STORY A:
THE ECOLOGY OF
FEAR
FOR DEER IN WASHINGTON STATE, LIFE
HAS BEEN PRETTY EASY.
Justin Delinger: The deer typically sleep until
about 9, they’ll hit the snooze a few times. …
They’ll get up, groom themselves, have a little
breakfast. Take a mid-day nap. … It’s kinda
nice. I like it. (Smiling)
BUT LIFE IS ABOUT TO GET A LOT LESS
COMFORTABLE FOR THESE DEER.
WOLVES HAVE RETURNED TO
WASHINGTON STATE FOR THE FIRST TIME
IN ALMOST 80 YEARS. AND DEER TOP THE
MENU.
WHILE THAT MIGHT MEAN A REDUCTION
IN THE DEER POPULATION, THE FEAR
WOLVES SPREAD CAN HAVE SURPRISING
BENEFITS FOR THE LARGER ECOSYSTEM.
AARON WIRSING STUDIES PREDATOR–
PREY RELATIONSHIPS FOR THE
UNIVERSITY OF WASHINGTON. HE AND
HIS GRAD STUDENT JUSTIN DELINGER
HAVE UNDERTAKEN A LONGTERM STUDY
TO LEARN HOW DEER’S FEAR OF
WOLVES CAN IMPACT PLANT
COMMUNITIES IN THE CASCADE
MOUNTAINS OF EASTERN WASHINGTON.
HISTORICALLY, AS MANY AS 400,000
GRAY WOLVES MAY HAVE INHABITED
THE WEST. BUT BY 1930, HUNTING AND
HABITAT LOSS HAD VIRTUALLY WIPED
THEM OUT.
Wirsing: For the next 80 years or so, this top
predator was completely absent from the vast
majority of the landscape.
BUT IN 1995, GRAY WOLVES WERE
REINTRODUCED TO YELLOWSTONE AND
NEARBY IDAHO. THEY’VE SINCE SPREAD
ACROSS THE WEST AND THE
POPULATION HAS GROWN TO MORE
THAN 1,600 INDIVIDUALS.
THE CASCADE MOUNTAINS ARE ONE OF
JUST A HANDFUL OF PLACES IN NORTH
AMERICA CAPABLE OF SUPPORTING
LARGE CARNIVORES LIKE WOLVES,
COUGARS AND BEARS.
TEN DOCUMENTED WOLF PACKS NOW
ROAM THESE WOODS. BUT IT’S STILL
JUST A SMALL FRACTION OF THEIR
HISTORIC NUMBERS.
Wirsing: At present we live in a world where big
predators globally are largely missing. And that
has very important consequences for the
structure of natural ecosystems.
WIRSING LEARNED THIS LESSON FIRST
HAND WHILE STUDYING TIGER SHARKS IN
THE WATERS OF WESTERN AUSTRALIA.
HE FOUND THAT WHEN MARINE
MAMMALS CHANGED THEIR FORAGING
BEHAVIORS TO AVOID BEING EATEN BY
THE SHARKS, IT ALLOWED SEAGRASS TO
FLOURISH.
AND HEALTHY SEAGRASS BEDS MEANS
INCREASED BIODIVERSITY – INCLUDING
MORE FISH AND OTHER SEA CREATURES.
Wirsing: My work with tiger sharks got me
thinking about whether top terrestrial
carnivores like wolves might have similar
effects on vegetation.
TO FIND OUT, WIRSING TURNED TO THE
FORESTS OF EASTERN WASHINGTON.
SINCE 2012, WIRSING AND DELINGER
HAVE CAPTURED MORE THAN 40 MULE
AND WHITETAIL DEER AND OUTFITTED
MANY WITH CAMERAS.
Delinger: It goes the long way, so the animal is
sort of pinned in.
Wirsing: Right.
AND BY PEERING INTO THE DAILY LIVES
OF DEER IN AREAS WITH AND WITHOUT
WOLVES, WIRSING HOPES TO GET AN UPCLOSE LOOK AT HOW WOLVES ALTER
DEER BEHAVIOR.
Wirsing: We're instrumenting them with a collar
that features a camera that sits on their chest
and records everything they see. We actually
have a window into exactly what the deer is
doing at every moment.
And that provides the kinds of insights that you
couldn’t get any other way.
( bird calls)
WHEN LIVING AMONG WOLVES, PREY
SPECIES LIKE DEER AND ELK BECOME
MORE RECLUSIVE. AND THAT CAN CAUSE
A CHAIN REACTION WITH FAR-REACHING
IMPACTS.
SCIENTISTS NOTICED THIS CONNECTION
AFTER WOLVES WERE REINTRODUCED
TO YELLOWSTONE IN 1995.
SINCE THEIR RETURN, ASPENS AND
WILLOWS ARE HEALTHIER, GRASSES
ARE TALLER , AND BEAVER, BISON AND
SONGBIRD POPULATIONS HAVE
INCREASED.
BUT JUST BECAUSE WOLVES CHANGED
THE LANDSCAPE IN ONE PLACE, DOES
THAT MEAN IT WILL HAPPEN
EVERYWHERE THEY APPEAR?
WIRSING AND DELINGER THINK THAT
SEEING THINGS FROM THE DEER’S POINT
OF VIEW COULD BE KEY TO ANSWERING
THIS QUESTION.
Justin: I think the most surprising thing is how
individual these deer are. It’s like a lot of
people. You get somebody that’s really high
strung or you get somebody that’s really
mellow
Wirsing: I love how you get in there and you
can actually see them nibbling the lichen. The
deer leans down to eat and the camera pans
down with it so you can get every single bite,
and when it leans up – you get a really good
panoramic view of its surrounding. That’s really
cool.
Wirsing: With this camera footage, we can
basically discriminate between the times the
deer have their head down snooping around for
food and when they have their head up in alert
position looking around. … Our deployments
so far are beginning to paint the picture that if
you’re a deer in a landscape that is being
hunted by wolves, you need to spend a lot of
time with your ears perked up and your eyes
peeled looking around for these animals,
because of course you don’t want to let the
wolves get too close.
We’re learning that probably the majority of the
impact predators have on prey species and
ecosystems is by being what we call an agent
of intimidation or in other words a threat.
By merely being a threat, predators can affect
entire prey populations, inducing many different
individuals to play it safe. And when the entire
prey population plays it safe, that’s an entire
population of deer that aren’t eating as many
plants and that can have huge benefits to plant
communities.
AND WHEN PLANTS THRIVE, THE ENTIRE
ECOSYSTEM BECOMES MORE ROBUST.
Wirsing : What we’ve learned as scientists over
the past several decades is that ecosystems
are more diverse when you have top predators.
And it’s entirely possible we’ll see the same
type of thing in Washington now that wolves
are back on the landscape.
BUT AS WOLVES RECOLONIZE THE WEST,
THEY ARE SOWING FEAR FAR BEYOND
THE FOREST.
MANY PEOPLE SEE THEM AS A THREAT
TO LIVESTOCK OR PETS. AND STATES
LIKE WYOMING, IDAHO AND MONTANA
HAVE RECENTLY ALLOWED WOLVES TO
BE HUNTED.
Wirsing : The number one factor today
determining whether wolf populations will be
successful or not is wolf tolerance. To some
extent, the negative attitudes humans have
toward wolves are a function of misinformation.
AND IT’S NOT JUST WOLVES. LARGE
PREDATORS AROUND THE WORLD HAVE
BEEN VILLAINIZED, WHEN IN FACT THEY
CAN HAVE A POSITIVE IMPACT ON THE
WILDERNESS WE LOVE.
Wirsing : That makes studies like the one I’m
conducting, on wolves and deer, especially
important . The more we understand the role
that the big predators play, the better the
argument we can make for the case for
protecting them.
QUEST SPOTLIGHT
BUMP: :05
( music )