Cave Swallows at Playa Corona

Dave Klauber sent in the following report of Cave Swallows seen January 1 at Playa Corona.
2 birds seen perched on a TV antenna on a house on a hill just east of the river outlet, turning left from the path to the beach. The rump was seen on one bird, which appeared very pale, buff/white possibly. From the front the head appeared completely dark, definitely no buff forehead. The throat and upper breast were orange/buff, and the remaining underparts appeared white or off-white. Using the National Geographic guide as a reference, the throat color on the melanogaster race of Cliff Swallow would have been much darker. When the bird flew I did not notice any coloration on the flanks, as would the West Indian race of Cave Swallow, so my guess is it was probably the southwestern pelodoma race, but that conclusion is not definite. The tail was mostly square, with a slight notch in the center.
The birds were observed about 7:30 AM January 1, 2008 for about 10 minutes, mostly perched. They were not present when I returned at 10 AM. It should be noted that southwestern Cave Swallows have been appearing with increased frequency the last 5 years on the northeast Atlantic coast in the USA, and also inland at Niagara Falls. They are typically seen in late November or early December.