not long ago most of earth was covered
in vast wilderness rich in biodiversity
as human populations expand habitats are
shrinking and becoming more fragmented
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many animals now face a new kind of
struggle to survive
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how can we protect the wildlife and wild
places that remain
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one of the foundations of conservation
now being applied across the world began
with the dreams of a young boy in Mobile
Alabama and of all things his love for
ants
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the great thing about living an old mold
bill when I was a boy was I could in any
direction be within 20 30 minutes of
natural areas some of them quite still
wild I could study butterflies I could
collect snakes I could learn everything
and I did it usually all by myself as a
kid but when Wilson was just 7 years old
a terrible accident changed the course
of his life I was fishing one day for
pinfish I pull one up too fast his sharp
needle-like fin hit my right eye and
ultimately I was blinded so I would grow
up from then on with vision and only one
eye but what I did discover was I have
an unusual acuity and my remaining eye
so I picked the subject I wanted to
study insects it never occurred to me
that I would ever be anything but a
naturalist entomology insects that was
my thing
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one group of insects would take Wilson
from the backwoods of Alabama all the
way to graduate school at Harvard
University answer the dominant insect
species on earth but when I started my
career we really didn't know much about
them in 1951 when I went up to Harvard I
knew I would make them the subject of my
doctoral thesis and ever since I placed
ants at the center of my professional
life the focus of a near obsession in
1955 Wilson embarked on his first great
adventure to collect and identify
insects across islands in the South
Pacific it was during that period of
exploration I was also thinking about
why different islands have different
species and different numbers of species
Wilson tallied the number of ant species
on each Island and when he plotted them
against the area of the island he
noticed an interesting relationship an
island that was ten times bigger and had
twice as many species
on Islands elsewhere reptiles and
amphibians showed a similar relationship
there actually was rules mathematical
regularity that nobody up until the
1960s have tried to reason out why it
was like that Wilson discovered what he
called a rule of thumb a general
relationship between the number of
species on an island in its area if this
rule was indeed general Wilson figured
that if all the species were removed
from an island then the same number of
species might repopulate it but how
could he test that he suddenly
remembered an extraordinary event
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on August 27th 1883 one of the greatest
volcanic eruption ever recorded laid
waste to the Indonesian island of
Krakatoa life on the island had been
completely wiped out that tragic event
made Krakatoa the perfect laboratory in
which to find out how species colonized
and recreated an ecosystem for decades
after the eruption naturalist recorded
the birds that returned to the
devastated island
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based on the number of bird species on
other Pacific Islands Wilson predicted
the number of species that would
repopulate Krakatoa a data from The
Naturalist matched his prediction but
they had a dog on me how many lifetimes
are gonna shake to really have
replications of this experiment a rare
event like Krakatoa was unlikely to
happen during Wilson's life he needed a
way to test the species area rule in a
controlled experiment though I decided
to create my own mini Krakatoa in the
Florida Keys we went down to Florida to
Florida Bay where there are thousands of
little mangrove islands little dots on
the map
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mostly insects lived on these mangrove
Islands if Wilson and his graduate
student Daniel sim brolof could
obliterate all the insects on the tiny
islands they could observe the species
that returned
we got an exterminator from Miami we
covered a number of islands so they
could be fumigated by the same technique
used to fumigate warehouses in order to
eliminate all of the creatures on this
little island please don't think of me
the destroyer of a biodiversity within
several months most of the islands were
crawling with a similar number of
species as before the fumigation
remarkably they filled up with species
but they were mostly different species
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simmer off also tested what happened
when animals were restricted to a
smaller area to do that he sawed off
parts of mangroves as an island got
smaller the number of species decreased
just as the species area rule predicted
the result strikingly confirmed our
hypothesis we figured out how to predict
the number of species that will arrive
and live on an island Wilson thought
that the lessons from these tiny islands
had very big implications the world can
be viewed as a series of islands
fragmented by human beings
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farms roads and towns are steadily
shrinking Earth's remaining natural
habitats creating islands in a sea of
humanity do these islands on land behave
the same way as Wilson's tiny mangrove
islands to find out in 1979 conservation
scientists launched a landmark
experiment in the Amazon by carving the
rainforest into different sized patches
and monitoring biodiversity one of the
most important things that the project
found is that these fragments really do
work as islands they function as islands
of forest that's surrounded by pasture
the effects of fragmentation are really
strongly felt by the monkey species they
spend all their day day and night up in
the trees it's very rare to see them
come to the ground and when you start to
isolate the forests resulting in these
forest fragments then these monkeys
basically get stuck in there
there are only two or three species in
these little islands as opposed to six
in the continuous uncut forest the
smaller forest patches supported fewer
species but the experiment also revealed
an important new finding something
Wilson could not have seen on his
mangrove Islands that only contained
tiny animals the larger species are more
affected just because they have larger
range requirements they need much more
area so things like Jaguars harpy eagles
spider monkeys when the forest is cut
and then we leave these little isolates
of fragments then we start to see some
of the species dying out the Amazon
experiment sounded an alarm
it showed that shrinking a habitat has a
greater effect on larger animals
conservationists elsewhere such as in
the Rocky Mountains
we're also discovering just how much
area some animals need
so we had this wolf called Louie the
wolf she started just below Banff
National Park and she moved a hundred
thousand square kilometers
she moved across two provinces three
states 30 different jurisdictions it was
that kind of movement of animals that
caused conservationists and scientists
to go wow we're not really thinking at
the right scale biologists realized that
even national parks might not be big
enough to support species with large
home ranges wildlife particularly bigger
animals they need room to roam well they
can't do that if there's too many human
activities and if they don't have the
ability to move through that sea of
humanity but if protected areas are
hemmed in how can you make them any
bigger I work for an organization that's
called the Yellowstone to Yukon
conservation initiative it was founded
in 1993 with a vision of connecting and
protecting habitats from down in Wyoming
all the way to the Arctic Circle in the
Yukon a 3200 kilometer stretch of land
one-way y2y reconnects existing
protected habitats is by purchasing land
to create a wildlife corridor
a larger continuous wilderness through
which animals can move our challenge in
order to conserve these species over the
long term is to make sure that we
resolve those potentially fragmenting
areas and try and reconnect them and
keep them connected
another important way to link habitats
is taking place on indigenous land in
western Montana we're here at the south
end of the Flathead Indian Reservation
this is the area where highway 93 cuts
through a really continuous block of
forested area highway 93 is a pretty big
barrier with a lot of traffic and so
previously animals had to try to run
across this highway the Confederated
Salish and Kootenai tribes with the
wildlife biologists here successfully
lobbied for the construction of bridges
and passages to connect habitats severed
by highway 93 we're in a really unique
area because we have the overpass over
here that allows animals to walk over
the highway and then we also have
associated under passes here the let
species walk under now that we've come
into the underpass the sound is
different the traffic volume is kind of
loud but when you get in here it's
muffled it's not as loud you can hear
the creek running through the middle it
sounds more natural in the middle of the
summer wildlife will just lay in these
things for hours they'll be drinking
water they'll just be resting they can
see things coming toward them so they
have some ability to see predators
approaching and it's just kind of cozy
for now
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a crossing structure like this makes a
connection between those two patches of
land so that animals can move through
and essentially makes them one big area
tracking which animals use them is a
measure of the project success I'm
sending up one of our wildlife trail
cameras on the overpass these cameras
are great and they're really useful
because they pick up motion that's what
sets them off and sets them to take
photos
we get mountain lions walking through
this structure black bear
Bobcats white-tailed deer in the why do
I region today we have at least a
hundred and six wildlife crossing
structures overpasses and under passes
that are dedicated for wildlife it's one
of the most robust crossing systems in
any landscape in the world
because of the efforts of communities
living alongside the wildlife the
species in this region have the room to
roam wildlife moving across the
landscape has a cultural value that we
care the wildlife that we're connected
to as a tribal people safely flow across
the landscape that we think about their
energy their species their young being
able to disperse all over so this was
really a mix of science politics and
tribal culture values that made what we
have here so special and so important to
our people
insights that began with ants on faraway
islands are now guiding efforts to
protect species great and small across
the globe
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in all my work now I want to drive home
to people just how complex the natural
world is and just how precious how much
there is still to be discovered and how
urgent it is that we conserve what is
left to us
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