Birds perched in rows on power lines are a familiar sight, as are flocks of startled birds that swoop and quickly change direction in the air before settling on a place to roost. This common congregating behavior may seem enigmatic, but power line perching actually serves a practical purpose.

High Visibility

Many bird species, especially starlings, are partial to power lines because the lines, like trees, provide safe, high perches. Perching on power lines allows smaller birds to survey the surrounding area for predators. Conversely, predatory birds may use the vantage point to scout for prey.

A Place for Singing

Birds such as vesper sparrows use power lines and other high structures as places to sing and be heard by other birds, especially during breeding seasons. Power lines are handy perches in deforested or open areas.

Weather Lore

Weather folklore maintains that birds lined up on power lines indicate rain.

Flocking Tendencies of Birds

The fact that many birds line up together on power lines is evidence of the flocking behavior of many bird species. Many birds congregate in huge flocks and engage in noisy, social behavior.

Potential Danger from Power Lines

It may seem that birds perched on power lines will inadvertently electrocute themselves, and this does sometimes happen. But when a bird on a power line does not come into contact with another wire, or anything else that will complete the circuit of electricity, it can safely rest on the charged line without injury. For this reason smaller birds are usually safe.

Source:

Bird Gard

Patuxent Wildlife Research Center

JSTOR

More Information:

The New York Times