Investigating a possible hazard to pelicans


Electricity: Reports of dead pelicans near power lines suggest that the large birds might be killed when their wings touch two wires.

June 02, 2000|By Tom Horton | Tom Horton,SUN STAFF

LATE LAST summer, reports began coming in from crabbers of a deadly trap that was killing nesting brown pelicans by the dozen in the remote reaches of the mid-Chesapeake Bay between Smith and Tangier islands.

The big birds, whose comeback from DDT and other pesticide poisoning has been one of the bay's success stories in recent years, apparently were being electrocuted by high-voltage power lines.

It seemed the pelicans, whose expanding population had reached north to the mid-Chesapeake only in the past few years, were big enough that their wings could make simultaneous contact with two wires, sending a deadly 7,000 volts through them.

I contacted the U.S. Fish and Wildlife Service, which protects migratory birds, and the Accomack and Northampton Electrical Cooperative, which owns the power lines. Both said they would look into it.

Recently I checked back to see what had come of their investigations. Mike Weaver, an agent with the Fish and Wildlife Service, said his agency has decided to take no action for the time being, because the power company has agreed to study the situation for possible remedies.

After interviewing crabbers, Weaver said, his agency thinks perhaps 15 to 20 pelicans were seen dead in the vicinity of the power lines. No one has seen the pelicans dying from contact with the wires, he said.

Michael Harrison, who manages a wildlife refuge on Smith Island for the Fish and Wildlife Service, said he checked "two times, and I've found dead pelicans ashore around [the lines]. But it was hard to tell what killed them."

The power company has hired Mitchell Byrd, an ornithologist from the Center for Conservation Biology at the College of William and Mary in Virginia, to spend the next few months observing the pelican colony that nests within half a mile or so of the high voltage lines.

Byrd said he has "never known pelicans to land on wires. They are not a perching bird."

Nor have there been reports of similar electrocutions anywhere else in the pelicans' range (Texas to Maryland), power company officials say. Possibly it is a rare juxtaposition of several factors, said Tim Hayes, a lawyer representing Accomack and Northampton.

The lines, carrying power from Tangier Island to Smith Island, are near the remote, predator-free nesting beaches preferred by pelicans; and they overlook a small channel that cuts in toward Smith Island from the bay, a place where the fish the big birds feed on congregate. In the meantime, the power company has reconfigured its lines slightly to open up "a bit more space" between the wires, said Hayes.

"There are still a lot of unknowns," he said; no one has actually related a dead bird to the power lines."

If there is good news, it is that, overall, the magnificent pelicans continue to flourish and expand.

A decade ago, it was rare to see one in the Maryland part of the bay. Last year, Michael Harrison says, "we went down there [near the power lines] and banded 430 in one day."

And a smaller colony has begun to flourish even farther north, on little Spring Island, a marsh dab between South Marsh and Holland Islands about 25 miles south of Cambridge.

What is surprising is that the pelicans have not only rebounded from DDT, they are now pushing north of places described in journals and other observations of early settlers.

Ospreys hold their own against geese invaders

Pelicans are not the only bay bird behaving unexpectedly. Last spring, paddling my kayak down the Wicomico River near Salisbury, I passed under a channel marker where ospreys always nest.

The ospreys were absent, but something moved -- a large snake I thought at first. But it was the neck of a mother goose, nesting 10 to 12 feet above the water.

It is obvious that so-called "resident geese" have been expanding rapidly around the bay and the East Coast. Maryland has an estimated 75,000 to 80,000, and climbing fast.

They are the result of nonmigratory Midwestern subspecies of our migratory Canada geese, brought here over the decades for game farms, live decoys and to ornament ponds.

I knew they were adaptable, but if they started taking over ospreys' nests, that could be a troublesome trend. They nest before the ospreys arrive each spring, so the nests are easily available to the geese.

I paddled by the invader goose's nest several times last year, and a goose was always on the nest while its mate swam nearby. I never saw whether it hatched a brood successfully.

This spring, I half expected to see more osprey nests taken over, but an osprey was back in its rightful place. Then, a couple of channel marks downriver, where an osprey was last year, a goose had taken over.

Bill Harvey, a waterfowl biologist with Maryland's Department of Natural Resources, says he has had reports of "a few cases" like the ones I've seen. As far as geese nesting and getting their flightless young successfully down from such a height, he says "geese have nested successfully on top of five-story buildings."

So far, the ospreys seem to be holding their own, but as the pelicans and the geese demonstrate, nature is anything but static and changeless.

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