Friday, July 08, 2005

Trump Baby I.D. tips: Blakeman --7/7/05

Photo by Lincoln Karim
July 5, 2005

Marie,

I mentioned in a recent post that it would be really good to be able to confidently separate and identify the eyasses. I looked at Lincoln's photo today of the two eyasses staring right at the camera and I noticed that the bird sitting on the right appeared to have a slightly light-colored patch on the lower edge of the upper bill, on the eyass's right side just under the nasal opening (the narr). This should be watched for, to see if the patch persists. If so, we have something to separate the birds early on.

Those on the ground there can be looking for similar distinctions. The bird facing the camera is starting to exhibit the rather uncommon (from my Ohio experiences) saturated yellow-beige (or whatever color it is) chest feathers. Ohio birds tend to be much whiter. I think this is a genetic trait passed down from Pale Male Sr. It appears in eyasses in previous years at the 927 nest. I don't think it's typical in any Eastern red-tail population. We will want to watch the chest coloration closely, as this might vary nicely between the two birds, allowing a good ID mark.

Right now, from what I can see, both birds appear to be equally sized. I have no idea if they are males or females. Even if I had both of them in hand, it's virtually impossible to sex them at this stage without comparisons of size differences. We'll just have to watch them closely. They will be exploding in growth in the next two weeks. Their behaviors, also, will change dramatically. Soon, the eyasses will begin to tear off bits of meat. The parents will soon terminate the bit-by-bit feeding that worked so successfully in the downy stage. The little blighters will soon enter a nestling adolescence and start to grab at food, squawk a lot at parents, even grab each other's food from time to time. Their feeding habits will be ever more crude and indelicate as they try to harden neuromuscular circuits involved in foot, leg, and mouth coordination patterns involved in eating. Even adults never become particularly adept at careful flesh-ripping. Their small brains don't devote much neuron space for fine delicate feeding habits. Feeding is rather crude for hawks of all ages, but especially so for inexperienced eyasses trying to feed themselves for the first times.

Sincerely,

John A. Blakeman

P.S. from Donna 7/7/05:
On the matter of telling the eyasses apart, at least
currently, the gape line of one is darker than that of the other.