On a hike, have you ever been on the opposite side of a fast-moving stream from a friend? It's really hard to hear them. Wind, rocks or trees also make communication difficult for people and birds. One ornithologist studied the effects of different habitats on birds' communication. Birds with high-pitched calls find it more difficult to contact a companion in the forest. That is because the thick vegetation absorbs and scatters higher sounds more than lower ones. The same principle would apply to birds who live in low, dense vegetation compared to those who live in open habitats. The low dense vegetation absorbs and scatters high pitches of birds. The open land will allow birds with high-pitched voices to be heard more easily.
Have you been fortunate to hear ruffed grouse drum their wings? It's a low sound and can be heard in the woods. Carolina wrens have adapted. Studies of them in Maryland and Florida found them to be able to communicate longer distances in certain habitats. In woods, their voices don't travel as far as in open areas. Wow. The reason I love writing these articles is that I learn such interesting behaviors and their causes like these.
These birds like to live in low brush near swamps or woods, but also woods in the suburbs and farms. They will stay there year-round. The warming temperatures in our area have allowed them to enlarge their territories farther north to Michigan, Massachusetts and New York. However, winters with much snow and ice kill many of the birds who cannot find food and shelter. The Christmas bird count in 1977-78 showed a 50 percent decline in their population. After that their numbers revived. However, 2003 was another bad year.
Carolina wrens adapt their songs to their habitats.
Photo by David Cooney Jr.
The Carolina wrens are true to their mates for life. No hanky panky with them. However, they have problems with cowbirds laying eggs in their nests. It's so bad that their populations have declined.
The Carolina wrens nest in roots of toppled trees and brush piles. After the first clutch hatches, the females will start a second brood. In the meantime, the males prepare new nests. Busy, busy, busy. The nests are built with twigs, strips of bark, leaves and grass and are lined with softer materials. The males also feed the first brood. Food includes insects found on tree leaves and bark and some seeds.
One of the most commonly known songs of these birds is "tea kettle, tea kettle, tea kettle." Both partners sing together at any time of the year. They sing anywhere from 27 to 41 songs. You'll have to listen a long time to hear more than one song, because they'll sing one many times before starting a new one.
Another wren, seen in our area, is the winter wren. You'll find it, if you're lucky, mostly in dense coniferous forests near water. Its diet includes spiders and in the winter, sometimes juniper or cedar berries. It looks for the insects in vegetation low to the ground, especially near logs. If you come across one, it probably will be bobbing. You might even see it completely submerge its head under water to catch an aquatic insect.
Are you old enough to remember Ethel Merman on the Ed Sullivan Show? The winter wren's song makes me think of her. That's because for its weight, it produces a song with 10 times the power of a crowing rooster.
These are the two wrens we might see this winter. How do you tell them apart? The Carolina wren is larger, 5 -inches long, compared to the winter wren at 4 inches. The Carolina is reddish brown above and buffy underneath. You can't miss the predominant white stripe over its eye. The tiny winter wren is darker than the Carolina and has a stubby tail and prominent bars on its sides and flanks.