At last, clear photos of the Angolan springbok

Rogerio Ferreira has just kindly supplied a good series of photos of the Angolan springbok (Antidorcas marsupialis angolensis), at https://biodiversidadeangola.com/mammals/scientific/9527.

As it turns out, the darkness of the pygal band and other markings, described by Groves (1981) and used as a partial justification to raise this taxon to full species-status by Groves & Grubb (2011), is not striking. The appearance is, after all, similar to that of subspecies hofmeyri, bearing in mind that even within hofmeyri the specimens from southeastern Botswana were paler than those from Namibia (Groves 1981).

In my view, the possibility that the Angolan springbok is a separate species (Groves & Grubb 2011) has not stood up to scrutiny. And even as a subspecies it is not nearly as distinctive as the black-faced impala (Aepyceros melampus petersi) is from the common impala.

If so, how would this change our overall view of subspecific variation in the springbok?

We can accept that the female horns vary in length along a south-north cline culminating in angolensis. However, clinal variation is not the same as subspeciation. If we assume that the geographical variation in body size and the relative length of the legs is phenotypic as much as genotypic in the springbok, what emerges is a species more noteworthy for its uniformity than for its subspeciation. It seems possible, after all, that the original wild springbok of the Eastern Cape, near Addo, was similar enough (except for the shortness of the female horns) that most naturalists would not have noticed any differences in body size or colouration from the Angolan springbok, 2500 km and 20 degrees of latitude distant.

And what this would mean in turn is that, although Science let the nominate subspecies disappear as a 'pure' entity before it was properly described, Nature may have, as it were, let us off lightly for that lapse.

Publicado por milewski milewski, 07 de mayo de 2021

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