Fracking is controversial but likely to have at least one real fan – the black-chinned hummingbird.

The noise of machinery at gas extraction sites in the US appears to benefit the nectar-loving birds, boosting their nesting capacity and the rate at which they pollinate flowers.

Scientists believe the racket of compressors is driving away the hummingbirds’ natural predators, enabling them to raise their chicks in peace despite the din.

The extraction of shale gas from rocks using powerful jets of liquid, known as “fracking”, has stirred up heated debate and is already widespread in the US.

Dr Clinton Francis, from California Polytechnic State University, led a study that compared numbers of hummingbird nests around noisy and quieter gas extraction sites.

His team found 36 black-chinned hummingbird nests on the noisy sites and only three where noise levels were much lower.

“This is noise from natural gas extraction activities,” he told the American Association for the Advancement of Science (AAAS) annual meeting in San Jose, California.

A black-chinned hummingbird going about its business.

“Some of these natural gas wells have very noisy compressors on top of them and others do not.
”It’s all about how quickly operators are trying to get the gas out of the ground.
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Our operating hypothesis, which we have confirmed, is that some of the major nest predators may be absent from the noisy sites.
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The hummingbirds may be benefiting from the absence of some key threats that they encounter during nesting.

“They are not the only species that appear to benefit from this noise. House finches are also there.”

A test involving artificial flowers containing “pollen” in the form of fluorescent powder confirmed that hummingbird pollination rates increased at the noisy sites.

“We found that a proxy for pollination rate, which was the movement of this fluorescent powder routinely used in pollination studies, was much higher in the noisier areas,” said Francis.

But he stressed that man-made noise generally drove wild species away.

“You have lower densities of most species in general and about a one-third reduction in the species richness,” he said.

“What you tend to lose are the very uncommon species that tend to be very sensitive.”

Black-chinned hummingbirds, which live throughout the southwest US, make their nests on the ground and have a number of predator enemies including snakes, jays and even mountain lions.

AAP