Washington Square female hawk with her completely crippled leg on Saturday 11/26/11.
Photo and caption by Lincoln Karim
The metal wildlife band now stuck on Violet the red-tailed hawk’s swollen leg has almost undoubtedly been on her leg for more than four years, presumably without problems for most of that time.
The band, if it is the one wildlife officials think it is, was put on Violet on Oct. 3, 2006, her hatchling year, in New Jersey near the Delaware Water Gap as part of an ongoing study of hawk migration patterns. That band is a size 7B, the correct size for red-tailed hawks.
Violet does not appear to have been documented again by humans again until October 2010, when the wildlife photographer and Pale Male chronicler Lincoln Karimphotographed a hawk in Washington Square Park with a swollen leg and a band jammed in the same position, halfway up her shin. It is widely believed to be Violet.
In December, Mr. Karim brought the hawk to the attention of the head of the federal Bird Banding Laboratory, Bruce Peterjohn, who, after some prodding from Mr. Karim, asked the Long Island-based raptor rehabilitator Robert Horvath to capture the bird and remove the band.
Mr. Horvath told us he did not attempt to do so because the bird was not nesting then and capture would have been difficult to impossible. (Five months later, when Violet’s difficulty with her swollen leg appeared to increase suddenly, it was Mr. Horvath who went to New York University and did the initial assessment of her, at which he recommended her immediate capture.)
The data about the band emerged when a medical rescue team led by the state paid a visit to Violet on May 12, a few days after Mr. Horvath’s visit. The rescuers, who decided not to capture Violet for now, were able to read the last five digits of the nine-digit band number and reported them to the Bird Banding Lab.
While there is a very remote possibility that there is another size 7B band with the same last five digits on another bird, the band is overwhelmingly likely to be No. 1177-60335, Mr. Peterjohn said.
That band was placed by a bander at Stillwater, N.J., on a first-year hawk as part of a 40-year study of migrating hawks along the Kittatinny Ridge in western New Jersey overseen by Giselle Chazotte Smisko, a wildlife rehabilitator with a master bird-banding permit who directs the Avian Wildlife Center in Wantage, N.J.
The study has revealed, among other things, a reduction in fall red-tailed hawk migration that is probably linked not to a drop in the number of hawks but to climate change, Ms. Chazotte-Smisko said.
Ms. Chazotte-Smisko said that the band in question was fitted by a bander with more than 20 years’ experience who has since developed medical problems and is unavailable to be interviewed.
The centuries-old practice of banding birds to track their movements was brought to North America by the ornithologist and artist John James Audubon in 1803. At the time, he tied silver cords to birds; today, the bands are made mostly of lightweight aluminum
While opponents of banding have blamed the band for Violet’s injury, Ms. Chazotte-Smisko said bluntly, “This bird would not be alive now if the band was the cause of the problem.”
Experts, including Dr. Elizabeth Bunting, the wildlife veterinarian who observed Violet up close on May 12, have speculated that Violet may have sustained an injury in the last year or so, such as a bite from a squirrel or other prey, and that the swelling in her leg from that injury pushed the band up from her ankle to her shin, where it is now lodged.
The sedentary period Violet went through when she was sitting on her eggs is likely to have made the swelling worse, Dr. Bunting said.
Update, 3:41 p.m. | Currently, Dr. Bunting said, Violet appears to have good circulation in her leg — despite the swelling, there is some space around the band. The swelling could be due to scar tissue or fluid retention, neither of which is life-threatening, and it is not clear what role the band is playing in the injury, she said.