Once a jay hides its food, does it really remember it?

The sower in the forest - Jay

The jay belongs to the genus Jay in the family Corvidae of the order Passeriformes. It is commonly known as the mountain monk or house bird. In Europe, the jay is often referred to as jay for short. The jay is of medium size, with an adult body length of about 32 cm, short wings, long tail, and fluffy feathers. Most of its body is reddish brown or tan, and the plumage color varies greatly between different subspecies (34), but the black, white, and blue horizontal stripes on the wings are the more obvious characteristics of this species; in addition, there are black cheek stripes from the beak to the throat.

The distribution range of the jay is very wide, from Western Europe to northeastern Africa, and a large area of ​​eastern and southeastern Asia. The jay is a forest bird that usually inhabits broad-leaved forests, mixed coniferous and broad-leaved forests, and coniferous forests. It can also be seen in forest parks in cities or on trees along the roadsides.

Jays are omnivorous animals, and the composition of their food varies with the seasons and environment. In spring and summer, jays generally feed mainly on animal food (such as ants, longhorn beetles, wasps, chicks and bird eggs, etc.), and also eat flowers and young leaves. In autumn and winter, jays mainly feed on fruits and seeds, such as pine, acorns and blackberries. Jays breed in forests on high mountains, nesting in early summer. Each time, 4 to 6 eggs are laid, which hatch after 16 to 19 days and fully grow feathers after 21 to 23 days. Both male and female birds feed their young.

In order to cope with the long and cold winter, jays often disperse and store some seeds for emergency use. This behavior of storing food not only provides food reserves for jays to survive the winter, but also provides opportunities for the spread of many seeds, thus having an important impact on the renewal of these plant populations.

Jay eating acorns (picture from the Internet)

Jays usually forage and store seeds in autumn and winter. They like to climb and jump between branches to forage. Unless they encounter very large or very hard food, jays usually only use their beaks to handle food without the cooperation of claws or toes. In addition to eating food immediately, they will temporarily store fruits or seeds in the crop and transport them to other places. The crop is a specialized organ formed by the middle or rear section of the esophagus, and is a storage place for food before digestion. The crop of jays is obviously enlarged, which is conducive to storing and transporting more food at one time. Jays can carry seeds to places hundreds of meters away from the mother tree, or even more than a thousand meters away. These seeds may be brought to the nest as food for the winter, or they may be buried on the surface for storage. Jays have the habit of dispersing seed storage: that is, they establish multiple storage points in a large area and bury only 1-2 seeds at each burial point. Corvids usually spread seeds in a targeted manner, that is, they bury seeds in specific microenvironments, such as the shallow surface layer and the dead branches and leaves layer in the woodland, usually 1-3 cm underground, which is very suitable for seed germination. Jays also bury a large number of seeds. It is reported that 35 jays can bury 200,000 acorns in one autumn.

There are two completely different fates for seeds that are scattered and stored: one is to be found and eaten again, and the other is to be "forgotten" and have a chance to germinate. Jays will store food along special and identical routes, and the storage points are generally distributed in areas where they often move or in their favorite habitats. This specific storage route helps to strengthen the jay's spatial memory of the storage location, so that it can retrieve food more accurately and increase the success rate of retrieval.

The calls of jays that we often hear are mostly rough and piercing screams, which are mainly used by jays to warn their companions when they find predators. In addition, this type of bird is also good at imitating the calls of other birds. Therefore, unless you can see it with your own eyes, it is easy to be misled by its sound alone. Sometimes jays will even imitate the sounds of their predators to avoid attacks, such as the gray forest owl. Other predators of jays include goshawks and peregrine falcons.

Jay profile:

Eurasian Jay

Scientific Name: Garrulus glandarius

Visibility: Common

Found: Alone or in small groups in densely wooded areas such as oak orchards

Figure 1: Jays active on the roadside in Angou