Jay
Garrulus glandarius
The Jays transport of acorns away from the shade of the tree may play a very important part in the regeneration of oak woodlands. Acorns can germinate in the dark, but oak seedlings require light environment to grow past the seedling stage. – A mature tree produces deeper shade than its seedlings can regenerate in.
Jays collect ripe and undamaged acorns for their winter stores to which they return for their food during the winter & early spring.
Some of the Jay’s acorns are eaten on the spot; but many are pouched, carried away and hidden in the ground to form a winter storehouse. They bury them individually in the soil carrying between 1 and 5 acorns per flight (one in its beak and the rest in the throat and oesophagus). Often they will carry the acorns distances of 100m to a few kilometres.
Jays hide acorns undamaged, so that some acorns have the chance to grow if left, (unlike the Grey Squirrel who often chews out the embryo of the nut before burying it, so even if it misses a nut store, the acorns are unlikely to grow).
By the time the Jay rediscovers the acorns they have usually stated to germinate, the bird generally only removes the cotyledon (1st leaves, not true leaves) and the young plant continues to grow.
The Jay remembers where they have planted the individual acorns, (they do not search by smell, simply remember where they are and can even locate them under 300mm of snow).
Like that of fox and squirrel, the Jay’s habit of hoarding seems to be a response to a super-abundance of food.
Habitat
Found in temperate parts of Europe, this bird keeps to the wood more
than any other British crow, they also visit hedgerows, town parks
and gardens, but are seldom far from trees.
Denmark, Sweden, Norway, Switzerland, Germany, Spain, France, Holland, Belgium, Italy, Greece (Do the Greeks eat it as food?), Crete, and the Ionian Islands in Asia Minor, and in Africa, in Barbary and Egypt.
Description
The most colourful member of the crow family. medium sized 350mm.
with a brown-pink body, blue wing-patch barred with black. Streaked
black and white crown feathers can be raised into a crest, giving
a domed appearance to the head. Black moustachial stripes. White rump.
Sexes are alike.
13.5"
Sound
Their true note is harsh resembling the syllables 'wrak wrak', could
also be described as a 'scaaarg-scaaarg' sound. They are great imitators.
(the bleating of a lamb, mewing of a cat, other birds, etc.).
Flight
Heavy and irregular wave like flight, effected with some degree of
apparent difficulty. In a scurrying sort of manner it is a series
of quick beats, with occasional short cessations. The Jays white rump
and distinctive blue wing-patch is conspicuous in flight. They seldom
settle on the ground; they glide cleverly through woods and thickets,
and keep flitting along hedge sides.
Habits
Restless - not long on one branch, but shift and change continually,
and when on the ground they hop about very awkwardly. Also said to
be a very wary bird.
In the spring, Jays become social birds, gathering for courtship ceremonies,
in which groups of Jays pursue each other slowly lapping their wings
and a great deal of calling. the ceremonies often speed up and reach
their climax in an excited chase through the branches of the trees.
Courtship consists chiefly of the male birds posturing and spreading
the wings to the females.
At other times, outside the breeding season, they move about in pairs
or small parties.
Anting
The jay will stand on the ground, with tail pressed against the earth,
twist its tail, spread its wings to let ants run through its feathers,
or squat with its wings spread and wipes its bill on its flight feathers.
It's a curious behaviour observed in the Jay and many other perching
birds such as starlings and blackbirds. The bird will be on an ant's
nest belonging to one of the ant species that squirts formic acid
at enemies rather than stinging them. They function of Anting is something
of a mystery, the best trail of logic is that the formic acid helps
kill parasitic feather lice.
Nests
In thick cover, the nest is built in a tall bush or hedge, generally
no higher than 7 or 9 metres from the ground and sometimes as low
as 1.2 metres. It is of an open shape. Both sexes build the nest with
twigs and sticks, bound with earth and lined with rootlets, straws,
grasses and hair. Some are better constructed than others.
Eggs
They lay one brood of 3-7 eggs between April and June. The eggs are
pale dull bluish green, greenish or yellowish white. Freckled all
over with two shades of olive-brown or purple. There are generally
one or two small black streaks on them, and there is often a ring
of darker spots near the larger end, but sometimes near the smaller.
They vary both in size and in degree of polish.
Incubation is about 16 days, by female only.
Young
The young spend about 20 days in the nest. They are fed by both parents.
It is 8 weeks until they are fully dependant.
The Jays will continue together long after the young have left the
nest. Jays are long-lived: some have been known to reach the age of
fourteen.
Feeding
acorns, eggs and young birds, insects and larvae in spring and summer,
occasionally worms, mice and lizards. They bury acorns for their winter
food and also store beech-nuts, peas, potatoes, fruit and berries.
To a lesser extent, they eat small mammals, molluscs, earthworms,
spiders. jays, along with crows, jackdaws, rooks and occasionally
tawny owls all rob exposed cup-nests regularly, however magpies search
more systematically and the eggs and young of other birds.
Bird Table
They are more likely to visit the bird-table in the early morning
before people are not about. Jays will come to the table for vegetable
scraps, which they carry away to eat or bury. Some have learnt to
take peanuts from mesh bags or wire spiral dispensers. In 1983, when
acorns failed in Europe, large flocks of Jays were seen coming into
gardens to feed at peanut bags.
Also see Feeding above.
Migration
Essentially sedentary, but northern birds disperse southwards when
food is scarce. This sudden invasion of birds is known as an irruption.
When they are obliged to migrate, they fly quicker, for fear of being
attacked by birds of prey, they often turn back to their starting
point, before they finally undertake the journey, and then it is performed
in haste, one flying behind another in a singular manner.
UK
Present all year, immigrants from the continent sometimes reach southeast
England.