Biological description of the Eurasian jay (Garrulus glandarius)

The Eurasian jay is a medium-sized passerine bird from the crow family (Corvidae). It is easily recognized by its pinkish-brown body, black tail, white rump, and a distinctive bright blue patch with black barring on the wings. The head shows a white throat and crown with black streaks, and a short black “moustache” stripe on each side of the face. Its strong black bill is well adapted for an omnivorous diet.

Habitat and distribution:
The Eurasian jay inhabits mainly deciduous and mixed forests, woodlands, parks, and large gardens. It is widely distributed across Europe, parts of North Africa, and Asia, ranging from Western Europe through Scandinavia, Russia, and Siberia to East Asia. It occurs on the continents of Europe and Asia, with small populations in northern Africa.

Size and weight:
Body length is about 32–35 cm, with a wingspan of 52–58 cm. Adults usually weigh between 140 and 190 g.

Lifespan:
In the wild, Eurasian jays typically live 5–7 years, but some individuals can reach over 15 years under favorable conditions.

Diet:
In summer, the diet consists mainly of insects, larvae, spiders, small vertebrates, fruits, berries, and eggs of other birds. In winter, plant-based food dominates, especially acorns, nuts, seeds, and grains. Jays are well known for storing acorns in autumn for later use.

Breeding:
Eurasian jays usually breed once per year. The breeding season starts in spring. Both parents build a well-hidden nest of twigs, lined with roots and hair, in trees or dense shrubs.

Offspring:
The female lays 4–6 eggs. After an incubation period of about 16–19 days, the chicks hatch. They are fed by both parents and fledge after roughly 19–23 days, remaining dependent on the adults for some time afterward.