Geography Reference
In-Depth Information
evict other cavity nesters from their own holes. In Mississippi, native red-
bellied woodpeckers lost more than half of their nests to starlings. Flickers are
also common victims of starling abuse. Usurped l ickers often renest, but
these later attempts produce smaller broods than the lost i rst attempts. As a
result, l ickers' productivity suf ers near starlings.
Although starlings have the potential to limit populations of many cavity
nesters, in practice this is rare. Flickers and red-bellied woodpeckers pro-
duce cavities of just the right size for starlings, so they are frequent and con-
spicuous targets for takeovers. While some nests of these species fail because
of starlings, over their entire range no ill ef ect of starling invasions is yet
apparent. In fact, of twenty-seven native cavity-nesting birds in the United
States that live among starlings, only sapsuckers show a rangewide decline in
abundance that researchers attribute to starling aggression. Jorge's research
in Seattle suggests why the detrimental ef ects of starlings are limited; most
live deep in the city, and nearly every one of the 120 starling nests we ob-
served was in a utility pole or building. Nesting in our homes is an old tradi-
tion of starlings—a century ago W. H. Hudson found them nesting under a
zinc strip covering a crack in the wall of his English village home—and we
suspect that it may well keep them from directly competing with many of our
native species.
Species that facilitate the presence of others, such as woodpeckers do by
creating cavities in trees, may be especially important in moderately disturbed
environments, such as a city's suburbs. Accordingly, subirdia's riches may be
particularly reliant on positive interactions among species that maintain and
extend diversity. As we remove old trees, trim dead branches, and generally
limit the natural decay process that chickadees, nuthatches, and creepers
require, we increase the importance of natural and novel actions to facilitate
the continued existence of these birds. Fostering woodpeckers by leaving and
recruiting snags in forest remnants naturally supports secondary cavity nest-
