A Boer goat isn't likely to crush the 4-inch bog turtles that share eight acres of public meadows with the ruminants. Photo: Maryland State Highway Administration

Drivers taking the newly opened Hampstead bypass in Carroll County, Md., will see an unusual solution to roadside maintenance: South African Boer goats. Meanwhile, over in New York, five Nigerian dwarf goats are dining on mugwort and bulrushes in a nature preserve that used to be a landfill.

These are two examples of how agencies are testing the effectiveness of plant-fueled mowers versus those that run on fossil fuels.

“Herbicides can pollute nearby waterways,” says Hempstead, N.Y., Supervisor Kate Murray. “Adding these goats to the town's workforce is an environmentally responsible way to control weeds.” According to Neil Pedersen, administrator of the Maryland DOT's State Highway Administration, “using goats demonstrates our vision of a greener highway system.”

Goats solved another problem for the department as well: how to manage vegetation on land inhabited by a threatened species. Mechanical mowers would slice up the bog turtles that live along the bypass, and cows would crush them.

The department is renting its goats — a herd of 40 — from a local farmer as part of a two-year, $10,000 contract that includes delivery, supplemental food, and veterinary care. The goats will graze eight acres from mid-May until the beginning of September.

The Hempstead Department of Parks & Recreation opted to buy four does and a buck, a $1,000 investment. There hasn't been a tick incident since it set a flock of insect-eating Guinea hens loose in the park four years ago, so employees seem to have little concern about adding animal husbandry to their responsibilities.

According to North Carolina Agricultural and Technical State University, goats eat 3% to 5% of their body weight daily.

They like grass but prefer woody shrubs and weeds such as leafy spurge and brambles because their highly flexible lips allow them to choose a plant's most nutritious parts, leaving the rest behind. In a four-year study by the state's Agriculture Department, a herd of 30 goats virtually eliminated multiflora rose bushes while growth of “favorable grasses and legumes” quadrupled.

Since 1999, goats have helped restore native grasses to 2,750 acres of urban forest for Denver's Parks and Recreation Department. The goats are moved from one weed-infested vacant lot to another from April through October. The service costs $4.50 per goat per day (two kids are charged as one adult).

Goats are smart and curious and will stand on their hind legs to reach food. They've been known to test fences, both permanent and moveable, and repeatedly escape once they identify a breach. They can also be confined by tethering, which is the method chosen for the 52-acre nature preserve in New York.

“We don't want visitors to feed them because that would be counterproductive to their purpose, which is grazing,” says Hempstead Spokesperson Mike Deery. “They're supposed to be gentle, but this isn't a petting zoo.”