Observations on Marine Mammals in Florida Waters

Abstract

Data are presented on the distribution, measurements and weights, ecology, and other aspects of the biology of 12 species of cetaceans, one pinniped, and the manatee in Florida waters. Most of the records are for the period from 1953 through June 1963, although some for earlier years are included. Records of cetaceans based on strandings or specimens washed onshore, dead specimens seen or collected in offshore waters, and skeletal materials from beaches include a probable one of the little piked whale (Balaenoptera acutorostrata) 1 of the humpbacked whale (Megaptera novaeangliae), 3 of the goose-beaked whale (Ziphius cavirostris), 7 of the pygmy sperm whale (Kogia breviceps), 2 of the sperm whale (Physeter catodon), 1 of the rough-toothed dolphin (Steno bredanensis), 18 verified or probable records of the short-finned pilot whale (Globicephala macrorhyncha), 17 verified or probable records of the bottle-nosed dolphin (Tursiops truncatus), 2 of the common dolphin (Delphinus delphis), and 1 of the long-beaked dolphin (Stenella longirostris). The latter is the second record of this species in Florida waters and apparently the third for North America. Observations on living cetaceans include 16 and possibly 18 verified or probable records for the Atlantic right whale (Balaena g. glacialis), 1 for the humpback whale, 2 for the killer whale (Orcinus orca), 3 and a possible 4th for the short-finned pilot whale, and 10 for the bottle-nosed dolphin. The sight record of the humpback whale apparently constitutes the first record of this species in the Gulf of Mexico. External, skeletal measurements, or both, of Florida specimens of Megaptera, Kogia, Physeter, Steno, Globicephala, Tursiops, Delphinus, and Stenella longirostris are given. One pinniped record obtained was of the California sea lion. (Zalophus californianus), and another probably also refers to this species. Both undoubtedly involve animals escaped from captivity. One individual apparently moved approximately 100 miles from where it escaped in about 10 days . Twenty-five records of dead manatees (Trichechus manatus) and 5 sight records are summarized. Of the former, 10 individuals had apparently been killed by cold, 3 by boats, and 2 by shooting. The cause of death of the remainder is unknown, although the death of 7 individuals in the Fort Myers area in the spring of 1963 coincided with a red tide epidemic in the Gulf to the north. Further evidence of the occurrence of seasonal movements in Florida manatee populations is presented.