page_title: Western jackdaw
section_title: Feeding
hierarchical_section_title: Western jackdaw / Behaviour / Feeding
caption_attribution_description: Русский: 4 галки English: 4 jackdaws (Corvus monedula subspecies soemmerringii) Photo by User:Monedula Date: 2007-05-14 Place: Yaroslavl, Russia
context_page_description: The western jackdaw, also known as the Eurasian jackdaw, the European jackdaw, or simply the jackdaw, is a passerine bird in the crow family. Found across Europe, western Asia and North Africa; it is mostly resident, although northern and eastern populations migrate south in the winter. Four subspecies are recognised, which differ mainly in the colouration of the plumage on the head and nape. Linnaeus first described it formally, giving it the name Corvus monedula. The common name derives from the word jack, denoting "small", and daw, a less common synonym for "jackdaw", and the native English name for the bird.
  Measuring 34–39 centimetres in length, the western jackdaw is a black-plumaged bird with a grey nape and distinctive pale-grey irises. It is gregarious and vocal, living in small groups with a complex social structure in farmland, open woodland, on coastal cliffs, and in urban settings. Like its relatives, jackdaws are intelligent birds, and have been observed using tools. An omnivorous and opportunistic feeder, it eats a wide variety of plant material and invertebrates, as well as food waste from urban areas.
context_section_description: Foraging takes place mostly on the ground in open areas and to some extent in trees. Landfill sites, bins, streets, and gardens are also visited, more often early in the morning when there are fewer people about. Various feeding methods are employed, such as jumping, pecking, clod-turning and scattering, probing the soil, and occasionally, digging. Flies around cow pats are caught by jumping from the ground or at times by dropping vertically from a few metres onto the cow pat. Earthworms are not usually extracted from the ground by western jackdaws but are eaten from freshly ploughed soil. Jackdaws will ride on the backs of sheep and other mammals, seeking ticks as well as actively gathering wool or hair for nests, and will catch flying ants in flight. Compared with other corvids, the western jackdaw spends more time exploring and turning over objects with its bill; it also has a straighter and less downturned bill and increased binocular vision which are advantageous for this foraging strategy.
  The western jackdaw tends to feed on small invertebrates up to 18 millimetres (0.71 in) in length that are found above ground, including various species of beetle (particularly cockchafers of the genus Melolontha, and weevil larvae and pupae.), Diptera, and Lepidoptera species, as well as snails and spiders. Also eaten are small rodents, bats, the eggs and chicks of birds, and carrion such as roadkill. Vegetable items consumed include farm grains (barley, wheat and oats), weed seeds, elderberries, acorns, and various cultivated fruits. Examination of the gizzards of western jackdaws shot in Cyprus in spring and summer revealed a diet of cereals (predominantly wheat) and insects (notably cicadas and beetles). The diet averages 84% plant material except when breeding, when the main food source is insects. A study in southern Spain examining western jackdaw pellets found that they contained significant amounts of silicaceous and calcareous grit to aid digestion of vegetable food and supply dietary calcium.
  Opportunistic and highly adaptable, the western jackdaw varies its diet markedly depending on available food sources. They have been recorded taking eggs and nestlings from the nests of the skylark (Alauda arvensis), Manx shearwater (Puffinus puffinus), razorbill (Alca torda), common murre (Uria aalge), grey heron (Ardea cinerea), rock pigeon (Columba livia), and Eurasian collared dove (Streptopelia decaocto). A field study of a large city dump on the outskirts of León in northwestern Spain showed that western jackdaws forage there in the early morning and at dusk, and engage in some degree of kleptoparasitism. The saker falcon (Falco cherrug) has been reported stealing food from western jackdaws on powerlines in Vojvodina in Serbia.
  Western jackdaws practice active food sharing – where the initiative for the transfer lies with the donor – with a number of individuals, regardless of sex or kinship. They also share more of a preferred food than a less preferred food. The active giving of food by most birds is found mainly in the context of parental care and courtship. Western jackdaws show much higher levels of active giving than has been documented for other species, including chimpanzees. The function of this behaviour is not fully understood, though it has been found to be detached from nutrition and compatible with hypotheses of mutualism, reciprocity and harassment avoidance. It has also been proposed that food sharing may be motivated by prestige enhancement.
caption: C. m. soemmerringii, foraging in pasture in Russia.
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