Kleptoparasitism

Kleptoparasitism (originally spelt clepto-parasitism,[1][2] 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.

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.

[5] The strategy has been widely studied in birds; in four families, all seabirds, the Fregatidae, Chionididae, Stercoraridae, and Laridae, it occurs in more than a quarter of the species.

Similarly, when potential victims are rare or widely dispersed, the time needed to find them may not be justified by the food that might be stolen from them, resulting in frequency-dependent selection.

[9][10] The largest monophyletic lineage of kleptoparasitic bees is Nomadinae (a subfamily of Apidae), which comprises several hundred species in 35 genera.

[12][13] Numerous other wasp families have genera or larger lineages of which some or all members are kleptoparasitic (e.g., the genus Ceropales in Pompilidae and the tribe Nyssonini in Crabronidae).

[16] Flies in the genus Bengalia (Calliphoridae) steal food and pupae transported by ants and are often found beside their foraging trails.

[17] 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.

Among opportunists such as the roseate tern, parent birds involved in kleptoparasitism are more successful in raising broods than non-kleptoparasitic individuals.

As the returning birds approach the colony, the frigatebirds, which are fast and agile, swoop in to pursue them vigorously; they sometimes seize tropicbirds by their long tail plumes.