Species of the day: Jay

By James Duncan

Learning & Engagement Officer

The characterful Jay (Garrulus glandarius) may well be regarded as one of Britain's finest looking birds. They really do look markedly at odds with their relatives, for they belong to the cosmopolitan Crow family, Corvidae. Whereas most exhibit a rather subdued and dour appearance (other than the Magpie), the Jay turns this on its head with a striking and outright flamboyant look. In essence, a pink crow seems an absurd notion, though it's this combination of pink, blue, black and white that may leave those unfamiliar with it thinking they've seen an escapee from a tropical aviary. The Jay can be a supremely vocal bird, its latin naming suggestive of loquacious and incessantly noisy vocalisations. 'Garrulus' by name, 'garrulous' by nature. In truth, it's genuinely hard to miss a calling Jay, for the most regular sound is a raucous screech, far carrying, harsh, intense and rather unpleasant. It's often uttered when the bird is on the move, the perfect time to look out for its rather floppy 'sink or swim' flight and distinctive white rump.  

It therefore seems logical that such a garish bird with a loud voice will be easy to spot, but the reality is the Jay is a remarkably shy and vigilant woodland species. As a whole, it's the most circumspect of its British family and a great deal of stealth will typically be required in getting anywhere near one. In recent years it has admittedly made a  move into suburban areas, perhaps as a result of habitat deforestation - its visibility has undoubtedly increased as a result. As with a number of other Corvids (Crows), the Jay saw intense persecution in the nineteenth century, largely owing to a habit of nest-robbing. In actuality, the nestlings of other birds comprise only a small part of the Jay's diet, utilised only in the breeding season when additional protein is beneficial for their developing young. The Jay is certainly an adaptable opportunist, something now demonstrated by birds visiting garden feeding stations. Despite widespread slaughter in the past, the skulking habits of the Jay made it hard to eliminate and fortunately it clung on. 

Contrary to its grating call, the Jay is somewhat surprisingly a fabulous mimic. Its extensive repertoire make it one of the most likely candidates for obscure woodland calls. Their impressive skills are really quite wide-ranging, including highly accurate imitations of other birds and a variety of mammal vocalisations. They've even demonstrated an impressive propensity for the replication of sounds created by man-made objects, those such as alarms, phones and vehicle engines. The social vocalisations made by Jays are unquestionably complex, though some of the strangest are those that arise from situations where they feel threatened. Renowned Ornithologist, Derek Goodwin, observed the replication of both predator calls and passerine alarm calls in agitated Jays, pondering the possibility of attempts to deliberately convey information through mimicry. What's clear is that like the majority of Corvids, the Jay is a highly intelligent species, scientific tests showing an advanced aptitude for planning, anticipation, self-control, tool use, 'gift-giving' (to the mate) and even an understanding of 'object permanence.' 

Though the Jay is an eclectic omnivore, the bulk of its diet is largely vegetarian. Its species name of 'glandarius' refers directly to its favoured food-source, glandis - acorns. Though a staple autumn and winter snack, the Jay is also a prolific hoarder, demonstrating magnificent foresight and memory in its quest to 'cache' acorns. This is in fact the predominant reason for their increased observability in autumn - a Jay may be witnessed undertaking a consistent procession of journeys to both procure and deposit acorns. The Jay's abundance is intrinsically tied into Oak woodland and individuals may converge upon suitable sites in their desire to collect. This will happen from September and a bird may carry around three to five acorns in both its beak and a sublingual pouch, located beneath the tongue. Each Jay may stash thousands of acorns, either concealing them in holes and crevices or underneath leaf matter. Their astonishing memory means many will be recovered, though those forgotten indicate the Jay may have been largely responsible for the wide-scale spread of Oak following the last Ice Age. It's amazing to consider the Jay's role in the propagation of one of our mightiest trees, a co-evolved association that can certainly be defined as a form of symbiosis, one formed over simply colossal periods of time.