Ranitomeya sirensis from the Cordillera El Sira in central Peru. Photo by Jason Brown. |
Distribution
Known only from the Cordillera El Sira in central Peru. Aichinger wrote that the type series was taken at elevations between 750 and 1560 m. The Cordillera El Sira is a large and extremely isolated mountain range, rising to elevations of over 2400 m. View type locality in Google Maps.
Natural history
This remains one of the most poorly known species of poison frogs. Aichinger suggested that this species was highly arboreal because of its remarkable agility and its long hands with well-developed finger discs. He also speculated that this species employed similar reproductive strategies as other species of Ranitomeya, as females were found to lay clutches of one or two eggs. Our observations are consistent with this idea, as we witnessed a putative courting pair in a phytotelm.
Conservation status
The extent to which this species occurs throughout the Sira is unknown. However, all confirmed sightings have taken place very near the type locality and it is thus possible that this species has a very restricted distribution. Although the habitat is protected by a communal reserve, population densities appear to be very low and as a result, may be more susceptible to declines. This species is highly desired by hobbyists, but fortunately, all smuggling attempts have to this point failed since no one can actually find the frogs.
Notes
Many consider this species to be the 'holy grail' of poison frogs. This species appears to be exceedingly rare, occupies a mysterious and isolated massif, and is enigmatic to the point that no one has the faintest idea of its evolutionary relationships. The Cordillera El Sira was bustling with scientific activity in the late 60s and early 70s, with biologists such as John Terborgh and Catherine Toft participating in regular expeditions into these mountains. In fact, Duellman and Toft (1979) published a large paper enititled "Anurans from Serrania de Sira, Amazonian Peru: Taxonomy and biogeography" based on the amphibian collections made during this period. Surprisingly, this paper made no mention of Ranitomeya (= Dendrobates) sirensis. It wasn't until 1976 that this species was first collected, found in elfin forest at 1560 m elevation by Dr. Werner Hanagarth. Ten years later, Manfred Aichiner, working on the amphibians of central Peru, conducted an extensive survey of the Sira. Aichinger and his team spent an entire year in the Sira, yet were only able to find five individuals, two of which escaped after capture. Since that time, several field parties have entered the Sira in an attempt to find R. sirensis, but have been unsuccessful. Recently, an expedition in 2005 led by Mark Pepper set out to retrace Aichinger's footsteps. The team reached the infamous Pato Rojo, an abandoned helicopter landing pad made by a Canadian gold mining company and later used by Aichinger. Upon reaching Pato Rojo, Pepper's team found nothing but thriving bee hive, and were forced to camp a few hundred meters below on the edge of a precipitous gorge on the western face of the Sira. After 4 days camping and hiking throughout the cloud forest of the Sira, the team left with nothing more than bruised egos and no frogs. In 2007, Pepper decided to return, leading a second expedition into the Sira along with Manuel Sanchez, Jason Brown, and Evan Twomey. After suffering several fall-related injuries and barely escaping a flash-flood, the team was lucky enough to find two adult R. sirensis hunkered down in a plant axil.
Aichinger assigned this species to the quinquevittatus group (= Ranitomeya). However, this species is morphologically unique among Peruvian Ranitomeya, lacking limb reticulation and possessing a large red ventral spot.
