Tuesday, March 3, 2015

How Wildlife Are Affected By Intense Cold

February 15 2015 Extreme ColdIntense cold is hard on all forms of wildlife, however, some of nature’s creatures are better adapted to deal with this type of adversity than others. Those animals whose geographic range extends well northward into Canada and Alaska have evolved various strategies to cope with prolonged bouts of sub-arctic weather and are quite capable of surviving the unrelenting cold that the Adirondacks has experienced this winter.

Conversely, some components of the Park’s fauna are on the northern fringe of their range and are better suited for functioning in a temperate region, such as southern New York and the mid-Atlantic States. These creatures are probably not faring well this season.

Moose, for example, have long, uniquely hinged legs that are ideally adapted to allow this massive creature to travel in places in which snow may accumulate over three feet in depth. Additionally, their heavy, dense coat provides them with an insulating layer of fur that keeps them warm when temperatures drop to 40 below. On the other hand, the white-tailed deer, with its shorter legs finds movement difficult in settings in which only 15 to 18 inches of snow exist. Also, the fur of deer only provide protection against temperatures in the minus 10 to minus 15 range. Once the mercury drops to 20 below, deer are forced to walk around to generate the body heat needed to maintain a favorable internal temperature. Should deer be unable to travel because of an icy crust, exhaustion, or a lack of energy from malnutrition, it will inevitably succumb to hypothermia and die.

The largest group of animals that remain in the Park throughout winter are the invertebrates, with all of these creatures retreating into some type of shelter during the late summer through mid autumn to wait for favorable conditions in spring. Some bugs instinctively seek out a spot under a piece of bark, inside the sapwood of a twig or small branch, or within the initially decaying matter near the center of an old, or dead tree. Many of these bugs are not only exposed to frigid temperatures for months, but also are forced to contend with the dehydrating effect of polar air. Bugs indigenous to the Park, however, are quite capable of remaining in a dormant state for a protracted winter season without suffering any ill affects. Invasive species that originate from a similar climatic setting in Europe, or Asia, are likewise well adapted to tolerate months of intense cold and especially low humidity levels lethal to many bugs. The invertebrates that have moved northwards over the past several decades are the organisms that are the most vulnerable to such unseasonably cold and dry winter weather.

Numerous other bugs, and an array of cold-blooded vertebrates, like the spring peeper, toad, wood frog, and red-backed salamander, pass the winter burrowed in the soil and should not be too adversely impacted by our current weather woes. Although it has been unseasonably cold, the snowpack that has blanketed the ground since the start of 2015 has been light, fluffy and in many places fairly deep, which has insulated the soil against the cold. Additionally, there has been a near total lack of thaws this winter. Thaws produce a layer of icy crust that is slightly more thermally conductive compared to snow composed of pure powder. Locations that are routinely plowed, such as roads, parking lots, and driveways, are especially prone for developing a deep frost line. In many of these plowed places this year, the frost extends a half dozen feet below the surface, while in stands of open hardwoods, the temperature may remain above freezing within less than 2 feet of the surface.

Creatures that pass the winter beneath the ice, embedded in the muddy bottom of our ponds, lakes, and marshes are probably unaware of the severity of this winter. Although the depth of the ice on many of these waterways is in excess of two feet, conditions below this transparent covering do not vary much from one year to the next. It is at the bottom of streams and brooks that conditions can fluctuate greatly, as the amount of rain, the number of thaws, and the intensity of the cold that can freeze the surface, all impact winter survival conditions in these waterways. I never attempt to determine how harsh the conditions are at the bottom of streams at this time of year for the various organisms that winter there. I simply wait to find out in the weeks following Memorial Day, as our black flies are great indicators of life in this winter retreat.

The past two winters have not been easy on some forms of wildlife. However, I still hear the male black-capped chickadee singing its “Feee-Be-Be” song early in the morning and the red-breasted nuthatch giving its soft, nasal sounding song during the day. Ravens and a few crows can be seen and heard throughout the winter, indicating there is an adequate amount of food for them to scavenge, and the weather has not been lethal to them yet.

Deer tracks along the sides of highways through the Park do not seem to be as abundant as in previous years, however, this is only my impression, as I have no scientific data to support such a statement. Nature is extremely complex and attempting to determine the impact that one season is having on any given wildlife population is a challenge. I always find it best to simply wait for spring and summer to note what creatures seem to be missing, and which ones are all too numerous.

Illustration: Extremely cold windchill temperatures on February 15, 2015. Courtesy National Weather Service.

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Tom Kalinowski is an avid outdoor enthusiast who taught field biology and ecology at Saranac Lake High School for 33 years. He has written numerous articles on natural history for Adirondack Life, The Conservationist, and Adirondack Explorer magazines and a weekly nature column for the Lake Placid News. In addition, Tom’s books, An Adirondack Almanac, and his most recent work entitled Adirondack Nature Notes, focuses on various events that occur among the region’s flora and fauna during very specific times of the calendar year. He also spends time photographing wildlife. Tom’s pictures have appeared in various publications across the New York State.

2 Responses

  1. Tom Vawter says:

    Nice, timely article on ADK natural history. Thanks, Tom.

  2. T Myers says:

    My chickadees don’t mind the cold we have been having because of the sun shining so much here in Ithaca. They have been singing away on sunny cold days. Especially since I have 6 bird feeders (3 sunflower, 1 safflower, 1 thistle & 1 suet) & a heated bird bath for them!! All the other birds & even the squirrels are enjoying the food & water I provide, as well. Me – with this year’s snow & February coldest month in recorded history – I’ll be singing when spring gets here!!