Light pollution is bad news for wildlife. The permanent full moons of modern urban-industrial zones cause birds to fly off course, sometimes to the point of crashing into buildings or even circling around lost until they drop out of the sky exhausted. Meanwhile, nocturnal predators are finding it a whole lot harder to maintain their way of life/survival without the benefit of darkness; some snakes, for example, tend to avoid hunting on full-moon nights. Disoriented baby sea turtles in Florida are now famously heading inland instead of out to sea. It’s a bad scene and, given just 75 years ago the world was mostly still dark at night, many bad effects remain to be seen.
But at least one bird is pretty stoked: the common redshank.
Dr. Ross Dwyer and a crew from the University of Exeter have been studying wildlife in the Forth estuary, one of the most industrialized coasts in Scotland, featuring both the Grangemouth oil refinery and Longannet power station The estuary also happens to house hundreds of thousands of migrating birds in the winter, including our friend the redshank. Dwyer wanted to see if the lights from the local industry affected the redshank’s foraging habits. His team took measurements of artificial light from US Air Force satellites — notably, the first time US military equipment has been used in an animal behavior study — and then hooked 20 birds up to a bunch of sensors. At any given time, they could tell where the birds were, and if they were feeding.
Tagging a redshank/Ross Dwyer
So redshanks forage both day and night, but they’re a whole lot better at it during the day because, well, they can see better. At night they keep at it, but inefficiently. In the unshadow of the refinery, the birds have things easier. “Artificial light from industrial areas strongly influenced the foraging strategy of our tagged birds,” says Dwyer, whose work is being published tomorrow in the Journal of Animal Ecology. “It was as if the 24-hour light emitted from lamps and flares on the Grangemouth oil refinery site created, in effect, a perpetual full moon across the local inter-tidal area which the birds seemed to capitalise on by foraging for longer periods at night and switching to a potentially more effective foraging behaviour to locate prey.”
Of course, it’s hard to argue that this is a net benefit. The redshank is getting along well now, but one imagines its current party lifestyle catching up with the estuary in time, with a diminished prey (worms, small fish) population. Rapid changes to an environment tend to not result in sustainable ecological equilibrium. Note also that as feeding gets more efficient for the birds because of their refinery neighbor, that same refinery (and other assorted area pollution) is steadily torching the estuary’s water quality, killing the same invertebrates the birds depend upon. So ultimately the habitat still gets worse. But, for now, party on, redshank friends.
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