page_title: Kleptoparasitism
section_title: Birds
hierarchical_section_title: Kleptoparasitism / Vertebrates / Birds
caption_attribution_description: English: Stealing fish every often
context_page_description: Kleptoparasitism is a form of feeding in which one animal takes prey or other food that was caught, collected, or otherwise prepared by another animal, including stored food. Examples of this last case include cuckoo bees, which lay their eggs on the pollen masses made by other bees, or the hosts of parasitic or parasitoid wasps. The term is also used to describe the stealing of nest material or other inanimate objects from one animal by another.
  The kleptoparasite gains prey or objects not otherwise obtainable or which otherwise require time and effort. However, the kleptoparasite might be injured by the victim in cases in which the latter defends its prey. Kleptopredation is the practice of choosing prey that has recently fed.
  Kleptoparasitism may be intraspecific or interspecific. In the latter case, the parasites are commonly close relatives of the organisms they parasitize.
  Animals that have extraordinarily specialized feeding methods are often targets of kleptoparasitism.
context_section_description: Kleptoparasitism is relatively uncommon in birds. However, some non-passerine groups, such as skuas, jaegers and frigatebirds, rely extensively on such behavior to obtain food, and others—including raptors, gulls, terns, coots, and some ducks and shorebirds—will do so opportunistically. Among opportunistic species such as the roseate tern, research has found that parent birds involved in kleptoparasitism are more successful in raising broods than non-kleptoparasitic individuals. Bald eagles have also been seen attacking smaller raptors, such as ospreys, to steal fish away from them. Among passerine birds, there are fewer known examples of kleptoparasitism, though masked shrikes have been recorded stealing food from wheatears, and Eurasian blackbirds have been seen stealing smashed snails from other thrushes.
  Skuas (including the smaller species known as jaegers in North America) are masters of piracy. Their victims are typically gulls and terns, though other fish-eating species (including auks) are also pursued until they disgorge their catches. The fact that skuas are swift and agile fliers—and that they sometimes gang up on a single victim—aids in their success rate.
  During seabird nesting seasons, frigatebirds will soar above seabird colonies, waiting for parent birds to return to their nests with food for their young. As the returning birds approach the colony, the frigatebirds (which are fast and agile) swoop in to pursue them vigorously; they have been known to seize tropicbirds by their long tail plumes. Many of the frigatebirds' colloquial names, including man-o'-war bird and pirate of the sea, are a clear reference to this kleptoparasitic behaviour.
  A study of kleptoparasitism in the magnificent frigatebird suggests that the amount of food obtained by kleptoparasitism may be marginal.
  Gulls are known to be perpetrators as well as the victims of kleptoparasitism, with some species frequently exhibiting this behavior, particularly during breeding season. While the victim is most often another member of the same species, other (principally smaller) gulls and terns can also be targeted. In the Americas, Heermann's gulls, and laughing gulls are known to steal food from brown pelicans; as the pelicans surface and empty the water from their bills, the gulls lurk nearby and grab escaping food items. Great black-backed gulls are skilled kleptoparasites, which have been observed to steal not only from other gulls but also from raptors. Several species of gull also steal food from humans, for example takeaway food at seaside resorts.
  Several species of coots and gallinules have been recorded engaging in kleptoparasitism. American coots often feed in the company of other waterfowl species, and occasionally will rob diving ducks—including ring-necked ducks, redheads and canvasback—when they surface with food. Eurasian coots steal from conspecifics, as well as from diving and dabbling ducks, and swans. Allen's gallinules rob both conspecifics and African pygmy geese.
caption: Flying cormorant has taken a fish from the one in the water
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