I got up early this cold windy morning after the front had blown in to take Honey to work and decided either the bird was gone or it would be hanging out at the feeding station where it was seen yesterday and someone would report it. Either way I was going back to bed. And sure enough after I got up I found the Cassin's Finch had been sighted again so I raced over to Resaca de la Palma and after a brief wait spent chatting with Robin Zurovec and John Yochum, the bird made it's appearance. Saves me a long trip to the Panhandle or West Texas to look for one.
Separating this species from female Purple Finch is not an easy task but the comments by the big brains on ID Frontiers all said Cassin's Finch mostly based on the white underparts with sharp streaking and the long straight culman. Cassin's Finch is a bird of the Rocky Mountain high country that periodically invades Texas when winter food crops are in short supply. This is the second record for the RGV with one occurring on South Padre Island during November 2000. As this appears to be a good montane invasion year, I'll still probably head up to the Panhandle or West Texas but I don't need to worry about finding a Cassin's Finch now.
A little post script: Here's a photo of the male Purple Finch from the SPI Convention Center on 4/4/13.
And a House Finch from the University of Texas at Brownsville campus.
So now I've seen all three of the normally occurring US Carpodacus (now Haemorhous) finches in Cameron county. Pretty cool.