Biodiversity | Subscribe News

Human Noise Has Ripple Effects on Plants

New research shows that birds and other animals change their behavior in response to human noise, such as the din of traffic or the hum of machinery.

Scarlet gilia

A growing body of research shows that birds and other animals change their behavior in response to human noise, such as the din of traffic or the hum of machinery.

But human clamor doesn’t just affect animals. Because many animals also pollinate plants or eat or disperse their seeds, human noise can have ripple effects on plants, too, finds a new study reported in the March 21, 2012, issue of the journal, ‘Proceedings of the Royal Society B’.

In cases where noise has ripple effects on long-lived plants like trees, the consequences could last for decades, even after the source of the noise goes away, says lead author Clinton Francis of the National Science Foundation (NSF) National Evolutionary Synthesis Center in Durham, North Carolina.

In previous studies, Francis and colleagues found that some animals increase in numbers near noisy sites, while others decline. But could animals’ different responses to human noise have indirect effects on plants, too?

To find out, the researchers conducted a series of experiments from 2007 to 2010 in the Bureau of Land Management’s Rattlesnake Canyon Wildlife Area in northwestern New Mexico.

The region is home to thousands of natural gas wells, many of which are coupled with noisy compressors for extracting the gas and transporting it through pipelines. The compressors roar and rumble day and night, every day of the year. The advantage of working in natural gas sites is they allow scientists to study noise and its effects on wildlife without the confounding factors in noisy areas like roadways or cities, such as pollution from artificial light and chemicals, or collisions with cars.

As part of their research, Francis and colleagues first conducted an experiment using patches of artificial plants designed to mimic a common red wildflower in the area called scarlet gilia. Each patch consisted of five artificial plants with three “flowers” each – micro-centrifuge tubes wrapped in red electrical tape – which were filled with a fixed amount of sugar water for nectar. To help in estimating pollen transfer within and between the patches, the researchers also dusted the flowers of one plant per patch with artificial pollen, using a different color for each patch. Din levels at noisy patches were similar to that of a highway heard from 500 meters away, Francis said.

When the researchers compared the number of pollinator visits at noisy and quiet sites, they found that one bird species in particular – the black-chinned hummingbird – made five times more visits to noisy sites than quiet ones.

Black-chinned Hummingbirds

“Black-chinned hummingbirds may prefer noisy sites because another bird species that preys on their nestlings, the western scrub jay, tends to avoid those areas,” Francis said.

Pollen transfer was also more common in the noisy sites. If more hummingbird visits and greater pollen transfer translate to higher seed production for the plants, the results suggest that “hummingbird-pollinated plants such as scarlet gilia may indirectly benefit from noise,” Francis said.




Pages: 1 2

Comments are closed.

A sample text widget

Etiam pulvinar consectetur dolor sed malesuada. Ut convallis euismod dolor nec pretium. Nunc ut tristique massa.

Nam sodales mi vitae dolor ullamcorper et vulputate enim accumsan. Morbi orci magna, tincidunt vitae molestie nec, molestie at mi. Nulla nulla lorem, suscipit in posuere in, interdum non magna.