The Jackdaw
What’s In a Name?
Western jackdaw; Eurasian jackdaw; European jackdaw; they all refer to the same bird – the bird that in English we call the jackdaw. Prior to the 16th century, it was even easier for English speakers as it was simply called “daw.” In Irish it is “cág.”
Jackdaw; daw; cág; or in Dutch, kaug; German, Dohle; Swedish, Kaja, are all onomatopoeic – in other words they derive from the birds’ call. The French name, choucas des tours, is a little more stylish of course and means “jackdaw of the towers,” maybe a reference to the association of the bird with churches and high buildings, but even here, choucas can be thought of onomatopoeically. The scientific name of the jackdaw is corvus monedula meaning “money eating crow.” Corvus is simply the Latin for “crow” and the “money eating” part may derive from its, possibly undeserved reputation for making collections of shiny objects, perhaps coins; more of which later.
The Collins Bird Guide (2nd ed.) the “Bible” of bird enthusiasts suggests that one of the most frequent of the jackdaws calls sounds like “kya” and “kyack.” It is therefore not too difficult to work out how “kyack” becomes “jack.” However, like “Jenny” wren and “Robin” redbreast, it may simply be a nickname but there is a further possibility that it may relate to size, “jack” being a synonym for “small.” Therefore, it may simply be a term for a small bird such as in “jack snipe” or “jack whimbrel,” where these are smaller than the ordinary snipe of whimbrel; the jackdaw is, of course, a small crow. The “daw” sound is said to relate to a less common, long, drawn out hoarse sound uttered by this small cro
Sociability
Throughout autumn and winter one of finest sights and sounds are the gatherings of hundreds, sometimes thousands of jackdaws preparing to roost for the night. The thousands of fluttering, black bodies has been liked to flying, black bin liners, flying bags and scraps of paper. As dusk grows, these “bin liners” emerge into the dimming sky, circling each other and moving as one body towards their roost, uttering a thousand “kyack, kyack” calls as they do so. There is something vaguely medieval about the whole image; as if it belongs to a time before industrialisation, when a spectacle like this could arouse a sense of awe and foreboding – it still does. But why do they do it? What is the point of this mass gathering of animated “bin liner.
A lot of birds gather in roosts of course during the winter. Starlings gather in the famous murmurations; small birds such as long tailed tits, pied wagtails and even smaller birds such as wrens; indeed, during the harsh winter of 1979, ninety six wrens are recorded as having snuggled (if that’s the right word!) together under one roof in Gloucestershire in England. Shelter and warmth are two of the obvious reasons, especially for small birds, who lose much more heat, proportionately, than larger species, owing to their greater surface area to volume ratio. Rooks will spend the night deep inside woodlands (not their usual haunt), often in association with jackdaws and it has been show that they will often roost on the side of the tree facing away from the wind, a fairly sure sign that this is for protection. However, they roost in pairs, not huddled together like long-tailed tits and they don’t specifically select coniferous woodland, which might make more sense if the reason was warmth, so something else must be going on. It has been speculated that these roosts also serve as “information centres.” Studies involving ravens show that roosts serve as an important source of information about good food sources. It is thought that this is also likely in their corvid cousins, the rook and the jackdaw too. Roosting behaviour certainly correlates with day length; the shorter the days become, so the roosting behaviour diminishes.
Like all corvids, jackdaws are highly intelligent and as is so often the case intelligence begets sociability – or is it the other way around? I suspect it’s the latter; if you live cheek by jowl with your neighbours you’ve got to be pretty smart in order to interact with them. This intelligent, social behaviour is demonstrated at roosting sites. For instance, during the autumn and winter many jackdaws, rooks and other corvids will leave colder and more deprived regions and join roosts of resident populations. Without the information provided at these roosts they may not survive the winter. It seems that whilst this benefits the incomers in terms of local knowledge regarding food supplies, it offers the residents advantages too. The dominant residents probably get the choice location in the roosting sites, such as the highest and most central positions, giving them greater protection, provided by the non residents located on the periphery of the nest. Something similar certainly seems to occur with older, dominant birds and younger, submissive members of the roost. Being in the centre keeps you warm and safe, whereas the higher up the tree you are, the less likely you are to be hit by random items of regurgitated food and droppings and other sundry, unsavoury items!
“Marriage” also plays a significant role in jackdaw hierarchy. Females have a lower social status than males and therefore do not get priority when it comes to food and shelter; however, once a female has paired, it achieves the same rank as its “husband” and so takes precedent over a lesser ranked male. Pair bonds are very strong, however, and a pair will usually mate for life.
All in all then, it seems that the apparent, random, disparate, behaviour and noisy calling at roosting time is a way of exchanging vital information and sorting out the hierarchy of corvid society.
Are Jackdaws Really Money Eating Crows
As we saw earlier, the scientific name of the jackdaw is corvus monedula – the “money eating crow” but just how true is it that jackdaws and their relative the magpie, are really thieves of coins and shiny objects? The empirical evidence suggests that it is not true at all. In experiments with magpies, researchers placed a collection of shiny objects; another collection of similar objects covered with matt paint and also a collection of food items, in separate locations in close proximity, the food being about 30cm away from the shiny objects. Over 64 occasions magpies only picked up a metal object twice and immediately dropped it each time. In fact they either ignored the objects or avoided them, often feeding less when they were present indicating what’s termed neo-phobia – fear of new things. Magpies are not jackdaws of course and they were also “married” magpies, so it’s just possible that “single” magpies might exhibit different behaviour. It is more likely that there is another explanation however. Jackdaws are both highly intelligent and curious and in captivity are known to investigate objects and apparently play with them. Certainly, both in captivity and in the wild, jackdaws and crows in general are known to present “gifts” of various items to human beings who have provided them with food. Of course, we can’t ask the birds what their intention is so it’s hard to know if they genuinely are gifts but in the wild, courting pairs do present gifts to each other, so it may be that this behaviour derives from that – a way of cementing a bond. As for the objects being bright and shiny, it could simply be that we notice the bright, shiny objects such as coins, because they are the items that are important to us or that bright, shiny objects are more easily noticed by the birds themselves. Either way, the scientific evidence isn’t there to support the legend.
Nesting
Jackdaws are cavity and crevice nesters and if the hole is sufficiently large, will even nest in nestboxes. They will also nest in tree tops as well as holes in trees and this explains their readiness to use nestboxes. The nest itself is not overly spectacular, consisting of just a few sticks or twigs and lined with hair, wool or fine plant matter. Their tendency to nest on chimney tops sometimes lead to sticks being dropped down the chimney to give the lucky recipient some free firewood. They can seem to become frustrated by these failed attempts to nest build and they resort to throwing down any old rubbish whilst screaming raucously!
There is one clutch of eggs laid in April or May and they lay between four and seven bluey green eggs, with light greyish markings on them, which hatch after 18-20 days having been incubated by the female. However, it is the male who feeds them. Following a further 30-33 days the young leave the nest but continue to be fed by both parents for about a week until they are able to fly properly.
In the wild jackdaws usually live, on average, for about 5 years; in captivity the oldest known is 15 years.
Folklore
The ancient Greeks and the early Christians appear to have believed that Jackdaws and indeed all corvids, were originally white. In the Greek myth a crow told the god Apollo that his wife, Coronis, had been unfaithful and so the god turned the messenger’s feathers black. The ancient Greeks also had a motto that said “the swans will sing when the jackdaws are silent.” Meaning, it seems, that the wise will speak when the foolish are silent. Given what we know about corvid intelligence this seems a little misplaced. Likewise, the Christians suggested that white corvids assumed black plumage in mourning for the crucifixion – except for the magpies who were too busy pilfering! Where that leaves corvids like the jay, with their multi coloured plumage, is hard to say.
In the ancient Roman world, Ovid considered jackdaws to be the bringers of rain, perhaps not surprising, given their tendency to form the large roosting flocks of autumn; Aesop got completely the wrong idea about the bird and apparently thought it stupid as it waited for figs to open and so starved as it lived on hope. His fox says it “feeds illusions, not the stomach.” Pliny, however, admired it for it’s destruction of grasshopper eggs.
As we have seen, jackdaws are partial to living on cavities on buildings and perhaps this is where the piece of folklore with which they’re most associated comes from, their status as a portent for either good or bad news but usually for the latter, particularly if it is a solitary jackdaw. A jackdaw falling down a chimney was also considered unlucky – well, it was certainly unlucky for the jackdaw!
A further connection to the supernatural was the belief that if a ruined castle or tower did not have jackdaws then it was certainly haunted. Perhaps this is where the French term choucas des tours derives from. I suppose we should be grateful then, that Rathfarnham Castle is both not a ruin and that it certainly has it’s share of jackdaws.