Nature's ugly clean-up crew coming to a roadway near you

By Beth Daley, Globe Staff

Stuck in traffic? Make sure the foot is on the brake and look up: A turkey vulture may be in view.

If you are really lucky, maybe you’ll see it gorge itself on a dead animal, as I did a few weeks back near the Blue Hills Reservation in Milton.

Gross? Maybe. Fascinating? Definitely.

The misunderstood vulture

Let's face it, these birds are never going to win a beauty contest. Their blood-engorged, bald heads are perfectly designed to poke into carcasses. They defecate all over their legs. They regurgitate dead animals and sling them at intruders.

But it’s a good time to spot the intriguing creatures: Migrants are passing through on their way north and roosting with the region's resident population. Hundreds of the birds, with their six-foot wingspan, are searching for dead animals in forests and along roads across Massachusetts.

But why the black birds are in New England at all is a mystery. Even though Buzzards Bay was supposedly named for vultures, there were none here at the time of European settlers. Scientists figure early settlers mistook ospreys or red-tail hawks for buzzards. The birds really began showing up in the 1950s in Massachusetts, but seem to have really exploded in the last twenty years or so, says Norm Smith, sanctuary director of the Blue Hills Trailside Museum.

Smith says Blue Hills had a resident pair by 1987 and as many as four nesting pairs have been spotted in the reservation at one time.

Before you give a “eww”, consider:

Turkey vultures act as nature's vacuum cleaner, eating road kill and other dead animals that could carry disease - and their strong digestive juices kill many germs. In fact, turkey vultures are actually cleaning their limbs when they expel their germ-fighting feces onto their own legs.

Hungry anyone?

"They are the clean-up crew," said Smith. He said the birds can travel 200 miles in a day searching for food.

Interestingly, ranchers in Texas used to kill turkey vultures over fears they spread anthrax and hog cholera, when the opposite was true.

The little-studied Southern native birds - named for their turkey-like head - are full of other mysteries. Every year - on March 15, four days before the swallows return to San Juan Capistrano, Calif. - the birds return to less romantic feeding grounds in Hinckley, Ohio.

Some biologists believe that minute warming climate changes have allowed the birds to expand their range. Others say strict environmental laws in Southern states mean farmers aren't leaving animal carcasses in the open, and the birds needed to push north to find food. Highways might have helped, with hot pavement helping create warm thermal winds the birds glide on, as well as an ample supply of road kill.

Whatever the reason. Look up. Watch them soar. It’s the best show on the roadway.