Birdwatching: The Acorn Loving Jay
Jays, our most handsome and distinctive members of the crow family, are shy birds and you never find them far away from trees. In autumn they are busy collecting acorns.
The jay belongs to the crow family, but it has much brighter plumage than its relatives. At close range it looks quite exotic. Its crest, delicately spotted with white and black on the forehead, is raised when it is displaying to other birds. It has pale blue eyes and a broad black moustachial streak; most of the body is pale pinkish-brown. The flight feathers are black and grey, with a conspicuous patch of white, and the wing coverts are beautifully barred with pale blue and black.
Elusive bird Jays are shy and restless birds. And you may find it hard to get a good view. Most often you just see them flying away, when the large, white patch just above the black tail is very noticeable. They have broad, rounded wings and their flight often looks weak and laboured. At a distance, jays can be mistaken for hoopoes, an unrelated bird found in Europe which is fairly similar in size and shape and also has black, white and pink plumage.
Oak woodland is the jay’s preferred habitat and you rarely find them far from trees. Unlike our other crows-magpies, carrion crows, rooks and jackdaws-jays seldom venture out into open fields. When they are searching for food in the trees or on the ground, they tend to hop and leap about, rather than walk or run.
Jays are often quite noisy, so you may hear them before you see them. The main call can be heard from far off. It is a loud, often twice-repealed, rasping shriek of alarm which they make when disturbed. People have also heard jays make a variety of chuckling and chirruping calls, a buzzard-like mew and even a low, warbling song.
The jay’s favourite food is acorns. In September and October when the acorns ripen you can see jays searching methodically for them in and beneath oak trees. However, instead of eating only what they require and leaving the rest to fall to the ground where all kinds of animals and birds would find them, jays hoard them. By making their own private larder, they can be sure of enough food to last throughout the year.
Jays can hold up to nine acorns at once in their especially large oesophagus, but more usually they take just three or four. They take each acorn to a separate place, usually within half a mile but sometimes up to 2 miles away from where they found it. Favourite hiding places are under leaves or roots, in small holes or amongst moss. Sometimes the jay actually makes a hole in the ground with its beak so the acorn is properly concealed.
Jays appear to have excellent memories. Because they know every detail of their local wood and they remember where most acorns are hidden. Even when snow covers the ground, they know exactly where to dig. In the summer many uneaten acorns begin to germinate, but jays can also recognise the fresh oak seedlings and dig them up to find acorn remains below.
The acorns are often ‘planted’ in suitable sites for growing and. When there is a surplus. Those that are not retrieved grow into trees and provide food for future generations of jays. So the jay’shabit ensures the survival of both the jay and the oak. It is probably also the most important method by which oaks spread uphill.
When eating an acorn, a jay usually holds it still against a branch or on the ground with its inner toes. Then with its strong, slightly hooked beak, it levers and tears off the shell to reach the nutritious core.
In spring you may find gatherings of jays known as jay ‘marriages’. These are probably courting birds trying to find mates. On some occasions up to 30 jays are present displaying and calling in great excitement.
Jays prefer to nest fairly low down in thick undergrowth-in bushes and small trees, and in evergreens such as ivy, or suckers next to a tree trunk. Occasionally they choose the outer branches of a large tree. Both the male and female help to build the well-concealed, robust nest. They use numerous small sticks and twigs and a little earth, and then line the nest with a thick layer of fine roots.
The female usually lays four to six eggs at the end of April or in May, and does most of the incubation. She is very difficult to spot because she crouches very low in the nest, only leaving when her mate comes to feed her and can stay on guard.
The eggs hatch after 16 days but the female still has to brood her family for the first week or so, because the tiny, featherless chicks soon chill if left uncovered for long. At this time the male finds all the food they need. To start with, the chicks look all beak and belly-because they are eating as much food as possible and growing quickly. By the time they are two weeks old, they are big and fat, and all the feathers are sprouting except perhaps the tail which is last to appear. When they leave the nest the young jays already have their adult plumage.
The jay parents collect a special diet for their nestlings. Mostly they choose leaf-eating caterpillars from nearby trees and bushes, storing them in their throats until they have enough to give each nestling a good mouthful. The chicks wait silently for a parent to land beside the nest, and then reach up and open their beaks wide. The parent carefully puts food down the bright orange-pink gape of each chick in turn. If one gets too much to swallow, some is taken away and given to another.
Nesting adult jays are secretive, and the nestlings are also fairly quiet, even when being fed-you may hear a few squeaks and squawks if you are close. Even the egg-thieving jay has to keep its nest-site secret from crows, magpies, squirrels and even other jays who rob the nest if they get the chance.
Just as small birds mob jays, so for the same reason jays mob their enemies.
Jays spend about three weeks in the nest but are not independent for another two months, so only one brood is raised each year. They can live for several years and some have been known to reach the age of 14. Throughout their lives jays tend to stay in one area. And most fly no more than four miles from their birth place. Very occasionally the British Isles is invaded by hundreds of jays from the Continent if food supplies there fail to support the jay population. In the past, when Britain was covered in forest, jays were probably numerous and widespread. However, they were persecuted because of their egg-thieving habit, and many trees have been cut down to make way for agriculture, so jays became quite scarce early in this century. Since then they have benefited from being unmolested, and from extensive afforestation. Some have spread into suburban areas and city parks, especially those with a good collection of trees such as oak, beech or sweet chestnut, and shrubs.