Anecdotes on the nature of ungulates, from a farm in Namibia

@tonyrebelo @jeremygilmore @botswanabugs @paradoxornithidae @matthewinabinett @martinmandak

In 2001, I was told the following by Elisabeth Straube, who had lived on a farm in the Khomas Hochland of Namibia, 135 km southwest of Windhoek (https://www.hakos-astrofarm.com/en/anreise/).

EQUUS HARTMANNAE

Over the years, Elisabeth had hand-reared various species of wild and domestic animals.

A neighbouring farm had a large population of Equus hartmannae (https://www.inaturalist.org/observations?taxon_id=129691). Intruders illegally killed a mother, orphaning its female infant.

When Elisabeth took this infant into her care, it was already in a thin and weak state. The milk of domestic Bos proved unsuitable, resulting in diarhhoea.

Despite time being against the survival of the infant, Elisabeth kept experimenting to find a solution. Based on advice from an elderly woman in the area, she followed local lore in giving the infant 4-5 tablespoons of dry, black tea-leaves. This did indeed stop the diarrhoea, buying some time.

Other farmers tipped off Elisabeth about the sweetness of equine milk compared to ruminant milk, so she resorted to klim milk (https://en.wikipedia.org/wiki/Klim_(powdered_milk)), and added fructose (fruit sugar). This she dispensed to the infant up to 14 times per day, in a wine bottle, solving the problem of surrogate lactation. Later, this infant would lick sugar from the sugar-pot on the tea table.

As the infant grew, it soon became jealous. It bit car tyres, and tried to bite humans. It would enter the house and jump between the chairs occupied by Elisabeth and others, as if to separate them. When still an infant (with long pelage on the belly), it tried to bite Elisabeth's husband.

This led to the infant/juvenile being banished to a property near Okahandja (https://en.wikipedia.org/wiki/Okahandja), at the age of about six months.

Several months later, Elisabeth visited this individual, which was locked in a kraal. The zebra recognised Elisabeth's voice before seeing her, and cried out immediately. It then accepted Elisabeth in reunion, despite the elapsed interval. Elisabeth was told by experienced locals that E. hartmannae will remain emotionally attached to a foster-mother for the rest of its life - even if this was a man, not a woman.

I infer that this reflects both the strength of maternal imprintation in Equus and the particular social structure of E. hartmannae.

ANTIDORCAS MARSUPIALIS

Antidorcas marsupialis has a reputation - somewhat paradoxical in view of its common name - of being unwilling to jump over fences, preferring to crawl under them.

However, Elisabeth observed the carcase of an individual of A.marsupialis that had tried to jump a fence. It had failed to clear the top wires, so that its hind hooves got caught. The animal died - in the way more familiar for Strepsiceros strepsiceros - hanging upside down with the tips of its fore hooves just above the ground (for a photo of a similar casualty, please scroll in https://pronamib.org/).

MADOQUA DAMARENSIS and RAPHICERUS CAMPESTRIS

Elisabeth hand-reared an individual of Madoqua damarensis. This animal covered its faeces, as does the domestic cat (Felis catus). It dug a hole with its hooves, then squatted over the hole to defaecate, then used its hooves again, to scrape earth over the faeces.

Elisabeth also hand-reared an individual of Raphicerus campestris steinhardti. She found that this species did not behave in a similar way.

STREPSICEROS STREPSICEROS

Elisabeth told me that, during a lean period, she observed that Strepsiceros strepsiceros zambesiensis on the farm were weak, and seemed incapable of jumping fences in the usual way. Several individuals were found to have failed to clear the top wires, and died hanging on the fence from their hind hooves. Under these conditions, Elisabeth found that the meat of culled individuals was dark red and, somewhat paradoxically, jelly-like yet not softened by cooking.

During the same period, when foliage was scarce, she observed that S. s. zambesiensis resorted to eating the spines and prickles - which are normally avoided by delicate movements of the lips and tongue during foraging - of shrubs such as acacias.

Elisabeth noticed this when she tried to prepare the tongues of the carcases for the table. The tongues - although appearing fairly normal on the surface - proved to be unfit for consumption, because numerous spines were lodged inside them.

These lodged spines and spine-tips included

• large and small spines,
• straight spines and prickles (short, curved thorns such as those of Senegalia mellifera (https://www.inaturalist.org/taxa/527007-Senegalia-mellifera), and
• both Vachellia (pale, straight spines) and Prosopis glandulosa (https://www.inaturalist.org/taxa/58160-Prosopis-glandulosa).

This observation indicates that

• when starving, S. s. zambesiensis can endure the pain of a riddling of the tongue with embedded spines, in an attempt to survive on the leafless twigs, and
• this does not result in so much inflammation that the tongue becomes obviously swollen.

SUS SCROFA

Elisabeth also hand-reared an individual of the domestic pig (Sus scrofa), and found it to be so intelligent and responsive that it made a particularly rewarding pet.

I find this surprising, for the following reasons.

Most mammals subjected to domestication have become decephalised in the process (https://www.inaturalist.org/journal/milewski/67392-decephalisation-in-domestication-part-1#), but this is particularly so for Sus.

Furthermore, there is little about the niche of the wild ancestor that would suggest an evolutionary pressure for intelligence exceeding that general for artiodactyls. If anything, one would expect minimal intelligence in Sus relative to other artiodactyls, because of the extreme fecundity of this genus.

Homo and Sus are in various ways biologically similar enough (omnivory, relatively pale muscle-tissue, sundry physiological processes) for Sus to be a suitable model in laboratory work in medicine. However, Homo and Sus could hardly differ more in pace of life (particularly in rates of growth and reproduction). This has been the basis for an extremely successful 'mutualism' in domestication, in which the gulf between Homo and Sus has been further widened by selective breeding in which fecundity has increased, and braininess has decreased, in Sus.

Thus, to find that, despite the conceptual framework outlined above, the domestic pig remains more intelligent than most artiodactyls, is deeply puzzling.

Publicado el junio 1, 2023 12:24 TARDE por milewski