Small bird mobs gang up to attack predators

It can be a tough gig to be a small bird. Predators are often lurking nearby, hoping to gobble you up at any given moment. But it turns out the old saying that “there is strength in numbers” may apply to these birds as well. Researchers have recently learned that some bird species will gang up and form small bird mobs to attack larger predators and keep them away.

A team of scientists recently conducted a study on birds in southeastern Brazil to observe this “mobbing behavior” in birds. These small bird mobs use a variety of tactics ranging from aerial swoops, threatening calls, and even full-on attacks on predators such as owls and eagles.

Scientists initially thought that the mobbing behavior was solely for protection, but they have now learned that it has a secondary purpose. The small bird mobs allow males to show off in front of females and demonstrate their ability to protect a nest or forage for food.

The team or researchers conducted an experiment in which they placed two owl models in a bird community. One of the models was a pygmy owl, a regular predator of small birds, while the other was a burrowing owl, which typically does not pose a threat. They found that the mobbing behavior was more intense with the less threatening owl, indicating that birds can asses the varying levels of risk in a predator.

“Females may use these mobbing events to assess a male’s quality, for example their motor skills which allow them to escape from an attacking predator,” said Dr. Filipe Cunha from the University of Zurich in Switzerland.

Dr. Cunha added that the small bird mobs also help socialize young birds and teach them to distinguish predators from non-threatening birds.

The team reported their findings in a paper published in the journal Behavioral Ecology and Sociobiology.

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By Rory Arnold, Earth.com Staff Writer

Source: Living Wilderness