A mixed-species feeding flock, also termed a mixed-species foraging flock, mixed hunting party or informally bird wave, is a flock of usually insectivorous birds of different species that join each other and move together while foraging. These are different from feeding aggregations, which are congregations of several species of bird at areas of high food availability.

While it is currently unknown how mixed-species foraging flocks originate, researchers have proposed a few mechanisms for their initiation. Many believe that nuclear species play a vital role in mixed-species flock initiation. Additionally, the forest structure is hypothesized to play a vital role in these flocks' formation. In Sri Lanka, for example, vocal mimicry by the greater racket-tailed drongo might have a key role in the initiation of mixed-species foraging flocks, while in parts of the American tropics packs of foraging golden-crowned warblers might play the same role.