One of the benefits of leaving large, dead trees standing is
that they often become magnets for wildlife.
Their decaying bark and wood attract countless species of insects, which
in turn become food for wild animals; they provide space for nesting and
roosting; and hawks, owls, and flycatchers, among other species, use them as
hunting perches. I realize that sometimes
these snags have to be removed, as they pose a danger to humans or to property,
but if a dead tree stands in a place that
isn’t inconvenient for people, I would argue that it’s better to leave it
alone.
My observations of birds in and around snags in the
neighborhood where I live bear this out.
Like most residential areas, my neighborhood has severely fragmented
forest habitats, which aren’t ideal.
However, within those tiny woodlands, the ages of the trees vary widely,
and there are some trees that have died.
Ecologically, this is a good thing!
If you have snags near your home, watch closely to see the variety of
birds and other animals that use them. For
example, I often see a Mourning Dove perched atop one particularly large and
prominent snag. I don’t know whether
this is always the same Mourning Dove, or whether several different individuals
like to use this perch. Woodpeckers,
including the species Red-headed and Red-bellied, hammer on this tree, as well
(juvenile Red-headed Woodpecker in the bottom photo).
One rather exciting find for me this fall was a migrating
Olive-sided Flycatcher foraging from this snag.
Although it isn’t exactly a rare bird, it is becoming scarcer, probably as a result of global climate change combined with habitat
destruction on its wintering grounds in Central and South America. Disturbingly, surveys show that populations
have declined 79% since 1970.
Olive-sided Flycatcher |
The bird’s distinctive feeding style usually involves
sitting at the top of a prominent perch and darting out to catch flying insects
that pass by. This neighborhood snag is
tall enough to provide an excellent vantage point for flycatchers to survey a
wide area, so while I was pleased to see an Olive-sided in it, I wasn’t really
surprised. The Olive-sided’s smaller and
paler cousins, Eastern Wood-Pewees, also hunt from the snag—although less habitually.
Olive-sided Flycatcher (left) and Eastern Wood-Pewee (right) |
The apex predators of the bird world, hawks and owls,
use snags, as well. Red-shouldered Hawks
are the ones that I most commonly see around here, probably because of the
creek that harbors the frogs, crayfish, and snakes that these lowland-loving
hawks like to eat.
Mississippi Kites left the neighborhood for their wintering
territories in South America well over a month ago, but while they were here,
they could be seen on occasion in the tops of the snags bordering the
fields. I sometimes see Red-tailed Hawks
here, as well, and I am sure that Barred Owls and Great Horned Owls use these
trees at night.
Mississippi Kite |
Another of the dead or dying trees around here that I enjoy
monitoring for wildlife is a moribund sugarberry. It happens to be a prop for berry-producing
vines, so wildlife can binge on those in addition to the sugarberries that grow
on the living side of the tree. I’ve
seen many species of birds feeding on the fruit, including tanagers, orioles,
bluebirds, mockingbirds, thrashers, vireos, and woodpeckers. As you might guess, the tree also attracts
lots of insects, so even non-frugivorous bird species—e.g., warblers and
gnatcatchers—can find a buffet there.
And woodpeckers really seem to like its dead top branches for drumming
and feeding. Here’s a sampling of some
of these birds:
Yellow-throated Vireo inspecting dead branches |
American Goldfinch |
Baltimore Oriole |
Since we're in the thick of bird migration right now, taking another look at snags is well worth the effort!