Capra (genus) - Taxonomy

Taxonomy

All members of the Capra genus are bovids (members of the family Bovidae) and caprids (subfamily Caprinae). All these are ruminants, meaning they chew the cud, and have a four-chambered stomach which plays a vital role in digesting, regurgitating and re-digesting their food.

The genus has sometimes been taken to include Ovis (sheep) and Ammotragus (Barbary sheep), but these are usually regarded as distinct genera, leaving Capra for goats and ibexes. In this smaller genus, some authors have recognized only two species, the markhor on one side and all other forms included in one species on the other side. Today, nine species are usually accepted:

• Spanish ibex (Capra pyrenaica)
• Alpine ibex (Capra ibex)
• Nubian ibex (Capra nubiana)
• Siberian ibex (Capra sibirica)
• Walia ibex (Capra walie)
• West Caucasian tur (Capra caucasica)
• East Caucasian tur (Capra cylindricornis)
• Wild goat (Capra aegagrus)
  • Domestic goat (Capra aegagrus hircus, sometimes referred to as Capra hircus; includes feral goat)
• Markhor (Capra falconeri)

The goats of the genus Capra have complex systematic relationships, which are still not completely resolved. Recent studies based on mitochondrial DNA suggest the Siberian ibex and the Nubian ibex represent distinct species, which are not very closely related to the physically similar Alpine ibex. The Alpine ibex forms a group with the Spanish ibex. The West Caucasian tur appears to be more closely related to the wild goat than to the East Caucasian tur. The markhor is relatively little separated from other forms—previously it had been considered to be a separate branch of the genus.

Almost all wild goat species are allopatric (geographically separated)—the only geographical overlaps are the wild goat (Capra aegagrus) with the East Caucasian tur (Capra cylindricornis), and the markhor (Capra falconeri) with the Siberian ibex (Capra siberica). In both cases, the overlapping species do not usually interbreed in the wild—however, in captivity all Capra species can interbreed, producing fertile offspring.