Loggerhead Key existed on the island in the early 1900s. Fauna of Loggerhead Key includes sea turtles, which are monitored by park rangers with the Dry Tortugas National Park to document nesting and hatching rates. The loggerhead sea turtle is also present on the island. In August 2016, a National Park marine biologist stated that 113 loggerhead turtle nests existed on the island at that time. This was the highest recorded nest rate compared previous years. The island also has brown pelicans. In 1972, hundreds of rhesus macaque monkeys were brought from India to Loggerhead Key by Charles River Laboratories. This was
Loggerhead shrike be energetically stressed and underweight. Insects are consumed in mid-flight, but vertebrates usually require more handling time and therefore more energy. Due to the shrike's small size in proportion to the size of its prey, it must rely on specialized adaptations to facilitate its hunting. The powerful, hooked beak of the loggerhead shrike allows it to sever the neck of a small vertebrate. Larger prey are subjected to impaling, in which they are pushed down into a sharp projection, such as a thorn or barbed wire. The bird can then tear off flesh by using the projection as an anchor.