Not all birds nest in trees or birdhouses. Some, like wild turkeys, simply scratch a shallow depression in the soil for their eggs. Open nests on the ground are easy pickings for predators. In one study, the US Geological Survey placed miniature video cameras by nests of grassland songbirds. A variety critters preying on eggs, nestlings or adults were caught on film, including a cowbird, red fox, ground squirrel, badger, hawk, snake, weasel, mouse, and even a white-tailed deer. (My husband thinks this list sounds like the diet of the Tasmanian Devil in the cartoon Devil May Hare.) When birds nest in active farm fields, their young may also succumb to early mowing; tilling; trampling by livestock, tractors or ATVs; or pesticides.
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Some observers think the Bobolink looks like it is wearing a tuxedo backwards. Their numbers are in decline. |
Still, the most serious challenge grassland birds face is shrinking habitat. Large expanses of open grassland are easy pickings for developers, since the land is already cleared and fairly flat, and usually has well-drained soil. In the space of five years, nearly 500 acres of prime habitat near Bradley Airfield has been lost to development. Of the 80 species in Connecticut that depend on grassland to nest and breed, 13 are on the State List of Threatened, Endangered and Special Concern Species. “If we let nature and development take their course, we will not have grassland birds in our State,” says Patrick Comins, Director of Bird Conservation for Audubon Connecticut.
A number of government agencies, nonprofit organizations, farmers, volunteers and private landowners recognize the need to work together to conserve grasslands. “We have to do it now, because we’re running out of time,” says Jenny Dickson of the CT DEP. Efforts include outreach and technical assistance, financial incentive programs, and rental or purchase of prime habitat.
When it comes to grassland for birds, bigger is better. The most important parcels to conserve are generally large (50-75 acres +), located near other open land, with few owners (for logistics reasons), where grassland birds are already found. Such areas might be airfields, corporate parks, closed landfills, cemeteries or active farms. An acre or two of meadow is not enough, although a few grassland birds like Bobolinks will nest on smaller fields of 5-8 acres or more. Different species have different preferences. Some prefer tall grass, others short. Some species nest where there are ‘cool-season grasses’ such as timothy, Kentucky bluegrass, tall fescue; while others stick with ‘native warm season grasses’ (often referred to as prairie or bunch grasses) like little bluestem.
The Bobolink and the Eastern Meadowlark are two local birds threatened by diminishing habitat. Landowners not concerned about high quality hay production for profit can do these birds a big favor by delaying mowing until at least July 15th. Waiting until late August is even better, as it gives another chance to birds that nest twice a year or failed in the first round. Established stands of warm-season grasses used for wildlife conservation require minimal maintenance, and can be mowed every three or four years depending on soil conditions. Raising mower blades to at least ten inches allows grass to recover quickly; six inches or higher may reduce destruction of active nests. Mowing around areas where birds are frequently seen, or leaving small patches unmowed can protect many nesting birds. Light to moderate, rotational grazing actually benefits grassland wildlife. Fields that are left idle often revert to forest.
Conservation measures like these can literally mean the difference between life and death for grassland birds. They also allow a wide array of butterflies, reptiles, amphibians, and mammals to co-exist with the scenic meadows we love. For more information on what you can do to help, email depgrasslandinitiative@po.state.ct.us, or call the DEP Sessions Woods office (860-675-8130) and ask to speak to someone from the Wildlife Diversity Program. |