Peregrines!

With 261 Peregrine Falcons counted over the last three days, it has truly been a fantastic time to see this animal in Cape May. If you spent any time at all at the hawkwatch in the Point this weekend, it is likely that this fast pointed shape is indelibly scorched into your retinae:


Most Peregrines that migrate through Cape May are fairly pristine, either as fresh juveniles or as recently-molted adults in fine feather. With all the wandering falcons in town, however, it is evident that not all adult-type (older than juvenile) Peregrine Falcons finish molting before migrating. At least three birds that passed the Point on Saturday were still growing new primaries in the outer "hand" of the wing. Here I don't discriminate between subadult and adult Peregrines, but it seems at least plausible that the birds that are overlapping molt with migration are subadults or younger adults. The birds in the photos below might just look like ratty falcons, but try to look past the lack of clean edges on the wings and you might be able to see the difference between the paler, more worn older feathers and the darker, crisp, fresh feathers that are recently replaced or growing in. At migration sites where most birders see Peregrine Falcons, we don't often get to appreciate feather replacement in raptors, but it really is a critical part of each bird's life. Without annual molt, these falcons wouldn't be able to maintain feathers of a quality that could support their breathtaking flights both in hunting and migration. Keep in mind that these falcons, like many other birds, typically replace their primaries one by one in sequence from the middle of the wing (inner primaries) moving towards the outside of the wing (outer primaries).

The color difference between the fresh block of newly replaced primaries in the middle of the "hand" and the paler, worn, unreplaced outer primaries is striking on this individual which is growing P7 (the fourth primary from the wingtip) on both wings. It is also interesting to notice on this individual that the recent wave of primary molt did not include the two innermost primaries on each wing, but instead started with P3 and moved outwards toward the outermost primaries.


These last two photos are of the same individual falcon, and show how different a single bird can look given the wing posture. In the photo with the wings almost fully spread open, the active primary molt and several sites of secondary replacement are obvious, whereas these areas are much less obvious in the second photo which shows the bird in a more close-winged glide.