"Crocodile Canyon"

POSTSCRIPT

Recent crocodile records in the Tagant, Mauritania. click to enlarge map

Several important changes in the status of Mauritania's desert crocodiles have occurred since the filming of Crocodile Canyon in 2003.

Firstly, as already reported, the desert crocodiles, and all former Nile crocodiles in West Africa, have been recognised as a separate species, Crocodylus suchus, here referred to as the Northwest African crocodile (Schmidt et al 2003).

Secondly, due to the hard work of Hemmo Nickel and his colleagues, including Irish herpetologist Tara Shine, the number of localities where crocodiles are now known to survive has increased considerably. The map above indicates most, but probably not all*, of the locations known in the Tagant which now number at least 26. Additionally, many more locations are reported from the Mauritanian provinces of Assaba, Hodh El Gharbi and Hodh Ech Chargui Provinces to the south and east (Nickel 2004, Cooper et al 2006, Padial 2006).

Most of the Tagant populations are in water-courses that form part of the Gabou Basin but some to the south and southwest (Silimbo, Toueijikit, Laout) are part of the Senegal River watershed and many provide a genetic link with more continuous crocodile populations further south.

It could be that the Mauritanian populations of Crocodylus suchus are the largest occurring in the Sahara, much larger than the isolated eastern Chadian population on the Ennedi Plateau.

In 2008 the Mauritanian Government submitted a proposal to the Ramsar Convention Secretariat to have the Tagant Plateau wetlands listed as a Ramsar Wetlands site (Tellería et al 2008). The proposal was ratified on 13th February 2009 and the Lac Gabou et le réseau hydrographique du Plateau du Tagant is now listed as addition number 1854 to the list of Ramsar sites of Wetlands of International Importance.

* It has so far proved impossible to locate three of the original five locations reported by the three French students in 1993 ie. Ederoum, Amzouzef and Rh Zembou.

Cooper, A., T.Shine, T.McCann & D.A.Tidane 2006 An ecological basis for sustainable land use of Eastern Mauritanian wetlands. Journal of Arid Environments. 67:116-141.

Nickel, H. 2004. Neues zum Status von Crocodylus suchus Geoffroy 1807, dem Nordwestafrikanischen Krokodil. Draco 5 (20): 48-53

Padial, J.M. 2006 Commented distributional list of the reptiles of Mauritania (West Africa). Graellsia 62(2):159-178.

Schmitz, A., P.Mausfeld, E.Hekkala, T.Shine, H.Nickel, G.Amato & W.Böhme 2003 Molecular evidence for species level divergence in African Nile Crocodiles Crocodylus niloticus (Laurenti, 1786). Compus Rendus Palevolution 2:703-712.

Tellería, J.L., H. El Mamy Ghaillani, J.M.Fernández-Palacios, J.Bartolomé & E.Montiano 2008 Crocodiles Crocodylus niloticus as a focal species for conserving water resources in Mauritanian Sahara. Oryx 42(2):292-295.