Lygodactylus williamsi


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Lygodactylus williamsi
Species Authority: Loveridge, 1952
Common Name(s):
English Turquoise Dwarf Gecko, Williams' Dwarf Gecko
Lygodactylus picturatus subspecies williamsi Loveridge, 1952

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(iii,v)+2ab(iii,v) ver 3.1
Year Published: 2012
Date Assessed: 2012-02-22
Assessor(s): Flecks, M., Weinsheimer, F., Böhme, W., Chenga, J., Lötters, S., Rödder, D., Schepp, U. & Schneider, H.
Reviewer(s): Bowles, P. & Cox, N.A.
Lygodactylus williamsi has been listed as Critically Endangered as it is only known from an extremely small area in Tanzania, with an extent of occurrence of approximately 20 km² and an area of occupancy of less than 8 km², within which it occurs as a severely fragmented population. This area is currently facing severe habitat destruction and fragmentation, and the species is heavily collected for the international pet trade.

Geographic Range [top]

Range Description: This species is endemic to Tanzania and is found within the Forest Reserves of Kimboza and Ruvu. It is also known from two localities in the vicinity of these forests (Flecks et al. 2012). Its extent of occurrence is approximately 20 km², and within this area it has an estimated area of occupancy of 8 km².
Tanzania, United Republic of
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: The subpopulation in Kimboza Forest Reserve was estimated to comprise approximately 150,000 adult individuals in 2009, based on the number of Pandanus plants in the reserve and the number of lizards per plant sampled (Flecks et al. 2012). This subpopulation is estimated to have declined by one third of its original size since 2004, based on a similar calculation of abundance derived in part from pre-collection literature (Flecks et al. 2012). Although population turnover is likely to replenish some of the losses due to off-take, both these estimates and the testimony of interviewees from the region indicate that the population is still in decline (Flecks et al. 2012). The status of the subpopulation at Ruvu Forest Reserve needs quantification.

Two further subpopulations outside of these forests occupy very small areas and do not contribute significantly to the total population. The four known subpopulations are not connected due to lack of suitable habitat in between (Flecks et al. 2012), and the population is consequently considered to be severely fragmented.
Population Trend: Decreasing

Habitat and Ecology [top]

Habitat and Ecology: This diurnal gecko species inhabits tropical forest at the eastern foothills of the Uluguru Mountains (Doggart et al. 2001, Spawls et al. 2004), where it exclusively dwells on Screwpine, Pandanus rabaiensis (Lambert 1985, Weinsheimer and Flecks 2010). This tree is associated with swampy areas or limestone substrata within the forest area. Usually, one male, one or more females and several juveniles inhabit one Pandanus plant (Bayliss 1994, Flecks et al. 2012).
Systems: Terrestrial

Use and Trade [top]

Use and Trade: This species is heavily exploited for the international pet trade; at least 15% of the population in Kimboza Forest was collected between December 2004 and July 2009 (Flecks et al. 2012). Although no official import or export figures exist for this lizard, which is not CITES-listed, and specimens may be exported under false names further complicating the collection of these data, trade appears to be ongoing at a similar level (M. Flecks pers. comm. March 2012).

Threats [top]

Major Threat(s): The species is threatened by habitat loss and fragmentation due to ongoing deforestation (illegal logging of timber, pole cutting, firewood collection, hunting activities, clearing for agriculture, and the increasing frequency of fires). The limestone formations on which the Pandanus plants grow are mined (Hymas 2000). Collection for the international pet trade directly affects the species at a scale likely to threaten the population (Flecks et al. 2012).

Conservation Actions [top]

Conservation Actions: There are no known species-specific conservation measures in place for this species. Although it does occur inside Kimboza Forest Reserve and Ruvu Forest Reserve, neither of these reserves is well-protected at present. There is an urgent need to control trade in this species, and CITES listing on either Appendix I or II is strongly recommended (M. Flecks pers. comm. March 2012). Lack of habitat protection represents a major threat to this lizard, and improved monitoring is required to ensure the security of the reserves from which the gecko is known (M. Flecks pers. comm. March 2012). The species is in need of special consideration in Tanzania's national wildlife and forestry management plans (M. Flecks pers. comm. March 2012). Research is needed to estimate the size and status of the population in Ruvu Forest Reserve, and to better-understand the effects of habitat fragmentation on this microhabitat specialist (M. Flecks pers. comm. March 2012).

Bibliography [top]

Bayliss, J. 1994. Preliminary biological investigation into Kimboza Forest Reserve, Morogoro Region, Morogoro District, Tanzania. TZ19: 42 pp.

Doggart, N., Lovett, J., Mhoro, B., Kiure, J. and Burgess, N. 2001. Biodiversity surveys in eleven forest reserves in the vicinity of the Uluguru Mountains. Morogoro. 101 pp (unpublished).

Flecks, M., Weinsheimer, F., Böhme, W., Chenga, J., Lötters, S. and Rödder, D. 2012. Watching extinction: The dramatic population status of the critically endangered Tanzanian Turquoise Gecko. Salamandra (in press).

Hymas, O. 2000. Assessent of the remaining forests on the Uluguru Mountains and the pressures they face. Dar es Salaam. 45 pp.

IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.1). Available at: (Accessed: 19 June 2012).

Lambert, M. 1985. A-herping in Tanzania, but hardly in Loveridge's footsteps. British Herpetological Society Bulletin 12: 19-27.

Loveridge, A. 1952. A startlingly turquoise-blue gecko from Tanganyika. Journal of the East Africa Natural History Society 20: 446.

Spawls, S., Howell, K.M., Drewes, R.C. and Ashe, J. 2004. A Field Guide to the Reptiles of East Africa. Second Edition. A&C Black, London. 543 pp.

Weinsheimer, F. and Flecks, M. 2010. Erkenntnisse zur Bedrohung des Türkis-Zwerggeckos. ZGAP-Mitteilungen 26(1): 22-24.

Citation: Flecks, M., Weinsheimer, F., Böhme, W., Chenga, J., Lötters, S., Rödder, D., Schepp, U. & Schneider, H. 2012. Lygodactylus williamsi. The IUCN Red List of Threatened Species. Version 2014.3. <>. Downloaded on 02 April 2015.
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