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Harbingers of
Climate Change
Acreek runs just below my house in Little Rock,
and from the trees along it I often hear the
buzzy call of an Eastern Phoebe. Despite its
drab gray plumage, this small flycatcher is popular
even among casual birdwatchers, both for its propensity
to nest near (and even on) our houses and for its
helpful habit of constantly identifying itself with its call: a
scratchy, insistent fee-bee.
In the past, I would have expected to hear the
phoebe less and less frequently as fall progressed.
Most birds in the flycatcher family flee our winter for the
tropics, where the invertebrates they eat aren’t stilled by
cold weather.
Something has changed, though. Now, even
in winter, I often hear that buzzy fee-bee in
the woods. To confirm my anecdotal
experience, I checked the past
five decades of records
of the Little Rock
The Blackthroated
Blue Warbler
is expected
to lose a
significant
amount of its
prime habitat.
Illustration by David Sibley
www.wilderness.org
By MEL WHITE
Christmas Bird Count (CBC), one of a series of midwinter
censuses held across the continent. Sure enough, from
typical Eastern Phoebe counts of zero or one in the 1960s
and 1970s, the most recent decade has seen an average
count of seven, including a high of 13.
Our lingering phoebes hardly rank as an aberration.
A 2009 report from the National Audubon Society
analyzed four decades of CBC data and determined
that 58 percent of bird species had shifted their winter
ranges northward; more than 60 species were found to
be wintering more than 100 miles north of their historical
ranges. While factors such as increased bird feeding
may play a part, sunflower seeds alone can’t explain this
phenomenon.
Something has changed, all right: We’re experiencing
a long-term trend of higher temperatures, and
birds are reflecting that fact in their practical responses.
Migration requires energy and brings multiple dangers.
If a bird can travel south in fall only 500 miles instead of
800 and still find the food, habitat, and survivable climate
it needs, why should it go farther? If earlier-warming
spring temperatures stir a Gray Catbird wintering
on the Gulf Coast, why shouldn’t it fly north
toward its Ontario home and get a head
start on nesting?
With so much else to worry
about regarding climate change,
some might look at birds
and ask: Is there a problem
here? Carolina Wrens
now nest in upstate
New York, where they
once weren’t found. People in
Alabama will see fewer Purple Finches in
winter, but people in Michigan will see more. Species
get in the elevator, move up a floor, and live happily ever
after. Right?
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