Predators and Pavement
With a few small changes, raptors can make a home at the workplace.
like their songbird cousins, many of the world’s great birds of prey are threatened by human activities. As more and more forests and grasslands give way to exurban sprawl, habitats that once provided natural cover and hunting opportunities become constricted. Office parks go up; raptor populations go down.
But are buildings and birds always incompatible? Charles Nilon, an expert on urban wildlife and professor of fisheries and wildlife at MU, thinks not.
Working with graduate student researcher Jonathan Hogg, Nilon has determined that businesses can, in fact, play an important role in raptor preservation efforts. The key, Nilon and Hogg found, is convincing commercial property owners and developers to forego sterile lawns in favor of native grasslands and woodlots.
“Greater amounts of cleared and developed space around businesses, such as lawn and pavement, have negative effects on raptor presence,” says Nilon. “In areas with more natural land cover of tall grass, woodlands and tree cover, [there are] a higher number of raptors. Simply adding certain trees and leaving tall grass can attract this wildlife.”
For their recent study, Hogg counted raptors at several business parks — or clusters of businesses — in St. Louis and surrounding counties. He also broadcasted raptor calls and recorded responses from resident birds. Hogg’s data showed that even minor landscape changes can make a difference.
“Raptors avoid business parks with large areas of pavement and lawns because they can’t find food, protection and nesting areas in these open spaces,” Nilon says. “We found that for each five percent increase in lawn cover, the number of raptors decreased by 12 percent.”
Hogg and Nilon also found that when conditions are right, raptors don’t seem to mind hanging out at the office. During the course of the study they detected 224 birds and eleven different raptor species spending time among the businesses. In addition, at least two sites showed evidence of nesting.
What’s more, the researchers found, accommodating the birds is surprisingly easy. All it takes, says Nilon, are “smaller areas of non-lawn habitat throughout the property, or on the edges of a business park.”
None of this, he adds, need affect either the utility or aesthetics of business properties. “Retaining natural habitat on the edges of the development, on slopes, or along streams contributes to biodiversity in the urban landscape with virtually no impact on the usefulness of the property,” Nilon says.
In fact, he says, previous research shows employees often prefer these more natural landscapes. The Wildlife Habitat Council and the British Trust for Ornithology, for example, report that a diverse wildlife population improves employee morale and encourages better relations with local communities.
Nilon and Hogg’s study was published in the August 5 issue of the journal Urban Ecosystems.