The young Peregrines were out in full force this afternoon in and around the Verizon Cell Tower on Hampshire St.  This has been a regular location for the young Peregrines over the past few years after they have fledged.  One of the two females, the one with leg band, BV/66 was seen on the rooftop on the Verizon Tower while taking a short break.  These young Peregrines spend a lot of time in playful mock combat and then time to res

Observed one of the peregrine fledglings in aerial flight with large loops and infrequent diving stoops. Quite an exciting show from the young fledgling. To my surprise, another fledgling joined the fun and the real show got underway! For over 20 minutes, they proceeded to engage in an amazing demonstration of playful mock combat. Here is
an explanation of mock combat from Cornell’s Birds of North America:

Play occurs mainly in young. Immatures will pursue adults, siblings, prey, and attack inanimate objects.  Playful pursuit of siblings begins 2–3 d after first flight, mock combat between siblings begins 4–5 d after. Mock combat progresses from flying parallel and occasionally rolling to extend feet toward siblings, to making short darting dives and grappling in the air, to using air currents to make vertical stoops. Latter develops within 3 wk of flying. Play in falcons may be an expression of joie de vivre or it may simply represent the maturation of neuro-muscular coordination and central control mechanisms involved in agonistic behavior and pursuit and 
capture of prey.