Wednesday, September 30, 2015

The Golden Treefrog: no longer an endemic to Trinidad

Phytotriades auratus. John C. Murphy

The critically endangered Phytotriades auratus (Boulenger, 1917) commonly known as the golden treefrog was thought to be an endemic species to Trinidad. This hylid grows to about 3.5 cm snout-vent length. In Trinidad, its distribution is restricted to the two highest peaks: El Tucuche (936 m) and El Cerro del Aripo (940 m). At these peaks, P. auratus is closely associated with the bromeliad Glomeropitcairnia erectiflora where it spends the majority of its known life cycle. However, a recent visit to Cerro Humo’s summit in eastern Venezuela brought about the discovery and first documentation of the species outside of Trinidad.
Rivas and de Freitas visited Cerro Humo, Venezuela in August 2014. While at the summit of Cerro Humo, they came across G. erectiflora on a fallen tree trunk along their path. Within the bromeliad, two P. auratus specimens were observed and photographed while a third was spotted on another bromeliad nearby (Rivas and de Freitas 2015). The significance of this find resulted in the range expansion and new country record for this critically endangered species. Given the geological history of Northern Trinidad and Venezuela, this find may not be considered surprising.
Perhaps the most significant aspect with the discovery of a population of P. auratus in Venezuela is that an additional population outside of Trinidad is potentially beneficial towards the conservation of the species. An estimation of the populations in Trinidad was first undertaken in 1995. Currently, an assessment of the Trinidad population is being updated using the eDNA (environmental DNA) method. This method involves collecting water samples from within the bromeliad and testing it for golden treefrog DNA. Based on the results, the number of golden treefrogs can be acquired and an estimate of population size can be deduced. An evaluation of the Venezuelan population is required and perhaps a similar approach can be used for the population in Cerro Humo. With potential threats to P. auratus’s conservation including climate change, habitat alteration, lack of legislative enforcement and the chytrid fungus, scientific research on the populations in both Trinidad and Venezuela is the first step towards reducing the threat status of the species.


Rivas, G. A. & de Freitas, M.  (2015)  Discovery of the critically endangered golden tree frog, Phytotriades auratus (Boulenger, 1917), in eastern Venezuela, with comments on its distribution, conservation, and biogeography.  Herpetological Review:  46;  153-157.