LOWELL —Each breeding season, peregrine falcons Yvonne and Persi raise their newly hatched chicks in a nesting box atop Fox Hall, an 18-story dormitory facility on UMass Lowell's east campus. But this year's proceedings began with a twist.
On May 28, state wildlife officials transferred two male chicks named Bill and Dave from a nesting area at Westover Air Reserve Base in Chicopee to the UMass Lowell site. The brothers joined Ursula — the lone female hatchling of Yvonne and Persi — on the Fox Hall roof where all three were tagged by the officials.
The foster parents immediately accepted the two brothers, as did their daughter, and the three chicks quickly bonded. The trio did everything together. They ate tasty morsels skewered by Persi and fed to them by Yvonne. They slept in a heap of white feathers under their mother's watchful eye. They strolled unsteadily along the precipitous parapet wall adjacent to the nest box.
Frolicking about is a typical rite-of-passage for young raptors and a prelude to the most ominous stage of the nesting season, fledging — or developing enough strength in their wing and breast muscles to fly.
On June 14, Bill and Ursula toppled over the metal clad parapet wall bordering the roof area. The fledgling daredevils flapped and glided downward fifteen-stories to the cafeteria roof below. Both were rescued and returned to the nesting site unharmed.
A couple of days later, Ursula disappeared altogether. And on June 18, the six-week-old fledgling was found on the cafeteria roof having died of a broken neck, presumably after flying into a window.
Later that day, Bill bolted during a rescue attempt and dashed a quarter mile to the St. Jean Baptiste Church on Merrimack Street, landing on the copper ornament that caps the rear dome, where he perched himself for the night.
The following day, Bill returned to Fox Hall where the wayward wanderer reunited with his brother and adoptive parents.
The fledgling process has come to fruition for Bill and Dave, thanks to their parents' steady guidance and the assistance of volunteers, state wildlife officials and UMass Lowell personnel.
Now seven weeks old, the two juveniles have entered the crucial final phase of their development as raptors — learning to fend for themselves under the auspices of their doting parents.
Currently, the charismatic brothers are honing their repertoire of flight skills: gliding, soaring, hovering and stooping — a dynamic maneuver by which peregrine falcons close their wings and dive almost vertically to catch prey in mid-flight (mostly pigeons, doves and swifts) at speeds that can approach 200 mph.
With flight training well underway, the two young winged marvels are now learning more advanced hunting skills — like killing and defeathering prey — under the wing(s) of their dedicated mentor, Persi.
Once these aspiring birds of prey complete their lessons, say in late July, they will be ready to assert their independence and leave the comforts of the nest site in search of mates and, perhaps, to launch a new cycle of birth and survival in the wild.