Kleptoparasitism

Kleptoparasitism is a way some animals get their food by taking it from others. It happens when one animal, called a kleptoparasite, takes food that another animal has caught or gathered. This often involves pushing or chasing to get the food away.

This behavior is common in many small insects, like certain bees, wasps, and spiders. For example, cuckoo bees are good at this, laying their eggs on food that other bees have prepared. Kleptoparasitism isn’t just for insects, though. Birds like skuas also use this trick, chasing other birds until they drop their food. Even big animals like lions and hyenas will take food from each other when they can.

This strategy helps when it’s easier to steal food than to hunt for it, especially when food is hard to find or when some animals can’t defend their food well. It’s a clever way many creatures survive in nature.

Strategy

Kleptoparasitism is when one animal steals food from another. This can happen between animals of the same kind or different kinds. Scientists have studied this a lot in birds, especially seabirds.

This behavior only works if it helps the animal more than finding food on its own. Stealing food takes time and energy, so the benefits must be worth it. When food is easy to find, animals usually look for their own. But when food is hard to find, stealing becomes a better choice.

Taxonomic distribution

Arthropods

Bees and wasps

Many bees called cuckoo bees lay their eggs in the nests of other bees. For example, Bombus bohemicus uses nests from other species. This follows Emery's rule, which says that social parasites in insects are often closely related to their hosts. The largest group of these bees is Nomadinae, with several hundred species.

Cuckoo wasps lay their eggs in the nests of potter and mud dauber wasps. Some wasps also act this way, like Polistes sulcifer, which uses a related species.

Flies

Some flies act as parasites, especially in the Miltogramminae group of Sarcophagidae family. Flies in Chloropidae and Milichiidae families also do this. For example, some milichiid flies visit spider webs to eat food left by stink bugs. Others follow ants or robber flies. Flies in the genus Bengalia steal food from ants, and Musca albina lays eggs in dung balls made by scarab beetles.

Dung beetles

Some smaller dung beetles do not collect their own dung but take it from the nests of larger dung beetles. For example, Onthophagus species enter dung balls made by Scarabeus beetles.

True bugs

Many water bugs are parasites on others of their kind. In one study, when the bug Velia caprai caught prey heavier than 7.9 mg, other bugs of the same species would join and share the food.

Spiders

Some spiders steal food from other spiders. This happens in five families: Theridiidae, Dictynidae, Salticidae, Symphytognathidae, and Mysmenidae.

Vertebrates

Birds

A few birds specialize in taking food from others, while many do it when they can. Skuas and frigatebirds often chase other seabirds for food. Other birds like raptors, gulls, terns, coots, ducks, and shorebirds also do this sometimes. Bald eagles have been seen taking fish from smaller birds like ospreys. During nesting seasons, frigatebirds wait near seabird colonies and chase returning birds to take their food. Gulls often take food from other gulls, terns, or even people.

Mammals

Spotted hyenas and lions often take each other's kills, as do cheetahs, bears, coyotes, and wolves. Crab-eating macaques and all hyena species also show this behavior. Sometimes, humans take food left by other predators like lions. Risso's dolphins have been seen chasing sperm whales, possibly to get food from them.

A [cheetah](/wiki/Cheetah) has killed an [impala](/wiki/Impala), creating a target for kleptoparasitism.

A little later, the hyenas have driven off the cheetah and are feeding.