Geography Reference
In-Depth Information
Pine siskin caught by a sharp-shinned hawk
a siskin and l uttered to the ground, where its sharp talons and strong feet turned
the songbird into a meal. We were saddened and simultaneously excited by the
drama we had just seen. Nature can be cruel here in subirdia, as everywhere. But
to an ecologist, predation is a sign of health that indicates an ecosystem with
ample prey to sustain and lengthen the food chains built atop them. Death is not
easy to watch, but it is a fundamental feature of ecological webs.
One might think that predator-prey links are rare in the suburban eco-
logical web, but that would be wrong. True, humans have little tolerance for
large predators near their homes; grizzlies, wolves, tigers, lions, and their ilk
are often excluded. But smaller predators often thrive among us, in part be-
cause we remove their enemies and in part because of the abundance of prey
that inhabits subirdia. In my neighborhood red-tailed hawks and raccoons
fatten up on baby crows whose parents have likely robbed eggs from the nest
of nearby Steller's jays that regularly eat the eggs and young of other song-
birds. Garter snakes prey on the eggs and chicks of ground-nesting birds such
as the dark-eyed junco and Wilson's warbler. Coyotes and bobcats mostly stay
hidden, but they are common.
