Jay (Garrulus glandarius): Autumnal acorn hoarder.
ACORNS DON'T ROLL UPHILL! Quite an obvious comment to make you might think. So, have you ever wondered how an oak wood establishes itself on a hillside? Probably not, but it's a question worth pondering over for a moment or two. Acorns don't float on the wind like ash or hornbeam keys and even if they could, how would they acquire a sufficient enough covering of soil to encourage germination? The solution to the oak tree's land acquisition conundrum lies with its most loyal inhabitant -- the jay.
Your first clue to a jay's presence in any woodland will most likely be a harsh, grating screech launched from the treetops, the bird sounding quite perturbed that you've had the temerity to enter its home and disturb it; a flash of white rump or an electric blue wing covert may be all that you see of these extremely wary corvids -- members of the crow family -- as their wavering flight propels them through the tree tops. The striking appearance of the jay is in stark contrast with its alarm call and a close view will reveal subtle streaks of black and white, of blue and black and a soft, smoky pink.
Unlike its cousins -- rooks, crows, magpies and jackdaws -- the jay is inextricably linked to woodlands, in particular oak woodlands, and you are unlikely to observe one away from an area without deciduous trees for any length of time. It is this link with broad-leaved woods that keeps the birds faithful to local areas and it is thought that they rarely travel more than three to four miles from their place of birth. This obedience to one locale has a distinct advantage; the jays get to learn every nuance of their home range inside and out, which coupled with their excellent memories, alerts them to any fresh opportunities or dangers that may become apparent.
During the late spring and summer, the jay can be quite elusive, keeping itself hidden away amongst thick foliage and guarding the whereabouts of its nest carefully. However, during early spring, it is possible to watch groupings of jays cavorting in courtship displays, often referred to as 'jay marriages', where one bird will often chase another in a slightly ponderous, lolloping flight. During the autumn they are conspicuous as they tirelessly gather their winter cache of acorns -- beechnuts and chestnuts will suffice if the acorn crop is poor -- making many hundreds of trips a day, back and forth from the same tree or woodland. It is often possible to get close views of this activity if you remain concealed at the base of a nearby tree or bush.
The oesophagus of the jay is larger than normal for a bird of its size. So large in fact, that it is estimated between ten and twelve average size acorns can be carried away in one go!
A jay sits in an oak tree, surveying its woodland habitat. Responsible for establishing new oak woods due to a preoccupation of hoarding and burying acorns during the autumn, it provides a welcome distraction in the winter sunshine.
Perched atop a decomposing tree stump, a jay contemplates where it is going to stash away its next hoard of freshly gathered acorns. Moments later, it flashes off through the tree tops in a burst of colour.
... it is possible to watch groupings of jays cavorting in courtship displays, often referred to as 'jay marriages'...
So, how do these oak trees start growing on hills and slopes? During the autumn, jays will start collecting their winter provisions in the form of acorns and, powered by the freedom of flight, these oak trees in waiting are transported to all manner of new locations, up hills and down valleys, into a pasture or hay meadow, wherever the jay feels inclined to keep its food safe for the months ahead. It is here that the acorns are buried under a layer of leaves, twigs or even poked into a top layer of soil. These larders are often spread over a radius of up to two miles away from the parent wood, thus ensuring that the oak genes from one location are spread into new areas. However, even the jay's excellent memory can't recall the exact whereabouts of every one of a possible four thousand acorns -- the estimated number gathered and stashed every autumn -- and it is these escapees that will eventually become the hand that feeds future generations of nature's very own forester.
Always curious and ever alert, a jay sizes up the peculiar, shining object pointing in its direction. They are thought to have photographic memories, enabling them to remember the precise layout of their woodland homes.