Update February 11, 2008: added a comparative spectrogram and improved audio of the bird - thanks to Chris Benesh - at the bottom of the page:
This "Southern" White-crested Elaenia (Elaenia albiceps chilensis ) was found by Dan and Honey Jones at the Sheepshead woodlot, South Padre Island on February 09, 2009 - here photographed and recorded by me on February 10, 2008. This is not only a new bird for Texas and the United States, it is a new species for the AOU Checklist Area (which extends to the southern border of Panama), as it has never before been documented outside of South America - indeed this form may never have been documented in the Northern Hemishpere before!:
Below there is a shot of the Texas bird on the left, with a small pic I took in Chile near the Straits of Magellan in Feb 1990 of a chilensis WC Elaenia - note that this individual was keeping its crest unusually flattened:
NOTE: - my recording is much weaker than most of those at Xeno-Canto, so adjust your volume accordingly...
Update February 11, 2008: Thanks to the efforts of Chris Benesh I am able to add an improved version of my audio recording (two notes), plus below a spectrogram comparison of my audio of the Texas bird (on the left) with a recording of E.albiceps chilensis by Sjoerd Mayer (Xento-Canto cat. #1652) (on the right):
