This spring, as hawks soar the winds that rush up Catskill cliff faces and mergansers dive the chilled waters of Lake Erie, a group of glossy ibises has been seen strutting the marshes of the Bronx.
The Bronx?
Really, the Bronx.
Here, each evening, flocks of ducks weave through housing project towers, bank into turns and splash down on ponds that lure them to the borough's three sprawling parks.
And here, as the sun rose Tuesday morning over pastel stillness at the mouth of Eastchester Bay, great blue herons and American egrets probed the glistening mud flats.
"The Bronx is a perfectly terrific place to find birds," said Peter Mott, a borough birder and volunteer for the 10,000-strong city chapter of the National Audubon Society.
Although the borough often carries a reputation as a concrete landscape of housing projects punctuated by the staccato blasts of car alarms, for some borough residents bird life gives the city another dimension.
For birders, the Bronx is a peninsula caressed by the waters of five rivers, a peninsula on whose air floats the singsong ramblings of the mockingbird, the sharp-tailed sparrow, the cerulean warbler and the mourning dove.
"I've been birding the garden for 10 years," said Debbie Becker, who leads free bird-watching tours at the Bronx Botanical Garden. "It's better than Jamaica Bay, because here you get more than water birds. And it's better than Central Park, because it's safer."
Becker's recent sightings at the 250-acre garden include orioles, cardinals, phoebes, kingbirds and warblers.
Spring is the season to see the northeast's birds, when the borough experiences an invasion as part of a huge seasonal migration. Their route, called the Atlantic flyway, is an aerial highway dotted with life, a windy passage that stretches from the South American rain forests to the Arctic Circle.
And each year, it's anybody's guess just what will stop along the way.
"The strangest thing I've seen is a pair of snow geese in Van Cortlandt Park," Mott said. "They usually go by us and fly over the Hudson River at two or three thousand feet. But I guess these guys just got curious."
Curious, too, the behavior of birders. On May 6, a borough bird-watching team will take on others from around the city in the Audubon Society's annual bird-a-thon, a friendly contest in which teams compete to identify the most species in a single day. Last year's Bronx team recorded 85, but lost to the Staten Island squad, which sighted 92.
"We may start at 3 a.m. in the north end of Van Cortlandt Park, trying to hear the great horned owls that live there," Mott said. "I think the winning team will need somewhere on the order of 100 species."
This may be achievable. The spectrum of habitat that local parks provide -- from deciduous forests and manicured golf course to island rookery and brackish swamp -- lure an eye-catching assortment of birds. If for many species the numbers are small (the Bronx is, after all, the Bronx), the variety is astonishing: in recent years some 238 species of birds have visited the borough, said David Kunstler, a wildlife manager for the borough's parks.
Pelham Bay and Van Cortlandt parks, whose combined acreage is nearly five times the 840-acre area of Manhattan's Central Park, provide the borough's main bird habitats.
"These are the two best parks in the city," Kunstler said.
North and South Brother Islands, abandoned by man, also provide prime sanctuary. Nests here face dazzling views of the midtown Manhattan skyline. In recent years, counts as high as 4,000 birds have been recorded in surveys on these small, isolated havens.
In a borough crowded with human life -- known population 1.2 million -- birds have endured some strange circumstances.
For instance, in past years one of the best places to spot raptors (birds of prey such as hawks and owls) had been in the vegetation atop the 86-acre Pelham Bay landfill, Kunstler said.
But a pollution safeguard -- a concrete cap on the dump to prevent rainwater from leaching through it and polluting the East River -- meant clearing the vegetation, an environmental necessity that has displaced many of the hawks. In spite of this disruption, birders said more birds have been alighting in the Bronx after a dip in sightings during the last decade.
"In the middle '80s, the decline was like a thud," Becker said. "You couldn't find a bird with a firecracker."
Recent arrivals now multiply the sounds of winter birds -- the screech of blue jays from a copse of sycamore, the plaintive honks of a flock of geese that paddle the pool of the Bronx Kill. The borough's four golf courses have echoed with the clucks of ring-necked pheasants, and recently -- wild turkey.
"I just heard a palm warbler a few days ago in Pelham Bay," Kunstler said, referring to a small yellow insect-eating bird with a brown cap, whose song birders describe as a gentle zhe-zhe-zhe-zhe. Becker said she too heard one -- at the Botanical Garden. It bodes well for more sightings this year.
"May is a great month," she said. "We get really good play -- it was a hot year on warblers last year."