This species is found in the mountains of central and western Mindanao Island in the Philippines. It has been found between 300–1,700 m asl. It probably occurs more widely than current records suggest on other nearby islands (A. Diesmos pers. comm. March 2018), however it is likely a range-restricted species (Sanguila et al. 2011).
Habitat and Ecology
This terrestrial species inhabits cool mountain streams and rivers in lower montane and lowland forests. It has been found above rocks covered with mosses, on rock crevices, and on leaf-litter near streams. It is generally restricted to undisturbed or minimally disturbed habitats, for example individuals only occupy habitats which are free or nearly free from logging and other human impacts (Alcala and Custodio 1995, Delima et al. 2006). However a few individuals have been found in secondary forest, plantations, small-scale agroecosystems, and in the floor of a cave surrounded by corn and pineapple farms and patches of disturbed lowland dipterocarp forest (Nuñeza et al. 2010, Warguez et al. 2013, Belleza and Nuñeza 2014). It breeds in streams, which is where the larvae also develop. Follow-up surveys at the type locality (Pasonanca Natural Park) resulted in important new natural history information as this site was first surveyed by E.H. Taylor about 100 years ago and had not been resurveyed until 2009 (Brown et al. 2012).
In the suitable habitat, this species is common (A. Diesmos pers. comm. March 2018). During 15–24 May 2004, seven individuals were observed in the vicinity of Mt. Mahuson in the Arakan Valley Conservation Area (Delima et al. 2006). The species was present at eight out of 14 sampled sites (N=39 individuals) in Mt. Malindang between October 2003 and December 2004 (Nuñeza et al. 2010). More recently, one individual was found over 54 person-hours at Wao, Lanao del Sur Province (Belleza and Nuñeza 2014) and five individuals were recorded from lower montane forest in Mt. Kalatungan, Bukidnon (Warguez et al. 2013). Due to ongoing decline in the extent and quality of habitat, the population is suspected to be decreasing.
The major threat is the destruction and conversion of both lowland and montane rainforest habitat on Mindanao due to small-scale agricultural activities, large-scale oil palm plantations, wood collection for charcoal production, and expanding human settlements (Philippines Red List Assessment Workshop May 2017). In addition, the quality of its stream habitat is subject to pollution due to agricultural effluents, soil erosion, and mine-tailings (Philippines Red List Assessment Workshop May 2017).
This species is recorded from several protected areas on Mindanao, including Mount Malindang National Park, Mount Apo and Mount Kitanlad Range Natural Parks.
Conservation measures should include the regulation and proper disposal of pesticides and herbicides, and the protection of the remaining rainforest, especially riverine habitats and gallery forests, on Mindanao.
More information is needed on this species' distribution, population status and ecology.
Red List Status
Listed as Least Concern in view of its wide distribution and presumed large population.
IUCN SSC Amphibian Specialist Group 2018. Ansonia mcgregori. The IUCN Red List of Threatened Species 2018: e.T54475A58477082. http://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T54475A58477082.en .Downloaded on 23 January 2019