A moderately large arboreal salamander, Bolitoglossa alvaradoi ranges in size from 106-155mm (total length), with a maximum recorded length of 159mm (6.25 inches). It has completely flat, webbed hands and feet, a prehensile tail, and large, protuberant eyes. Coloring within the species is highly variable, and individuals have been found to show coloration changes between the day and night. In general, B. alvaradoi has a uniformly black or dark brown venter and olive green to dark browm dorsum. The back may be marked with black spots, blotches, or a light middorsal patch of cream or tan coloration. At night, the darker ground color may lighten to gray, tan, or reddish brown with a pattern of scattered black or dark brown spots. Lightening of the dorsum may be so extreme that coloration patterns visible in the day are no longer discernible at night. Males and females may be distinguished by the number of costal grooves between adpressed limbs: males show only 1.5 to 2, females show 3 to 4. B. alvaradoi is similar to B. lignicolor but may be distinguished by the lack of light ventral spots and streaks, as is seen in the latter.(Leenders 2001; Savage 2002)
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Costa Rica
Bolitoglossa alvaradoi is a rarely seen arboreal nocturnal salamander presumed to live in forest canopies where it makes use of bromeliad microhabitats (Wake 1987)
. Alvarado's salamander is found only in several fragmented populations on the Atlantic slopes of Costa Rica in moist or wet lowland forests and premontane rainforests, at elevation ranges from 700 to 1,150 m (2300 to 3750 ft).(Savage 2002; Leenders 2001)
Trends and Threats
According to the Global Amphibian Assessment, B. alvaradoi is considered endangered on the basis of a fragmented population covering less than 5000 square kilometers. There is also evidence of a decrease in habitat quality and subsequent population decline due to smallholder farming and wood extraction.
Possible reasons for amphibian decline
General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
A Spanish-language species account can be found at the website of Instituto Nacional de Biodiversidad (INBio).
Leenders, T. (2001). A Guide to Amphibians And Reptiles of Costa Rica. Zona Tropical, Miami.
Parra-Olea, G., García-París, M., Wake, D. B. (2004). ''Molecular diversification of salamanders of the tropical American genus Bolitoglossa (Caudata: Plethodontidae) and its evolutionary and biogeographical implications.'' Biological Journal of the Linnean Society, 81, 325-346.
Savage, J. M. (2002). The Amphibians and Reptiles of Costa Rica:a herpetofauna between two continents, between two seas. University of Chicago Press, Chicago, Illinois, USA and London.
Wake, D. B. (1987). ''Adaptive radiation of salamanders in Middle American cloud forests.'' Annals of the Missouri Botanical Garden, 74(2), 242-264.
Originally submitted by: Ketti Augusztiny (first posted 2004-11-02)
Edited by: Tate Tunstall (2009-11-02)
Species Account Citation: AmphibiaWeb 2009 Bolitoglossa alvaradoi: Alvarado's Salamander <https://amphibiaweb.org/species/3952> University of California, Berkeley, CA, USA. Accessed Mar 26, 2023.
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Citation: AmphibiaWeb. 2023. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 26 Mar 2023.
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