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The nest
ENES
An avoidable threat

Every badly designed pole is a trap

Ten years walking power lines in central Argentina, pole by pole, recording what we find at the foot of each one.

Two researchers beside a dozen electrocuted raptors collected under a single power line
Birds collected under a single power line. Each died on landing. · Photo: M. Flores

What happens

Raptors use power poles as perches: they are the highest point in the landscape and a good vantage from which to hunt. On a well-designed pole this has no consequence. On a badly designed one, a large bird spreading its wings can bridge two conductors, or a conductor and an earthed component, closing the circuit.

The discharge is almost always fatal, and it disproportionately affects the species with the largest wingspan — precisely those that are most threatened.

Barn owl dead at the top of a pole, above a nest built on the same structure
A dead barn owl above, and an occupied nest below, on the same pole.
Talon of a raptor showing electrocution burns
The burn on the foot is what confirms the cause. Without that detail, a dead bird at the foot of a pole is just a dead bird.

The fieldwork

473
poles surveyed on route RP20
906
poles surveyed on route RP15
10
years of continuous recording

The survey means walking the lines on foot, pole by pole, recording remains, high-risk structures and evidence of electrocution. It is slow, unglamorous work, and it is what turns impression into evidence.

When power lines kill · CECARA channel

It can be solved

There are proven, low-cost solutions: insulating conductors near the pole and changing the arrangement of the crossarms, so that a large bird cannot bridge two live components when it spreads its wings.

Most are cheaper than repairing the line after a fault. The electrocution of a large bird causes power cuts, and in rangeland it also starts fires.

Why it matters

A modified line stops killing from the next day onwards. It is one of the few threats to biodiversity that can be solved with a technical decision and a work crew.

Publications on the subject · Report a case with SilentSong