Smaller birds chase these predators out of their territories so that they will be safer at night. Owls in particular elicit intense mobbing behavior, as they often prey on sleeping birds. Mobbing calls may also act as warnings to other small birds, may call in even larger predators to go after the target of the mobbing, and may inform a predator that it has been spotted, causing it to move to another area with unsuspecting prey. Our Birding Warblers video features a segment on pishing. It’s this phenomenon that’s behind the success of pishing, in which a birder imitates mobbing calls to bring birds into view. The mobbing birds tend to use similar-sounding call notes, regardless of their species, and this may act to recruit other individuals to form a mobbing flock.

Often, several different species join forces to mob this common threat. In some cases you’ll run across a group of birds harassing a perched predator. In these cases you often see a single smaller bird chasing a larger bird in flight (sometimes two or three join the chase as the larger bird crosses territories). Mobbing is also used by birds as a way to protect themselves and their young against predators. For example, in the early spring Red-winged Blackbirds chase not only rival blackbirds, but almost any other bird, big or small, that crosses their territory. Birds may chase other birds away from their territories or a food source. Mobbing can happen at any time of year, but it is especially common in spring as birds experience surges of hormones, become territorial, and begin to nest. Common targets of mobbing are hawks, crows, ravens, herons, and owls. They typically do this in an effort to drive away potential predators from a breeding territory, a nest or young, or a nonbreeding home range.Ĭommon mobbers include chickadees, titmice, kingbirds, blackbirds, grackles, jays, and crows.

You witnessed a behavior called “mobbing,” where smaller birds swoop and dash at flying or perched larger birds (and sometimes mammals).

A falcon who chases a warlike crane