The Pentair building on the north side of I-394 just west of Highway 100 has for years been location of a nesting site for Peregrine Falcons. The nest box is on the east side at the 14th floor. The birds are easily seen, when present, from parking lots to the building’s east.
This year, two falcons fledged. They have been seen recently cavorting with one of the adults in the air near the building. Monday, I photographed the two juveniles there. Both were perched on their nest box at mid-afternoon. One then moved to the north side of the building, perching high to groom.
I watched for about 40 minutes, hopeful that the bird would fly. It did so, making a quick circle of the building, returning to the ledge where it had done its grooming, then flying south and out of sight, its high-pitched call fading behind it.
The age of the birds can be determined by plumage. One bird was perched on its box with its back to me. The terminal band on its tail indicates a bird hatched this spring. Age of its sibling became evident when the bird flew along the building’s north side. The bird is brownish rather than the steely Peregrine grey. The markings on its breast are streaks instead of bands. It lacks the full white breast of an adult bird. The light-colored tail tips can be seen.