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Fatal attraction: light that kills

Cardinal
Credit: Espace pour la vie (Claude Lafond)
Cardinal
Fatal attraction: light that kills

Red-eyed vireos, cardinals, cedar waxwings… Corpses by the thousand blanket the ground. In Lennox, Ontario, 10,000 birds died over two rainy nights from flying into industrial smokestacks. In Georgia, in the U.S., 50,000 birds died of exhaustion by following the light beams issuing from a military base. Nighttime lighting every year kills tens of millions of birds. Fatalities are higher during fall and spring migrations, especially if the weather is bad. These lights kill all sorts of birds. Four hundred and fifty different species have been counted in the case of the city of Toronto alone.

An evolution too slow to adapt

After millions of years of evolution, birds have adapted to the natural lighting emanating from the Sun, the Moon and the stars. The incandescent bulb was invented in 1879. Today, 136 years later, birds still have not become accustomed to artificial lighting.

During migrations, many birds travel at night, stop at dawn, rest and store up fat for the rest of their journey. They’re guided in this by the stars and by the Earth’s magnetic field. Most birds have worse night vision than humans. Night migration is therefore not easy for them.

Blinding halos

Small songbirds, the most abundant victims, fly less than 400 meters high and are very easily affected by artificial lighting. During storms (rain, or when it’s foggy), artificial light strikes water droplets, diffracts in every direction and crates a halo around each of them. This disrupts birds’ vision and their sense of direction. Not really knowing where they’re headed, birds whirl around inside that dazzling halo and wear themselves out. Some will die of fatigue, others will fly into one of their fellow creatures or a wall. In the early morning, those who’ve survived this hellish night will touch down on the ground, totally exhausted. Some will be the victims of predators. Others won’t succeed in sufficiently regaining their strength and possibly won’t survive the night to come.

Solutions

In Québec, birds also die as the result of collisions with buildings that are lit up at night. But there are solutions: turn off nighttime lighting, choose fixtures that direct light downwards and not up, use strobe lights or low-energy (LED) bulbs, and above all, minimize lighting during spring and fall migrations, especially during storms or periods of fog... Isn’t it time we did something?

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