This species is known from the Taita Hills, in Kenya. It seems to be restricted to the Dawida and Mbololo forest blocks, and has not been found in Sagalla and Kasigau despite targeted searches (Measey et al. 2009, Harper et al. 2010, Malonza et al. 2010). The estimated area of occupancy (AOO) is c. 4.3 km2 (Loader et al. 2009), although it is likely to occur in more forest fragments within its extent of occurrence (EOO), but that outside Sagalla and Kasigau targeted searches have not found it. It occurs from 1,397-2,200 m asl (Malonza et al. 2010).
Habitat and Ecology
This species can be found in remnant forest patches. During the daytime it is buried in deep, wet forest leaf litter or associated with decomposing logs. It may also be found low down on tree branches (Loader et al. 2009). The species reproduces by direct development. The female guards a clutch of 30-40 terrestrial eggs until they hatch into froglets, which then disperse into the surrounding forest (Malonza et al. 2010).
The population of the Taita Hills Warty Frog is considered to be severely fragmented, with over 50% of the global population scattered between isolated forest patches (Measey et al. 2009, Malonza et al. 2010), with little to no dispersal between these patches. Insufficient data are available to quantify population trends in this species; however, as this frog is rare in heavily-disturbed forests it is likely to be declining (P.K. Malonza pers. comm. 2010).
This frog appears to be restricted to remnant forest patches, some of which are under pressure from an increasing local human population which utilizes forest products (i.e. cutting sticks and collection of dead wood) (Rogers et al. 2008, Pellikka et al. 2009). It is rare in heavily-degraded forest (P.K. Malonza pers. comm. December 2010).
Most of the main forest patches where this species is found are protected, but are subject to fuel wood extraction by local smallholders (Rogers et al. 2008, P.K. Malonza pers. comm. 2010). The Taita Hills have been designated as a Key Biodiversity Area (KBA) in which, as an endemic species, C. dawida is a flagship species (Malonza et al. 2010). Several eucalyptus and pine plantations in the area where the species occurs have been earmarked for conversion back to indigenous forest (Loader et al. 2009). Planned studies aim to investigate the life history of the Taita Hills Warty Frog and the feasibility of restocking depleted populations as a long-term conservation measure (P.K. Malonza pers. comm. 2010). More research is needed into this species' distribution, population status and natural history.
Red List Status
Critically Endangered (CR)
Listed as Critically Endangered because its area of occupancy (AOO) is estimated to be only 4.3 km2, its distribution is considered to be severely fragmented, and there is a continuing decline in the extent and quality of its habitat in the Taita Hills of Kenya.
Prior to its description this species was considered to belong to a widespread form, Callulina kreffti (Loader et al. 2009). C. kreffti as now understood is a restricted-range species that may be endemic to the East Usambara Mountains (Loader et al. 2010, 2014).
IUCN SSC Amphibian Specialist Group 2014. Callulina dawida. The IUCN Red List of Threatened Species 2014: e.T175363A1422889. http://dx.doi.org/10.2305/IUCN.UK.2014-3.RLTS.T175363A1422889.en .Downloaded on 10 December 2018