If you do any bird watching at all, chances are that you have seen birds sitting on power lines.
Every birdwatcher knows that passerine (perching) birds tend to congregate on power lines, and power lines are a great place to start looking for certain line-loving species.
But what’s the attraction of power lines for birds?
Why Do Birds Sit on Power Lines?
Over the last 100 years, birds have learned to treat power lines as another feature of the landscape.
Powerlines offer birds a place to perch where ground-dwelling predators like cats and coyotes can’t reach them.
Birds use power lines for resting, roosting at night, and even for hunting.
Some birds you will commonly see sitting on power lines include blackbirds, bluebirds, swallows, martins, doves, pigeons, grackles, starlings, kestrels, kingbirds, and strikes.
You may see larger birds, such as eagles, geese, hawks, herons, ospreys, and buzzards perched on utility poles, and golden eagles, ospreys, red-tailed hawks, flycatchers, monk parakeets, and great horned owls will build their nests on them (the poles, not the lines).
In much of the country, the best place to get a glimpse of raptors, like eagles, is a power line towering over open grassland.
This leads us to the obvious question that first comes to mind when you see birds on power lines and utility poles: Why aren’t birds sitting on power lines electrocuted?
The Reason Birds Don’t Get Shocked When They Sit on Power Lines
Power lines are insulated, but even the surface of a power line is high-voltage.
If you touch a live power line that has fallen to the ground, you will be electrocuted.
Birds don’t get electrocuted, however, as long as their bodies don’t provide the power line with a ground.
As long as the bird’s body has the same electric potential as the power line, current flows through the power line, not through the bird.
There are many situations in which birds do get electrocuted when they touch power lines.
Birds can get electrocuted when their wings touch two lines at the same time. This is one of the reasons you never see large birds sitting on power lines.
They can (and sometimes do) get electrocuted as they approach the power lines, or they try to fly between power lines.
Birds that nest on utility poles can get electrocuted if they step on a power line as they are leaving their nest.
This happens to a large number of fledgling eagles and herons.
And birds can be electrocuted when they touch another bird on a different power line.
This can happen when a parent tries to catch a chick or during courtship when male and female birds feed each other.
Power companies try to protect birds by spacing lines apart far enough that birds won’t touch two lines at the same time.
They also install nesting platforms so birds will not build their nests at the power line level. But there are many benefits of power lines for birds.
Benefits of Power Lines for Birds
The most obvious benefit of power lines for birds is safety from predators.
Birds roosting overnight on a power line are not going to be attacked by a raccoon, a dog, or a cat.
Eggs in a nest built on a power pole are safe from squirrels, snakes, opossums, and ground-dwelling creatures.
Crows and buzzards perch on power lines to look for road kill. They don’t have to spend as much energy flying from place to place.
Some species of crows can’t build nests in treeless areas unless there are power lines. The presence of power lines has helped them expand their range.
There are species of birds, like kestrels, that build their nests on power poles even in wooded areas, to protect their eggs from squirrels.
Both pigeons and hawks use power lines as navigational tools.
Power lines help them figure out where they are going on intercity migrations. But power lines also pose significant hazards for many birds.
Hazards for Birds Posed by Power Lines
Some birds are at special risk for colliding with power lines.
Birds that have short wings and heavy bodies, like grouse and bustards, have difficulty changing course in time to miss a power line.
Birds that have a narrow field of vision, like storks and cranes, simply don’t see power lines.
Raptors, such as eagles, are at 10 times greater risk of electrocution on rainy days, because their feathers get wet.
Birds that fly in large flocks are in greater danger of injury from power lines, because the birds at the back of the flock will not see them.
Nocturnal birds like owls run into power lines because they cannot see them.
Newly erected power lines are dangerous for migrating birds that do not know they are there.
But even when power lines don’t electrocute birds, the electrical grid can pose other dangers.
Nests built on utility poles are more exposed
Birds that build open nests on top of utility poles leave their eggs and young more exposed to rain, wind, storms, and UV light.
Chicks are in greater danger from raptors that can swoop down and eat then,
Electromagnetic fields make birds more active
The electromagnetic radiation generated by power lines makes birds more “hyper.”
They are more likely to break eggs and accidentally drop their young out of the nests.
Electromagnetic fields interfere with the development of the chick inside the egg
Electromagnetic radiation, like other kinds of radiation, interferes with the development of the embryo.
Hatchlings may be born with birth defects, or eggs may not hatch at all.
Removal of vegetation underneath power lines confines birds to either side
Trees can’t be allowed to grow underneath power lines.
Regular removal of vegetation underneath power lines creates barriers for smaller birds, such as hummingbirds, limiting their range for both feeding and breeding.
Other birds are “cooped up” with their predators or with birds that will try to take over their nests.
Some birds are in danger of going extinct because of power lines
For other birds, power lines are not just inconvenient. The endangered blue crane of South Africa faces extinction because of collisions with power lines.
Every year, about 12 percent of all blue cranes die in collisions with power lines.
Iberian eagles in Spain are dying off for a different reason related to power lines.
Every year, about 15 percent of all Iberian eagles are electrocuted on power lines.
Frequently Asked Questions About Birds on Power Lines
Q. Why do all the birds on a power line face the same way?
A. You are more likely to see all the birds on a power line facing the same way when there is a wind blowing.
They orient their bodies, so they experience the least possible force of the wind.
In some conditions, birds would be blown off the power line if they had their backs to the wind.
Q. Is seeing birds on a power line a sign of a coming storm?
A. Flocks of birds flying together may rest on power lines as they are traveling a long distance to escape a storm.
Gathering on power lines, however, is not necessarily a sign of impending bad weather.
Q. Do birds charge on power lines?
A. No, a bird’s body cannot convert the electromagnetic radiation generated by a power line into energy.
But sitting on a power line instead of flying or fighting predators helps a bird conserve energy.
Q. Why do birds gather on power lines at dusk?
A. Birds that regularly gather on power lights at sundown, such as grackles, are using them as a safe place to roost overnight.
They will look for other places to spend the night if the weather is cold or windy.
Other kinds of birds will spend a single night on a powerline when they are migrating, and do not know where to go.
Q. Do birds sit on power lines for warmth?
A. In the winter, power lines are colder than other places birds can stay. However, they save energy by not having to fly.
Q. Is there a way to discourage birds from sitting on power lines?
A. There are many reasons people want to discourage birds from gathering on power lines.
Some birds, like grackles, make noise all night. Birds in groups leave droppings that can cover the ground.
Birds that regularly roost on power lines will peck at insulation for nesting material.
They can expose live wires. Woodpeckers damage wooden power poles.
And the occasional electrocuted bird will fall to the ground, attracting scavengers, or decay in nearby trees or shrubbery.
Four ways of keeping birds off power lines near your home include:
- Installing strobe lights. If you live in an urban area, strobe lights are usually the best way to keep birds off power lines near you. Your neighbors are much less likely to object to strobe lights than sound deterrents. The downside of using strobe lights is that they work much better at night than during the day.
- Removing attractive features. Avoid feeding birds near power lines. Get rid of soft grasses, twigs, and other nesting materials. Don’t place a bird bath near a power line.
- Putting up a visual deterrent. Smaller birds will be intimidated by a mechanical owl or a scarecrow. The higher you can place the visual deterrent, the better it will work.
- Activating sound deterrents. As a last resort, you can get rid of roosting birds with a sound cannon or a synthesizer that imitates the noises made by predators of the species you are trying to remove. This approach works best in rural settings, where there aren’t any neighbors to object.
When nothing else works, you can always call your municipality’s animal control officer or look for a pest control company online.
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