Shrike
(This 923rd Buffalo Sunday News column was first
published on November 30, 2008.)
Northern
Shrike — photo by Willie D'Anna
The
robin-sized bird flew low over the pasture but then soared up to light on the
very highest twig of a leafless maple. There it perched upright and appeared to
scan the open fields below the tree.
It
might have been a robin or a jay or a blackbird, but its actions suggested the
possibility of a rarer species. It was too far away, perhaps a hundred yards
across the field, to tell what it was without a better look, so I set up my
telescope.
And
indeed, there in the fifty-power eyepiece I found the bird I hoped to see. It
was a Northern shrike.
Shrikes
are achromatic birds, that is, "colorless" birds of grey, white and
black. They are easily mistaken for another grey and white bird, the
mockingbird, for mockingbirds also flash white patches in their darker wings
and tail when in flight. However, my closer look through the scope showed the bird's
black mask and heavy hooked bill, sure marks that told me that this was a
shrike and not a mockingbird.
I
have described that sighting as a single event, but it really represents an
episode that I have experienced perhaps a hundred times over my lifetime of
birding. The Northern shrike is an uncommon winter visitor here on the Niagara
Frontier, a few beginning to appear in mid-October and all off to their breeding
grounds in northern Quebec and Labrador by mid-April. A day of winter birding,
especially along the Lake Ontario plains, usually turns up one of these birds.
Shrikes
represent an example of convergent evolution. They are songbirds, their DNA
placing them between flycatchers and vireos on our checklist, but they fill a
carnivorous ecological niche similar to that of hawks and owls. Just like that
of our smallest hawk, the kestrel, the shrike's diet is made up of large
insects, small rodents and other birds. To serve that diet shrikes are armed
with their down-curved hawk-like beak.
Northern
Shrike with a Downy Woodpecker
photo by
Dave Spier
(See also Spier's blogs and an additional photo
site.)
We
have become accustomed nowadays to television pictures on nature programs of
carnivores killing their prey, but for most of us watching a shrike fly after
and catch a small bird like a goldfinch, drive it to the ground and sever its
spine with a sharp blow is still not a pleasant experience. But that is the
role of this species.
Many
years ago in Rochester a group of us went to a home where a shrike had been
reported. As we walked along the side of the house, the shrike suddenly dashed
directly toward us around the corner. In its talons hung a beautiful male
cardinal, then a rare bird in the north. Seeing us, the shrike quickly veered
and flew off with one of the dead cardinal's red wings still hanging open. The
homeowners had witnessed the shrike swoop in, quickly dispatch the cardinal and
carry it off their feeder tray.
The
shrike has a unique habit: it impales prey it has not totally consumed on a
thorn or caches it in a twig crotch for later consumption. I once was surprised
to see a chickadee feeding on a dead junco that was cached in this way. Clearly
proteins come where you find them.
So
those of you with feeders, be on the lookout for these so-called butcherbirds.
I have already had reports of them this winter visiting regional feeders - as
if you don't already have enough trouble with sharp-shinned and Cooper's hawks
taking your chickadees and finches.
I
urge you not to dislike these uncommon birds. Like everything on earth, they have
their largely predetermined life role. In fact it is we who upset nature by
setting out dickeybird feeders and in the process creating these perfect
smorgasbords for hawks and shrikes.
The
closely related and difficult to distinguish Loggerhead shrike, a bird of the
south, occurs here very rarely in summer. A pair formerly nested on my in-laws'
property in northern Alabama and Bill Watson and I saw one of the dozen or so
recorded locally over the past twenty years at the Iroquois National Wildlife
Refuge. Now this species' population is being augmented by a project north of
Toronto and hopefully we will someday see a few of those birds migrating
through our region.-- Gerry
Rising
Note: Rich Guthrie has written an interesting column about shrikes. You can find it at his blog.