Seedlings at quiet sites were four times more abundant than at noisy ones. When looking at how noise changed the fate of seeds from one of the dominant trees in the ecosystem, piñon pines, the researchers found evidence of the opposite effect. This wasn't a surprise, as previous research has shown that the hummingbirds actually prefer noisy sites this may be because their predators, western scrub jays that eat the hummingbirds' nestlings, flee human noise, Francis and colleagues suggest. They found that the hummingbird visits were five times more common at the noisy sites, and more pollen was also transferred among fake flowers at the noisy sites - good news for flowers at noisy sites. To see how noise at the New Mexico wells affected pollination, the researchers put out artificial flowers resembling a common flower, the scarlet gilia, pollinated by black-chinned hummingbirds in both types of sites. Not all species lose out because of human noise - some can benefit - but if any play important ecosystem roles, such as pollinating plants, dispersing seeds or preying on other species, the effects of noise could trickle down to other members of the community, according to Francis. The researchers compared these sites to others located farther away, where noise consisted of an occasional bird call or, more rarely, a distant plane or car, Francis told LiveScience in an email.
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