Is Chalcides ebneri Lost Forever?

By Bouazza Abdellah – Dec 25, 2024

Ebener’s skink (Chalcides ebneri), a skink species endemic to northern Morocco, is on the edge of extinction. Known from only two localities, it has not been seen in the wild for 54 years, raising urgent conservation concerns.  The species is listed as Critically Endangered by the IUCN due to its extremely small range (less than 100 km²),  the likelihood of highly fragmented populations and ongoing habitat degradation (Bouazza & Martínez del Mármol,  UICN 2024 in progress ).

The Ebner’s skink was first discovered by Richard Ebner during an expedition between Fez and Jbel Zalagh in 1930. The first specimen found (Fig. 1) was described as a subspecies, Chalcides ocellatus vittatus var. ebneri (Werner 1931). Later, in 1981, Pasteur raised it to species level based on differences in colouration (Pasteur, 1981).

Figure 1. Holotype of Chalcides ebeneri collected by Richard Ebner between Fez and Jbel Zalagh  in May 1930 (source MCZ)

In 1970, Yves Vial recorded two specimens near Karia Ba Mohamed (Fig. 2) and reported the presence of the species in Rafsaï (Bons & Geniez 1996). However, the Rafsaï record is considered to be a misidentification of Chalcides colosii, which has been confirmed in that area (Martínez del Mármol et al., 2019).

Figure 2. Adult. Karia Ba Mohamed. Photo: © Yves Vial

Extensive surveys conducted between Fez and Rhafsai, including the Karia Ba Mohamed area, have failed to find any evidence of a surviving population of C. ebneri (e.g. A. Bouazza, G. Martínez del Mármol, D. Donaire). Instead, we only observed only Chalcides polylepis, which is known for its resilience to habitat destruction. Martínez del Mármol et al. (2019)  believe that the combined effects of habitat loss and, perhaps competition with C. polylepis may have led to the extinction of C. ebneri.

The story of Chalcides ebneri highlights the urgent need for effective habitat conservation and detailed population monitoring to prevent further loss of Morocco’s threatened herpetofauna. Immediate action is crucial to protect species that remain vulnerable to habitat destruction and other threats.

Notes: The validity of this species remains uncertain without genetic analysis, as it may represent a striped morph of Chalcides colosii, a species found in nearby areas that differs only in its colour pattern (Martínez del Mármol et al., 2019).

References

• Bons, J. and Geniez, P. (1996). Amphibiens et Reptiles du Maroc (Sahara Occidental compris), Atlas
  biogéographique.  Asoc. Herpetol. Espanola, Barcelona.
• Martínez del Mármol, G., Harris, D.J., Geniez, P., de Pous, P. and Salvi, D. (2019). Amphibians and Reptiles of
  Morocco. Edition Chimaira, Frankfurt au Main.
• Pasteur, G. (1981). A survey of the species groups of the Old World scincid genus Chalcides. Journal of Herpetology, 15(1), 1–16. https://doi.org/10.2307/1563640
• Werner, F. (1931). Ergebnisse einer zoologischen Forschungsreise nach Marokko: unternommen 1930 mit Unterstützung der Akademie der Wissenschaften in Wien. 6. Skorpione. Hölder-Pichler-Tempsky.