Geography Reference
In-Depth Information
malls provides a place for Brewer's blackbirds, while crows and gulls patrol
the paved urban core. Simply not doing the same thing everywhere increases
the diversity of habitats and therefore the variety of birds that exist within
cities.
As we seek to reduce uniformity within a city, we must also consider
how to reduce it between cities, especially those in distinct ecological re-
gions. Consistent and unimaginative landscaping practices are a major ho-
mogenizing force that increases the chances that many cities will harbor the
same few species of birds. At regional and continental levels, retaining na-
tive vegetation and landscaping to conform with, rather than contradict,
this natural background can stall the march to uniformity. To date, homog-
enization is most evident in the frequently disturbed, highly modii ed parts
of the city—suburban lawns, bare land, and paved downtowns. Scrui ng
up these places with native grasses, shrubs, cacti, and trees not only saves
energy and natural resources by reducing maintenance, but also helps keep
habitat locally diverse and regionally distinct. Many native plants could easily
be retained if developers and builders carved lots carefully from existing veg-
etation rather than pushing it aside to ease their operations. In this way,
neighborhoods in Phoenix, Arizona, for example, could retain iconic saguaro
cacti and palo verde trees to distinguish themselves from neighborhoods
among the coastal chaparral of San Diego, California. By scraping entire lots
bare and then replanting them with a standard mix of nursery stock, unifor-
mity among neighborhoods and cities rises and bird diversity declines.
General practices that reduce the uniformity of cities will benei t a wide
variety of birds, but special features of disproportionate importance some-
times require individual attention as well. Monroe, Washington, for instance
is home to around twenty thousand migrating Vaux's swifts each spring and
autumn, because it retained a large, brick chimney once used to vent heating
exhaust from a school's furnaces. The swifts, no longer able to i nd large, hol-
low trees to roost within, instead swirl en masse into the old chimney. The
