documentaries if you have I’m pretty
sure that at least one you’d have seen
at least one scene where a large
predator or Pierce as the villain maybe
if you’re lucky you hadn’t seen the
predator as the protagonist of the
narrative but there is one untold
chapter in this age-old conflict between
hunter and hunted and it is the most
important story of all it’s the story
from the prospective of the entire
ecosystem simply put ecosystems are
controlled from the top down with
predators acting as the linchpins and
gears without them if ecosystems would
gradually become impoverished 1-port got
the message before most other people did
in his poem the bloody fire Robinson
Jeffers acknowledged the role of
violence in shaping our world the very
first examples he uses involve the arms
race between predator and prey predation
is one of the most important of all
evolutionary forces and a major cause
behind the diversity of life on earth
but the Predators fangs only begin to
gauge the full force which bite the fear
of those fangs are even more potent
force on each oh the fear can influence
where animals will be and how they
behave simply because they are afraid of
being eaten this makes predators the
unwitting guardians of their habitats
perhaps the best known example of this
phenomenon which is known as a trophic
cascade happened in Yellowstone National
Park wolf fur eliminated from
Yellowstone in 1930s in a misguided
attempt to protect our wildlife but in
the 1990s wolf through reintroduced and
what happened afterwards if no legendary
throughout the scientific community soon
after the wolf to return from the
unexpected
it began to happen young aspen
cottonwoods and willows began to grow
while many causes played the role in the
disappearance of E streamside trees the
biggest factor was one no park manager
would ever dress it was the
overpopulation of elk now that one of
the top predators was back the elk were
being held back once more but recent
research indicates that while the elk
populations did drop the drop by itself
was not significant enough to cause to
stop their damage by itself there was
another factor associated with returning
wolves that factor was here Rauf
pointing success rate depend greatly on
the terrain or on slopes and or on thick
vegetation herbivores animals cannot
gain of PT bait the walks it is
therefore advantageous for the prey to
keep visitors short and rare which
leaves them in less time to deport
devour the sprouting trees this change
in the tray behavior didn’t end with the
new growth it has a cascading effect
hence the term trophic cascade with more
trees more rich held of screen together
reducing erosion the growth of plant
cover combined with the rise in insect
populations a lot bird populations to
increase beavers also benefited from the
newly emerging role of stench and their
dams created habitat for more species to
influence a wolf has in a highly
polarized topic mostly due to prejudice
from hundreds and ranchers and it’s
often understated or even download deny
even today perf this is that ecosystems
are complex things and so scientists
criticize an emphasis on any individual
factor Oberyn another but it still
remains the case that the wolf is one of
the most influential ecological forces
in the West elsewhere mountain lions
have also have had a similar impact in
Zion National Park the same researchers
who studied Yellowstone’s wolf cascade
have also found evidence of Pumas doing
the same
in-sine canyon itself where Pumas have
been eliminated the population density
of ear is unnaturally high and many are
showing signs of malnutrition there are
only a few hardy species vegetation
growing and the riverbanks of Aaron in
comparison another Canyon within the
same part which is shown on the left
still has a high density of Pumas and
there is also greater density and a
greater diversity of plant and animal
life on the canyon bottom on the other
side of the world under the study shows
that trophic cascade can also take place
under the water Western Australia has
one of the last healthy seagrass pains
in the world and in an Iowa and in an
eerie parallel to the wolf of
Yellowstone tiger sharks in fittingly
named shark bay or the guardians of
these planes and its smallest
inhabitants dugongs which of the Pacific
relatives or manatees grazin seagrass
and they can destroy large patches of it
but when tiger sharks are present they
avoid digging into this into the sand to
dig out the route because this makes
them borrow up to shark attack not only
that both dugongs and dolphins as well
as seaters up desert the shallows where
they prefer to eat instead sticking to
deeper waters where they can see sharks
coming in comparison sea snakes prefer
to head the opposite way into the
shallows to heighten sharks when tiger
sharks are absent also named pls pc come
even is spread out it is the fear of
sharks the dick teach when and where or
given species who eat meaning this and
this in turn determines the structure of
the entire ecosystem the impact of
sharks is even greater in coral reefs in
every single pristine read that has been
sampled by scientist the biomass of
prisoners is five times the biomass of
their prey it will seem unlikely that
such an ecosystem as shown here could
ever exist but there’s a simple answer
the lower on the food chain of
population is the faster in replaces
itself therefore the prey fish please
fasten three large fish that eat them in
the large fish weed
from the top predators this rapid
replenishment rate would lead to prey
species take over running the reef
ignore the fact predators constantly
kept them down it’s important to note
that the Predators are having such an
impact on the planet despite the fact we
had drastically reduced their numbers
how great ordered for influence p is the
fourth set of modern predators was here
that president dude that falls that
included the three animals that they’re
showing up showing off in on the screen
there’s favoritest cat the marsupial
lion and a giant carnivorous lizard we
usually don’t think of them as modern
animals because we don’t see them in
modern ecosystems anymore but they are
and they belong in today the majority of
extinct I see general 20 were killed off
by human activities and not because of
natural causes as many people assume
they lived in modern ecosystems that are
still around and he lived with modern
species that restaurant including
ourselves the parents of extinction the
parents of extinction revealed a natural
climate change can’t possibly have been
the cause behind the most extinctions
I’ve seen here large animals die die out
when humans invade regardless of whether
the climate was changing or not in fact
many of the animals that should have
benefited from a warming climate also
went extinct at this time furthermore a
large number supposed to natural changes
that occur to ecosystems at these times
are not about typing caused by humans it
doesn’t actually take much for even a
small human population to have a make a
dent in the water I population it’s
really since we do more than just hunt
animals we can also change habitat now
you might be wondering what does this
have to do with trophic cascade well
because the well this means that on
every continent except Africa and parts
of Asia where megafauna evolved
alongside hunters that use peers and
fire none of the ecosystem sunland
actually have all the necessary
components it leaves many of their hurry
borders without most of their
predators which is the fed up or trophic
cascade and this time to resort to
catastrophic the evolution of large
animals worldwide has mostly stopped
there are no forces pushing for further
evolution anymore this comes at the
obvious expense of the ecosphere there
will be no replacement in the far future
millions of years from now for the
animals that we are turning of today
their future ecosystems will be
uninspiring unstable and prone to
collapse on a more short-term view loss
of multiple species means that the role
of keystone predator foster on your hand
for them meaning the ecosystem as a
whole is much less resilient for example
in North America still had saber-tooth
cat the job of controlling bison
populations will be much better feel
than it is right now then again it could
have been worse we could have lost a few
predators that still we still have today
except that things seem headed that way
today even if some predator regaining
lost ground anti-predator sentiment is
rising once more worldwide hundreds of
thousands of vehicles bullets traps and
personnel or used to kill predators or
the auto hatred or to earn money almost
every large player in the world world is
losing ground to humanity despite the
fact wars in the lower 40s have regained
less than five percent of your natural
range keep her treating them as if they
are far more common than they used to be
and their slots trying to swallow them
again as seen in the recent case where
the profanity spac in Oregon was killed
off shirts are being killed in a raid at
eleven thousand four hundred and
seventeen every hour with no sign of
this slowing down anytime soon and there
are even some animal rights activists
and philosophers who believe it killing
all predators or facing forcing them to
survive on nothing but plan it’s a
better option than protecting them they
see
servation is increasing the net amount
of suffering because they think
ecosystems are evil they believe animals
are better off dead and not suffering
then as part of functioning ecosystems
the abolitionist project headed by David
Pierce in particular seeks to eliminate
all predators in the name of producing
sources of pain but would that really
reduce the amount of suffering that
happens or as we have seen would that
actually increase the amount of
suffering more importantly is it really
justified is suffering the only more
concerned that matters here I don’t
think so if he lose the monsters that
once ruled this world we might lose more
than the ecosystems a living we might
lose a perv ourselves think about these
questions how many of the great thinkers
of the human hit of human history have
experienced the natural world how strong
is the natural world in human size and
most importantly what does it mean for
humans if we caused the destruction to
bury forces and led to us existing in
the first place but there are ways we
can help so we never have to worry about
these questions ever the following
organizations up on the screen or some
organizations that are working
specifically for predator conservation
predator defense predator conservation
and keep on carbs three organizations
work in North America to reduce predator
persecution and stop anti-predator
legislation and for fans marine
carnivores there is shark savers and
national Geographics pristine cease
project and remember what is what most
people perceive as negative or evil what
is purified by many is often the exact
opposite in its effect the great paradox
of the Predators is that they enrich
life not only because they help
ecosystems but because of your spiritual
value I personally miss the
fact that wolves and mountain life used
to be found right here in Niagara and
i’m guessing the many in this audience
who probably agree with me life isn’t
about avoiding suffering license about
experiencing diversity and being
connected to the rest of the world to
let all recognize just how much the
so-called villains of our world really
matter let’s do everything in our power
to restore track them to full glory
thank
[Applause]
[Music]
[Applause] you