Glimpses
of sunshine were hard to find over the past few days. So low and heavy were the
damp, gray clouds that I worried they might crush my soul. We’ve had a few nice
days, though, and a week ago I was biking 30-40 miles per day on dryer, warmer
roads. On those days, despite gray clouds, flickers of sunshine abounded.
Or
rather, flickers themselves abounded. Northern flickers are one of our few
migratory woodpeckers (sapsuckers are another), and as flocks of them swirl
north on the leading edge of spring, they bring flashes of color to the
landscape. You have to wait for it, though. Their backs are muted tan with
black checks that blend in perfectly with the dried grass now carpeting road
ditches. I almost never see one on the ground. It’s a delightful surprise,
then, when they suddenly flush ahead of your car or bike and swoop into the
woods with flashing bursts of gold. The yellow feathers on the undersides of
their wings are secret bits of sunshine.
Why
are these woodpeckers on the ground, anyway? That’s not where we spot downies,
hairies, pileateds, and our other woodpeckers. In a little twist of habit,
flickers use their long, pointed bills and their even longer barbed tongues to
probe the ground and lap up ants. They also munch on beetles, flies, butterflies,
moths, caterpillars, snails, and fruit.
As
I zoom past on my bike, the flickers often give a squeaky “skew” as they
startle, and then shout their kikikiki alarm calls from back in the trees.
These sounds are also used as part of their mating ritual and to defend the
area surrounding their nest. That’s enough of a responsibility to make their
calls a significant part of the symphony of spring, but they’ve also learned to
choose their battles.
Unlike
many other animals, flickers don’t defend an extensive feeding territory from
their neighbors. In 2003, a couple of scientists from Saskatchewan worked out
the “calculations” behind this behavior. It all comes back to the ants.
Some
ants live in huge anthills full of thousands of individuals. You’d think that
would be a valuable bonanza for a pair of flickers to claim for their own.
Unfortunately, the types of ants who live in huge colonies are also the most
aggressive species, and according to the researchers, they are “unpalatable
prey.” If you’ve ever disturbed one of those big anthills and been bitten, you
might agree. Now imagine putting your face down in there!
The
more docile ants who make up 45% of flickers’ diets live in smaller, ephemeral
anthills. These anthills are easily washed away by rainstorms. After a short
rainstorm, the ants are back to rebuilding within just a couple of hours. During
several days of rain, though, they avoid coming to the surface. Even when it’s
not raining, the ants are sensitive to high temperatures because their tiny
bodies dry out quickly. So, in both rain and heat, they remain out of view
underground.
Northern flickers are woodpeckers who spend much of their time foraging for ants on the ground. Photo by Larry Stone. |
The
upshot of all this ant behavior is that flickers need to be able to forage
throughout a wide home range—up to 1 mile in diameter—to make up for the
unpredictable nature of their favorite food. Defending a feeding territory
might result in them not having access to enough resources when the weather
turns foul. In addition, small anthills are easily overharvested. So, several
pairs of flickers may end up feeding in the same area based on the weather and consequent
availability of ants.
With
the cool, rainy weather and soggy ground, flickers probably can’t feed on ants
right now anyway. Luckily they can be flexible. Rainy day foods include insect
larvae, caterpillars, ant colonies under rocks, and the many things that crawl
around in cow pies.
So,
the flickers are probably just as eager to have some dry weather as I am. While
we wait, they are generous enough to share their beautiful colors and raise my
spirits with their flickering bits of sunshine.
Emily’s second book, Natural
Connections:
Dreaming of an Elfin Skimmer, is now available to purchase at www.cablemuseum.org/books and will soon be available at your local independent
bookstore, too.
For 50 years, the Cable Natural History Museum has served to
connect you to the Northwoods. Come visit us in Cable, WI! Our new Curiosity
Center kids’ exhibit is now open, and the Grand Opening is on May 25!
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