kleptoparasitic

Kleptoparasitic describes an organism that obtains food by stealing it from another animal that has captured or is in the process of capturing prey. This feeding strategy, kleptoparasitism, is a form of social or parasitic interaction in which the thief benefits while the victim bears a cost, such as reduced foraging efficiency or lost meals.

Kleptoparasites employ several behaviors to acquire food. They may chase and harass a forager to force it to relinquish prey, steal items directly from the victim’s catch, or exploit leftovers and dropped food at feeding sites. The interaction can be opportunistic, occurring when prey is concentrated or when the thief is able to intercept a meal with minimal risk. In some systems, kleptoparasitism involves provisioning by one individual for another (for example, in some bird-mobbing contexts), but the core idea remains theft of food already captured or carried by another.

Taxa and examples are diverse. In the open ocean, frigatebirds and great skuas frequently steal prey from other seabirds. Gulls, terns, and waders often engage in opportunistic theft at rich foraging grounds. In aquatic systems, remoras are sometimes described as kleptoparasites for feeding on the scraps of larger hosts’ meals. Kleptoparasitism also occurs in some invertebrates and mammals, though less prominently studied than in birds.

Ecological and evolutionary implications include costs to hosts, such as wasted energy and reduced intake, and potential defenses like mobbing, guarding resources, or shifting foraging times. The term derives from Greek klepto (steal) and parasitos (parasitic).