There was a time when myth and science were entwined
When mermaids and unicorns could mysteriously appear
And devilfish flew the oceans
Nature was weird
When science revealed the truth behind these imaginary creatures
it found real animals lay behind the legends
Today, science still makes astonishing discoveries
but nature seems just as weird
It's just that fact has broken free from fiction
In Weird Nature,
real animal behavior is set against human backdrops
They give us astonishing insights
The spiral tusk of the unicorn has been traced to a white whale
just as wonderful as the legend
The narwhal uses its twisted horns and jousts like a medieval knight
The mermaid's forked tail belongs to the dugong
Half seen its body and face can appear surprisingly human
The devilfish is a Manta ray
They leap to shed parasites and then briefly glide like phantom craft
Weird Nature takes you into a world
where imaginary human setting showcase animal behavior
that is absolutely real
What is weird is best defined when compared to our own lives
Our first weird journey shows the wonderful ways that animals move
Life began in the oceans
This imaginary wreck brings together some early forms of motion
Jellyfish are the only animal
to move by wafting water through a pulsating skirt
But such graceful jet propulsion is no match for the tides
A strange ancient mollusk improved the concept
The nautilus jets water through a siphon that can move to control direction
It controls depths by regulating gas in a series of buoyancy chambers in its shell
Flame scallops jet propel by clapping their shells like castanets
They jet water from either side of their hinge
They dance to escape predators or to find new places
The Spanish dancer's technique is more elegant
It flamingos by rippling the ribbons along its body
The frills of its costume are actually gills
and despite its romantic name,
it's really a sea slug
The seahorse can't move its armoured body in sinuous ways like other swimming fish
Instead, a fin that quivers 20 times a second whirls it around
Shimmering side fins act as steering propellers
Jointed legs were an exciting new movement in evolution
Spiny lobsters use them to conga
Their procession provides safety in numbers
as they move to deeper water to avoid winter storms
The slipstream from the leader cuts drag for those behind
Legs helped animals make the next evolutionary step
Today we prefer faster options
But legs have been invoked since the first amphibians crawled from the sea
They dragged their bodies along using four legs splayed to the side
In California, the Mt. Lyell salamander
uses its tail as a 5th leg to negotiate the Sierra Nevada mountianside
They are also special in more human terms
The wheel was hailed as one of our greatest inventions
But as these creatures prove,
we were simply reinventing it
Rolling is the quickest way down a hill
as this salamander has discovered
It's designed to flex like a rubber tyre so it doesn't feel the bumps
The pale moth caterpillar was common
but its talent for doing wheely is a new discovery
It rolls with its caterpillar track on the inside
Salamanders and caterpillars were born to rock'n'roll
so this behavior is second nature
The salamander's more normal motion
can cause problems for heavier creatures that move in the same way
For the early reptiles,
crawling along the ground was literally a drag
Crocodiles had an odd solution
Walking on stilts cuts friction on rough ground
but these flat feet have to rotate forward to take a step
It may be slow,
but it saves energy
and most crocs use this stiff-legged walk whenever the going gets rough
The Australian freshwater croc
shows an even strange gait when provoked by predators such as the saltwater croc
It gallops, but not like any other animal
Its front feet work together in opposite motion to the back
As the front feet hit the ground,
the back swing forward
when the back push away,
the front reach out
Galloping horses were once painted like this
In truth, only freshwater crocs run in this seesaw way
It can reach 15 miles an hour and easily lead to safety
Evolution has taken many weird twists and turns
Each year, 20 million leapers of a more playful kind
arrive in the world's toyshops from a tiny part of Mexico
The jumping bean is really the seed of a desert shrub
Only a few show this odd leaping
The seeds, imported as novelty toys
seem to have a mind of their own
There really is a mind behind the jumping
a moth caterpillar lives and feeds inside the seed
The caterpillars flip their home to escape
They not only feel the heat
light makes them jumpy
They fuss and fidget into the shade
This behavior is a lifesaver in the hot Mexican desert
The caterpillar repairs the damage by weaving a silken wall
It grips onto the silk wall when it leaps
and the shape of the bean helps it roll
For weirdness,
the Mexican jumping bean is hard to beat
But sifaka lemurs from Madagascar turn leaping into a surreal ballet
The secret of their graceful pogoing stems from a life in the trees
They can leap 30 metres with ease
These acrobatic skills have to be modified for the challenge of moving over the ground
The legs act as springs
and feet curled for gripping become landing pads
With no branches to grab the arms are free to act as stabilizers
Every move of the legs is complemented by a matching move of the arms
The balletic poses maintain perfect balance
Sifakas only show such bizarre and beautiful motion
because they evolved for a life in the trees
The same is true of the bushbaby
This time slice sequence shows the various poses of a bushbaby adopts as it jumps
It leaps 2.25 metres in height,
equivalent to us clearing two stacked double-decker buses
To achieve this, the legs and feet act like springs,
converting the energy of impact back into propulsion
It really does have a spring in its step
It waits until the peak of its jump before reaching out
Its tail acts as a counter balance
It's like a rubber ball with a brain
almost impossible for a predator to catch
This sequence freezes a bushbaby as it becomes airborne
But gliding animals specialise in prolonging their time in the air
The golden tree frog of Malaysia is a treetop acrobat
Usually it hops just a few metres
but if it meets a golden tree snake,
it happily makes a leap into the unknown
As it plummets,
spread limbs slow its descent and its webbed feet double up as a parachute
The Javan flying frog goes one better
Its webbed feet have evolved into miniature wings
Instead of parachuting,
it paraglides at an angle
But it's the Wallace frog that achieves aeronautical perfection
Its huge webbed feet become aerofoils that slow and control its descent
It glides as far forward as the distance it falls
As well as winged feet, its whole body is aerodynamically shaped
This is classic evolution
one feature progressively improved until perfection is achieved
Lizards lack webbed feet,
so they expand other body features to get their wings
The flying gecko's impressive glide angle is due to winglike fringes on its body
Every available edge has an aerodynamic extension
But it's the Draco lizard whose design really flies
A huge aerofoil turns the Draco into a living frisbee
while its tail steers like a rudder
Foldable ribs act as support struts to create the perfect wing
The golden tree snake uses other aeronautical traits for its leap of faith
It loops its body for the ultimate takeoff
and projects forward to gain a head start
It then flattens into a ribbon,
and swings through the air using S-shaped waves of its body
The star of this jungle airshow is the owner of the most extravagant wings
From 18m up, the Wallace frog glides 80m forward
The gecko soars 100m
but nothing beats the flying frisbee
The Draco reaches a full 200m
Even a flying snake makes 150 complete with controlled landing
A lack of legs has made snakes devise other weird ways of moving
In the deserts of the American southwest,
off road travelling is notoriously difficult
Shifting sand is one of the most challenging surfaces to negotiate
The horned rattlesnake's solution
is to touch the sand with as little of its body as possible
Appropriately, its nickname is the sidewinder
Like tyre tread, a snake's scales usually grip the ground as it moves
but sand simply gives way
So the snake makes an S-shape with its body
and lifts the loops in a rolling corkscrew
This continually shifts the points of contact to stop that sinking feeling
As waves of grip pass down the body,
the snake rapidly picks up speed
Its hidden prey can also make a surprise move
Sidewinders avoid being buried by sand
others welcome its smothering embrace
This predator spends much of its life lurking just beneath the surface
It can swim through shifting sand like an eel up a river
because the grains act like liquid rock
The sand swimmer's wedge-shaped head parts the grains like the prowl of a boat
Its over slung upper jaw stops it swallowing sand
and it can close its nostrils to avoid suffocating
As the snake submerges,
its polished scales slip through the grains as if immersing in water
Nature shows many wonderful forms of travelling
those that seem weird are usually the least familiar
But although we think we are normal,
in nature, it is we who are peculiar
Our two legs place us among the world's oddest animals
We are the only mammal to regularly walk like this
Sometimes other primates hint at the origins of our strange bipedal walk
Proboscis monkeys use it to cross mangroves
A few scientists think we were once semi-aquatic,
walking like this kept our heads above water
Others believe that freeing the hands for gripping or carrying
allowed the landed to bring back food to a family
Whatever the reason, animals that walk like us seem strange
We find it weird to see our actions mirrored in other animals
In the age of the dinosaurs we might have felt more at home
many were also bipedal
Today a few unrelated lizards continue in their footsteps
Like a miniature tyrannosaur,
the collared lizard hunts on two legs
But it is more agile than any dinosaur
and size for size much faster
Being smaller gives speed and maneuverability
Most bipedal lizards live in deserts
This kind of running need space
When hunting other lizards,
two legs give it the edge
The tyrannosaur's modern equivalent
But while this lizard uses two legs for speed,
we now prefer alternatives
The dinosaur's real descendants are birds
Because they fly,
we rarely notice that they walk on two legs like we do
but the road runner is an exception
Its comical humanlike gait made it a cartoon character
To save energy for its sprint,
the road runner exposes a solar panel
This dark skin patch raises its body temperature 7 degrees
It's primed for a superheated performance
To the road runner,
our open roads are race tracks,
good for chasing insects and lizards
Its tiny legs take it to 26 miles an hour
If our legs moved this fast,
we would overtake any speeding bike
Because two-legged running limits our own speed,
we use artificial means of travel, such as flying
But even though it can fly,
the strange road runner chooses to run on two legs for speed
Our machines take us ever faster
and we sometimes pay the price
But when we smile at the road runner's bipedal running
are we recognizing our own weird nature?
Subtitles by Andrew and Hattie www.mvgroup.org