snow and cover large territories. Snow track surveys next winter will help biologists understand whether lynx or bobcat ranges changed in response to the deep snows this winter.
The flora: There’s good and bad winter news for the plant inhabitants of New England, too. The snow cover could be good for plants because it keeps the ground from really hard, deep freezes and protects plant roots (or rhizome in the cause of the threatened small whorled pogonia).
Jesup’s milk-vetch needs ice scour on the Connecticut River to reduce invasive plants that occupy its very limited habitat on the ledge banks of the river. Because quite a bit of ice has built up on the river this winter, biologists said they will have to wait and see how the ice responds to warming temperatures. If ice clears the invasive plants from the ledge banks, biologists said they could see some great new habitat for the plant.
It is the Furbish’s lousewort that is
possibly in the most precarious position of New England plants this winter. This species of lousewort is an endangered plant that is found in only one place on Earth, the banks of the St. John River in northern Maine. This member of the snapdragon family lives on the river’s edge and depends on periodic scouring of the riverbanks in spring by pieces of ice the size of your house!
If the riverbanks are not scoured frequently enough, shrubby vegetation like alders shade out the lousewort. If scoured too frequently, then the plant does not have time to establish and reach maturity.
Ice scouring about once every 5 to 7 years is just about right. Climate change is altering the St. John River dynamics by increasing the rate and intensity of spring floods and ice scouring. Thus, the lousewort is not as successful at establishing new populations. Biologists will have a better sense of how ice scouring affected existing populations and habitat when the Maine Natural Areas Program surveys are conducted later in the year.