Why do birds sit on power lines above busy street intersections?

Answer 1

The simple and correct answer is safety. They need to perch where there is the least danger from predators and power lines provide that. The reason you don't see it in trees is because the branches aren't long enough.

Communal birds gather at dawn and dusk, and other times of day as they feel necessary, for social purposes and as lookouts, checking for predators, food sources, and so on.

For simple social purposes they could gather anywhere, but for safety they choose to meet, even for purely social catch-up times, in the highest convenient places.

Given a choice between trees of the same height which are bare, lightly-leafy, or heavily foliaged, they'll go for the perches in that order: bare branches will be their first preference.

Power lines offer the perfect alternative to branches, even when bare trees of similar height are available. Power lines allow a brilliant all-round view without as many obstructions as trees present, with the added bonus that cats cannot climb concrete power poles, and even when the poles are timber they're still too high for the average cat - and even the most determined cat can't tiptoe along a power line.

A building-top of the same height or higher than power lines offers a far less safe alternative, since they are ideal territory for predators, including cats and snakes.

Next time you see a flock of birds up on a power line, have a look at them and work out why they've chosen that particular line rather than others nearby. Their favourite perch might give them the best view of their nesting area (at breeding time), or of the areas where they source their food. Crows might choose lines close to the nearest Macdonald's around school closing time, when kids might throw containers with leftover chips into the bins; swallows could be watching for a swarm of insects to start up; sparrows might have an eye on the local bakery for when crumbs are dumped or dropped.

Insect-eating birds also find food flying past up there and can swoop after a passing bug without having to maneuver through branches. You'll notice some of these birds regularly flying off the wire to catch something in mid-air, and then come straight back to join the others.

Power poles, as well as rooftops and high bare branches also offer good grooming areas. When birds are grooming one another, especially in breeding season when they've mates or chicks to groom (this is for bonding, as well as hygiene), they are vulnerable because so much of their attention is on the social pleasures and diligent work involved in grooming, for both birds. So these high, clear places mean predators can't easily sneak up on them while they're distracted.

You will notice that even when most of the flock are somewhere else, there'll probably be a lookout here and there, up high, ready to sound the alarm if they spot something stalking their community members, or see some new berries have ripened up the road.

Bird-lookouts benefit many species, not just the family of the duty sentry. All birds in an area know the calls of all the other birds, and act upon them.

Crows (and, where I live, cockatoos) are among the most efficient guards, frequently on sentry duty much higher than smaller birds, and so very often sound the first warning, which is picked up by the other species.

They also spot new food very quickly, and again the other birds listen out for the news.

Other animals - rats and other small mammals - also are guided by the warning calls of birds. Many little creatures owe extensions of their short lives to a watchful crow up there on duty.

So, your birds gathering up there on the power lines are part of one big neighbourhood community, just like we humans, getting together to swap news and gossip, watching out for one another, checking on the kids, finding good places to eat, and just generally going about their day-to-day business.

It's not all just flying about having fun...

Answer 2

I believe in the Winter in the Northeast they sit above the highways where it is probably warmer from the vehicle traffic. As the heat from Cars and trucks rises and as slight as the temperature change is , it is enough to make a difference I think for a small brain they are smart enough to know what makes them warmer when it is brutally cold out.

This time of year you literally can see hundreds of birds crunched together as close to each other as possible. You can see them all over the State highways where there are many wires hanging over highways rather than interstate highways which typically don't have many wires over hanging highways.

Answer 3

I believe the real question is why on wires overhanging highways?

Answer 4

Birds will gather around the same electrical power line because they are social animals. This animals are often also seen flying together.

Answer 5

Birds tend to fly in groups. When one gets tired, it lands, and the others follow.

Answer 6

So they're not lonely and bored with themselves