Cities are brimming with wildlife. There are coyotes, bats, insects and, of course, birds, to name a few. Of those groups, the birds are probably the ones that most people care about, and the species that we most want to encourage to make homes in our yards. But how much do our backyards really matter? Quite a bit, a recent study finds, even in the big city. And what you decide to plant can affect which and how many species live near your house.
J. Amy Belaire and colleagues at the University of Illinois at Chicago conducted surveys in residential neighborhoods of the city that bordered forest preserves along the Chicago and DesPlaines rivers. Belaire walked transects through the neighborhoods, walking away from the preserves and stopping every 100 meters to spot birds and listen for their songs. The team tallied up 36 different species — 20 migratory, 12 year-round native and four nonnative species. Most common were Northern cardinals, American robins, American goldfinch and house sparrows, Belaire and her colleagues reported in the December Ecological Applications.
The researchers also surveyed the people in those neighborhoods to determine what kinds of resources were available to the birds in their yards. That included types of trees and shrubs, whether there were plants with fruit or berries and the presence of birdfeeders and birdhouses. The team also asked about the use of insecticides and if homes had cats or dogs that were allowed outside. Then they matched up that survey data with the bird data to see which factors affected species diversity and numbers of birds.
Trees were very important. Their presence supported lots of native and migratory bird species, and yards that had a mix of deciduous and evergreen trees were the best. Native birds also did well when yards had plants with fruits and berries. But when cats or dogs were allowed outside, native bird species tended to avoid those areas and nonnative birds moved in. Birdfeeders and birdhouses, though, made surprisingly little difference.
“Our results suggest that urban conservation agendas would benefit from ‘thinking outside the park’ and highlighting to residents the positive collective effects of minor yard enhancements,” the researchers write. They suggest “planting fruiting shrubs or trees, increasing presence of evergreen trees and restricting outdoor activities of both cats and dogs, all of which could be promoted by homeowners associations, municipal incentive programs and conservation groups communicating with residents.”
The National Wildlife Federation has recommendations for creating a bird-friendly habitat, such as installing plants native to your area and keeping dead trees in your yard. If you’re willing to work with your neighbors, think about banding together to become an NWF Certified Community Wildlife Habitat. The program raises the profile of green communities and can help improve your neighborhood’s health and water and air quality, as well as provide more space for wildlife.
And by registering your backyard with the Cornell Lab of Ornithology YardMap project, you can help scientists collect information on how green spaces affect birds. With data from yards, parks and other green spaces across the country, researchers will be able to figure out which planting and other practices benefit birds the most and tell us how we can best help our avian friends.