Rupicapra

The genera Rupicapra and Lepus: two case studies

An example of a genus whose taxonomy was badly neglected during most of the 20th century is Rupicapra. Chamois (genus Rupicapra) are goat-like ruminants confined to steep, rocky habitats at high altitudes, cool in summer and generally snow-covered in winter; evidently during glacial periods, when these conditions extended to more low-lying areas, the populations which are presently isolated were able to expand their ranges, which is presumably how they dispersed between massifs in the past (Camerano 1916a; Lovari 1987).

Lydekker, in line with his stated policy of “classing nearly related kinds of animals as races of a single species, rather than as distinct species” (Lydekker 1913: vi), placed all then-known chamois taxa in a single species, Rupicapra rupicapra, with seven subspecies. Slight changes to this arrangement were made by Couturier (1938), who accepted the single-species model without query and described two further subspecies while casting doubt on the validity of some of the others; and by Blahout (1972), who described a further subspecies. It was not until the work of Sandro Lovari in the late 1970s and 1980s (Lovari 1987; Lovari & Scala 1980) that the single-species model began to be challenged: beginning with behavioural studies contrasting Abruzzo and Alpine chamois, later incorporating the chamois of the Pyrenees, then proceeding to morphological studies, Lovari and his colleagues were able to separate western European chamois into two contrasting forms, which they regarded as two species [R. rupicapra (Linnaeus, 1758), Alpine; and R. pyrenaica Bonaparte, 1845, Pyreneean, Galician and Abruzzo] (summarised in Lovari 1987).

Groves & Grubb (2011) —who provisionally recognised six species in the genus—utilised the metrical datasets of Couturier (1938) to compare skull and horn shape in as many of the described subspecies of chamois as possible (Figs 4 and 5) (Lovari & Scala 1980, had previously also done something similar, though curiously omitting nominotypical R. rupicapra from the Alps). They could find no difference between specimens from the Massif de Chartreuse (Rupicapra rupicapra cartusiana Couturier, 1938) and those from the Alps (rupicapra); in agreement with Lovari’s (1987) model, it was clear that that the Pyrenean (pyrenaica) sample was absolutely different, but so was the sample from the Carpathians (carpatica), despite the latter being entered as an “unknown” in their Discriminant Analysis because of the small sample size. The small Abruzzo sample, entered as an “unknown” again because of the small sample size, was closely allied to pyrenaica; and two other samples (Balkans, balcanica Bolkay, 1925, and Caucasus, caucasica Lydekker, 1910), also entered as “unknowns”, were (on the limited data) indistinguishable from rupicapra. These results confirmed and partly extend those of previous authors (Lovari 1987; Lovari & Scala 1980).

Genetic studies have shown complex reticulation among the populations of chamois. Whereas Y chromosome DNA supports Lovari’s two-species model (Pérez et al. 2011), mtDNA reveals three well-separated clades (Rodriguez et al. 2009), one of which unites Abruzzo ornata Neumann, 1899 (a subspecies of R. pyrenaica in the two-species model) with Chartreuse cartusiana Couturier, 1938 (a subspecies of R. rupicapra in that model: indeed, indistinguishable from Alpine rupicapra in Groves & Grubb 2011). Autosomal microsatellites distinguish each of the described taxa, and to integrate different sources of evidence Rodriguez et al. (2010) proposed a hypothesis involving complex reticulation in the area centred on the Alps, south-eastern France and Italy. Interestingly, a three-species model, invoking historical hybridization, was originally proposed a century ago by Camerano (Camerano 1916a, 1916b), even without examination of materials from the Chartreuse population.

This brief survey of late-twentieth-century research on a single genus, Rupicapra, highlights how much remains to be discovered if one moves beyond assuming the taxonomy of the larger-sized European mammals is well established. In this case, it was behavioural research which led the way; morphological, morphometric and genetic studies followed.

As long as the taxa of Rupicapra were all classed as subspecies, in line with the practice of most European biologists, their conservation status remained in threat. Rupicapra ornata, for example, has been susceptible to a number of threats other than those produced by its long-term small population size. In the late 1980s, it was proposed to restock this tiny Apennine population with individuals from the Iberian Peninsula, with the aim of increasing its genetic variability (Nascetti & Cimmaruta 1997). In Slovakia, nominotypical rupicapra from the Alps has been used to create new populations adjoining, and so threatening, the endemic Rupicapra (cf. rupicapra) tatrica Blahout, 1972 through artificial introgression (Crestanello et al. 2009). More recently, it was hypothesised that the origin of the Apennine chamois was due to an historic but undocumented introduction of Iberian chamois into the Abruzzo Apennines by the Royal Borbone family for hunting purposes (Masseti & Nappi 2007), a view reinforced by the absence of firm evidence of surely identified Rupicapra cf. ornata among Pleistocene remains in Central and Southern Italy (Masseti & Salari 2012), but the recent finding of a whole skeleton referable to R. ornata from the Late Pleistocene in the Simbruini Mountains (Salari et al. 2014) finally confirmed the autochthony of the Apennine taxon.

The taxonomy of southern chamois (R. pyrenaica and R. ornata) has several points in common with those of some southern hare species: Lepus corsicanus De Winton, 1898 and Lepus castrovejoi Palacios, 1977, the first limited to Central and Southern Italy and including Sicily, the latter endemic to the Northern Iberian Peninsula. The two taxa belong to an ancient lineage of Lepus timidus -like hares formerly found in southern Europe. They are clearly closely related, and it has been proposed on the basis of mtDNA and/or nuclearDNA to unite them into a single species (Alves et al. 2008; see also Angelici & Luiselli 2007), ignoring the morphological evidence: Palacios (1996) had previously discussed their close plylogenetic affinity but decided to treat them as separate species because of the unique enamel structure of P/ 3 in castrovejoi. In addition, L. corsicanus in Italy shows a clear geographic structure in both molecular and morphometric data (Pierpaoli et al. 1999; Riga et al. 2001; Mengoni et al. 2015), with the Sicilian population appearing quite distinctive. This brief summary highlights not only the unique history of the mammal fauna of the island of Sicily, and unequivocal conservation implications (cf. Gippoliti & Amori 2002), but it further underscores the essential role of taxonomy as the foundation of both comparative biology research and conservation policies. Indeed, Lepus corsicanus has been excluded from the latest edition of the National IUCN Red List (Rondinini et al. 2013), because of the healthy status of the Sicilian population, a decision that overlooks the conservation needs of the continental Italian population (cf. Angelici & Luiselli, 2001); this is yet another unfortunate result of the absence of a true taxonomic revision utilising the new and more abundant materials now available. As stressed by Cotterill et al. (2017), conservation policies should be embracing the insights into evolutionary history revealed by the refinement of taxonomic knowledge. A proactive strategy should incorporate this new taxonomic knowledge to mitigate the impacts of unprecedented global change on ecosystems and their dependent species.