Bird Observer - The New England Birding Journal

Bird Observer

The Birding Journal for New England

December 2015

Vol. 43, No. 6

A New Peregrine Falcon Nest at Boston University Medical Campus

Jeffrey Boone Miller


June 22, 2015. Young falcons visited by a parent (Photograph by the author).

Here’s what I usually see from my office window: a sliver of sky, a handful of locust trees, distant rooftops, and, dominating all, an almost featureless concrete wall that is twelve stories high. In this cityscape, birdlife is usually limited to pigeons, starlings, gulls, the occasional crow, or, on a good day, a Red-tailed Hawk.

One morning in March 2015, however, out of the corner of my eye, I noticed something zip by my window that was big, dark, and fast. My first thought—maybe just a hope—was falcon. It took a few days before I finally got a good look. Yes, it was a Peregrine Falcon (Falco peregrinus). This bird was perched on an inaccessible ledge that is almost the only feature of that concrete wall across the street from my office. About ten stories up but two stories below the roof, this southeast-facing ledge is part of the Dr. Solomon Fuller Mental Health Building, which is located on the corner of Albany and East Newton streets on the Boston University Medical Campus in Boston.

By the end of March, I felt sure that I was seeing two falcons, but I never saw them together until early April when they appeared on the ledge together. Through 8x binoculars, I could see that one was somewhat smaller than the other. Upon enlarging the digital images that I took with a 300-mm lens through my all-too-grimy window, I could see that one bird was unbanded. The other bird, however, had two bands on the left leg— upper black over lower green—and one grayish band on the right leg. This banding and color scheme is currently the standard for eastern Peregrines, with the right leg band made of metal with a unique nine-digit identifying number and the two left bands carrying alphanumeric codes (Center for Conservation Biology 2015). Unfortunately, the codes were not distinct enough to read in my much enlarged photos of the bird in flight.

Because the falcon’s ledge was so high above the street, the view from my fourth floor office was from below. Indeed, there was no location in our building where I could observe the site from above. However, over the next few weeks, I stole glimpses away from my work as life picked up pace for the falcons. Here are the highlights:

April 28, 2015: At about 8:00 am, the two falcons were back on the ledge where they engaged in a series of brief copulations. At this time, I could see that the male was banded and the female was unbanded.

Mid-May through mid-June: Several times, I saw one falcon land on the ledge, often with a prey item, eat and preen for several minutes, and then move out of my sight as the second falcon appeared and flew off. Perhaps handing off incubation duties? Prey items were typically pigeons or starlings, though one was an unidentifiable rodent.

June 17: Babies! The heads of two downy youngsters appeared above the ledge when one parent arrived with food. The babies continued to appear at times over the following days (see photo). I thought they appeared to be three to four weeks old, with one perhaps a few days older than the other.

July 3–7: On July 3, both youngsters were present and active on the ledge, indulging in much flapping of wings and even short hopping flights from one end of the ledge to the other. Meanwhile, one or both parent birds were often perched on and calling loudly from the roof of my building directly across the street. On July 6, one youngster remained on the ledge, but both were gone on July 7. It appeared that both had fledged successfully.

Shortly after the falcons fledged, I contacted Tom French, Assistant Director of the Natural Heritage & Endangered Species Program in Massachusetts, about this nest. He referred me to Anita DeStefano, a professor of Biostatistics at Boston University, who also had observed the nest and sent me several excellent photos, and to Dave and Ursula Goodine, who are volunteer Peregrine Falcon monitors for the Massachusetts Division of Fisheries and Wildlife. Unfortunately, there was bad news about one of the fledglings; Tom French reported that it had been hit by a car on July 6 and was not expected to survive. On the other hand, the second fledgling may have had better fortune, because as of October, a juvenile Peregrine is still making occasional flights past my window.

Ursula Goodine was able to read the bands and identify the male. The code on the male’s bands—a black zero over a green Z—identified him as a bird hatched in Manchester New Hampshire and banded by Chris Martin of New Hampshire Audubon in 2008. Ursula gave him the name Zorro in 2010, and the Goodines have been following him since then. In 2010 and 2011, they observed him with young near Boston Children’s Hospital, though the nest site was not found. In 2012, Zorro and his mate reared two chicks on Buick Street on the Charles River Campus of Boston University, but he was not seen in 2013 or 2014. Thus, it amounted to an unexpected reunion when the Goodines found Zorro at the new nest in 2015. As for the unbanded female, it is unknown where she came from or even if she is the only female that has been with Zorro since 2010.

Peregrine hatching typically occurs about four and one-half weeks after eggs are laid and fledging occurs about six weeks after hatching (White et al. 2002). On this timetable, the two young falcons I observed would have hatched around May 25 from eggs laid around April 24. Perhaps due to the late arrival of spring weather after the brutal winter of 2014–15, this timing was delayed three to four weeks compared to the early April egg-laying common in Massachusetts (Massachusetts Division of Fisheries & Wildlife 2015).

This new nesting site had characteristics typical for middle-latitude Peregrines (White et al. 2002). In particular, the site had a partial southern exposure, was about a hundred feet above the ground, and was not at the highest part of the structure. In addition, Peregrines usually re-use a nest built by another species, and my colleagues told me that this site had been used by Red-tailed Hawks several years ago—before my arrival at the university—and sticks remaining from the hawk nest can be seen in the photo. However, 2015 appears to have been the first use of the site by Peregrines.

The reintroduction of Peregrine Falcons to the eastern United States is one of the great conservation success stories of our era. Nonetheless, Peregrines remain rare with only about 30–35 active nests known in Massachusetts as of 2015 (Boeri 2015, Massachusetts Division of Fisheries & Wildlife 2015). Remarkably, Boston University hosted two successful Peregrine nests in 2015. In addition to the one I’ve described, there was a nest with three chicks on a dormitory tower at the Charles River Campus (Boeri 2015, Laskowski 2015), which is about three miles from the Medical Campus. In 2014, I also saw a pair of copulating Peregrines in Cambridge at Harvard University’s Memorial Hall, where a nesting platform has been built after the eggs failed to hatch in 2014 (Powell 2015). One is tempted to conclude that Boston falcons find our universities to be particularly hospitable. Nesting sites are often reused by Peregrines for many years, with the Custom House Tower in Boston a good example. So I can hope that a pair will be outside my window next year, but, if not, I at least have this year’s memory to soften the view of that concrete wall.

References


Jeffrey Boone Miller is a Professor of Neurology and Physiology at the Boston University School of Medicine, a member of the Board of Tutors in Biochemical Sciences at Harvard University, and an Associate Editor of Bird Observer. Jeff is an advocate for birding locally and habitat preservation. He thanks Kathleen Buckley, Anita DeStefano, Dave and Ursula Goodine, and Tom French for information.

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