From my good friend Tom Lera:
Sharp-nosed Bat (Rhynchonycteris naso)
These are common bats and fairly easy to see roosting over or beside water during the day. A distinctive feature is the way that they roost in groups of anything from 3 to 45 in a line one above the other about 2 to 4 inches apart.
They roost on the lower side of a large branch, the steep face of a bank, below a bridge or, as in this photo, on the lower side of a leaning tree trunk. From a distance they look like a vine wrapping around a branch, but as you get closer you see that they are bats.
The natural enemies of the Sharp-nosed bat are hawks, falcons and herons.