Hawk Watch Monday October 11, 2010

Today was a very interesting one at the Hawkwatch. There were a few Sharp-shinned Hawks up in the air before dawn, and over the next three hours they came through in their usual large numbers. Then, as if someone flipped a switch, there was a dramatic changeover in the breakdown of Accipiters. It went from 242 Sharpies and 35 Coops in the first three hours to 123 Sharpies and 335 Coops over the next four hours.

The increase in Cooper's Hawks after the morning can be explained rather easily, since they just don't become active as early in the day as Sharp-shinned Hawks (they are rather like Buteos in this respect). However the reason for the decrease in Sharp-shinned Hawks is less clear in my eyes. If this mid-day decline is correlated to the increase of Cooper's Hawks, as I suspect it is, then the most likely two factors in my eyes are 1) There are less Sharp-shinned Hawks flying due to the increase in agile predators in the sky (Cooper's Hawks will hunt Sharp-shinneds given the chance), and 2) The Sharp-shinned hawks get extremely high (becoming essentially invisible from the ground) in the sky in order to stay above the soaring Cooper's Hawks. Either way, it is certainly an interesting phenomenon.

Larger Buteos and other late season migrants (notably Turkey Vultures) are increasing in number, and today was great for them with the good thermals. American Kestrels and Peregrine Falcons also put in respectable showings, as did Northern Harrier.

From off the data sheet the highlights were scant, although 2 Eastern Meadowlarks that came over the platform at point blank range early in the morning were treats for all who were present (Which, I believe, was just me). Also seen were a Solitary Sandpiper, 2 Dunlin, and a Cliff Swallow (the latter seen by Tom Johnson), none of which were tallied among the 139 species of yesterday's Big Sit.

Cape May
Cape May Point, New Jersey, USA
Daily Raptor Counts: Oct 11, 2010
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Species            Day's Count    Month Total   Season Total
------------------ ----------- -------------- --------------
Black Vulture               11             39             85
Turkey Vulture              68            215            413
Osprey                      28           1492           4233
Bald Eagle                   9            134            310
Northern Harrier            49            462            933
Sharp-shinned Hawk         434           6112          11332
Cooper's Hawk              456           1495           2379
Northern Goshawk             0              0              0
Red-shouldered Hawk          5             16             21
Broad-winged Hawk           76            637           1090
Red-tailed Hawk             23             80            219
Rough-legged Hawk            0              0              0
Golden Eagle                 0              0              0
American Kestrel            53           1447           4246
Merlin                      17            799           1620
Peregrine Falcon            56            759           1036
Unknown Accipiter            0              0              0
Unknown Buteo                0              0              0
Unknown Falcon               0              0              1
Unknown Eagle                0              0              0
Unknown Raptor               0              0              0

Total:                    1285          13687          27918
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Observation start time: 06:00:00 
Observation end   time: 16:00:00 
Total observation time: 10 hours

Official Counter:        Doug Gochfeld

Observers:        

Weather:
Very light NW wind through mid-day, which then gave way to an onshore south
breeze. Partly cloudy.

Raptor Observations:
Very good push of Cooper's Hawks, especially relative to Sharp-shinneds. 

Non-raptor Observations:
Solitary Sandpiper, Dunlin, Chimney Swift, Barn Swallow, Cliff Swallow.

Predictions:
Light and variable west winds swinging around towards north or northeast by
the late afternoon. Scatted Thunderstorms. With so much uncertainty as to
what exactly the weather will actually do, it is difficult to say how the
flight will be.