Justification
This species is listed as Near Threatened due to its limited distribution (with an extent of occurrence estimated at about 1,200 km2) and because it is subject to a decline in the extent and quality of its habitat due to the loss of karst forest, although this is presently regarded as localized and the species may be more widespread than presently known. It is therefore considered inappropriate to define locations based on the extent of threats, and while the habitat is fragmented as a result of both natural and anthropogenic processes it can be found in high densities where it occurs and is not considered to be severely fragmented. The species is consequently close to but does nor fully qualify for listing as threatened under criterion B1.
Geographic Range Information
This species is endemic to Hispaniola. It occurs on the southern shore of Samaná Bay and adjacent areas, on the northern slopes of the Cordillera Oriental in the northeastern Dominican Republic (Henderson and Powell 2009, Chávez et al. 2021). In 2018 it was reported from the vicinity of the Pueblo Viejo Mine in the Cordillera Central, a significant range extension to the west (Chávez et al. 2021). Subsequent survey work has confirmed its occurrence in additional localities, extending its range as far west as Aniana Vargas National Park, with records from the intervening area in surveyed areas of Los Haitises National Park and the slopes of the Cordillera Central (Chávez et al. 2021) The localities are all close to the Yuna River or in montane areas where streams flow into this river, and the distribution appears to follow the karst formations of Los Haitises and El Hatillo (Chávez et al. 2021). The straight-line distance between the easternmost and westernmost localities is 82.2 km, making this one of the most widespread members of the genus on Hispaniola, and it may have a wider range than presently known (Chavez et al. 2021). It has a known elevation range from sea level to 257 m asl. (Chávez et al. 2021).
The species has an estimated extent of occurrence of around 1,200 km2.
Population Information
This species was previously considered very hard to find, with multi-hour intensive surveys required to reliably record individuals (S.B. Hedges pers. comm. 2016). Surveys conducted at six localities between 2018 and 2019 collected 52 mature specimens (Chávez et al. 2021). Where the species is common (including some sites near Pueblo Viejo Mine) it was possible for teams of 3–6 experienced surveyors to capture over a hundred animals in a day, and at a site close to Caño Hondo (in the eastern portion of the species' range in Los Hatises National Park) "dozens" were found in an hour (M. Landestoy pers. comm. 2021). Animals were more commonly found in areas with scattered rocks on the ground than in areas with stretches of continuous bedrock; as the former are easier to survey it is unclear whether this is a genuine habitat preference or a sampling artefact (M. Landestoy pers. comm. 2021).
Genetic analysis conducted by S.B. Hedges (reported by Chávez et al. 2021) indicates that population differentiation between sampled localities is low, indicating that a single widespread species is involved, and a paper reporting the full results is in preparation (M.J. Rodriguez-Bobadillo et al. in prep.). The habitat is fragmented as a result of both natural barriers and anthropogenic change since European colonization, and the low genetic diversity reflects prehistoric rather than current levels of gene flow (S.B. Hedges pers. comm. 2021). Where it occurs this species can nonetheless be highly abundant, and the population is therefore not considered severely fragmented.
Habitat and Ecology Information
This forest species inhabits mesic environments including abandoned cacao plantations, mogotes, and cave entrances; where it is found under rocks, leaf litter and other surface debris (Henderson and Powell 2009). The eastern sites lie within the Ombrophile Rainforest, with the known sites characterized by secondary forest and a ground layer of dense, wet leaf litter; organic debris; and scattered clusters of karst rocks (Chávez et al. 2021). The Cordillera Central sites lie within a matrix of agricultural land and secondary forest, the latter in small patches with partial ground cover of wet leaf litter and karst rock clusters (Chávez et al. 2021). In both areas trees reach heights of up to 30–35 m and the dominant species include Anthoxylum and Cecropia; eastern localities exhibit a greater diversity of tree and associated plant species (Chávez et al. 2021). The species appears to be restricted to karst habitats, and animals were mostly encountered beneath karst rocks in and close to tropical forest during the 2018–2019 surveys (Chávezet al. 2021). Its abundance appears to be influenced by the presence of karst rock in shaded conditions (M. Landestoy pers. comm. 2021). These authors hypothesize that it is displaced from leaf litter over soil by sympatric congeners. Leaf litter microhabitats on rock platforms - where herbaceous vegetation and sufficient humus were abundant - were, however, "productive" sampling spots for this species (M. Landestoy pers. comm. 2021); temporary removal of this structure during surveys suggests that the animals use this as either core habitat or retreat sites (M. Landestoy pers. comm. 2021).
Threats Information
This species is threatened by habitat loss due to agricultural expansion. The species is found in areas that are or were historically covered in karst forest, and the loss of both tree cover and the underlying karst is likely to threaten some subpopulations (Chávez et al. 2021). Based on the species' currently-known distribution and apparent abundance, and its occurrence in protected areas that retain suitable habitat, it is unlikely to be at immediate risk of extinction "barring catastrophic climate events", but more widespread destruction of karst habitat should be considered a future threat (Chávez et al. 2021).
Use and Trade Information
There is no known use of or trade in this species.
Conservation Actions Information
There are no known species-specific conservation measures in place for this species. It is known from Los Haitises National Park, which encompasses a large portion of the known range and half of the known localities (with another at the border), and Aniana Vargas National Park (Chávez et al. 2021). Although a previous Red List assessment indicated that Los Haitises National Park is currently ineffective in protecting the forest against deforestation, forest is still present in the known localities within the reserve. Further research is recommended to clarify variation within this species and to determine whether it is more widespread than presently known (Chávez et al. 2021). Effective protected area management is needed to ensure the survival of this and other species on Hispaniola.