The 52-year-old probation officer wants to do something about the homeless, particularly those who nest in the bushes around City Hall.

But it is not humanitarianism that has driven Somerville to make repeated calls to City Hall groundskeepers, urging them to shoo away these denizens of the dank corners and to clean up the detritus the homeless leave behind.

City Hall, says Somerville, has become a resting place for many species of migrating birds, some of which are hardly found in these parts. The homeless and the mess they leave behind in the few patches of greenery outside one of the world's tallest freestanding masonry structures are threatening City Hall's fine-feathered sanctuary status, says Somerville, who is such an avid birder that she sports a vivid 6-inch-tall tattoo of an ivy-billed woodpecker on her left calf.

"I have been watching birds for years and, during April and May, I have been checking out City Hall," says Somerville. "It is amazing how many birds stop over to feed at City Hall before moving on."

The birds, she says, come from as far away as Colombia, the Caribbean and Panama. "Sometimes exhaustion will drive a bird, nearly starved, at an unsafe and unfriendly area."

Welcome to City Hall. Which may be hospitable, Somerville says, only because the place is crawling with bugs, which the birds like to feed on.

Every weekday for the past two months, toting her "$1,000 Leica 8x32 binoculars that I won in a $5 raffle," Somerville says she visited the plaza "before 9, after court, during lunch, after work, whenever convenient."

It was in the little patch of trees and undergrowth on the northwest corner of the plaza that Somerville spotted a wide array of birds, like brown thrashers, wood thrushes, hermit thrushes, mourning warblers, ovenbirds, catbirds and even the illustrious yellow-bellied sapsucker. "It is amazing that the birds came here even with the scaffolding up around City Hall," she says.

"They live underneath the bushes, right next to the building where the scaffolding is," says Somerville. "Every day, there is more and more trash from the homeless. They have huge pieces of cardboard that they sleep on. It covers the ground and destroys whatever greenery is underneath it. They leave bags full of blankets. I've even found toilet paper back there."

"It was the first time I noticed birds other than the ones in my backyard," says Somerville. "I went on a bird walk out in Peace Valley in Bucks County. They were like little jewels hiding in the bushes and trees."

Most people, says Somerville, have no real appreciation for just how many splendid feathered creatures there are.

"It may be all around you, but unless you have binoculars and know what they sound like, you may never see them," she says.

Somerville says she was first attracted to City Hall several years ago upon sighting a sapsucker there, yellow-bellied variety. Far rarer than the wool-suited sap sucker, which has long infested the inside of City Hall, sucking the sap of fat city contracts and feasting on the ooze of raw power.

"Once I started seeing yellow-bellied sapsuckers, I came back the next year and looked more closely," Somerville says excitedly. "You never know what you are going to find."

"Today, 5-31-02, I went over to City Hall to check on my migrants, having found three common yellowthroats and nothing else on the 28th," she writes in a letter. "I checked behind the bushes on the northwest side and, as usual, got mad at the trash the homeless left."

Somerville says she was ready "go up to the eighth floor of City Hall and complain, but hesitated after seeing a mourning warbler.

However, after several more days of looking for birds amid the refuse, Somerville finally made the call to the Hall.

"I now have second thoughts about the Œhomeless,'" she writes. "They are giving the homeless a bad name. They gotta go.

"I interviewed a few," she adds. "One said that they smoke pot and drink beer all night; another said that urine helps the plants. ŒGod doesn't waste anything,' he said. I watched a pile of defecation on one of the cement benches take over a week to disappear. Eventually a strong rain took care of it."

Somerville says city contractors failed to respond to her complaints. They "said the area is not supervised at night ... only the underground terminal area.

I know that the mayor has lots on his mind these days, what with the Edison mess and the Lex Street disaster.

But still, I wonder what the administration -- which has come down heavily against panhandlers -- has to say for conditions outside its massive stone palatial headquarters .

And I want to know whether the mayor has seen sapsuckers outside his office window.

Spokesman Frank Keel says he's not aware of the damage Somerville describes, but would be happy to see proof.

"I can appreciate the plight of the homeless," says Somerville. "Having been a probation officer for the past nine years, I am quite aware of the issues that keep them there. These are not homeless that are ruining the scant habitat at City Hall. These are self-centered, lazy, hedonistic, destructive, nocturnal bums."