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HOW
DO HURRICANES AFFECT WILDLIFE?
by Whit Gibbons
September 26, 2004
This year's
hurricanes and associated tornados have left many people reeling with
personal losses of property, pets, and even lives. Homes, highways, and
entire communities have been destroyed. Clearly, hurricanes can be devastating
from a human perspective. But how do they affect our native wildlife?
The answer
is simple. The overall impact of hurricanes or other natural disasters,
such as earthquakes or forest fires, on natural ecosystems and wildlife
communities is minimal, compared to the way people can be affected. We
do not perceive wildlife as suffering the devastating effects from hurricanes
like people do as we measure impacts differently for wild animals than
we do for people. With people, and even with pets, we empathize with each
individual who suffers. We see dozens of examples on news channels of
someone stranded atop a car floating down a swollen river, people examining
the remains of their former home, or police searching for a missing person.
With wild animals, we may hear of a few stories of the plight of individual
animals, but for the most part we are concerned with how the whole population
fared. Few people care about the fate of a single mockingbird as long
as plenty are around to sing in the spring. And a hurricane will not change
that as long as healthy populations of mockingbirds are already present.
On another
scale, few animals have "personal property" that can be lost
in a hurricane. All a possum or lizard has to do is survive. One group
of animals that do have structural assets are birds with nests. But most
hurricanes occur in late summer and fall, a time when relatively few birds
have nests in trees that can be blown down. Hurricane season is stated
as being officially from June through November, but only about 10% occur
before August, and more than half occur in September and October. In keeping
with nature not being bound by man-made rules, three officially designated
hurricanes have occurred outside the declared season, two in May and one
in December.
Among other
property losses by wildlife, beavers probably lose dams due to powerful
flooding associated with hurricanes. But in keeping with being beavers,
they simply set about repairing the damage as soon as the water level
declines, with little overall effect on their lives. Gopher tortoises,
the big turtles of the Southeast, that make their homes in deep burrows
they dig into sandy areas can have flooding damage from a hurricane. But
their homes become livable again as the water subsides, and some tortoises
may actually move to another burrow.
Despite
the timing of hurricanes on a seasonal or annual basis, the ancestors
of all our native wildlife evolved to deal with them. On a few trips over
the years to coastal areas to see incoming hurricanes, I have observed
some of the approaches used by native plants and wild animals to weather
the storms. Palm trees with their type B personalities will bend like
fishing poles, becoming parallel with the ground against awesome winds.
Oak trees rely on brute strength that works for moderately high winds,
but even the biggest cannot persist against category four or five hurricanes.
During Hurricane
David many years ago, Steve Bennett, Garfield Keaton, and I were the lone
inhabitants of Kiawah Island when the storm came ashore with category
one winds, which were enough to get our attention. We noticed that the
underbrush of bushes was alive with shorebirds that hunkered down beneath
them. Occasionally, one would try to fly, reach a height of four feet,
and immediately disappear inland at 75 miles an hour. A few individual
birds no doubt perished, but the long-term damage to native shorebird
bird populations was minimal.
Hurricanes
do not significantly affect wildlife, and clearly no type of wildlife
has any effect on hurricanes. But do people have an effect on hurricanes?
The cause or even extent of climate change, aka global warming, purportedly
being brought about by carbon dioxide emissions emanating from industrial
countries like the United States, remains equivocal. But one thing for
sure is that a warmer ocean off the coast of Africa will create a spawning
ground for more powerful hurricanes than will a cooler ocean. It's called
cause and effect.
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