|Red fox with mouse|
Structural adaptations are physical traits, handed down through genetics that help an animal better survive in its environment. In the case of winter conditions, an obvious example for most mammal species is the pelage, or their covering of hair or fur. In fall, most mammals in Ohio replace their thinner summer coats with a dense winter coat, which is why fur bearer trapping seasons are scheduled for late fall and into winter. These thick coats are comprised of two layers, an inner dense undercoat which traps air and provides warmth, and an outer layer of guard hairs to repel water, protect the undercoat, and provide camouflage.
Have you ever noticed that the northern members of a species seem to be a bit larger than their southern counterparts, even though they are the same species? It has to do with how their bodies deal with heat. In the south, where summers are very hot, bodies need to remove heat in order to protect vital organs. In the north, the opposite is required; heat needs to be retained during the cold months. So how does size help? Think of a cube. For every one additional increase of surface, the volume increases three fold. So the larger and stouter northern animals have more mass relative to surface area to protect internal organs. Likewise, the thinner and lanky southern versions have a larger surface area in relation to their volumes to help dissipate heat.
Other behavioral adaptations are learned. Humans, for example, have learned to build shelters which have enabled them to live in climates in which they would otherwise not be physically adapted to survive. Just like Eskimos, many species of wildlife, particularly game birds like ruffed grouse and pheasants, rely on snow for insulation and to protect them from the harsh winds. When woodlots and fence rows are removed, the wind driven snow moves on rather than forming snowdrifts along the fences, leaving these species susceptible to the elements.
Some species have adapted other ways to cope with unfavorable weather. Many species of birds choose to avoid the cold altogether and fly to areas where food is abundant. Migration is an adaptation to capitalize on the seasonally abundant food sources as they occur in different regions of the world.
In the end, every species has adapted unique ways to help them survive in their environment. For Ohio’s wildlife, that includes winters just like the one we are experiencing this year. Although, to some these conditions may seem unbearable, most all of the native wildlife species are well adapted to these conditions. For more information about a particular species that interests you, visit the Species Guide Index at wildohio.com.