Agricultural development, industry, and urbanization have contributed to the loss of much of the native habitat and the endangered status of animals such as Attwater's prairie chickens, whooping cranes, Kemp's Ridley sea turtles, and Houston toads. During the winter, whooping cranes are present in the bayside marshes, while peregrine falcons and piping plovers are found along the coastline. More than 300 bird species have been recorded for the island, including numerous species of gulls, terns, waterfowl, wading birds, and a variety of songbirds including the seaside sparrow.
Songbird migrations can be equally dramatic.
The fascinating flying methods of magnificent frigatebirds, black skimmers, and black-shouldered kites are entertaining to watch. During winter, look for sandhill crane, northern harrier, and short-eared and burrowing owls on the interior grasslands. Tracks in the sand provide evidence of raccoon, badger, coyote, black-tailed jackrabbit, opossum, and feral hogs. White-tailed deer are frequently seen. Be alert for Atlantic bottle-nosed dolphins while riding the ferry to the island.