I had a note in my inbox titled “odd molt?” and the subject of molt always interests me. So, I opened the email from my friend Matt, and he was wondering what was up with the juvenile Broad-winged Hawk (right) he photographed in Texas on April 24th. He mentioned Bill Schmoker photographed it alongside him, and Bill’s picture is below as well. Juvenile Broad-winged Hawks are just starting to molt this time of year. Some birds start in mid-April, and some start as late as late May/early June. When I was counting hawks in the East in spring throughout the ’90s, I found that some of the early juveniles (late April) had just started their molt, and many of the later birds (up to a month and a half later) had just begun their molt. My questions were: why were these birds showing up later, and why were these late birds also starting their molt later? It couldn’t be because they were headed so much further north than the earlier migrants since they were already as far north as Lake Ontario. So, I wondered if the earlier birds were in better health and the later birds were possibly a bit less healthy? I don’t know, but the observation was always interesting to me. And, if there are any hawk watchers out there who want to follow up with a study, that would be wonderful.
Anyway, back to the bird in the photos — the tail having one-half adult feathers is not a result of molt. Raptors do not molt one side of the tail first, then proceed to the other half; the normal molt sequence is much different and stuttered than that. Most likely, this bird lost its feathers by accident or some type of trauma where the feathers were pulled out and were replaced with adult feathers (which is normal, juvenile or juvenile-like feathers would only come in if the bird was very young). I have seen other examples of this on Red-tailed Hawks and Cooper’s Hawks, and it always looks odd.
This post was written by Jerry Liguori. You can read more about Jerry and his legacy at HawkWatch International here.
