Monday, October 11, 2010

Viscachas to Spiny Rats – A Caviomorph Showcase

Mammals may be the most difficult form of wildlife to photograph, rarely being numerous and almost always quite wary. On my tours, while I can get quite a few butterfly, bug, and flower shots, and once in a while a few bird photos using digiscoping, I rarely get to photograph mammals.

These two adorable creatures are the Northern Mountain Viscacha, Lagidium peruanum. Viscachas are closely related to the better known Chinchilla, another rodent from the high Andes which is now critically endangered in the wild. Normally found in rocky cliffs and boulder fields in the high Andes, a few pairs, like these, make their home in the centuries-old stone structures of Machu Picchu. I've seen them on every visit to this amazing place.

These mammals belong to a well-defined subset of rodents that originated in South America, with a few species spreading northward when the Panama land bridge closed about three million years ago. These rodents belong to the parvorder Caviomorpha with distant relatives in the suborder Hystricomorpha in Africa and Laos (see the video of Laotian Rock Rat first seen alive by one of my clients, David Redfield). It has been suggested that the caviomorph rodents are so distinct that they should be considered their own order separate from Old World and North American rodents, but more recent genetic information shows that they are indeed related to other  rodents.

A familiar member of this group is the North American Porcupine, which like the others 14 species of New World porcupines actually originated in South America. Most people also probably have heard of the Capybara, Hydrochoerus hydrochaeris, the largest living rodent. This one was a pet at Explornapo Lodge where I was leading a tour this past July. It and this dog were inseparable buddies.

Another member of this group of rodents is the agouti, this one a Central American Agouti, Dasyprocta punctata. They are common in tropical rain forests, especially fragmented ones that have lost their big predators such as Jaguar and large eagles. In more remote areas where the big predators still exist, agoutis can be scarce and very wary.

This is the Common Yellow-toothed Cavy, Galea musteloides, a close relative of the Guinea Pig. This one was on my recent Bolivia – Peak of Diversity tour near the Red-fronted Macaw preserve.

Surprisingly rat-like are another group of caviomorphs called spiny rats. They are in the same family as the Nutria and the social Degu from Chile. The only one I have ever seen was this Ferreira's Spiny Tree-Rat, Mesomys hispidus in my cabin at Chalalan Lodge in Madidi National Park, Bolivia several years ago.


  1. Are the North American pikas any close relation to the viscachas, cavies etc.?

  2. Pikas are actually in the same order as rabbits and hares – Lagomorpha. The Lagomorphs are the closest relatives of Rodentia though.