As Reported by Mel Cooksey:
A post-breeding Curlew Sandpiper was spotted, apparently a female, in the flats at the mouth of the Cayo del Oso in Corpus Christi. Mel spotted the bird about 7:30 PM on Monday, August 17th, and worked frantically with the remaining light to get digiscope photos, but could not.
Directions: Go to the intersection of Ennis Joslin and Ocean Drive. Park in the parking lot of the closed restaurant on the north side of the intersection. Walk down into the flats about ¼ mile or so, to the edge of the water in the very center of the flats. The flats are dusty dry, maybe slightly damp in the morning. Walk to the waters edge, and scan the shallow pools, around the short vegetation and small mangroves. There are LOTS of shorebirds here, with hundreds of Western Sandpipers as the main species, so it may take awhile to find the bird if it is still there.
Description: You are looking for a Dunlin-sized bird, although not as "squat", a bit more delicate, and longer-legged, although not as long-legged as Stilt Sandpiper. The main feature is some remnant blotchy rufous feathers on the belly. These show up well. The bird is in pretty advanced molt, well on its way to full basic. The back feathers appear to be a combination of black/white/gray mostly old feathers. There are some cold gray new feathers mixed in, maybe mostly around the scapulars. The belly appears to be mainly whitish, with some black spotting. I noticed no rufous feathers around the head or throat; they were whitish gray and appeared to be very lightly streaked. If you are chasing this bird, just look for the rufous markings on the belly. If you have The Shorebird Guide by O'Brien et. al., check the molting female at photo 5 on page 297. This is very close to our Oso bird. I noticed a whitish area at the lower back, and don't know if this was feather wear, or the white rump exposed below primaries.
A key feature is the bill shape. It is all black, very thin and gradually decurved throughout its length, with a thin tip. Dunlin has a slightly heavier bill, with a more abrupt droop at the tip. Here is a photo of Dunlin and Curlew Sandiper together, to illustrate bill shape.
It is really too early for Dunlins, although I did see one in full basic plumage at this location on Saturday. There are numerous Stilt Sandpipers present. Be advised there is also a Red Knot present, which would likely be the only other bird with reddish blotches on the underparts. There are lots of dowitchers, mainly Short-billed.
I was able to see the bird fly for a short distance, and clearly observed the white rump with NO central line, and gray upper tail feathers. My total observation time was about 20 minutes, at about 70-80 feet. The bird probed and picked at the surface, and was quite active. There is lots of scattered short vegetation which makes photography rather difficult. Especially when you're a lousy photographer like me. Will try again on Tuesday, August 18th, in the morning for photos.