Friday, March 23, 2012

Best Day of the Year and the Wave Continues-ALERT

Migration Today:
Swainson's Hawks-618
Turkey Vultures-10

Discussion:
A dark morph among some light morphs 3/23/12
Wispy high clouds dominated the sky today. Temperature was warm, 60-s to low 70's. Several watchers came out for the show. We thought that fresh breezes would stimulate the hawks early. The watch began at 6:30A. The flight began at 8:20A, a long wait. Swainson's Hawks roosted on trees leading into the Fun Farm and the date farm as well as isolated trees. At least 60 SW's moved from perches to the ground early. Only a few appeared to be feeding, probably on flying ants. The first liftoff brought the hawks close to the day site. By 9:10A most of the hawks were airborne. Kettles formed and dissipated as the hawks meandered back and forth before streaming toward Coyote Canyon. The day site counted 435 Swainson's. Additionally, 126 SW's were counted flying close to Coyote Mountain. These hawks flew from an outlying area to the east. At 10A a large kettle of Swainson's Hawks was sighted very high toward Coyote Mountain. Additional hawks joined the kettle. At least 50 and probably more SW's were moving close to the mountain toward Coyote Canyon.

Question:
I keep hearing about morphs? What is a morph? A morph is a genetic variation, like blond, brunette, redhead. Most of the Swainson's Hawks we see are light morphs, some are very dark and some rufous or intermediate. Strangely the literature indicates that only 10-15% of California Swainson's are light in summer. See the variation between light and dark in the photo above. Swainson's Hawks do not have subspecies and only Red-tailed Hawks have more color variety.



Evening Watch:
Two hundred plus Swainson's Hawks and 50 Turkey Vultures dropped in this evening. The SW's are roosting across the road from the evening watch site on Borrego Valley Rd. The whereabouts of the TV's is unknown.

Prediction for Tomorrow:
The wind should be light so expect lift off between 8 and 9A. The best place to watch the kettles form are at the evening site on Borrego Valley Rd,  or on Di Giorgio north of the Springs RV Park and at the day site on Di Giorgio Rd.

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