A high-flying, seven-year romance -- one that produced more than two dozen young peregrine falcons on a skyscraper above the Inner Harbor -- has ended.
Blythe, a female peregrine who had raised young consistently on a 33rd-floor ledge outside the United States Fidelity and Guaranty Building since 1985, hasn't been seen since March 1, said John Barber, a company official who watches over the birds.
She may be dead, Mr. Barber and others fear, since desertion of a mate is almost unheard of among the falcons.
Within two weeks of Blythe's disappearance, however, a new female of unknown origin showed up and quickly became engrossed in courtship behavior with Beauregard, Blythe's mate.
"We continue to see a lot of courtship," said Mr. Barber, a former Smithsonian Institution ornithologist. The birds have been seen making mid-air exchanges of prey, dramatic aerial dives on each other and exhibiting other behavior that indicates a bond is forming, he said.
"Beauregard is courting very, very hard," Mr. Barber said.
The male has occupied the skyscraper, which is similar to the birds' natural cliff habitat along inland rivers and in mountains, since 1983. The dark blue coloring on Beauregard's back indicates the bird probably was hatched in a nest in the Arctic Circle, Mr. Barber said.
The USF&G falcons have always laid eggs around March 12, which is early for peregrines in the region. Mr. Barber said it is hoped that Beauregard's new mate, which has yet to be named, will be incubating eggs within several weeks.
Such a quick turnaround in a pair is not uncommon. In fact, peregrines are famous for it.
Scarlett, the first falcon to occupy the USF&G aerie, died of a throat injury in 1984. Blythe, hatched in a New Jersey nest the year before, showed up on the building within four days.
As Beauregard and his new mate try to forge a bond, Mr. Barber said he will try to determine what may have happened to Blythe. Someone may find a carcass or a numbered band that was attached to one of her legs, he said.
Baltimore's falcons are some of the most famous peregrines in the world. They have been the subjects of numerous press accounts about the recovery of the species, including one in the current issue of National Geographic magazine.
Peregrines, bald eagles, ospreys and other predatory birds suffered greatly from DDT poisoning until the pesticide was banned in 1972. DDT built up in the food chain and caused a thinning of egg shells in peregrines and other birds. Consequently, the species was wiped out in the East by about 1960.
Scarlett was released from the old Edgewood Arsenal, now part of Aberdeen Proving Ground, after being raised in captivity. She and Beauregard are believed to have produced the first wild peregrine chicks in the East since the 1950s.
Now, nearly 100 peregrine pairs nest east of the Mississippi River.Seven pairs nested in Maryland last year, including one on the Chesapeake Bay Bridge and another on the Francis Scott Key Bridge.