Borrego Valley Hawkwatch: Unusual Week-Many Hawks Spending Time In Town-March 13-March 20, 2015

Leaders:
March 13-Rose
March 14-Hal
March 15-Wes
March 16-Herb
March 17-Laura
March 17-Steve
March 19-Joe
March 20-Hal

Migration:
March 13-0
March 14-116 Swainson's Hawks
March 15-52 Swainson's Hawks; 34 Turkey Vultures
March 16-145 Swainson's Hawks
March 17-192 Swainsons's Hawks
March 18-0
March 19-9 Swainson's Hawks
March 20-326 Swainson's Hawks

Discussion:
Almost every day we had Swainson's Hawks on the ground feeding on caterpillars. The caterpillars of the White-lined Sphinx Moth must be very tasty. Hundreds of hawks have been staying in the valley eating the critters. See the life history below. So each day we have some migrants, some hawks staying and new hawks entering the valley. Hawks are arriving all afternoon. They most likely see other hawks on the ground and zero in on the feeding grounds. It has been a chore to count hawks this season. Mainly because of the change in typical behavior. Only a fraction of the hawks on the ground migrate each day. As of March 20th estimates of the number of hawks in town is around 600. I have been raising some of the caterpillars (feeding them California Primrose from my yard). They now have entered the Pupa stage. I am patiently waiting until they become adult flying moths. I began the project March 10. Also below is the adult Painted Lady and the Chrysalis (same as pupa). There are perhaps a few hundred thousand Painted Ladies in the valley. Check out the Youtube for March 13-http://youtu.be/isKSi24qOrw