Identifying the beasts in Caesar’s forest

In his book, Commentarii del Bello Gallico, the first parts of which saw publication in 49BCE, Julius Caesar makes much of a giant forest which in those days spread of much of what is now modern Germany.

The great Roman general’s tome is, of course, primarily his account, written in the third person, of the military campaigns he conducted in Gaul, but it also contains a couple of sections describing the vast oaken wilderness, known in the Classical world as Hercynia Silva, or the Hercynian forest.

And it is this digression that interests Chase D. Brownstein of the Stamford Museum in Connecticut, US. In a paper published in the journal Historical Biology, the researcher uses Caesar’s description of Hercynia, together with those of other ancient writers, to map changes in the population of large mammal fauna in the forest from the end of the Pleistocene – about 11,000 years ago – to the beginning of the Roman Empire (which any high school student will tell you began after Caesar’s assassination).

The forest is mentioned in works by other Roman writers – notably Pliny the Elder and Tacitus – as well as by earlier Greek authors including Aristotle and Herodotus, but it is on Caesar’s description of the animals it contained that Brownstein decides to focus.

It is quite a strange passage, which in the past has led many scholars to dismiss it as fanciful. The general describes, for instance, a large deer, from which “between the ears, a single horn comes forth” – quite possibly a source reference for the myth of the unicorn.

Then he mentions animals he calls “alces”, which look like large, hornless goats. The legs of these animals, he tells his readers, “do not possess joints and knots”. If they accidentally fall down, he says, they are unable to get up again.

Third, he mentions the fearsome “uri”, “in size a little below the elephants, and in look and colour and form like bulls”. These are unlike Roman oxen, are extremely aggressive, and are prized as hunting trophies by the locals.

Of the three species described, the first is by consensus of later scholars the least controversial. Most who have attempted to identify it converge on Rangifer tarandus – better known as the reindeer. If so – and Brownstein refers to more accurate descriptions of the animal, at least in terms of the number of horns it possessed, by Pliny the Younger – it indicates that reindeer were common much further south than they are today.

The identity of the “uri” over the years has been considerably more controversial. The name used by Caesar doesn’t help: it derives from “urus”, a term seemingly employed at the time to describe any large, exotic animal.

Previous scholars have suggested that it was a European bison (Bison bonasus bonasus) or Eurasian aurochs (Bos primigenius primigenius). The matter further complicated by the suggestion made in 2016, on the evidence of early cave art that the European bison itself may have been a hybrid of the aurochs and another species, the Steppe bison (Bison priscus).

Pliny the Elder confirms the existence of both the European bison and the aurochs in the Hercynian forest, but Brownstein plumps for the latter in his target text.

“Caesar describes the massive size of the aurochs as elephantine in proportion, and both he and Pliny the Elder remarked on the speed and strength of these animals,” he notes.

Finally, the goatish alces, he argues, were very likely to have been European moose or elk. Pliny also describes the animal – adding the telling detail that it possessed an enlarged lip.

Both authors note the elk habit of sleeping while remaining upright, leaning against a tree – a behaviour that led, reasonably enough, to the assumption that it had unjointed legs. (Interestingly, Brownstein notes, this assumption has a long history, beginning way earlier than late Republican Rome, designed “to boost the mythos of the European moose as a fantastical wild animal”.)

Perhaps as important as the mega-fauna Caesar does mention, Brownstein says, are those he doesn’t. Commentarii del Bello Gallico contains no references to either brown bears or wolves, for instance, suggesting that perhaps these two species had become locally extinct by then.

Not, the researcher cautions, that Caesar’s descriptions of the forest wildlife should be regarded as authoritative. Because he “was conducting a military campaign, the presence of … errors is rather unsurprising”.

Also, in the Classical period, reportage was always a mixture of firsthand observation and secondhand sources, so it is always possible that Caesar never actually laid eyes on the uri, alces, or the large deer with the single horn.

Even if that was the case, it does not mean that the descriptions are worthless.

“The passages … are important for representing a glimpse of a more ‘untouched’ Holocene European mammal fauna, and can thus be used to help model the shifts in the distribution of megafaunal species on the continent through time,” Brownstein concludes.