Do dogs keep birds away from urban parks?

If we want to encourage birds to flock to city parks, we should make some areas off-limits to dogs, researchers say. According to a new study in Israel, pooches can lower the diversity of bird species in urban gardens.

The researchers arrived at this conclusion through a painstaking study. One team member, Yair Paker of Tel Aviv University in Israel, visited 25 public gardens in Tel Aviv and Holon, Israel and counted birds at one to two spots in each garden. Paker conducted the observations at each spot 21 to 25 times during the early mornings from 2008 to 2009 and ended up counting 14,278 birds from 65 species. Nearby trees, shrubs, people, cats, and dogs were also recorded.

Next, the team tried to figure out which features of the gardens were linked to higher bird diversity. The parks, which ranged from 0.96 to 2.44 hectares, contained a mix of lawns, trees, and shrubs. Birds favored areas with a rich variety of trees and shrubs rather than gardens dominated by lawns. And parks with a lot of human and canine visitors tended to have fewer types of birds.

“To minimize this effect we recommend creating areas in gardens that will be inaccessible to people and dogs,” the authors write in Landscape and Urban Planning. “This can be done by planning trails in such a way that relatively large areas of shrubbery will be far from them, and also by keeping dogs on leash, as required by law in Israel.”

The researchers also found that alien tree and shrub species were more common than native species in 84 percent and 76 percent of the parks, respectively. But native birds, not surprisingly, were more likely to feed on the native trees. So even though alien trees are often taller and have large, attractive flowers, urban planners should think twice about letting those species dominate the gardens. Roberta Kwok | 15 November 2013

Source: Paker, Y. et al. 2013. The effect of plant richness and urban garden structure on bird species richness, diversity and community structure. Landscape and Urban Planning doi: 10.1016/j.landurbplan.2013.10.005.

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