Mobbing

Northern Mockingbird mobbing a crow
Photo Courtesy & © William C. Webb
Birding.About.com

Mobs reveal a dark and terrifying side of human nature, whether it be the chaotic urban masses crying for the guillotine during the French Revolution, or a shadowy crime syndicate ruled by a guy named Joe Bananos. Many birds practice a different sort of mobbing, wherein there is rarely an injury and the little guy prevails.

When a predator such as an owl, a hawk or even a large snake ventures into a location, they may be detected by a resident bird. That sentinel will make a noisy, dissonant fuss to recruit reinforcements who will join in harassing that hawk or owl. Just who participates is a matter of size matching and a species’ predilection. Tiny predators such as a screech owl or a merlin will be plagued by tiny birds, with chickadees often leading the charge.

When you hear crows or magpies stirring up a ruckus, chances are that a large hawk such as the red-tail, or perhaps a great horned owl, is at the center of the melee. As the harassment escalates, the hawk will typically take wing in a disgruntled huff, trailed by its fussing mob. By remaining perfectly still, an owl can sometimes become seemingly invisible, its smaller marauders gradually losing interest and dispersing.

Why a predator doesn’t lose its temper and turn on its unwelcome mob I don’t know, but I have not seen it happen.

And the purpose of mobbing? Perhaps in loudly announcing a predator’s presence, the hunter’s advantage for stealth and surprise is lost. Or maybe the mob is just telling the hawk or owl to: “Push off and leave our neighborhood!”

By imitating an owl’s call or by producing the right dissonant “pishing” noise, like this “pishpishpish”, I can sometimes lure a small mob briefly into view, one often led by a valiant chickadee. Soon recognizing my deceit, after a few minutes, the group will quickly disperse, leaving me to smile at just what a frisky mob that was!

Credits:
Photo: Courtesy Birding.about.com: Photo Copyright © William C. Webb
Text: Bridgerland Audubon Society – Jim Cane