This species is restricted to Silhouette Island, in the Seychelles, occurring above 150 m asl. Its extent of occurrence (EOO) is estimated to be 15 km2, while its area of occupancy (AOO) is estimated to be 7 km2 based on the area polygon for occupied habitat for the single known population (J. Gerlach pers. comm. March 2012). It is known from a single threat-defined location (J. Gerlach pers. comm. March 2012).
Habitat and Ecology
It is restricted to forest over 150 m asl, and is closely associated with the palm Phoenicophorium borsigianum, most individuals being found in axils of the palm. Its breeding habits are unknown, but it probably takes place by direct development, with the eggs being laid on the ground, or in leaf axils, or both.
It is common in its small range, with a maximum population density of 30 animals per hectare, and a total population estimate of fewer than 20,000 animals. Population monitoring from 1994-2010 recorded declines in population density in lower altitude sites of over 50% over 16 years, while high altitude sites retained stable populations over this time (Gerlach 2011, J. Gerlach pers. comm. March 2012). Its population is not considered to be severely fragmented sensu IUCN guidelines.
Habitats on Silhouette island are deteriorating in quality due to invasion by introduced plants, principally cinnamon Cinnamomum verum, but S. pipilodryas appears to be tolerant of current levels of invasion (J. Gerlach pers. comm. March 2012). However, the main threat is considered to be climate change: while this species has been identified as being more tolerant of dry conditions relative to other Sooglossid frogs (Gerlach 2011), since 2003 population declines have been recorded in lower altitude sites associated with changes in rainfall patterns (J. Gerlach pers. comm. March 2012). Climate change is projected to lead to a 10% decline in area of occupancy within ten years, and complete loss of suitable habitat by 2100 (Gerlach 2011, J. Gerlach pers. comm. March 2012).
It is present in the Silhouette National Park (J. Gerlach pers. comm. 2012). There is a need for close monitoring of the population status of this species; this was initiated in 1996 but was forcibly terminated in 2011 (J. Gerlach pers. comm. 2012). Captive colonies have been successfully maintained, although successful captive breeding has yet to be recorded for this species (J. Gerlach pers. comm. March 2012). The development of captive breeding techniques is recommended for this species, as well as improved habitat management to minimize the impact of invasive species (J. Gerlach pers. comm. March 2012).
Red List Status
Critically Endangered (CR)
Listed as Critically Endangered because its extent of occurrence (EOO) is estimated to be 15 km2, its area of occupancy (AOO) is estimated at 7 km2, it is known from a single threat-defined location, and there is an expected continuing decline in the number of mature individuals, its AOO and quality of its habitat due to projected changes in rainfall patterns in the Seychelles.
IUCN SSC Amphibian Specialist Group, 2013. Sechellophryne pipilodryas. The IUCN Red List of Threatened Species 2013: e.T59048A15435789. http://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T59048A15435789.en .Downloaded on 19 November 2018