The Jays: Gardeners of the Forest
Among the birds that populate our fields, and especially our vineyards, there is one species that stands out for its size, gorgeous plumage, and raucous call: the Eurasian jay (Garrulus glandarius).
A Eurasian jay perched on a tree trunk, photograph byAna Mínguez
What immediately distinguishes our protagonist from the magpie, similar in size and shape, is its beautiful plumage: a pinkish brown hue gives way to snow white feathers below the tail (ornithologists call this area the rump) with distinctive black colouring along the wings.
The most striking feature of the jay's plumage, visible in flight or when perched, is a panel of stunning metallic blue feathers with a smattering of black streaks on the upper part of its wings (the shoulders).
Another unmistakable trait of the jay's appearance is the exceptional size of its head, quite disproportionate in relation to the rest of its body. It is even more impressive when the jay raises its crest.
The jay has a broad pointed beak, the same black colour as its wide facial markings. The top of its head sports black and white stripes and slopes down to bright grey eyes. Its legs are pale pink in colour. Jays are generally 35 cm in length, with a wingspan (the distance from wing tip to wing tip) of 58 cm, and weigh around 180 grams.
Eurasian jay, photograph byAna Mínguez
Jays are widespread across the entire Iberian peninsula with a clear preference for woodlands with the occasional open field. They like mixed, holm oak, or oak forests – or any kind of woodland with abundant brush. They're also a common sight in city parks and gardens.
Noisy and skittish, jays have a loud, raucous call (hence their scientific name: Garrulus) which they use to express fear or as a warning cry. They mainly eat berries and wild fruit, but can display behaviour more commonly seen in birds of prey when they hunt rodents, reptiles, or insects. During their breeding period, they sometimes take eggs or hatchlings from the nests of other birds.
Eurasian jay, photograph byAna Mínguez
However, the most curious behaviour of this member of the crow family must be its habit of burying acorns, nuts, chestnuts, and other forest fruit in autumn as provisions for the winter. In doing so, the birds scatter vegetation which encourages reforestation – this is why many consider jays to be the gardeners of our forests.
Given that jays can easily adapt to their environment and aren't particularly picky eaters (they're even known to scavenge for carrion), the Eurasian jay is not a particularly vulnerable species. That being said, like all woodland birds, jays are threatened by advancing desertification and ever more frequent forest fires, both consequences of climate change.