I know it is quite late for this particular bird, but I honestly can not fathom it being anything else. Bird was similar in size to the nearby Piedbills, so too large for a Least, and too small for a Horned. Bird was wet from diving, but the head was all dark except for what appeared to be some lighter colored individual feathers behind the eye and ear region. a bit of flash of longer feathers at one point when it was preening but lost that when it dived again shortly. The eye appeared to be red, but I only got a quick look before it dived and then came up too far away in the pond for me get another look. Bird was on the right side of the bridge when I first approached to observatory pond around 5:00 pm. Vicki Crutchfield Live Houston and work in Galveston, TX Cell : 409-789-1178