BULLETIN FLORIDA STATE MUSEUM


to fruit diets in the dry season. M. brachyotis also eats nectar and
pollen. An individual captured in mid-December was thoroughly
dusted with the pollen of a balsa tree (Ochoroma lagopus).
 TONATIA. Insect, arachnid (spiders), and lizard fragments were
 found in the fecal samples of T. bidens. Insects, arachnids (whipscor-
 pions), and plant materials were found in the feces of T. sylvicola on
 BCI. A very large male cicada (Fidicina mannifera) that weighed 2.5 g
 was carried into a net by a T. bidens in July of 1974. The prothorax of
 the dead cicada had been crushed by the bat's teeth. Because this
 event occurred in the mating season of the cicadas, during the loud
 nocturnal chorusing, it posed the question of how Tonatia locates such
 insect prey. Do these bats find such prey via echolocation or by sounds
 produced by the insects?
 Two T. bidens, one male and one female, were released on separate
 occasions into a large outdoor flight cage on BCI. Both individuals
 were immediately attracted to calling male cicadas that I held by
 forceps inside the cage. The cicadas were plucked from the forceps by
 the flying bats and eaten after the bats had roosted. Female cicadas
 (which are not capable of singing) held so that their wings could not
 move in the forceps were ignored by these bats; however, when the
 wings were allowed to flap noisily, the bats again were attracted to the
 cicadas and ate them. During later experiments large nocturnal
 grasshoppers, katydids, beetles, and moths placed on the inside cage
 screening were "gleaned" from the screening and eaten by these bats.
 It is obvious that T. bidens was able to locate cicadas from sounds pro-
 duced by the cicadas, but whether other large foliage-clinging insects
 were echolocated or detected from insect-produced sounds or detected
 by some other sensory system remains an interesting question.
 PHYLLOSTOMUS. Insects and fruits were found in the fecal samples of
P. hastatus on BCI. It also has been reported by several authors to eat
birds and rodents (Gardner 1977).
 VAMPYRUM. V. spectum (the false vampire bat), the largest New
World bat, feeds primarily on birds, rodents, and bats (Vehrencamp et
al. 1977). A hollow roost monitored by Vehrencamp et al. in Costa Rica
had remains of doves, parrots, trogons, cuckoos, anis, and many other
birds weighing between 20 and 150 g. These authors suggested that
Vampyrum locates prey primarily by olfaction, striking animals at
communal roosts with strong odors. D. J. Howell and I kept a Vam-
pyrum alive in captivity for three weeks on a diet of small bats and
birds (10-120 g). When released in a large room with small fruit bats
(10-20 g), the false vampire would fly up behind its flying victim and
slap it into its jaws with a wingtip. One morning at sunrise on BCI, a
false vampire circled about an Artibeus jamaicensis I was untangling


Vol. 24, No. 4