 (uplifting chiming music)
 (emotional orchestral music)
- [Narrator] Every year,
all around the world,
 our planet goes through some
 incredibly drastic changes.
 Mountains shed their leaves
 and gain caps of ice.
 Valleys thaw themselves
 and allow life to return.
 Entire lakes can
 appear overnight.
 Millions of animals travel
 for hundreds of miles.
The shifting of our
seasons can create some
of the most dramatic
stories to ever unfold.
 With this series, we're going
 to try and tell these stories
 and shine a light on
 both the pedestrian
 and the highly unusual
 transformations
that occur around us every year.
 On this first episode,
 we're going to take a look
 at spring in the
 wetlands of Wisconsin.
 The Lac Lawrann
 Nature Conservancy
 is a perfect stage for
 these stories to play out.
 Situated on the edge of the
 Milwaukee River in West Bend,
 Lac Lawrann is a 137
 acre nature preserve
with wetland, forests, prairies,
 and the glacial landscape
 that shaped most of Wisconsin.
 The Conservancy
 serves this refuge
 to over 300 species of plants,
 200 species of birds,
 and a wide variety
 of mammals, reptiles,
 and amphibians.
 Lac Lawrann was
 established in 1955
 by Lawrence and Ann Maurin.
At the time, it was a forgotten
and abused patch of land
 with a history of railroad
 and industrial use.
 The couple purchased
 it with the goal
 of returning it to
 its natural beauty.
 (emotional orchestral music)
 They spent 25 years
 working towards this end,
with fantastic results.
 It had become a sanctuary
 to the wildlife of the area
and one of the most
beautiful places around.
 The Maurins donated this land
 to the West Bend Park &amp;
 Forestry Department in 1979
 with the stipulation that it
 must be maintained as
 a nature conservancy.
 We'll be looking at many
 of this marsh's inhabitants
and how they interact
with the warmer weather
that returns with April,
 like how a certain
 wetland flower
 has evolved to flourish here
 and how many birds migrate
 back to these lands
 as the frosts recede.
 We'll also look at
 some of the creatures
 that hibernate here
 over the winter.
 And hopefully, through it all,
 we'll be able to truly see
and understand spring as
it affects the wetlands.
 Winter is a harsh and
 difficult time in the north.
 And though it may not
 seem like it at times,
 it does eventually
come to an end.
 (chirping)
 As spring arrives
 here in Wisconsin,
 the frosts of winter
 tend to linger a bit
 before giving way to our
 brighter, greener tomorrow.
 (bright peaceful
 orchestral music)
 Most plants can't
 grow until the snow
 has completely receded and
 the soil has fully thawed.
 But in our marshes and lakes,
 there are many ways
 that life carries on.
 Spring is a time of renewal,
 a time for nature to expand,
 rebuild, and flourish,
 and a time for it to recycle.
The natural world is a
very efficient machine.
Everything is reclaimed
with enough time.
 In fact, throughout the world,
 and especially here
 in the wetlands,
death is a crucial and
ubiquitous part of the process.
 Here in this stagnant
 pool of still water,
 we can see the intersection
 of life and death.
 To us humans, it looks like
 a pure pool of liquid decay
 because something
 deep inside of us
 knows that drinking
 it would be lethal.
 But to the millions
 of bugs, fungi,
 and microorganisms
 that thrive here,
 there couldn't be
 anything better:
 a perfect little cauldron
 for them to reclaim
 what other organisms
 had borrowed.
Water like this is also perfect
 for all kinds of plants
 that feed off of the rich,
 recently replenished soil,
 (optimistic orchestral music)
 plants like this duckweed
 that forms on top of the water
that thaws before much
of the ground around it.
Some grass is also able
 to grow through this warmer
 water early in the season.
 This here is a flower bud
 from a weird little plant
 known as skunk cabbage.
It's called that because
of the skunk-like odor
 that its flowers emit when
 they bloom or are damaged.
 The plant uses this
 odor to attract flies
 and other carrion-feeding
 pollinators to
 help it reproduce.
 It can grow this
 early in the year
 because it is a
 thermogenic plant.
 That means it can raise its
 temperature to help melt
 the frozen soil that would
 otherwise block its path.
It is one of only six known
plants that are capable of this.
 Another oddity of
 this little weirdo
 is that it grows
 down instead of up.
 It has what are known
 as contractile roots.
Every season, its roots pull it
 deeper into the soil
 as the stem grows,
 keeping the flower
 just at the surface
 as it burrows further down,
 eventually becoming almost
 impossible to remove.
 But plants aren't
 the only things
 that return in the spring.
 (splashing)
 (chirping)
 (ethereal orchestral music)
One of the many migratory birds
 that returns to Wisconsin's
 wetlands during the spring
 is the sandhill crane.
Despite weighing
up to 14 pounds,
 these greater sandhill cranes
 can soar for great
 distnces with ease
 due to their exceptionally
 large wingspans.
 Much like hawks and
 eagles, they make use
 of thermal updrafts to
 keep themselves afloat
with minimal exertion required.
 They return to this
 area every spring
 to nest around early April.
 Sandhill cranes mate for life.
 As they leave the
 care of their parents
 at around one year old, they
 form groups of juvenile cranes
 that will travel together
 until eventually pairing off
 anywhere from the
 ages of two to seven.
After they pair off,
they will start mating,
 producing a new clutch
 of eggs every year
for the rest of their
20-plus year lifespans.
 There is very little
 that distinguishes a male
 from a female of this species.
The easiest way to differentiate
a pair is by its size;
 the female will be smaller.
The adults are large
enough to defend against
 most of the predators that
 they might encounter here.
 But they are still
 hunted by a number
of large land predators,
 such as wolves,
 cougars, and bobcats.
 (peaceful orchestral music)
 The much more vulnerable young
 are hunted by many
 smaller predators,
 some that hunt the chicks,
 but many that hunt the eggs.
 Therefore, the adults rarely
 leave the nest while brooding.
 Despite all this,
 they're not shy.
 Mating pairs will participate
 in what is known
 as unison calling,
 where they will trumpet out
 a loud, distinctive melody
 that echoes hauntingly
 through the woods around them.
 (echoing bird calling)
 The pair here has its nest
 situated on a narrow strip
 of marsh between two hills
 at the edge of a lake,
 the perfect location
 to raise their young.
 Their last chick has
 already left them
and they have laid their
new clutch of eggs.
 They now stand guard,
 rarely allowing
 their precious young
 out of their sight.
 They have everything
 they need here,
 and will likely stay here
 until their new chick
is old enough to
leave with them.
 (emotional orchestral music)
One of the more familiar
migrating waterfowls
 is the Canada goose.
 With a range that spans
 through almost the entirety
 of North America,
 much of Europe,
and parts of
Australia, they are one
 of the most iconic migratory
 animals in the world.
 However, they were once a
 highly threatened species
 that needed to be brought back
 from the brink by
 human intervention.
 At the start of
 the 20th century,
loss of habitat and overhunting
had resulted in severe declines
in the population of
these now common birds.
 Today, their numbers
 have exploded so much
 that many regions are
 labeling them as pests
 for their aggressive
 behavior and overpopulation.
 They are an example of both
 successful conservancy efforts
 and mismanagement of wild
 populations at the same time.
 There are two major factors
 to the current success
 of the Canada goose.
 One is the lack of
 natural predators.
 Most of the animals that
 had previously hunted them
 are now much less prevalent,
 especially in the areas
that these geese
thrive the most.
 Which leads us to
 the second reason
 that they do so well today:
man-made landscapes offer ideal
conditions for them to live.
Well-maintained lawns,
man-made water features,
 and abundant food
 from human scraps:
 it all creates the perfect
 environment for these animals.
 This effect is so great that
 these normally migratory birds
have started to show a
major shift in behavior.
 Entire populations will stay
 in warmer climates
 all year round,
 no longer migrating and
 overpopulating very quickly,
 causing significant
 issues for the places
 in which they take up
 these permanent residences.
With their aggressive
behavior towards humans,
the toxicity of their waste,
and other disruptive behaviors,
they've become a major
problem for many areas.
 The USDA has even gone so far
as to start controlling
wild goose populations.
A mere hundred years after they
 were threatened with
 possible extinction,
 their numbers have
 become so great
 that we must again intervene,
 this time to bring
 them under control.
These population control efforts
 are aimed specifically
 at nonmigratory geese
 so as to not disturb
 the migration patterns
 of the birds that are
 behaving normally,
 and to avoid violating the
 Migratory Bird Treaty Act.
 (playful peaceful
 orchestral music)
 For the most part,
 here in Wisconsin,
 we only see the
 migratory individuals.
 It's too cold for
 them in the winter,
 so they head south every year,
 returning once the
 snows have melted
 and the waters have thawed.
 These are their
 breeding grounds.
 They make their nests on
 whatever bits of raised land
 they can find near
 a body of water.
 After laying their eggs,
 they usually start a molt
 that leaves them flightless
 until their chicks
are old enough to fly with them.
This could be part of the reason
 they become so aggressive
 around anything
 that approaches their young;
 neither of them can fly.
 Due to the conditions they
 look for when building a nest,
 they often run into another
 common resident of a marsh,
beavers.
 (peaceful orchestral music)
 Beavers were also once
 hunted nearly to extinction.
 Originally having a population
 of greater than 200 million,
 the North American beaver
was extirpated from much
of its native range.
 It wouldn't be here today
 without conservancy efforts
 taken in the mid to
 late 20th century.
They were one of the main causes
 for early expansion
 westward in North America,
 being highly prized
 for both their pelts
 and their castoreum,
 the musk glands
 they use to coat their fur,
 for medicines and perfumes.
Today, their population
has recovered
 to around 15
 million individuals,
 still a fraction of
 what it once was.
 Beavers are what are
 known as keystone species.
 Their presence has
 significant positive effects
 on the ecology of
 the area around them.
The ponds they create with
their dams provides new habitat
 for many wetland
 plants and animals.
 Areas in which beavers
 were reintroduced
 saw significant increases
 in biodiversity and often,
 the return of
 previously threatened
 or extirpated species.
The main purpose behind
their damming of rivers
 is to create water deep enough
in which to build their lodges.
 These lodges are where
 they store their food,
 raise their young, and stay
 warm through the winter.
These wetland bunkers
provide them protection
 from all varieties
 of would-be threats,
 the only entry requiring
 them to dive under water.
This is just one
of the many ways
 that local wildlife survives
 the deep freeze of the north.
 Painted turtles
 survive the icy cold
by burying themselves in the mud
 at the bottom of the
 ponds they live in.
 They hibernate through
 the winter months,
 slowing their bodily functions
to survive until
the next spring.
 As the warmth returns, they
 emerge from their mud burrows,
much like a flower
greeting the April sun.
 They spend most of their time
 in the early spring
 basking in this sun,
 their cold-blooded nature
 making them lethargic
 until it warms even further.
 If you look at them, they
 may seem pretty tough to eat,
 with their hard outer shells
 and retractable limbs,
but that doesn't stop
them from being hunted.
 Raccoons are capable
 of prying them
 from their protective
 shells, but the real danger
 comes from those
 who hunt their eggs.
 (ominous emotional
 orchestral music)
 (moves into optimistic
 orchestral music)
 Garter snakes are
 exceptionally common
 throughout North America.
 While completely
 harmless to humans,
 they do produce
 a very mild venom
 that they use to subdue any
 live prey they come across.
 In Wisconsin, we have a couple
of different subspecies
of garter snake,
 this one being the
 Plains garter snake.
 This particular subspecies
 is said to be one
 of the most cold-tolerant
 snakes on Earth,
 sometimes even
 exiting hibernation
on particularly warm winter days
 to bask in the sun
 for a little while.
 Before they enter hibernation,
 they will typically
 go without eating
 for a couple of weeks
 to prevent having food
 rot in their stomachs
 while they sleep.
They exit their communal
hibernation dens
around early April, and
will almost immediately
 start looking to mate.
The females will
emit a pheromone
that attracts all nearby males.
 This leads to some
 intense competition,
 and will sometimes
 result in mating balls
 of up to 25 competing males
 swarming a prospective mate.
 Their diet consists
 of anything they
can get their mouths
around, living or dead.
 That said, they generally
 prefer one food in particular:
 (croaking)
 amphibians.
 (peaceful energetic
 guitar music)
 These wood frogs are
 currently trying to mate.
 Common to most of the
 northern United States
 and Canada, wood frogs usually
 spend most of their lives
 near the pool where
 they were born.
They breed in temporary
pools like these
 so as to avoid the predatory
 fish and other aquatic animals
that exist in permanent
lakes and ponds.
 This means that their young
 must mature fast enough
for them to escape
before the pools dry up.
To help with this, wood
frogs exit hibernation
rather early in the
year, giving their young
 time to develop before the
 heat evaporates their home.
They have a particularly
high cold tolerance.
 During the winter, they will
 freeze completely solid,
 allowing even their
 blood to turn to ice.
 They keep just enough
 of their organs thawed
by producing a number of fluids
 with lower freezing points
 that pump through them,
just barely keeping them alive.
 The males will spend
 the early parts
of spring croaking in a chorus,
 hoping to draw the attention
 of a potential mate.
 They rely on the communities
 they're a part of
for a number of reasons,
like finding a mate
 and protecting their eggs
 by clumping them together.
But they're not the only animals
that rely on communities
in Wisconsin.
 (emotional orchestral music)
 By this time of the year,
white-tailed deer have
already finished mating.
 The females are now getting
 ready to give birth.
 They usually birth
 one to three fawns
 some time in late spring.
 For the first four
 weeks of their lives,
 they are unable to stand, and
 remain hidden in vegetation,
 being nursed only
 a few times a day
 to avoid detection
 from predators.
The deer here have also learned
to use the hiking trails
to be quieter as they
move through the forest.
 This is just one
 of the many stages
 upon which these
 stories play out.
 Every single day,
 (optimistic orchestral music)
 there are millions of
 these tales of life
 and death,
 played out where
 no one sees them.
 But it's all in a
 delicate balance.
 Much of what was seen
 here is the result
 of significant conservation
 efforts taken in the past,
 and many of these
 plants and animals
will likely go away if we
don't continue to protect them.
 Even the seasons themselves
 are starting to be disturbed.
 There is no longer a
 single place on the surface
 of the Earth that isn't
 affected by our pollution.
Microplastics carried in
the wind have been found
 on the most remote
 mountain tops known to man,
 and climate change
 is wreaking havoc
 across every ecosystem
 all around the world.
 Nature is where all of the
 world's beauty comes from,
 and we're still
 throwing it away.
This is the only Earth we have,
and it's not invincible.
 You hear about the terrible
 state of things like this
 all the time, and
 yet so few people
 actually try to do
 anything about it.
 We try to push off
 this responsibility,
 telling ourselves
 that we're not so bad,
 or that the changes
 we make won't matter.
 But this is going
 to take all of us.
 No one person, or government,
 or corporation let the
 world start to die.
 It's gonna take
 just as many people
to fix this as it did
to make things this bad.
 So now's the time to start.
 Even if it's a small change,
 something that
 doesn't take much,
 it's time to actually
 do something.
 Because if you don't,
 no one else will.
 On the next episode
 of Seeing Seasons,
we take a look at
summer in the mountains.
 (peaceful piano music)
