Species of the week

Zanzibar Day Gecko, a green gecko that occurs in Ilha de Moçambique

Scientific name: Phelsuma dubia
Common name: Zanzibar Day Gecko, Bright-eyed Day Gecko, Dull-green Day Gecko
Order: Squamata
Family: Gekkonidae
Conservation status: Least concern
Diet: largely insectivorous but will also take soft fruits, nectar, pollen and plant exudates.
Size: till 160 mm


Geckos occur throughout the warmer parts of the world, with 108 genera and more than 1130 species found worldwide.
The geckos assemblage in Southern Africa is extremely diverse, and some of the lineages appear to be ancient.
The skin is shed periodically and comes off in patches, which are eaten by the gecko.
The majority of geckos are nocturnal but this is one of the 30-40 species of day gecko in the genus Phelsuma.

Physical description
Geckos have only small scales on the head and the teeth are small, numerous and cylindrical.
The eyes are usually large (especially in nocturnal species), and are covered with a transparent skin with unmovable eyelids. Day geckos as P. dubia, have dilated digits and in comparison to other geckos, have relatively small eyes.
Since the eyes cannot blink, they are usually cleaned with the tongue.

fotografia 2

Reproduction
Oviparous, the female can lay up to six clutches of two eggs each following a single copulation. The eggs are glued to a suitable substrate, the female generally standing guard over them while they dry. Sometimes females return to eggs over the next several days, and may eat the shells once the young have hatched. Incubation period is generally 40-45 days sometimes over 50.
Both adults and eggs can be found high in trees, with heights of over 2 m recorded, and presumably eggs may also be laid in the crowns of palms.
Sexual maturity may be reached within eight months.

Habitat
The species is generally found at low altitudes and occurs in hot coastal areas. It can be found predominantly in palm trees (including coconut palms) and banana trees, but also in large shrubs and anthropogenic habitats, including in buildings, gardens, plantations and other cultivated areas.

Distribution
This is the most widespread species of Phelsuma, occurring in coastal Kenya and Tanzania (Dar es Salaam, Bagamayo, Singino and Zungomero, and the island of Zanzibar), Mozambique (Ilha de Moçambique), all four of the major islands in the Comoros archipelago, and Madagascar (native).
In East Africa its distribution is fragmentary, but It is at least locally abundant in most of its range. Plus, it is likely that those populations (in Tanzania and Mozambique) are a result of introductions by humans.

Threats
This species is well-adapted to human habitation and no major threats have been identified.
However, collection for the pet trade is a serious pressure on subpopulations in East Africa, however the species may still be expanding its range north in Kenya.
The species is subject to a decline in the number of mature individuals in East Africa, where it occurs as a severely fragmented population, and as such is considered at local risk of extinction in Tanzania and Mozambique. In fact, Tanzania has failed to meet export quotas apparently due to the difficulty in obtaining specimens, and researchers surveying in Tanzania report that the species has become much rarer.

Conservation status
Phelsuma dubia has an ability to thrive in secondary habitats and to tolerate human disturbance mean that it is extremely unlikely to be threatened with extinction. Reducing quotas and controlling trade is thought to be required to preserve subpopulations in Tanzania and Moçambique.

Curiosities

  • A high proportion of geckos have pads under their digits. These pads are made up of minute hairs that adhere strongly, even to very smooth surfaces such as glass, allowing geckos access to a wide array of microhabitats.
  • There is some trade in this species for the international market, which is described as being “very popular” among reptile hobbyists and the species is bred in captivity. CITES documentation reports a little over 15,500 animals exported from Tanzania and Madagascar between 1994 and 2003, with no exports reported from Madagascar (with the exception of three individuals in 2005) since a ban was imposed in 1994.
  • Research is needed to clarify the taxonomy of this species and to identify the origins of East African sub-populations.

Sources:
  • IUCN Redlist
    Raxworthy, C.J., Spawls, S., Msuya, C.A., Malonza, P. & Hawlitschek, O. 2014. Phelsuma dubia. The IUCN Red List of Threatened Species 2014: e.T172946A1374984.http://dx.doi.org/10.2305/IUCN.UK.2014-3.RLTS.T172946A1374984.en. Downloaded on 27 May 2016.
  • Cites
  • Reptile database
  • Alexander, G., Marais, J., (2007). A guide to the reptiles of Shouthern Africa. Cape Town, Random House Struik.
Pictures
  • Harith Farooq