formation on reproduction for seven other rare spe-
cies of bats were added: Hylonycteris underwood!
(Fig. 7.3) and Anoura cultrata (nectar feeders); En-
chisthenes hartii, Platyrrhinus vittatus, and Sturnira
mordax (frugivores); and Myotis oxyotus and Myotis
riparius (aerial insectivores; LaVal 1977). A checklist
of mammals from several OTS sites, including Monte-
verde, provided the first comprehensive appraisal of
mammal distributions in the area. This checklist in-
cluded 71 species for the Monteverde region, and
listed another 11 species as "expected to occur" in the
region (Wilson 1983). Dinerstein (1983) reported that
he encountered 35 species of bats in Monteverde. The
first Costa Rican records of the Doubtful Oak Bat
and Tacarcuna Bat were from Monteverde (Diner-
stein 1985). Alston's Brown Mouse was studied by
E. Hooper and colleagues (Hill and Hooper 1971,
Hooper 1972, 1975, Carleton et al. 1975, Hooper and
Carleton 1976). This mouse is almost wholly diurnal,
with the greatest activity taking place in the morning
(0700-1100 hr). It feeds predominantly on insects.
Vocalizations contain both sonic and ultrasonic com-
ponents. Adult mice have a repertoire of squeaks of
various intensities and a long (10 sec), sustained call
that has been termed a song. The songs carry well in
Figure 7.3. Underwood's Long-tongued Bat (Hylonycteris
underwoodi). Photograph by Barbara L Clauson.the field and some are audible to the human ear. The
Brown Mouse is one of four species of singing mice in
Monteverde (see Langtimm, "Singing Mice," p. 236).
Small-eared shrews are extremely abundant but
seldom seen in the Monteverde area (Woodman 1992,
Woodman and Timm 1993). Blackish Small-eared
Shrews occur in a wide array of habitats from 870 to
1800 m. Two other species of small-eared shrews
occur at higher elevations in the Monteverde region,
and one is being described as a new species by
N. Woodman and R. Timm.
In a revision of the pygmy rice mice of the genus
Oligoryzomys, Carleton and Musser (1995) reported
that two species (O.fulvescens and O. vegetus) occur
at Monteverde, which is one of the few locali-
ties where the two species are sympatric. The only
reported species in this genus in Costa Rica was
O. fulvescens. However, O. vegetus (Fig. 7.4), which
was previously known only from Panama, has now
been captured in the Monteverde community, in the
MCFP, and on adjacent Cerro Amigos. In the Monte-
verde area, O. vegetus ranges in elevation from 1400
to 1760 m. Oligoryzomys fulvescens occurs only at
lower elevations in the community (1400 m), and in
the Guanacaste and Caribbean lowlands.
Other studies that include specimens from Monte-
verde are concerned with the taxonomy of shrews
(Choate 1970) and opossums (Gardner 1973), phyloge-
netic relationships of rodents (Carleton 1980, Steppan
1995), taxonomy of deer mice (Huckaby 1980), bioge-
ography of rodents (McPherson 1985,1986), distribu-
tion of pocket gophers (Hafner and Hafner 1987), sys-
tematics of water mice (Voss 1988), ecology and distribu-
tion of bats and rodents (Timm et al. 1989), systematics
of spiny pocket mice (Rogers 1989,1990), and distribu-
tions of rodents and bats (Reid and Langtimm 1993).
Reid (1997) provided an extremely useful, beau-
tifully illustrated guide to the mammals of Central
America. Much of this work was based on her stud-
ies of living and preserved specimens of mammals
from Monteverde. Emmons (1997) also provides a
well-illustrated field guide to the neotropical mam-
mals; her emphasis, however, is on species found
below 1500 m. Another guide (Timm and LaVal 1998),
an illustrated key to the Costa Rican bats, is designed
for use in the field and has up-to-date diagnostic char-
acters and taxonomy designed for students, wildlife
managers, and the lay public.7.3.2. Community Structure and
Reproductive Ecology
Most mammals reproduce seasonally. The ultimate
cause is generally seasonal variation in food avail-
ability mediated by ambient temperature or rainfall.226 Mammals