The bambis, part 1: introduction to the category of diminutive ruminants

Ruminants span a remarkable range in body sizes. I define 'bambi' as that faunal category consisting of all those species and subspecies of ruminants with a body mass less than 15 kg in the adult female.

Bambis are about 100-fold less massive than the largest ruminants, particularly giraffes and large bovines.

Bambis appear to have evolved from larger ancestors at least ten times, in various regions of the world, and are as diverse ecologically as they are phylogenetically.

They include chevrotains and musk deer, several clades of deer, and several clades of African bovids. Most species hide in dense vegetation. The greatest concentration of bambis is in Africa-Arabia, which is also the only region in which bambis extend to arid environments.

In subsequent Journal Posts I will explore some of the many aspects of bambis intriguing to the naturalist. The following collage of photos gives some sense of the topics.

The body-form of bambis varies from short-legged, as in the genus Pudu of the Andes, to long-legged, as in the genus Neotragus of central Africa.

This difference is so great that even the infants of pudus stand with straight legs (see https://www.zooborns.com/zooborns/2012/09/how-do-you-do-little-pudu.html) whereas even the adults of pygmy antelopes stand with folded legs (see http://www.ultimateungulate.com/Artiodactyla/Neotragus_pygmaeus.html).

Both klipspringers (Oreotragus) and musk deer (Moschus) climb well. However, their hooves differ greatly. Those of klipspringers are so upright that the animals cling to surfaces by means of their hoof-tips (see https://www.flickr.com/photos/davidbygott/15188787881). They climb by being, in a sense, 'hyperunguligrade'.

By contrast, musk deer (see https://whatsinjohnsfreezer.files.wordpress.com/2014/02/moschus-deer-feet.jpg) climb by means of the parts of the feet other than the hooves; they remain in some sense digitigrade.

And, finally for now: some bambis have become almost emancipated from vegetation cover, being able to flee with some endurance.

The smallest gazelle on Earth, the recently extinct Gazella saudiya, was restricted to the semi-deserts of Arabia. It had longer horns and was probably more gregarious than any other bambi. (No photos exist but the closely-related dorcas gazelle is indicative: https://image.nanopress.it/r/845X0/viaggi.nanopress.it/wp-content/uploads/2013/06/Gazzella-Dorcade.jpg).

In southern Africa, a large-eared subspecies of the steenbok (Raphicerus campestris steinhardti) is so arid-tolerant that it lives at the edge of the barren Namib (see https://en.wikipedia.org/wiki/Steenbok#/media/File:Steenbok_(Raphicerus_campestris)_running_composite.jpg).

to be continued in https://www.inaturalist.org/journal/milewski/55475-the-bambis-part-2-diminutive-deer-of-the-americas#...

Posted on June 25, 2021 10:37 PM by milewski