Клептопаразитизм: кража пищи в животном мире.

Type of animal feeding strategy

Kleptoparasitism (originally spelt clepto parasitism, meaning "parasitism by theft") is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, such as when food is scarce or when victims are abundant. Many kleptoparasites are arthropods, especially bees and wasps, but including some true flies, dung beetles, bugs, and spiders. Cuckoo bees are specialized kleptoparasites which lay their eggs either on the pollen masses made by other bees, or on the insect hosts of parasitoid wasps. They are an instance of Emery's rule, which states that insect social parasites tend to be closely related to their hosts. The behavior occurs, too, in vertebrates including birds such as skuas, which persistently chase other seabirds until they disgorge their food, and carnivorous mammals such as spotted hyenas and lions. Other species opportunistically indulge in kleptoparasitism.

Some true flies (Diptera) are kleptoparasites; the strategy is especially common in the subfamily Miltogramminae of the family Sarcophagidae. There are also some kleptoparasites in the families Chloropidae and Milichiidae. Some adult milichiids, for example, visit spider webs where they scavenge on half eaten stink bugs. Others are associated with robber flies (Asilidae), or Crematogaster ants. Flies in the genus Bengalia (Calliphoridae) steal food and pupae transported by ants and are often found beside their foraging trails. Musca albina (Muscidae) reportedly shows kleptoparasitic behaviour, laying eggs only in dung balls being interred by one of several co occurring dung rolling scarab species.

Scarab dung beetles relocate large amounts of vertebrate dung, rolling balls of the material to their nests for their larvae to feed on. Several smaller species of dung beetle do not gather dung themselves but take it from the nests of larger species. For example, species of Onthophagus enter dung balls while Scarabeus beetles are making them.

Many semiaquatic bugs (Heteroptera) are kleptoparasitic on their own species. In one study, whenever the bug Velia caprai (water cricket) took prey heavier than 7.9 g, other bugs of the same species joined it and successfully ate parts of the prey.

A few bird species are specialist kleptoparasites, while many others are opportunistic. Skuas (including jaegers) and frigatebirds rely heavily on chasing other seabirds to obtain food. Other species—including raptors, gulls, terns, coots, and some ducks and shorebirds—do so opportunistically. Among opportunists such as the roseate tern, parent birds involved in kleptoparasitism are more successful in raising broods than non kleptoparasitic individuals. Bald eagles have been seen attacking smaller raptors, such as ospreys, to steal fish from them. Among passerine birds, masked shrikes have been recorded stealing food from wheatears, and Eurasian blackbirds have been recorded stealing smashed snails from other thrushes. However, the amount of food obtained by kleptoparasitism in the magnificent frigatebird may be marginal. Gulls are both perpetrators and victims of opportunistic kleptoparasitism, particularly during the 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, as brown pelicans surface and empty the water from their bills, they sometimes have their food stolen by Heermann's gulls and laughing gulls, which lurk nearby and grab escaping food items. Great black backed gulls are skilled kleptoparasites, stealing from other gulls and from raptors. Several species of gull steal food from humans, for example takeaway food at seaside resorts.

The relationship between spotted hyenas and lions, in which each species steals the other's kills, is a form of kleptoparasitism. Human hunters may commonly take the remains of fresh kills from other carnivores, such as lions and Eurasian lynx. Risso's dolphins have been observed charging "head on" at sperm whales, causing them to open their mouths; it has been suggested that the observed harassment results in some regurgitation, and that the food is then eaten by the Risso's dolphins. The behaviour is rare and may be opportunistic.