Kleptoparasitism

Kleptoparasitism is a special 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 some 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 experts 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 get the chance.

This strategy works well when it’s easier to steal food than to hunt for it, especially when food is hard to find or when some animals are too weak to defend their food. It’s a clever survival tactic used by many creatures in nature.

Strategy

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

This behavior only works if it helps the animal more than trying to find 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 stick to finding their own. But when food gets scarce, stealing becomes a better choice, and animals may fight more to get the food.

Taxonomic distribution

Arthropods

Bees and wasps

Many types of bees called cuckoo bees lay their eggs in the nests of other bees, often in the same family. For example, Bombus bohemicus takes advantage of several other species in its group. This follows Emery's rule, which says that social parasites in insects are usually closely related to their hosts. The largest group of these parasitic bees is Nomadinae, which includes several hundred species.

Cuckoo wasps lay their eggs in the nests of potter and mud dauber wasps. Some wasp species act this way too, like Polistes sulcifer, which uses a related species. Other wasps also show this behavior, either by living in the host's nest or by attacking already parasitized hosts.

Flies

Some true 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 feed on leftover food from 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) (and eaten part of it), creating a target for kleptoparasitism.

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