Revealing the sleeping habits of birds, most birds do not sleep in their nests!

Birds are common animals in our lives. They have various shapes and habits, and also different ways of sleeping. We may think that birds sleep in their nests, but this is not entirely correct. This article will introduce some interesting phenomena about birds sleeping. Let's learn about them together!

1. Bird nests are not the primary sleeping place for birds

We often see birds building nests on tree branches or in bird boxes provided by humans. These are places where birds breed. However, after birds have finished hatching eggs or raising chicks, they will no longer return to the nest to sleep. This is because after a period of use, the nest will become very dirty and messy, and may also have parasites or other germs. Therefore, except for birds that are hatching or feeding their offspring, most birds will not sleep in the nest.

So where do birds sleep? It depends on the species and the environment. Generally, birds will find a safe, secluded place to rest, such as a tree, bush, cave, rock crevice, chimney or other shelter. Some waterfowl or wading birds sleep near water or on small islands, using the sound and vibration of the water to alert predators. Some nocturnal birds, such as owls, sleep during the day and are active at night.

2. Birds have different sleeping positions and ways to stay warm

We might imagine that birds sleep standing on their two legs, but this is not always the case. Some birds stand on one leg and tuck the other leg into their body to keep warm; some birds sleep lying on the ground or on branches; some birds even sleep hanging upside down on tree trunks.

So how do birds maintain balance and stay warm?

First, birds have a special muscle structure in their toes, called the flexion reflex, which allows them to automatically tighten their toes and grip support when they relax.

Secondly, birds have two layers of feathers, one is the down layer and the other is the flight feather layer. When birds sleep, they fluff up the down layer to form a thermal insulation layer. At the same time, they hide their heads under their wings or in their feathers to reduce heat loss.

3. Birds can sleep in one hemisphere

When humans and most mammals sleep, the entire brain enters an unconscious state. However, birds can control their sleep more finely. They can use a method called unihemispheric slow-wave sleep (USWS), which means that one side of the brain is asleep while the other side is awake, and one eye is open while the other is closed. In this way, birds can stay alert while sleeping and respond to danger at any time.

The extent and frequency with which birds use unihemispheric slow-wave sleep depends on their environment and how safe they feel. If the environment is safe, the birds will sleep more deeply; if the environment is uncertain, the birds will sleep more lightly. Some migratory or aerial birds, such as swifts or albatrosses, can even use unihemispheric slow-wave sleep in flight, that is, they can sleep in the air.

4. Birds sleep in groups

In addition to using unihemispheric slow-wave sleep to protect themselves, birds have another defense strategy, which is sleeping in groups. Many birds gather together at night to form a common sleeping area called a roost. Some roosts may have thousands or even tens of thousands of birds participating. The advantage of doing this is that it can increase the chance of discovering predators and distract the attention of predators, increasing the chance of survival of each bird.

Of course, not all birds sleep in groups. Some are more independent or territorial and will sleep alone or with a mate. Others change their sleeping habits depending on the season or food resources.