The Seychelles Skink (Mabuya sechellensis)

A common sight on the ground in the woodlands of Denis, and indeed throughout the central Seychelles archipelago is the Seychelles skink (Mabuya sechellensis). This species is endemic to the central Seychelles.

On Denis this coppery-brown lizard gets up to approximately 22-23cm in length – including its tail. It has a distinct pale stripe running from above the eye down the top of each flank fading out at the tail. This stripe is emphasised by rows of darker patches running above and below it (see photos). This pale stripe and the pale belly in turn make the flanks appear as a brown stripe. The striping varies in prominence from island to island with adults in some populations reportedly not having stripes.

On some islands the skink can reach very high densities (e.g. Cousin) but this is not the case here. On Denis one generally first notices a skink by a rustle in the undergrowth as it seeks to avoid our great marauding feet! The best way to observe them I have found is by moving off the paths into areas of broadleaved woodland and just finding a comfortable perch. Once still, one rapidly becomes aware of the movement of the skinks across the forest floor and they often approach as curiosity brings them in search of food.

Gerlach (2007) states that the skink has been introduced to Denis and some credence is provided to this idea by the fact that no skinks were recorded on Denis’ nearest neighbour Bird in 1908 (Fryer 1910) but were subsequently found in 1939 – a timeframe highly suggestive of a human vector. For Denis though it is not so conclusive. Skinks were recorded in 1908 and it is definitely possible that they could have arrived on Denis during its 14,000 year history through natural means – i.e. “rafting” on floating vegetation.

Regardless the skink, as a species endemic to the central archipelago, is treated as native species and serves an important role in the ecosystem feeding omnivorously on insects, fruit, detritus and carrion. Skinks also provide a source of food for moorhens and interestingly the endangered magpie-robin which is highly adept at swooping down on an unsuspecting young lizard and despatching it clinically by 2 or 3 hard “thwacks” against a stone before consuming it.

The skinks lay 2 or more oblong, leathery white eggs and cover them with soil. We do anticipate that as sea bird colonies increase on the island that the detritus they bring – small fish, droppings, eggs and dead birds – will see a corresponding increase in the skink population.

Refs:
Fryer, J.C.F. (1910). Bird and Denis Islands, Seychelles. Trans. Linn. Soc. Land. (2)14: 15-20.
Gerlach, J. (2007). Terrestrial and Freshwater Vertebrates of the Seychelles Islands. Backhuys Publishers. The Netherlands.