By: Nadine Berrini

If you’re a bird watcher, bird hunter, or an all-around wildlife enthusiast you may have wondered how to improve the habitat for birds on your land.

Two of the most important things forestland owners can do for forest birds are to create vertical structure and to keep dead wood. Vertical structure is the architecture of the forest; it refers to the heights of trees and other plants—from the canopy to the forest—floor. Different birds use different parts of this structure for breeding and foraging. Likewise, snags (dead or dying trees) provide roosting, perching, foraging, and nesting sites for about 40 species, from chickadees to woodpeckers.

Grassland birds, which have been in steep decline for decades, populate Vermont’s hayfields, meadows, and pastures. Many of these birds build their nests on the ground, raise young, and forage for insects such as caterpillars and grasshoppers in summer months. Mowing earlier or less frequently, when economically feasible, can minimize the impact of haying on nesting birds.

To illustrate specific ways landowners can support bird habitat, we’ve highlighted three birds that use varying landscapes.

Forestland: Scarlet Tanager

Over 70 percent of the birds found in Vermont forests during the summer are migrants. One of these birds is the bright red scarlet tanager, which comes to Vermont from South America to breed. Scarlet tanagers build nests mostly in deciduous trees 20 to 30 feet above ground. Though fairly common in Vermont, this bird is often overlooked because it prefers the high canopy of mature, interior forestland.

While the scarlet tanager population in Vermont is considered stable, nine other species that are threatened are likely to benefit from improving scarlet tanager habitat; these include the black-and-white warbler, the rose-breasted grosbeak, the veery, and the yellow-bellied sapsucker.

The scarlet tanager and other forest-interior birds require mature forests. These birds don’t do well near the edges of forests because predators, including jays, raccoons, and cats, are more likely to be in these areas, as are “brood parasites”—birds that lay eggs in a host bird’s nest to the detriment of the natural brood. “For most birds, the edge is the least desirable place to be,” said Jim Shallow of Vermont Audubon. “They either like open grasslands, shrubby areas, or forest. Edges tend to be vectors for predators and can have an effect as much as 100 meters into the woods.” Vermont Audubon recommends that landowners create irregular edges or “feather” edges. Feathered edges have more trees closer to the uncut forest and gradually fewer trees closer to the harvest area. The shape of a woodlot (e.g. a circle as opposed to a long rectangle) can create more interior and less edge as well.

The value of an individual 50-acre woodlot to the scarlet tanager will vary depending on the surrounding landscape. In a landscape that is 50 percent forested the scarlet tanager needs around 70 acres of habitat. The less forested an area, the more acres are required. “Just because you see a bird doesn’t mean it’s nesting successfully,” said Chip Darmstadt, director of Central Vermont’s North Branch Nature Center, about a scarlet tanager he saw in his neighborhood.

Other techniques landowners can use in forested areas are:

1. Designating tracts that will be mature at each stage of the forest management plan;
2. Maintaining corridors between regenerating forest and mature tracts;
3. Placing buildings, camps, and roads near the edge of forested blocks;
4. Maintaining a well-developed understory, which provides food and cover for birds;
5. Preserving old growth stands;
6. Removing invasive plants; and
7. Leaving diverse species of trees when cutting.

The Environmental Quality Incentives Program (EQIP) through the Natural Resources Conservation Service (NRCS) has begun to offer more incentives for forest conservation practices and is expected to continue to expand its offerings in this area.

Grassland: Bobolink

The bobolinks that come to Vermont to breed in our hayfields and meadows in the spring have traveled as far as 6,000 miles to get here—all the way from the grasslands of Bolivia, Argentina, and Brazil. A medium-sized songbird, the bobolink lives in the northern U.S. and southern Canada from May to August. During this time the male bobolink displays breeding plumage of a white back-side and black belly with a tuft of straw-yellow on the back of his head.

The bobolink population is in decline due to troubles on both sides of the migratory journey. While they’re thought of as beneficial to U.S. and Canadian agriculture because of the insects they eat, bobolinks are shot as agricultural pests by the rice farmers of South America. Also, development and reforestation have seriously reduced their breeding grounds. And lastly, with earlier haying schedules, bobolink eggs and chicks are often destroyed by mowers. In the past 30 years, populations of grassland birds have fallen over 70 percent. In Vermont, the bobolink population has declined 73 percent in the last 40 years.

The bobolink begins the journey to its northern breeding grounds in early March. Traveling by night, it arrives in Vermont in May, when courtship begins. In early June, clutches of 4-6 eggs are laid in open-cup nests built into depressions formed at the base of clumps of grass. Eggs incubate for 11-13 days and chicks fledge in another 10-14 days.

Farmers often make their first cut in June, when bobolinks are in the midst of incubating eggs and raising chicks. While later mowing would help nesting birds, it often results in nutritional losses in the hay. The Environmental Quality Incentives Program (EQIP) Grassland Bird Initiative offers eligible farmers $100 per acre to mow prior to June 2 and then not mow again for 65 days. The purpose of this program is to give grassland birds a chance to reestablish successful nests while allowing for an early cut of hay. The Wildlife Habitat Incentives Program (WHIP) also offers delayed mowing incentives.

Mowing patterns may also help. Fledged young and mature birds will have a better chance of escape if mowing starts in less bird-friendly areas, such as near structures, and then moves in rows toward the rest of the field. Likewise, mowing from the center out will allow more birds to escape. If you notice birds coming and going from an area, consider leaving that patch until the next mow. Also, some recommend raising the blade to six or more inches to reduce nest destruction.

Consistency is essential to bobolink conservation. Bobolinks will return year after year to a field where they’ve had success. It is better to forgo early mowing on one small unproductive field consistently than to change mowing cycles after a couple of years.

Mixed terrain: Wild Turkey

Wild turkeys, historically abundant, disappeared from Vermont as most of the state was cleared for agriculture. In1854, the last native Vermont wild turkey was seen. In 1969, wild turkeys captured in New York were released in Hubbardton and Pawlet. By 1973, there were 600 wild turkeys in Vermont. Today it’s estimated that there are 35,000. Other Northeast states did the same, and the reintroduction of the wild turkey is now considered a significant wildlife restoration success story.

Wild turkeys live in Vermont year-round. They thrive in the southern part of the state and in the Champlain Valley where there’s a good mix of hardwood forest and open land. The deep snows found in northernmost Vermont and at higher elevations make these areas more difficult for turkey survival. In addition to being a challenging game bird, wild turkeys are an important prey species to coyotes, fox, bobcats, hawks, and owls among many others.

With a home range of about 1,000 acres, wild turkeys require a varied landscape including: forests that provide nuts for food, tall trees for roosting, and conifers for winter protection from deep snow; open fields for insects and cropland for forage; and shrubs and tall grass for food and nesting sites. Because wild turkeys travel so far, individual landowners can’t singularly provide improved habitat for turkeys but can manage their land to meet some of the turkey’s needs.

Wild turkeys begin nesting in early spring in shrubby areas with sufficient cover remaining from the previous year. To successfully protect against predators, the nesting area needs to be well hidden. After eggs hatch in early June, hens take their young to fields to catch insects. Because the young can’t fly for three weeks, it’s recommended that hayfields be mowed from the center out. Once young turkeys can fly they begin to roost in trees to avoid predators. To encourage roosting, leave large trees with horizontal branches.

In winter, wild turkeys rely on spring seeps (places where groundwater comes to the surface) as an important food source. When other foodstuffs are buried beneath deep snow, the melt around seeps allows turkeys to forage. Seeps are found in both forests and old fields. Landowners can increase the amount of food provided by seeps by thinning the forest canopy to about 70 percent, leaving mast-producing trees, such as oak, hickory, and beech, and planting fruit-producing trees and bushes, such as crabapple and raspberry. It is also helpful to remove woody stems that don’t produce food items, along with invasive species such as the Russian olive and multiflora rose.