winter range. During exceptionally cold weather, 

 water temperatures suitable for the animals may 

 not be maintained. During the prolonged and ex- 

 ceptionally cold winter of 1976-77, 34 manatees 

 died in northern and central Florida in areas 

 north of their historic winter range; many of 

 them had been associated with power plant ef- 

 fluents (Campbell and Irvine 1978). 



PRIORITY INDEX 



Not assigned. 



DESCRIPTION 



The manatee is a large gray or brown fusiform 

 aquatic mammal that lacks a dorsal fin. It is nearly 

 hairless except for stiff whiskers covering the 

 muzzle and widely scattered, fine hairs on the 

 back. The forelimbs are modified into flippers, 

 and the paddle-shaped tail is flattened hori- 

 zontally. Hind limbs are absent. The sexes are dis- 

 tinguished by the position of the genital opening; 

 the distance from the anus is greatest in males. 

 Within its range, the manatee is the only large 

 aquatic mammal exhibiting these characteristics. 



Manatees are usually 3 m long, with a maxi- 

 mum length of 4.6 m reported (Hartman 1979b). 

 Adult weights range between 360 and 540 kg, 

 with a maximum of approximately 1,000 kg 

 (Hartman 1979b). 



Illustrations of manatees have been published 

 in many popular and scientific articles: Simpson 

 (1930), Ledbetter (1960), Walker, et al. (1964), 

 Hartman (1969),Stephens(1972),Okeefe (1973), 

 Vietmeyer (1974), Campbell and Powell (1976), 

 Hartman (1979a), and Reynolds (1979). 



RANGE 



During the wdnter months, U.S. populations 

 appear to be restricted to peninsular Florida, 

 south of Crystal River on the Gulf coast and 

 Titusville on the Atlantic coast. In the St. Johns 

 River, the animals occur from Jacksonville south 

 to at least Lake Monroe (Layne 1965; Hartman 

 1974). 



During the winter, manatees in northern and 

 central Florida congregate around natural and in- 

 dustrial warm-water sources (see Hartman 1974 

 for a list of sites). Winter distribution has expanded 

 northward during the last few decades from 27° 

 52' to 39° 21' on the east coast and from 26° 45' 



to 27° 45' on the west coast. The expansion is 

 probably due to the proliferation of industrial 

 and power-generating plant warm-water dis- 

 charges (Moore 1951b, 1953; Layne 1965; 

 Hartman 1974). 



During the summer, manatees that congre- 

 gate at winter warm water refugia appear to 

 disperse, moving north along the Atlantic and 

 Gulf coasts, occasionally as far as the Carolinas 

 and extreme western Florida. Rarely, sightings 

 are reported in Louisiana and Mississippi and 

 historic records document sightings as far north 

 as New Jersey (Hartman 1974, Campbell and 

 Powell 1976). Sightings north of Georgia are 

 unusual and may represent vagrant individuals. 

 Historic information suggests that the northern 

 Gulf of Mexico coast may once have been more 

 frequented by manatees during the summer than 

 it is now (Lowery, 1974). It is unlikely that 

 manatees could survive there in the winter due to 

 the low water temperatures. 



Occasional sightings in extreme southern 

 Texas may represent remanents of a population on 

 the northern Mexico Gulf coast (Husar 1977). 



Trichechus manatus occurs around many of 

 the Caribbean islands: Puerto Rico, Hispaniola, 

 Jamaica, Cuba, and Andros (Husar 1977). Recent 

 sightings have been reported for Grand Bahama 

 Island (Odell et al. 1968). 



In Central and South America, the West Indian 

 manatee occurs from at least central Mexico 

 south along the coast to the region of Alagoas 

 State, Brazil (Bertram and Bertram 1973, White- 

 head 1977). It also penetrates the Orinoco River 

 in Venezuela to Apure Falls (Mondolfi, 1974) and 

 up the Amazon River an undetermined distance 

 (Bertram and Bertram 1973). 



RANGE MAP 



The range maps (following) show the present 

 distribution, historic range, peripheral sightings, 

 and critical habitat of the West Indian manatee in 

 the United States. 



STATES/COUNTIES 



Alabama: Baldwin, Mobile. 



Florida: Bay, Brevard, Broward, Charlotte, Cit- 

 rus, Clay, Collier, Dade, De Soto, 

 Dixie, Dural, Escambia, Flagler, 

 Franklin, Gilchrist, Glades, Gulf, 



