Jackdaw: Menacing-Looking Affable Crows

Ever since I saw the jackdaw nearly 25 years ago in Kashmir, I have been intrigued by the question of why this small member of the crow family has conspicuous, penetrating white eyes and small round pupils, which on its black face appear quite menacing. This led me to read many research papers, but I still don’t have a satisfactory answer.

Coloeus monedula has many monikers: European jackdaw, Eurasian jackdaw, western jackdaw, or simply, jackdaw (in India). It is widely distributed in Asia, Europe, the Atlas Mountains of Morocco, and the highlands of Ethiopia. As happens in most widely distributed species, jackdaws come in many variations. Four subspecies are recognised currently. Its genus has been changed from Corvus to Coloeus. Both genera represent crows, ravens, rooks, and jackdaws. Some taxonomists separate the western jackdaw (Coloeus monedula) from its smaller cousin (found in China, Japan, Eastern Siberia, Mongolia, and Korea) from the eastern jackdaw (Coloeus dauuricus). 

A jackdaw is a small crow, about 34-40 cm in length, about three-quarters the size of a house crow (Corvus splendens), and slightly less than half the size of a large-billed crow (Corvus japonensis). The three species are sometimes seen together in the Kashmir Valley. Unlike its cousins, the jackdaw is more gregarious and affable, mostly seen foraging in flocks of 30-100 birds on lawns, recently plough fields, and grasslands. Their method of feeding is quite comical — each bird struts on short legs determined to unearth hidden morsels in the form of grubs, insects, worms, eggs, and any scraps left by humans. At Kashmir University campus, where I have spent many mornings watching these birds on the green lawns, I was always fascinated by how they space themselves out. While searching for food, they may cross paths with each other, but fights are rare. Their spacing is dynamic — it changes as the birds move like an army searching for hidden anti-personal mines. 

Mr Syed Intesar Suhail working in the Wildlife Department, Government of Jammu and Kashmir, and perhaps the finest ornithologists from Kashmir, says “Jackdaws have a special place among corvids in Kashmir. While the two larger species, namely the house crow and the large-billed/jungle crow are known to be ‘clever’ and ‘naughty’, in Kashmiri folklore the jackdaw is regarded as gentle and docile”. Its local name is kavin that translates to “female crow” suggesting that Kashmiris treated it as the female of the house crow, he adds.

For a long time, along with other crow species, jackdaws were regarded as pests in many European countries and persecuted by farmers. Thanks to the new awakening on the role of each species in the ecological web, that persecution has stopped and they are now found in the millions. They are of “Least Concern” on the IUCN Red List, their population stable or increasing and not requiring conservation actions.

Nesting behaviour

Jackdaws pair for life. Unlike most corvids, they make nests in holes in cliffs, large trees, and even old derelict houses. In the Kashmir Valley, large, wizened chinar trees, riddled with holes and cavities, provide them nesting opportunities. Some large trees may have small nesting colonies of jackdaws. In Naseem Bagh of Kashmir University’s campus, more than 300-year-old chinars are their favourite breeding areas. The female lays two to five pale blue or blue-green eggs that result in altricial (naked and blind) chicks after 17-18 days. Both parents feed the chicks, which grow quickly, opening their eyes after 6-7 days and fledging in four to five weeks. Once they exit the nest, they depend on their parents for another month or so but soon start searching for their own food. Juveniles or immature birds are lighter in colour than adults (particularly head and neck area). Crows are known for their large bills, but jackdaws have characteristically shorter and more pointed bills than other crows. (I guess it helps them dig grubs from the tangle of grass roots).

Unlike the house crow, whose nests are heavily parasitised by koels, there is no record of a jackdaw raising koel chicks though both species are found in the Valley. Perhaps koels find the jackdaw’s dark nest hole/cavity too intimidating to enter to lay their eggs. 

The Social Network

Jackdaws breed, forage, fly, rest, and roost together. Even in a flock, pairs stay close to each other. Every evening, flocks upon flocks fly over the vast Kashmir University campus heading to their favourite roosts in the tall trees near the famous Hazratbal and Shalimar Bagh. There are many roosts scattered all over the Valley. Why particular trees are used and not others is unknown. Perhaps they decide through their collective knowledge which is the best place to spend the night, away from predators. Some roosts are traditional, so this knowledge is passed through generations. Many species, such as mynas, sparrows, weaver birds, and starlings, roost similarly in large numbers, which decreases the chance of any individual being preyed upon. Mathematically, we say that in a large flock, the probability of getting killed is one divided by the number of individuals in a flock.  

Intesar says, “In terms of numbers and size of congregations, jackdaws in Kashmir outnumber fellow corvids. The species is a resident breeder in Kashmir, and the populations are enormously augmented in winter with the arrival of migrants. The numbers in autumn and winter are so huge that large swarms flying against a setting sun are a common sight in the Kashmir countryside. I believe there would hardly be any place outside the Kashmir Valley in the Indian subcontinent where jackdaws exist in such large numbers.”

Another endearing aspect of the nature of these flocking birds is food sharing. In a paper published in 2006 in the journal Animal Behaviour, it was shown that jackdaws shared food with several individuals, regardless of sex and kinship, and “Active food sharing, where the initiative for the transfer lies with the donor, appeared to be much more common in jackdaws than in any primate species studied so far.”

Jackdaws call frequently. Calls can vary from a pleasing melodious chak-chak (when flying or foraging) to chough-chough, to a hoarse arrrrr and khaarrrr (when alarmed). 

Jack attack

Jackdaws have many predators, from eagles to falcons and pine martins (Matttes mattes). A study in Sweden found that nest predation caused 74 per cent of breeding failure. In another interesting paper, Cooperative hunting of Jackdaws by the Lanner Falcon (Falco biarmicus), published in the Journal of Raptor Research in 1999, Giovanni Leonardi has shown that the Lanner falcons pair and hunt jackdaws cooperatively. Three types of attacks are described: surprise attacks (17.6 per cent), non-surprise attacks (21.6 per cent), and partial surprise attacks (60.8 per cent). The greatest success rate for falcons was on a solitary jackdaw. This clearly explains the value of living in groups. More eyes to pick out dangers quickly, and groups act as defence mechanisms. Predators are also confused by a milling mass of birds.

Coming back to my initial question: why do jackdaws have white eyes? Some scientists have said that white eyes are more likely to evolve in cavity-nesting birds than non-cavity-nesting birds; and in birds where two or more individuals contribute to coordinated parental care rather than the absence of it. I know cooperative breeding birds such as jungle babblers and large grey babblers also have white eyes (with a small dark pupil), but they do not nest in cavities, while many species of cavity/hole-nesting owls do not have white/yellow eyes. Tits nest in cavities/holes and have dark eyes. Perhaps we need more research on this topic. Nature does not reveal all its secrets.