Fossil Bats 1 15 



with aquatic habitats, including such obligate freshwater species as gar, 

 Lepisosteus; bowfin, Amia\ Siren and Amphiuma; two species of ranid 

 frogs; Alligator; two species of water snake, Nerodia; four species of 

 kinosternid mud turtles; a number of species of ducks, rails, herons, and 

 egrets; and the round-tailed muskrat, Neofiber alleni. The large compo- 

 nent of aquatic vertebrates supports the sedimentological and paleobo- 

 tanical evidence that the deposits were formed in a shallow freshwater 

 pond or marsh. Based on the presence of a number of strictly terrestrial 

 forms in the fauna, several other habitats were certainly present in the 

 immediate vicinity, including mesic hammock and pine flatwoods. 



The presence of a diverse bat fauna at Vero is somewhat difficult to 

 explain in the context of the freshwater pond or marsh habitat sug- 

 gested by Weigel (1962). In Weigel's scenario of Vero (1962:49), "Bats 

 flew over the pond and marsh in search of insects. . . ." It is true that bats 

 commonly fly over open water, both in search of insects and to drink, 

 but bats are usually absent or extremely rare in fossil deposits sampling 

 such habitats. A large number of Pleistocene sites in peninsular Florida 

 were deposited in marshes, swamps, or fluvial environments, several of 

 which have abundant microvertebrate samples. Yet, except for Vero, 

 only two specimens of fossil bats are known from Florida sites sam- 

 pling such habitats — the type specimen of Molossides floridanus 

 {-Eumops glaucinus floridanus) from Melbourne, and a mandible of 

 Lasiurus intermedins from the Glyptodont Site, Catalina Gardens, 

 Pinellas County. 



The roosting ecology of the bats recorded from Vero provides some 

 insight into the problem, as all six species are known to roost in trees. 

 None of the bats from Vero normally roost in caves in the southeastern 

 United States. In contrast, the two most abundant and widespread bats 

 found as fossils in northern Florida cave and fissure deposits are Myotis 

 austroriparius and Pipistrellus subflavus, both of which roost in caves at 

 certain times of the year. The absence of these two species from the 

 modern fauna of south Florida, except for accidental occurrences, is 

 almost certainly related to the absence of dry caves south of Citrus and 

 Marion counties. 



Unlike any other Quaternary bat fauna known from Florida, Vero 

 offers a unique view of the late Pleistocene and Holocene bat fauna 

 associated with riparian habitats. Generally, tree-roosting bats and bats 

 associated with freshwater habitats are rare or totally absent from fossil 

 sites deposited in caves, fissures, or sinkholes in north Florida, as in the 

 case of Nycticeius humeralis and Eumops glaucinus. The exact mode of 

 deposition of the bat fossils at Vero is still a matter of speculation. 

 Perhaps the bat carcasses accumulated in hollow trees alongside the 

 pond or marsh and were eventually washed in when the trees fell. The 

 great abundance of other small mammals in the Vero deposit, especially 

 shrews and small rodents, suggests the possibility of a raptor roost in 

 the vicinity of the pond, most likely that of Tyto alba. 



