This species is known from coastal Kenya at Changamwe (its type locality), the Shimba Hills (Longomwagadi Forest near Kwale town), Kaya Jibana Forest (Kaloleni-Kilifi) and Bonje Village (Kilifi) where it occurs from sea level up to approximately 400 m asl in farmland (Malonza and Müller 2004) and forest habitat (P.K. Malonza and V. Wasonga pers. comm. June 2012). A single specimen was recorded from the Shire Highlands of Malawi, most probably from Mount Zomba or Mount Mulanje (Nussbaum and Hinkel 1994). However, based on its distribution, the Malawi record is questionable (P.K. Malonza and V. Wasonga pers. comm. June 2012) and recent caecilian fieldwork in Shire Highlands failed to record any specimens from the genus Boulengerula (H. Müller and M. Wilkinson pers. comm. August 2012). Nevertheless and until there is further taxonomic clarification, for the purposes of this assessment this record is considered as valid. There are four threat-defined locations including the Malawi record. Using its range as a proxy, its estimated extent of occurrence (EOO) is 990 km2.
Habitat and Ecology
This is a soil-dwelling species of lowland moist forest. It has also been found in agricultural areas within stream valleys in the plantations of coconut palms, banana and cashew nuts; however, it is absent from both flat agricultural areas and steep cultivated slopes (P.K. Malonza pers. comm. August 2012). On the assumption that its breeding biology is similar to that of other species of Boulengerula, it is oviparous with direct development.
It is known from 10-20 specimens from the two main sites in the Shimba Hills and the sites near the type locality; three specimens were recorded in April 2012 in Shimba Hills (P.K. Malonza and V. Wasonga pers. comm. 2012). As a burrowing species, it is rarely encountered in its forest habitat and even more rarely outside the forest in agricultural areas, indicating a preference for forested areas (P.K. Malonza pers. comm. June 2012). However, the current population trend and size are unknown. Furthermore, while its population appears to be severely fragmented and its distribution in Kenya seems to be patchy, this may be due to low sampling effort for lowland caecilians in East Africa.
Assuming that soil moisture and temperature maintained by vegetation is important for the species, and bearing in mind the species' preference for forest over cultivated habitat, possible threats are habitat disturbance and conversion. In the Shimba Hills, forest disturbance is an ongoing occurrence due to elephant activity; however, the subpopulation occurring in the forest patches of the Shimba Hills National Reserve is relatively secure (P.K. Malonza pers. comm. August 2012). In Kaya Jibana Forest, human disturbance of the forest (cutting of poles and collection of fire wood) threatens the habitat. In Changamwe and the surrounding areas, additional threats are farming and human encroachment; specifically, the intensification of agriculture, application of pesticides and herbicides, the slash-and-burn method, and expanding human settlements (P.K. Malonza and V. Wasonga pers. comm. June 2012). In the Shire Highlands of Malawi, deforestation and the intensification of agriculture are also ongoing (D. Gower and S. Loader pers. comm. August 2012).
This species occurs in the Shimba Hills National Reserve and Kaya Jibana Community Forest; parts of the Shire Highlands are also afforded some level of protection (D. Gower pers. comm. August 2012). Despite these protections and in light of the species' preference for forest, increased protection and proper management of its known habitat is needed. Research on the distribution, population status, breeding habits, and the effect of ongoing threats is needed, as well as clarification on taxonomy of the Kenyan and Malawi subpopulations (D. Gower and S. Loader pers. comm. June 2012).
Red List Status
Listed as Endangered in view of an estimated extent of occurrence (EOO) of 990 km2, because it is known only from three or possibly four threat-defined locations, and due to the ongoing decline in habitat quality and extent in coastal southern Kenya.
It is possible that the different subpopulations attributed to this species are taxonomically distinct.
IUCN SSC Amphibian Specialist Group 2013. Boulengerula changamwensis. The IUCN Red List of Threatened Species 2013: e.T59495A16943655. http://dx.doi.org/10.2305/IUCN.UK.2013-2.RLTS.T59495A16943655.en .Downloaded on 18 November 2018