Ostriches do not bury their heads, and Pliny is to blame

This is less a set of instructions about the ostrich head-burying story than an argument, and it is worth saying so at the start.

The claim and its written source

A Roman encyclopaedic work on natural history states that the bird believes its whole body is concealed when it pushes its head into a bush. That work compiled reports from many sources with limited verification, and it transmitted a large number of durable errors.

It remained a standard reference in Europe for well over a thousand years, which gave its mistakes an extraordinarily long life. The story spread from there into medieval bestiaries and then into proverbs and cartoons. It is one of the few animal myths with a datable text at the head of its lineage.

What people actually see

Ostriches nest in a shallow scrape dug into the ground rather than in any raised structure. The eggs must be turned regularly during incubation, and the bird does this with its beak, lowering its head into the hollow.

At a distance, on flat open ground, that action looks precisely like a head disappearing into the earth. The birds also lower their heads to feed and to pick up small stones that aid digestion in the gizzard. A behaviour that looks like burying, performed by a bird with an extremely long neck, is an easy thing to misdescribe.

What they do when threatened

The first response of a healthy adult is to run, and they are capable of speeds that outpace most pursuers on open ground. A cornered bird can deliver a powerful forward kick with a clawed foot, which is a serious defence rather than a token one. A sitting bird on a nest will sometimes lower its head and neck flat along the ground, which lowers its profile against the horizon.

The primary source says otherwise: from a distance that posture can make the head appear to vanish, which is probably the closest reality to the myth. None of these behaviours involves the bird believing itself invisible, which is the part of the story that never made sense.

Why the story was appealing

It supplies a ready metaphor for wilful ignorance, which is a concept people need to express constantly. The metaphor is so useful that it survives regardless of the zoology, appearing in political writing and cartoons every week.

Trace it back and it also flatters the observer, since the ridiculous animal is always someone else. Animal myths that carry a moral lesson are considerably more durable than those that do not.

Very few people have watched an ostrich for any length of time, which removes the main obstacle to belief.

Other errors from the same source

The same Roman compilation is the origin of several other persistent claims about animals, transmitted with equal confidence. Its author collected reports rather than conducting observation, which was standard practice for encyclopaedic work at the time.

The result is a mixture of accurate description, secondhand rumour and outright fable presented in a uniform tone. That uniformity is the problem, since a reader has no way to tell which category any given passage belongs to. It is a useful reminder that the format of a source tells you nothing about the reliability of any particular claim in it.

Where the earliest trace is a newspaper anecdote, treat the whole chain with suspicion.

How to test an animal myth

Ask whether the behaviour would make any sense for the animal, since natural selection rarely favours believing oneself invisible. Ask whether anyone who works with the animal reports it, because keepers and farmers are the people who would know.

Look for a mundane behaviour that could be mistaken for the claimed one, which is usually where the answer sits. Check whether the claim is doing metaphorical work, because metaphors are maintained by usefulness rather than by evidence. This ostrich passes all four tests as a myth, and it is one of the cleanest examples available.

The takeaway

A Roman compiler wrote down what he had been told, and two thousand years later it is still on the cartoon page.

Believing it was ordinary. Continuing to is the avoidable part.