throughout south Florida, but is sometimes 

 found in greatest numbers on the shallow 

 grass flats in Florida Bay. Small egrets 

 and herons probably all feed occasionally 

 on the shallowest, exposed flats, but are 

 generally limited by water too deep for 

 them to wade. The ecology of wading birds 

 and their feeding behavior have been re- 

 viewed by Kushlan (1976, 1978). Odum 

 et al . (1981) reviewed the extensive avi- 

 fauna of the mangrove regions of southern 

 Florida. 



5.6 MAMMALS 



Some marine mammals also feed in sea- 

 grass beds. Odell (1979) reported that 

 although 27 species of marine mammals were 

 either sighted alive or reported stranded 

 on beaches in south Florida in recent 

 years, only 2 were common: the manatee 

 ( Trichechus manatus ) and the bottlenose 

 dolphin ( Tursiops truncatus ) . 



Although the range of the manatee was 

 formerly much larger, now it seems largely 

 confined to the protected regions of 

 Everglades National Park. Odell (1976) 

 surveyed the manatee distribution in 

 the Everglades region. Of a total of 

 302 herds with 772 individuals, 46? were 



sighted in Whitewater Bay, 20% in the Gulf 

 of Mexico, 23% in inland waters, and only 

 1% in Florida Bay. A later study (Odell 

 1979) reported no manatee sightings in 

 Biscayne Bay. 



The bottlenose dolphin is the most 

 common marine mammal in south Florida 

 waters and feeds over grass flats, even 

 those less than 1 m (3.3 ft) deep. In the 

 Everglades National Park region, Odell 

 (1976) reported that 36% of the animals 

 seen were in the Gulf of Mexico, 33°i were 

 in Whitewater Bay, 20% were in inland 

 waters, and 11% in Florida Bay. The rela- 

 tively low numbers in Florida Bay were 

 probably due to the extreme shallowness 

 which would preclude swimming for this 

 large mammal. Bottlenose dolphin are 

 opportunistic feeders, primarily on fish. 

 Their diets are not well known, but they 

 consume large quantities of mullet in 

 Florida Bay. 



By comparison with the Everglades 

 region, Biscayne Bay had a low dolphin 

 density. Odell (1979) found that in 

 aerial surveys of the two regions, 11.4 

 animals were sighed per flight hour in the 

 Everglades area, while only 1.25 animals 

 per hour were seen in Biscayne Ray. 



56 



