Globally Threatened Amphibian Species Part 1

Globally Threatened Amphibian Species 225
VU Colostethus olfersioides (A. Lutz, 1925)
Vulnerable A2ac
Order, Family: Anura, Dendrobatidae
Country Distribution: Brazil
Current Population Trend: Decreasing
© Ivan Sazima
Geographic Range This species is known from Rio de Janeiro State, northwards along the coast to Alagoas State,
in south-eastern Brazil. It occurs up to about 400m asl.
Population It used to be a very common species, but it has recently declined and is now absent from several localities
at which it was previously common.
Habitat and Ecology This diurnal species occurs in the leaf-litter of primary and secondary forest. It can also tolerate
signifi cant habitat disturbance and is found in gardens and plantations. They lay their eggs in temporary pools, and
after they hatch they are carried on the backs of the adults to streams where they complete their development.
Major Threats Habitat loss, due to deforestation and agricultural development, is ongoing, but probably has not
been severe enough to cause the declines that have been observed. Chytridiomycosis could be implicated, although
the species occurs well below the elevation at which conditions are normally suitable for chytrid.
Conservation Measures It is known to occur in several protected areas, such as Parque Nacional da Serra da
Bocaina. Research to determine the causes of the current decline is urgently needed.
Notes on taxonomy: Colostethus carioca, C. capixaba and C alagoanus are probably synonyms of this species (V. Verdade pers.
comm.).
Bibliography: Cochran, D.M. and Goin, C.J. (1970), Eterovick, P.C. et al. (2005), Izecksohn, E. and Carvalho-e-Silva, S.P. (2001), Lutz, B.
(1954), Rivero, J.A. (1988), Verdade, V.K. (2001)
Data Providers: Sergio Potsch de Carvalho-e-Silva, Vanessa Verdade
VU Colostethus pulchellus (Jiménez de la Espada, 1871)
Vulnerable A2ace; B1ab(i,ii,iii, iv,v)
Order, Family: Anura, Dendrobatidae
Country Distribution: Colombia, Ecuador
Current Population Trend: Decreasing
© Francisco José López-López
Geographic Range This species occurs in the inter-Andean páramos of southern Colombia (in Nariño and Cauca
Departments) and northern Ecuador (south to Cotapaxi Province), and on the eastern slopes of the Andes from southern
Colombia south to the headwaters of the Río Pastaza in Ecuador. Its altitudinal range is 1,590-2,970m asl.
Population It has disappeared from sites where it used to be abundant in Ecuador, but is still common at Cosanga
in Napo Province. It remains common in Colombia.
Habitat and Ecology An inhabitant of both dry and humid montane forests. It is a terrestrial species, and breeding
takes place in streams. It can be found in secondary growth near streams, but not in open areas.
Major Threats The major threat to this species is habitat loss as a result of agricultural development (including
the planting of illegal crops), logging, and human settlement; introduction of alien predatory fi sh in streams, and
pollution resulting from the spraying of illegal crops, are additional threats. There is heavy deforestation as a result
of wood extraction at Cosanga, where the species survives in Ecuador. The cause of declines observed in Ecuador is
not clear, but could be due to habitat loss, climate change, and/or chytridiomycosis.
Conservation Measures In Ecuador, its geographic range overlaps with the Parque Nacional Sumaco Napo-Galeras,
Reserva Ecológica Antisana, Parque Nacional Llanganates, and the Reserva Ecológica Cayambe-Coca. It occurs in
several protected areas in Colombia. The species requires close population monitoring, especially in view of the
potential risk of chytridiomycosis.
Notes on taxonomy: The populations from the Carchi basin might represent a distinct species (Coloma 1995).
Bibliography: Coloma, L.A. (1995), Jiménez de la Espada, M. (1875), Ruiz-Carranza, P.M., Ardila-Robayo, M.C. and Lynch, J.D. (1996)
Data Providers: Wilmar Bolívar, Luis A. Coloma, Santiago Ron
EN Colostethus ranoides (Boulenger, 1918)
Endangered B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)
Order, Family: Anura, Dendrobatidae
Country Distribution: Colombia
Current Population Trend: Decreasing
Geographic Range This species occurs north of Villavicencio, in
the eastern foothills of the Andes, Meta Department, Colombia, at
450-800m asl.
Population It is rare, and was last seen in 2001, despite recent
survey work in its range.
Habitat and Ecology It is a terrestrial, diurnal species that occurs
in foothill forest and lays its eggs in leaf-litter. The males probably
take care of the eggs, and then move the larvae to small streams
for their continued development.
Major Threats Habitat loss caused by agricultural expansion
is the main threat to this species, and oil extraction may pose a
future threat. It is also threatened by the introduced bullfrog, Rana
catesbeiana.
Conservation Measures Although it occurs in several small
private reserves, ex situ populations should be established because
the entire range of this species is nearly entirely deforested and
introduced bullfrogs could eliminate the species from remaining forest fragments. Further research and survey
work is required to better understand its current population status and in order to advance appropriate conservation
measures for this species.
Notes on taxonomy: This species was removed from the synonymy of Colostethus brunneus by Silverstone (1971).
Bibliography: Rivero, J.A. (1988), Rivero, J.A. and Serna, M.A. (1988), Ruiz-Carranza, P.M., Ardila-Robayo, M.C. and Lynch, J.D. (1996),
Silverstone, P.A. (1971)
Data Providers: Andrés Acosta-Galvis, Jose Vicente Rueda, Fernando Castro
CR Colostethus ruizi Lynch, 1982
Critically Endangered B1ab(iii,v)+2ab(iii,v)
Order, Family: Anura, Dendrobatidae
Country Distribution: Colombia
Current Population Trend: Decreasing
Geographic Range This species is known from Fusagasuga,
between Alto de San Miguel and Aguadita, on the western flank of
the eastern Andes, Cundinamarca Department, Colombia, between
2,410 and 2,469m asl.
Population It is rare, and is known from only six individuals. Its
range has been completely deforested, except for one private tract
of land 11ha in size. Four expeditions since 1995 have failed to turn
up any individuals of this species.
Habitat and Ecology It lives on the forest floor and along streams
in cloud forest; it is not found outside old-growth forest. Its breeding
habits are not documented, but it is assumed that breeding and larval
development take place in streams.
Major Threats Deforestation for the planting of crops and cattle
grazing is the primary threat to this species.
Conservation Measures The species is not known to occur in any
protected areas. Surveys are urgently needed to determine whether
or not this species still persists in the wild.
Bibliography: Lynch, J.D. (1982b), Rivero, J.A. (1988), Ruiz-Carranza, P.M., Ardila-Robayo, M.C. and Lynch, J.D. (1996)
Data Providers: Wilmar Bolívar, Jose Vicente Rueda