Chubu Electric Power Co. has adopted a unique method to deter crows from nesting on transmission towers and causing blackouts by building artificial bird nests far from the power lines.
Until recently, the company tried chasing the birds away from the
towers with little success. Instead, the company found that providing
“love nests” for mating crows is more effective in ensuring that the
electricity flows without interruption.
“It looks like the baby has fledged and left the nest safely,”
Takahiro Sugiura said as he viewed a transmission tower with binoculars.
Sugiura is a 23-year-old employee handling power transmission at the
Hamamatsu electric center, a unit of Chubu Electric in Shizuoka
A basket made of resin about 40 cm in diameter was placed high on the tower away from the power lines.
The center has installed baskets in 327 of the 1,120 towers it
manages, selecting those structures on flat ground where crows tend to
build their nests.
Nesting typically begins between February and May.
Metal clothes hangers that a crow has used to make a nest on a power
pole could fall and cause a short circuit. | CHUNICHI SHIMBUN
Crows often use metal clothes hangers and twigs as a base material,
but they don’t hold up well to wind and rain and tend to fall away.
Sometimes when this happens the hangars get caught in the power lines,
causing a short circuit.
Of the failures that occur in power facilities managed by Chubu
Electric, approximately 100 a year are caused by crows, second only to
lightning strikes, which account for a few hundred cases.
During the nesting season, Chubu Electric and other utilities are kept busy climbing towers to remove crow nests.
Electric companies have installed bird spikes and stretched wires
around beams to prevent crows from building nests on the towers, but the
birds can usually get around such obstacles and continue building their
It was the Hamamatsu electric center, which suffers particularly
heavy damage from nests in Chubu Electric’s coverage area, that came up
with the plan to build safer alternatives for the birds.
When they began installing artificial nests in 2004, many mating crows started moving in and laying eggs.
The artificial nests have significantly reduced the number of natural
nests that have to be removed and have reduced the risk of power
Chubu Electric Power Co. employees watch a crow building a nest in Hamamatsu, Shizuoka Prefecture. | CHUNICHI SHIMBUN
After seeing the positive results, Chubu Electric has now placed more
than 2,000 artificial nests in five prefectures — Aichi, Gifu, Mie,
Shizuoka and Nagano.
Hoping to encourage even more crows to use the artificial nests, the
center last year put some in towers where they had removed natural ones,
but in places where they won’t interfere with the power supply.
As a result, the rate of artificial nest usage increased by 4 percentage points to 67 percent compared with the previous year.
Not only has the number of natural nests decreased, dispatching staff
to clear nests from transmission towers has been reduced from 55 times a
year to 27.
It costs ¥15,000 to purchase and install an artificial nest, but only ¥5,000 to move it to a different location.
Based on the center’s analysis, 90 percent of crows like to build
their nest 30 to 50 meters above ground, which explains why they prefer
“The more effectively we install artificial nests, the more crows use
them,” said Hiroshi Saito, 52, assistant head of the center’s power
“Instead of leaving it up to the crows to decide where to nest, we
must guess the best locations for them to do so and work on preventing
power failures,” he added, asking people to let the utility know when
they find natural crow nests on power facilities.