Species Guide: Eurasian Jackdaw (Coloeus monedula)
Family: Corvidae
The Jackdaw, often called the western or Eurasian Jackdaw is a small, highly social member of the crow family. Widespread across much of Europe, western Asia, and parts of North Africa, Jackdaws are familiar in both countryside and urban settings. They are noted for their sociable flocking behaviour, intelligence, and distinctive pale eyes and grey nape.
Appearance
Jackdaws are compact corvids with glossy black feathers offset by a grey-silver nape and neck sides (the “hood”). Adults have strikingly pale, silvery eyes; juveniles appear browner with darker eyes until their first year. The bill is short and stout compared to larger corvids. Feathers often reveal purple, blue, or green iridescence, depending on subspecies and light. Sexes are visually similar.
Diet
Jackdaws are opportunistic omnivores and adaptable foragers. Their diet spans insects (e.g. beetles, flies, ants), as well as other invertebrates (e.g. spiders, snails), occasional small vertebrates (e.g. rodents, bats), eggs and nestlings, carrion, seeds, grain, and fruit. In towns they exploit human food sources, scavenging at bins, refuse sites, and near habitation. They also engage in kleptoparasitism (stealing food). Their versatile diet enables them to thrive in diverse habitats.
Habitat
Jackdaws occupy a range of open or semi-open landscapes: farmland, parkland, woodland edges, coastal cliffs, and urban areas. They mostly nest in cavities, hollows in trees, cliff crevices, church steeples, chimneys, or building gaps. So the availability of protected nesting sites determines local presence. Northern and eastern groups may migrate to milder climates in winter.
Behavior
Social structure & flocking: Jackdaws are extremely gregarious. Pairs are usually long-term (often lifelong) and remain within larger flocks. Flocks grow in autumn and birds form large communal roosts; winter roosts can number many thousands at favored sites.
Vocalizations / call: The Jackdaw’s call is a sharp metallic “chack” or “chak/kyak” that is very characteristic. They are vocal birds that use a range of calls for contact, alarm, and social interaction; they also produce scolding calls when predators are spotted and use calls within pair bonds.
Foraging & tool-use: Foraging is mostly on the ground using behavior such as pecking, clod-turning, probing and occasional digging. Jackdaws are curious and manipulative, turning over objects and investigating items, traits shared with other corvids and linked to advanced cognition.
Breeding / life cycle: Jackdaws typically reach sexual maturity in their second year. Pairs commonly breed in colonies and use cavities for nests, lining a stick nest with softer material. A usual clutch size is about five pale bluish/green eggs with brown speckles. Incubation is performed by the female; young fledge after roughly 4–5 weeks.
Biometrics2
| Wing Span | 70 cm |
| Body Weight | 220 grams |
| Longevity | 7 Years |
Natural Predators
Adult Jackdaws can fall prey to larger birds of prey (e.g., hawks, falcons and eagles) and certain mammalian predators (e.g. mustelids like stoats/weasels, foxes, and domestic/feral cats). Eggs and nestlings are especially vulnerable to small mammalian nest predators, corvids or raptors. Jackdaws use alarm calls and mobbing behavior; recruiting other birds to harass or drive off predators, and larger flock sizes help reduce individual predation risk.
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Conservation Status
Global status: The jackdaw (western jackdaw / Eurasian jackdaw) is currently assessed as Least Concern on the IUCN Red List at a global scale, reflecting a very large range and a large overall population in much of its distribution.3
Regional trends & threats: Although globally common, jackdaw numbers have shown regional variation: some areas have experienced declines while others have seen recovery or increases. Key pressures when declines occur include:
- Loss of nesting sites (modern building renovations, removal of old trees or closure of chimneys and steeples), which reduces available sheltered cavities.
- Persecution and culling where they are seen as agricultural pests (raiding grain or fruit, or taking eggs), leading to historical hunting and ongoing control in some places.
- Poisoning, collision and secondary effects of pesticides can reduce local populations or food availability.
- Changes in food availability from agricultural intensification or waste-management changes that alter scavenging opportunities.
Conservation measures typically focus on protecting nesting sites, mitigating conflict with farmers (non-lethal deterrents), and maintaining suitable habitat mosaics. In many countries jackdaws are still abundant and not highly threatened overall, but local declines merit monitoring and targeted conservation action.
U.K.
Conservation Status
Global
Conservation Status
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CITATIONS
- Avibase – The World Bird Database [Accessed 04/10/2025] ↩︎
- RSPB [Accessed 01/10/2025] ↩︎
- IUCN Red List [Accessed 01/10/2025] ↩︎
References
- Golley, M. (2016) Field Guide to the Birds of Britain and Ireland. 2nd edn. London: Bloomsbury Publishing Plc. [Accessed 01/10/2025]
