Thursday, May 21, 2009

Thunderstorm

A thunderstorm brought an abrupt end to what had started out as another wonderful, warm spring-like day. One moment the sky was full of hawks - the majority broadwings - and the next a chilly wind started blowing from off the lake, the temperature took a steep dive and all the hawks were instantly gone.

In that suddenly dark, suddenly empty sky, a Whooping Crane appeared briefly on the horizon! I saw it well enough to know instantly what it was, and had it in the scope for about 15-20 seconds, but the bird was not close enough for me to see any leg bands. A white crane with dark wingtips against a dark sky is quite a stunning image!

Before that, once again an interesting buteo was seen from the platform. I have no photos of this bird, but it was seen reasonably well by several observers. I took notes of what I saw and I'll describe this bird for you. In essence, the bird was a redtail with a whitish tail. As readers of this blog may remember, some weeks ago there was that "Krider's-like" bird with a tail that was whitish basally, reddish distally. Its underside was very lightly marked, with only the faintest hint of a belly band, and no markings on the underwing coverts. It had a very light head. Today's bird was very different. It had a 'normal belly band' and the head was 'normally dark'. The only two things that struck me as different from the average redtail, were the whitish tail, and the absence of a dark trailing edge on adult-shaped wings. What do I mean by that last qualification? Well, the shape of most buteo wings is subtly different between adults and juveniles. Anyone who has ever spent any time observing juvenile and adult Red-tailed Hawks side by side, will probably have noticed that the tails on young redtails tend to be slightly longer than on adults, and that the wings of adults tend to be broader, with more of a bulge on the trailing edge, than those of juveniles. Adults normally have a dark trailing edge on those broader wings - but today's bird didn't. Juveniles tend to have light primary panels - as discussed in one of the earlier postings - but today's bird didn't.

Hopefully this bird sticks around a little longer and will come in for better views and photo ops, because it exhibits traits associated with light or intermediate morph Harlan's Hawk, a subspecies of the Red-tailed Hawk.

The photo at the top shows a Bald Eagle and a small part of that broadwing flock. Practically all birds were seen in the first hour of the count, which included 3 Bald Eagles, 2 Northern Harriers, 1 Sharp-shinned Hawk, 319 Broad-winged Hawks, 4 Red-tailed Hawks, 4 Rough-legged Hawks, 1 Golden Eagle. Like one of yesterday's Golden Eagles, this bird had very limited white in the wing, and is probably one of those two.

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