After pulling in to observe the Woburn Peregrines, had a nice show from three Cooper’s Hawk in an active series of aerial loops and active chase sequences.  The participants included two adult Cooper’s and a juvenile.  The juvenile Cooper’s has yellowish eyes and thin dark breast streaks.  At one point, the unbanded male peregrine falcon asserted his territorial defense with two chase efforts and then was satisfied with no further action!  The juvenile Cooper’s was a beauty to watch and photograph in fading late day low light!