(MCFP). The absence of any obvious change in amphib-
ian habitats and the persistence of bird species known
to be sensitive to deforestation suggest that subtle but
critical changes in the environment have taken place
(see Sec. 5.4.3). The extent of these changes is unclear,
but recent work suggests that many amphibian popula-
tions in the highlands of Costa Rica and western Panama
have been affected (Berger et al. 1998, Lips 1998,
Bolanos, unpubl. data). Future studies should assess
the status of anuran populations in areas surrounding
Monteverde. A study of salamander populations is also
needed. They declined in the late 1980s (see Pounds,
"Monteverde Salamanders," pp. 172-173; Fig. 5.4), but
their status is uncertain. Ring-tailed and Monteverde
Salamanders were found in small numbers during
1990-94 (Pounds et al. 1997), but not the remaining
three species (Appendix 8). The sampling techniques,
however, were appropriate only for frogs and toads.
Reptiles. The recognition of an amphibian crisis
(Phillips 1994) implies that amphibians have suffered
more disappearances than reptiles. A reptile crisis,
however, would be harder to recognize. Whereas
Monteverde's frogs and toads announce their pres-
ence through song, the snakes and lizards are mute.
Many are secretive or occur at low densities ordi-
narily. Nevertheless, there is evidence that reptile di-
versity has declined (see Sec. 5.4.1). Two species of
anoline lizards (the Cloud Forest Anole and Montane
Anole; Fig. 5.5) were previously common at a site on
the upper Pacific slope (1540 m) but disappeared from
there in the 1990s. The Green Frog-Eater, the fourth
most common species of diurnal colubrid snake in the
Penas Blancas valley in the mid-1980s, has not been
seen since 1987. Likewise, the Green Keelback, pre-
viously among the three most common diurnal snakes
on the upper Pacific slope, has been missing since- Abroad survey of reptile populations is needed.
5.2. Distribution and DiversityThe severity of a faunal collapse may depend in part
on how the spatial configuration of the underlying
causes is superimposed on local patterns of species
distribution and diversity. In this section, I summa-
rize these patterns for the Monteverde region and
examine the disappearances of anuran populations
in relation to them. Most of the declines and dis-
appearances reported from around the world have
taken place in highland areas (Wake 1991); lowland
populations seem relatively unaffected (Pechmann
et al. 1991, Voris and Inger 1995, F. Bolanos, unpubl.
data). Little is known, however, of the geographic
patterns of the declines within highland areas, which
comprise a variety of climatic and vegetation zones.Figure 5.4. Endemic Monteverde Salamander (Bolitoglossa "subpalmata"). Photograph by Michael
and Patricia Fogden.153 Amphibians and Reptiles