The Neotropic Cormorant is very common on the Mexican border. The Galveston area also supports a large population. This cormorant is the only one that ranges over the entire tropical American region of Western hemisphere thus having the name neotropic. It was known as the olivaceous cormorant in earlier times.
The neotropic is a blackish bird with a long tail that holds its neck in a S shape. The pointed posterior edge of the gular skin is often pointed with whitish border. Their bill is long with a hook on the end. Juvenile cormorant begin brown and slowly shift to black with their adult plumage.
Cormorants swim well and dive for fish from the surface. The staff and volunteers know the cormorant at the center is feeling better because it is doing a great deal of vocalizing. This consists of a low gutteral pig-like grunt. Every time they hear it everyone’s head snaps to attention thinking someone just brought in a pig.
Upon leaving the water the cormorants hold wings and tail open in a “spread eagle” fashion to dry them. And while holding the wings out to dry seems like a good idea, why do so few exhibit this trait, all sea birds and water birds get their feathers wet. Some researchs believe that the “spread eagle” pose is a method of themal regulation. Vultures often great dawn in this same pose as if to capture every possible ray of energy. Cormorants pose in this manner once they return from a dive, so the spreading of the wings could provide better surface area for drying, but also aid in capturing the sun’s warmth. A unique feature for these birds is how they water proof – or don’t. Because they spend a great deal underwater their feathers are not meant to make them buoyant. In fact buoyancy would be a negative for a bird that dives into the water and propels itself with its feet to capture prey. Experts disagree on the types of waterproofing substances the cormorant produces and whether all feathers are groomed with it or if only the thin layer of down that protects the skin (as compared to a duck). Only the cormorant’s hairdresser knows for sure.
The Neotropic Cormorant is more delicate when compared to their North American counterparts such as the Double-crested Cormorant. So without scale to tell you if this cormorant is on the big side or the little side and without a birding guide to tell you the small physical differences, the Double-crested Cormorant can only perch on a flat surface like a piling, the Neotropic Comorant can perch on wires and is often seen hanging out on the lines tying a fishing boat to the dock.