1. Where the Ostrich Myth Began: Pliny the Elder's Ancient Roman Book
The oldest record of this myth comes from the ancient Roman naturalist Pliny the Elder (23–79 AD). In his book *Natural History*, he wrote that ostriches stick their heads into bushes and think their whole bodies are hidden [1]. Notice that the word "sand" does not appear in this text. It is not clear how the story changed from bushes to sand. However, historians estimate that this specific sentence became the basis for the modern myth [2].
2. Three Situations When an Ostrich Lowers Its Head to the Ground
Ostriches do lower their heads close to the ground in several specific situations. The first is when they are tending to eggs in a nest. To turn the eggs, they lower their heads [3]. This turning action is explained as a way to distribute heat evenly to all parts of the egg [4].
The second situation is when they swallow sand or small stones. This helps their stomachs grind up food. As they peck at the ground for these stones, their heads get close to the soil [3].
The third situation is when they feel danger they cannot escape. In this case, they lie flat on the ground and keep still, pressing their head and neck flat against the earth [5]. The important detail here is that they press their head "flat" against the ground, not "bury" it.
Note: This lying flat behavior happens when the ostrich feels it cannot escape a threat. It is a reaction to danger, not a way to hide from curious visitors.
3. Why an Ostrich's Head Can Look Buried From a Distance
Another clue lies in the color of the ostrich’s head and neck. According to the San Diego Zoo, these parts are a pale color that blends in with the color of the soil. From a distance, this makes it look as if the head is buried in the sand [5].
Ostriches are the largest birds in the world. A male stands about 2.1–2.7 m (7–9 ft) tall, and a female is about 1.7–1.9 m (5.5–6 ft) tall [5]. When a bird this tall lies down in a nest on the ground, the head at the end of the long neck becomes hard to spot from far away. When you combine "lowering the head" with "blending into the soil color," it is easy to see how the illusion of a vanished head is created.
4. How Ostriches Really Defend Themselves: Running Away First
When an ostrich senses danger, its first reaction is usually to run away. It is said that they can reach speeds of nearly 70 km/h (about 43 mph) over short distances [6]. However, this is a top speed for a short dash. They do not keep running at this speed for a long time.
Lying flat on the ground and staying still is a behavior used only when they feel they cannot escape [5].
Note: National Geographic Japan notes that ostriches run first when danger approaches, reaching nearly 70 km/h. This order is the opposite of the myth that they hide their heads to avoid danger.
5. How the Ostrich Myth Became the Phrase "Bury Your Head in the Sand"
In English, there is a common phrase: "bury your head in the sand." It means to ignore an unpleasant reality. This expression comes directly from the ostrich myth [7]. Phrase dictionaries explain that Pliny was the first to record this story. However, his text was about bushes, and it is not clear exactly when the idiom itself was born.
Note: This is an example where a metaphor has taken on a life of its own, separate from the actual behavior of the animal.
6. A Simple Experiment to Test the Ostrich Head Idea Yourself
If you want to explore this further, you can try a simple experiment at home. Place small brown objects on brown paper. Move away from them gradually and check how they look from different distances. You can see how things that are clear up close appear from far away.
If you visit a zoo with ostriches, look for moments when they lower their heads. Think about what they are doing at that moment. If a zookeeper is giving an explanation, ask them questions about the bird’s behavior.
For further reading, the Japanese edition of National Geographic has an article about ostriches that you can read in Japanese.