Last Sunday we got our first major snow storm of this winter. Starting early that day it continued to snow and blow all day and on into Monday leaving about 6 inches of fresh, drifted snow. Tuesday we got another 3 to 4 inches of snow. During these snowfalls some of the winter birds were scarce in the Arboretum. By the weekend it had warmed up to the mid 30s thanks to a couple sunny days. Saturday was a day of melting snow, bright sun and very little wind. There were a few dozen Mallards swimming in the open water by the big spring in Wingra Woods while several Robins flew around in the woods nearby.
Sunday was a very different experience. It was a gray, overcast day that started out around freezing with dropping temperatures into the 20s F throughout the day. A stiff northwest wind increased during the afternoon. The snow-covered trails had been heavily used by skiers, hikers and joggers during the previous nice sunny days.
Suspecting that birds might be hard to find with the gray light and increasing wind, a group of about 30 visitors set out toward Longenecker Garden to see what birds could be found. Right from the front steps we spotted some Turkeys near the edge of the west parking lot. Proceeding into Longenecker we noted the absence of finches that often feed in the birches. While walking through the crabapples to cross the road to the trail by the golf course we noticed more Turkeys and one of the visitors pointed out a Red-tailed Hawk perched low in a small tree on the north side of the road. The hawk stayed perched as we circled around it and headed down the trail, giving us nice views. As we approached where the trail nears Wingra Fen we watched a Red-bellied Woodpecker feeding in a small tree. Unlike yesterday when there were dozens of Mallards swimming by Big Springs and there were numerous Robins flying around, today there were no birds at the spring. Instead we could hear and feel the northwest wind, so we decided to head up to Wingra Woods parking lot to return to Longenecker. On our way through Wingra Woods we heard and then saw a lone Crow flying to the west. Approaching the pinetum hill in Longenecker we watched five Crows playing in the wind.
Those were the last birds we saw while walking through Longenecker, along the edge of Galistel Woods and back toward the Visitor Center. Three Black-capped Chickadees caught our attention as they flutter near the ground in front of the small research building. They were keeping well out of the wind.
Five species seems a very low number of birds to find in an hour and a half walk. Some of the reasons you might expect this low number are the weather, with a strong wind, falling temperatures and overcast sky. The time of day might account for less bird activity. Birds usually feed early in the day and often are less active by late morning through early afternoon. In winter small birds sit out cold windy weather and feed when the wind dies. Three of the species we saw, the Turkeys, hawk and Crows are larger birds that are not affected as much by the cold and wind. Of course, there are not that many species of birds that over winter in the Arboretum and most are in lower numbers than during other seasons.
How do birds survive the winter here with the cold and snow? Feathers, which are unique to birds and distinguish the Class Avies, have a lot to do with birds being able to over-winter. Feathers permit flight in most birds, which allows them to find food and water. Flight aids them in finding protected perches to roost overnight. Feathers can be specialized for many different functions. Down feathers are modified for insulating birds. If you have ever worn a garment insulated by down feathers, you know how warm these feathers are due to their ability to trap warm air near the body. When combined with contour feathers and wing feathers that fold around the body, our winter birds are able to maintain a warm core body temperature even in below zero temperatures. Feathers allow birds to escape from predators and other threats, including humans.