Rare and endangered species are those whose population numbers are low and therefore at risk of going extinct (USFWS 2013c). Rare or endangered species are at risk for genetic drift, genetic bottlenecks, and decreased breeding pairs. A population’s numbers may decrease for many reasons. When a species’ population numbers fall dangerous low, they are eligible for addition to the Rare and Endangered Species Act of 1973 list (USFWS 2013c). The U.S. Fish and Wildlife Service and the National Marine Fisheries Service administer the Act (USFWS 2013c). Some of the Federal Trust Species found on the Texas coast are the whooping crane, brown pelican, loggerhead sea turtle, Canada goose, eastern oyster, red drum, white shrimp, and blue crab (USFWS 2013c).