Each year Big Bend National Park naturalists track rare bird sightings. These are bird species listed as rare, accidental, hypothetical or not included in the Bird Checklist published by the Big Bend Natural History Association in cooperation with the National Park Service. Lack of rain in the winter of 2005 and spring of 2006 resulted in a late spring migration through the Big Bend area. Also park naturalists speculate that two fires occurring in the Sierra del Carmen Mountains of Mexico during the first half of May probably contributed to sightings of many unexpected species in the Park during the latter part of May. The information presented below was obtained from the US National Park Service.

Brown Pelican and Bonaparte's gull move from hypothetical to confirmed

A highlight and first sighting for Big Bend National Park was a Bonaparte's gull  photographed by Mark Flippo at the entrance to Sant Elena Canyon on March 1. Mark also receives credit for the rare Snow goose on April 3rd, probably the same bird seen by Shane Pruett on March 26 at Rio Grande Village. The least grebe, seen by this birder over 20 years ago, continues to be a rare sighting at RGV near McDaniels Ranch pond. Peter McGregor provided photos of a brown pelican he spotted at Hot Springs from May of 2005, moving the brown pelican to the main list. The Brown pelican spotted by Peter was immature, but his crystal clear digital images showed this species as a first sighting for Big Bend National Park.

The Tropical parula (right) was spotted at Panther Junction by Bob and Angie Dean on March 3rd. The Tropical parula is accidental to Big Bend. The American bittern was seen twice in March on the Rio Grande Village Nature Trail. Two bitterns were seen in April at the same location. The Painted redstart was observed by a number of birders in Boot and Pine Canyons from March 17 through the end of May. The Painted redstart (above left) is sporadic in Big Bend.
A number of rare and accidental warblers were noted including Hooded warbler (left) and the Canada warbler. The Red-faced warbler (pictured to right) is reported, but verification is pending on this accidental species native to parts of Arizona and the central Rocky Mountains. The rare Rose-breasted Grosbeak was observed four times in late April through mid-May by David Elkowitz, Mark Flippo, and George Grier. These were seen at Rio Grande Village Campground, Store, and near Daniels Ranch.