This species has a highly fragmented distribution on Hispaniola, which suggests that it has declined from a previously more uniform distribution. It has been recorded from sea level up to 1,091 m asl (Henderson and Powell 2009). Surveys from 2008-2010 have recorded this species in ten geographical localities of the Dominican Republic, including Montecristi, Dajabon, Nalga de Maco, Santiago Rodríguez, Salto de la Damajagua, Loma La Canela, Monte Plata, Sanchez Ramírez, Samana and Los Haitises. These surveys have expanded its area of occupancy (AOO) since its last assessment in 2004. However, even considering this expansion, the occupied area (herein taken as a proxy for AOO, although the actual AOO would be more restricted as some sites consist of small ponds beyond the margins of which frogs cannot survive) in the Dominican Republic is estimated to be 1,074 km
Habitat and Ecology
It occurs in mesic broadleaf forests, riparian forests including remnant forests, mangrove forests, grasslands, marshes and agricultural landscapes including rice plantations, coffee and cacao plantations, and the presence of livestock (Pueblo Viejo Dominicana Corporation pers.comm. January 2012; Pueblo Viejo Dominicana Corporation pers.comm. July 2012). Recent surveys have revealed that, of a total of 53 transects, the species was found primarily in different forest types (N=40), but it was also recorded in wetlands (N=10), agricultural areas (N=2) and grasslands (N=1) (Pueblo Viejo Dominicana Corporation pers.comm. July 2012). Most of the surveyed transects (N=41) had various land use practices in the surrounding area, with only 12 transects surrounded by unaltered forests (Pueblo Viejo Dominicana Corporation pers.comm. July 2012). In terms of micro-habitat occupation, it is mainly found on shrubs and reeds (up to 2 m high) alongside and within streams, lagoons and flooded pools. Males call in flooded pools after heavy rain and eggs are laid in still water where the larvae also develop. Although this frog is found in habitat types that are contained within a variety of different land uses, the survey results above suggest that it requires forests and/or wetlands as the main habitat pockets to subsist within these different landscapes. In any event, its individual sites tend to be isolated from one another, making them vulnerable to trampling by livestock and local extirpation (R. Powell pers. comm. February 2012).
This species has always been hard to find, but even so it appeared to be in decline prior to the 2004 assessment, with many historic subpopulations that seemed to disappear. It was not recorded during extensive searches of the Cordillera Central in the Dominican Republic in suitable habitat from 1998 to 2000. However, more recent surveys conducted between 2008-2010 have documented approximately 340 mature individuals in ten localities including the Cordillera Central. Although single individuals have been observed, the species is more commonly heard actively calling in groups ranging from 3-80 individuals. These surveys have also detected breeding populations. This species was last recorded in Haiti during a survey conducted in October 2010 at Plain Formon, Massif de la Hotte. The population is considered to be severely fragmented as per the IUCN Red List Guidelines, i.e. it occurs in fragmented habitat patches, it has a poor dispersal ability and limited gene flux, and 50% or more of individuals are found in isolated and fragmented habitat patches.
In Haiti, severe degradation of streams has already significantly altered one of its breeding habitats, and streams in Hispaniola in general are being severely impacted by deforestation due to agricultural activities, logging and charcoaling (B. Hedges pers. comm. February 2012). Suitable habitat where the species is currently found is being impacted by mining activities (Barrick Gold Corporation 2012). Infrastructure development is also a threat in some areas in the Dominican Republic. The presence of chytrid fungus has been confirmed in individuals at Nalga de Maco and Loma La Canela, although it has not been determined whether this is a threat to the species (G. Ross pers. comm. March 2011).
Its range includes several protected areas in both Haiti and the Dominican Republic, although most of these are in need of improved biodiversity conservation management. Small isolated populations outside of protected areas are thought to be at a very high risk of local extirpation within the next ten years if there is no intervention (R. Powell pers. comm. February 2012), so additional habitat protection is urgently required. Further survey work is necessary to determine the current population status of this species in the wild in Haiti, and to determine whether chytrid is a threat. The Dominican governmental agency Ministerio de Educación Superior, Ciencia y Tecnología (MECyT) is currently financing a three-year Dominican conservation project on threatened frogs due to climate change (RANA-RD), and which is expected to contribute towards a national Dominican amphibian conservation action plan with policy recommendations (C. Marte, M. Rodríguez and L. Diaz pers. comm. March 2011). Barrick Gold Corporation is funding a biodiversity project to establish assurance colonies of this and other Hylids impacted by its mining operation, and is also involved in building capacity and collecting additional biological information (Barrick Gold Corporation 2012).
The Amphibian Ark Conservation Needs Assessment process (Amphibian Ark 2011) conducted in the joint IUCN-Amphibian Ark workshop where this species was reassessed identified that further conservation actions for this taxon should include in situ conservation and conservation education.
Recent phylogenetic analyses found that there is almost no genetic variation among Dominican populations of this species, suggesting relatively high levels of gene flow or migration. There is no evidence of cryptic species.
IUCN SSC Amphibian Specialist Group, 2013. Osteopilus pulchrilineatus. In: IUCN 2014