BULLETIN FLORIDA STATE MUSEUM


creek samples) but only 0.5 percent of the individuals sampled at
forest stations (17th most abundant species in forest stations). All
other species in the guild are approximately equally abundant in creek
and forest samples. Comparisons with Buena Vista second growth
samples are not made, because most species in this guild were under-
represented at Buena Vista from lack of harp-trapping.
 It appears that a spatial mechanism, specialization in foraging
 microhabitat, permits Trachops cirrhosus, Tonatia sylvicola, and
 Tonatia bidens, all similar-sized gleaning carnivores, to partition food
 resources within the same macrohabitat. T. cirrhosus seems to
 specialize on prey in low foliage along creeks, T. sylvicola on prey from
 groundstory forest foliage, and T. bidens on prey from trees in the
 forest and along creeks.
 FEEDING BEHAVIOR.-The gleaning carnivores eat rather large
 prey items relative to their body weight. It probably is common for
 them to carry prey to a night or day roost for consumption (Wilson
 1971b, Vehrencamp et al. 1977, pers. observation).
 Data on activity cycles are too scant for meaningful analysis. M.
 brachyotis, M. crenulatum, T. sylvicola, and T. cirrhosus appear to
 have a major peak of flight activity in the first two hours after sunset.
 SLOW-FLYING HAWKING INSECTIVORE GUILD
 Eight species belonging to three families constitute the slow-flying
hawking insectivore guild. Four species belong to the Emballonuridae,
two to the Vespertilionidae, and two to the Mormoopidae. An addi-
tional species, Thyroptera tricolor (Thyropteridae), is known only from
a single 1973 sighting in recent years on BCI. T. tricolor perhaps
should be included in this guild if a population still exists on BCI;
however, the species is probably near extirpation on the island because
of plant succession that has resulted in the disappearance of most
large-leaved groundstory plants (e.g. Musa and Callithea) used as
roosts (Findley and Wilson 1974).
 BODY SIZE.-Mean body weights of species in this guild range from
4.2 to 22.6 g (Table 15). Wing morphology and flight behavior (Bonac-
corso, unpubl. data) suggest that species within the same family are
most similar in foraging behavior. Thus, species are grouped in
subguilds by families.
 FOOD SELECTION.-All species of this guild feed largely on small
flying insects. Prey items are eaten on the wing rather than carried to
roosts. Some emballonurids hover around tree foliage and feed to some
extent on insects attracted to host trees (Bradbury and Vehrencamp
1976). One BCI fecal sample from Pteronotus parnellii examined by
Terry Erwin contained leg parts of a small alleculid beetle. All other
samples await species identification.


Vol. 24, No. 4