MAJOR FUNDING FOR THE DESERT
SPEAKS HAS BEEN PROVIDED BY

ASARCO, INC., AN INTEGRATED
PRODUCER OF NON-FERROUS METALS

AND OTHER INDUSTRIAL MINERALS
AND PRODUCTS.

ASARCO, INC., ADDING VALUE
TO NATURE'S RESOURCES.

[MUSIC WITH
SOUNDS OF NATURE]

THE CAST AND CHARACTERS
OF THE SONORAN DESERT

ARE REALLY DERIVED FROM
AN OLDER DRAMA.

THAT'S THE GREAT
TROPICAL FOREST SHIELD

THAT ONCE COVERED MOST
OF THE GLOBE.

TO GET A BETTER LOOK AT
THESE BEGINNINGS

WE'VE TRAVELED DOWN TO THE
SOUTHERN END OF THE

MEXICAN STATE OF SONORA, NEAR
THE HISTORICAL TOWN OF ALAMOS.

HERE AN UNUSUAL FOREST
COMBINES CACTUS

WITH DECIDUOUS TREES AND LONG
DRY SPELLS WITH REAL WET ONES.

GEOGRAPHICALLY WE'RE
AT AN IN-BETWEEN PLACE,

NOT FAR ENOUGH SOUTH THAT WE'RE
RUNNING OUT OF TYPICAL

SONORAN DESERT BUT NOT SO FAR
AS TO BE TYPICALLY TROPICAL.

AND WE'RE AT KIND OF AN
IN-BETWEEN ELEVATION, TOO;

A FEW THOUSAND FEET. THIS
IS A CROSSOVER ZONE AND

MANY SPECIES REACH THEIR
MOST NORTHERN LIMITS HERE

OR THEIR MOST SOUTHERN LIMITS.

SO THEREFORE THE DIVERSITY
HERE IS JUST INCREDIBLE.

THIS IS TRUE FOR PLANTS,
ANIMALS, BIRDS AND INSECTS,

REALLY FOR ALL LIFE HERE.

THE CHANGE IS WITHIN A THIRTY
MILE AREA OF WHERE WE LIVE

HERE UP FROM THE SONORAN
DESERT THORN SCRUB

INTO THE TROPICAL
DECIDUOUS FOREST.

WE HAVE A GREATER
ACCUMULATION OF RAINFALL HERE,

APPROXIMATELY TWICE THE AVERAGE

OF WHAT THE SONORAN DESERT
RECEIVES A YEAR.

THE MONSOONS, VERY MUCH
LIKE THE SONORAN DESERT,

BUT THE MONSOONS HERE JUST
COME IN IN THE AFTERNOON.

IN THE MORNINGS WE HAVE
BEAUTIFUL BLUE SKIES

AND IN THE AFTERNOON THESE
HUGE STORMS BUILD UP

AND YOU CAN SEE THEM COMING
IN FROM MILES AWAY.

AND THEY COME IN AND THEY JUST
DELUGE WITH RAIN

IN THE AFTERNOONS AND IT
IS JUST MAGNIFICENT.

AND THE ACTIVITY CHANGE
IS BEYOND BELIEF

WHEN THINGS WAKE UP IN THE
SUMMER, JUST BEYOND BELIEF.

THE ANIMALS, THE
FROGS AND TOADS,

ARE SO ABUNDANT YOU HAVE
TO WATCH WHERE YOU WALK.

THE HIGHEST TREES ARE,
TWENTY METERS IS A HIGH TREE.

BUT THIS REALLY IS A SHORT
TREE FOREST WITH AN OPEN

CANOPY, AND WHEN IT LEAPS
OUT IT BECOMES A DENSE CANOPY.

SO UNDER IT THE SHRUBS
ARE MEDIUM HEIGHT

AND OUR UNDER STORY IS ABUNDANT
BUT MOSTLY IN THE RAINY SEASON.

A GREAT MANY FORBS AND SMALL
VASCULAR PLANTS ARE

GROUND COVERS FROM A
MILLIMETER HIGH

ALL THE WAY TO TWELVE
INCHES HIGH.

BUT AS YOU WALK THROUGH THE
FOREST IT'S A CONSTANT CARPET

OF GREEN UNDERNEATH
THE, THE HEAVY CANOPY.

AND MOST OF THESE PLANTS
COULDN'T HANDLE IT VERY WELL

IN THE OPEN, HOT TROPICAL
SEASON OF THE WINTER

BECAUSE THERE IS AN AWFUL
LOT OF SUN IN THE WINTER.

FIG TREES AND THE ARROYOS
OCCUR IN THE ARROYOS USUALLY.

WE HAVE APPROXIMATELY
FIVE SPECIES OF FIGS

IN THE IMMEDIATE AREA.

THEY'RE HUGE TREES,
SOME OF OUR BIGGEST

IF NOT OUR BIGGEST CANOPY TREE.

AND AS THE BIRDS
MIGRATE THROUGH, IT'S PROBABLY

ONE OF THE GREATEST SECURITY
BLANKETS THAT THEY HAVE.

IT PROVIDES A BIG
CANOPY FOR THEM.

WELL, THE LEGUMES
ARE VERY INTERESTING.

WE HAVE AN ENORMOUS AMOUNT
OF LEGUME SPECIES

AND THEY ARE THE GREATER
PERCENTAGE OF OUR SPECIES

HERE IN THE WAY OF TREES.

THE BARKS AND THE FORM OF
THE DIFFERENT LEGUMES

IS JUST A CONSTANT
SOURCE OF FASCINATION.

THE GENUS BURSERA IS A SUCCULENT
TREE THAT OCCURS IN THE TROPICS.

PROBABLY THE MOST SOUTHERLY
DOCUMENTED BURSERAS DO OCCUR

IN ARIZONA AND WORK
THEIR WAY DOWN SOUTH

AND AS THEY WORK, THEY
ARE MUCH, CONSTANTLY

MANY MORE SPECIES THE
FURTHER SOUTH YOU GO.

IN THE UNITED STATES THE
GENUS BURSERA IS REPRESENTED

ONLY BY BURSERA MICROPHYLLA
IN THE SONORAN DESERT.

BUT BEING ESSENTIALLY
A TROPICAL GENUS,

THE FURTHER SOUTH YOU
GO OR THE FURTHER INTO

THE AMERICAN TROPICS YOU GO,
THE MORE SPECIES YOU FIND.

SO HERE THE GENUS IS REPRESENTED
BY APPROXIMATELY FIVE SPECIES

AND FURTHER SOUTH
BY MORE AND MORE.

THIS TREE BEHIND ME IS
A BURSERA GRANDIFOLIA

AND IT'S IDENTIFIED BY THE
RED EXFOLIATING BARK

ON A METALLIC GREEN.

COLOR COMBINATIONS I SEE LIKE
METALLIC RED OVER SILVER,

SILVERY BLUE, OR JUST
PLAIN POWDERY WHITE,

AND VARIOUS COMBINATIONS
OF METALLIC COLORS LIKE THAT.

THEY'RE REALLY QUITE
BEAUTIFUL AND AMAZING.

IT'S HARDLY APPLICABLE TO
USE SEASONAL HERE.

APPROXIMATELY EVERY SIX TO EIGHT
WEEKS THERE'S A MAJOR CHANGE

IN THE ANIMALS, BIRDS
AND THE PLANT LIFE.

AS FAR AS RAIN GOES, WE
HAVE GENTLE WINTER RAINS

THAT BRING ON OUR, BRING
ON THE BLOOMING OF THE TREES

IN THE SPRING IN THE
EARLY PART OF THE YEAR.

AND WE HAVE THE HEAVY
SUMMER RAINS, MONSOONS,

WHICH GIVE US A VERY LUSH CANOPY
AND EXTREMELY HEAVY FOLIAGE.

MORE WATER TRANSLATES
INTO MORE GREENERY

SO YOU RUN INTO WETTER, GREENER
VERSIONS OF EVERYTHING,

INCLUDING REPTILES SUITED
TO LIVING ABOVE THE GROUND.

ART, IT'S ALMOST LIKE
A JUNGLE IN HERE.

WHAT KIND OF ANIMALS
CAN WE EXPECT TO FIND?

WELL, HERE WE ACTUALLY
FIND QUITE A FEW SPECIES

THAT ARE COMING UP
FROM THE TROPICS,

REACHING THE NORTHERN
LIMITS OF THEIR RANGES

AND THEY'RE GENERALLY SPECIES
THAT ARE FROST SENSITIVE

THAT CAN'T, CAN'T ENDURE
FREEZING WINTERS

AND REQUIRE CONSIDERABLY
MORE MOISTURE AT LEAST

THROUGH THE SUMMER AND
WINTER SEASONS THAN

DO MOST OF THE SONORAN
DESERT ANIMALS.

I EXPECT WITH ALL THESE TREES

WE CAN FIND ANIMALS LIVING UP
THERE CAN'T WE?

THERE ARE QUITE A
FEW THAT ARE ADAPTED

TO LIVING IN TREES AND SHRUBS
AND SO ON.

THERE HAVE BEEN SOME
REMARKABLE ADAPTATIONS

TO ARBOREALITY AMONG THE SNAKES
WHICH OCCUR IN THIS ENVIRONMENT.

THE VINE SNAKE FOR EXAMPLE
IS MARVELOUSLY ADAPTED

FOR CLIMBING, HAS A LONG,
SLENDER BODY FORM,

A COLOR THAT LOOKS
VERY MUCH LIKE A VINE

AND HAS A POINTED HEAD WHICH
BLENDS VERY EFFECTIVELY

WITH THE VEGETATION.

THERE'S ANOTHER ARBOREAL
SNAKE THAT KIND OF PARTITIONS

THIS ARBOREAL NICHE SOMEWHAT
WITH THE VINE SNAKE.

IT'S CALLED THE BLUNT
HEADED SNAKE AND IT'S EVEN

MORE THINLY CONSTRUCTED, VERY
LIGHT IN BUILD.

IT HAS A DISPROPORTIONATELY
LARGE HEAD

BUT BECAUSE IT'S SO
MUCH THINNER THAN THE VINE SNAKE

IT CAN WORK THE OUTER LIMBS
OF THE TREES AND SHRUBS,

THOSE WHICH WOULD BE
TOO FRAIL TO SUPPORT

THE WEIGHT OF
THE VINE SNAKE.

SO IN THIS WAY THEY'RE
BOTH ABLE TO EXPLOIT

THE SAME GENERAL HABITAT TYPE
BUT UTILIZING DIFFERENT NICHES.

TWO VERY INTERESTING TREE FROGS
REACH THEIR NORTHERN LIMITS

HERE IN SOUTHERN
SONORA ALSO.

WE HAVE THE MEXICAN TREE FROG
WHICH IS A TROPICAL SPECIES,

GOES ALL THE WAY DOWN INTO
CENTRAL AMERICA AND COMES UP,

FOLLOWS THE TROPICAL DECIDUOUS
FOREST HABITAT UP INTO SONORA.

PERHAPS EVEN MORE INTERESTING
IS THE MEXICAN LEAF FROG.

BEFORE THEY
LAY THEIR EGGS,

THE FEMALES GO DOWN TO THE WATER
AND SIT IN THE SHALLOW WATER

AND TAKE UP WATER
THROUGH THEIR SKIN

AND THROUGH THEIR CLOACA
WHICH THEN THEY TRANSPORT

UP TO THE LEAVES AND THIS AIDS
IN THE DEPOSITION OF THE EGGS.

IT MOISTENS THEM
AND KEEPS THEM

FROM GETTING TOO DRY AS THEY ARE
DEPOSITED.

UNLIKE MOST OTHER TREE
FROGS WHICH TEND TO HOP

AND ARE RATHER ACTIVE
IN THEIR MOVEMENT,

THE MEXICAN LEAF FROG
MOVES VERY DELIBERATE STEPS

AS THEY FIND THEIR WAY
THROUGH THE VEGETATION.

IN FACT, IT MOVES IN A
MANNER VERY SIMILAR

TO THAT WE ASSOCIATE WITH
CHAMELEONS IN AFRICA

WHERE THEY REACH OUT AND GRASP
A LIMB AND THEN REACH UP

WITH THE OTHER FORELIMB AND MOVE
VERY SLOWLY AND DELIBERATELY

AND FINALLY TAKE UP A STATION IN
THE SHRUBS OR LOW GROWING TREES.

THE TERM "DRY, DECIDUOUS
TROPICAL FOREST" MIGHT SOUND

AT FIRST LIKE A CONTRADICTION
UNTIL YOU REALIZE, OF COURSE,

IT'S NOT WET AND DRY
AT THE SAME TIME.

IT'S WET OR DRY BY TURNS.

AND WHEN IT'S WET,
IT'S MUCH WETTER

THAN THE SONORAN DESERT
TO THE NORTH.

WHEN THE RAINY SEASON BEGINS
USUALLY IN LATE JUNE

OR EARLY JULY, BECAUSE ITS
ALREADY VERY HOT,

THINGS RESPOND QUICKLY AND
THE CACTI VIRTUALLY DISAPPEAR

UNDER THE CANOPY
OF FOLIAGE

AND THE ANIMALS COME ACTIVE
AGAIN,

MORE ACTIVE THAN
THEY WERE BEFORE.

AND REALLY IT'S THE
BEGINNING OF THE LIFE

CYCLE FOR MOST ANIMALS
AND PLANTS IN THIS AREA.

I HAVE A PARTICULAR
INTEREST IN THIS REGION

BECAUSE THE ORIGIN OF THE
SONORAN DESERT IS TO BE FOUND

HERE IN THE TROPICAL
DECIDUOUS FOREST.

BOTH AREAS HAVE GREAT
SIMILARITIES WHICH ARE APPARENT

IF YOU START LOOKING AT THE
VEGETATION

A LITTLE MORE CLOSELY.

ALMOST ALL THE PERENNIAL
PLANTS THAT ARE FOUND IN

THE SONORAN DESERT HAVE
THEIR CLOSEST RELATIVES

IN THIS REGION HERE.

BOTH AREAS HAVE A NUMBER
OF THE SAME SPECIES,

SUCH AS, ORGAN PIPE
CACTUS, PALO VERDE TREES,

CORAL BEANS, ELEPHANT
TREES AND SEVERAL OTHERS.

AND MOST OF THE OTHER PERENNIALS
HAVE VERY CLOSE RELATIVES HERE

ALTHOUGH THERE ARE MORE
SPECIES HERE

THAN THERE ARE IN THE
SONORAN DESERT.

DURING THE DRY SEASON IN
THE DECIDUOUS TROPICAL FOREST

THE HUMIDITY STILL
TENDS TO BE A BIT HIGHER,

SO THE DROUGHT IS NOT AS SEVERE

AND THE SUMMER RAINY SEASON IS
CONSIDERABLY HEAVIER.

SO YOU HAVE MUCH THICKER
VEGETATION HERE

AND A GREATER DIVERSITY
OF SPECIES,

PARTLY BECAUSE OF THE
HIGHER RAINFALL

AND PARTLY, PROBABLY
MORE IMPORTANTLY,

BECAUSE FROST IS
MUCH MORE RARE.

IF YOU WERE TO
CHARACTERIZE THE SONORAN DESERT,

FOR INSTANCE, THE SIMPLEST
DEFINITION WOULD BE

THAT IT'S A DESERT AREA
THAT'S CHARACTERIZED

BY SEASONAL DROUGHT WITH
PRIMARILY A SUMMER RAINY SEASON

AND THE VEGETATION IS DOMINATED

BY LEGUME TREES AND COLUMNAR
CACTI.

AND TO DESCRIBE HERE THE
DECIDUOUS TROPICAL FOREST,

IT'S PRETTY MUCH THE SAME.

IT'S A SEMI-ARID AREA,
NOT AN ARID AREA,

A SEMI-ARID AREA WITH
PRIMARILY A SUMMER RAINFALL

AND THE DOMINANT
VEGETATION IS

LEGUME TREES AND COLUMNAR CACTI.

THE MAIN DIFFERENCE IS
THE RAIN IS GREATER HERE,

THERE'S LESS FROST AND THE
NUMBER OF TYPES OF PLANTS

IS MUCH GREATER HERE.

THE GROWTH FORMS OF THE PLANTS
MAY BE DIFFERENT IN TWO PLACES.

SO THINGS THAT ARE TREES
HERE MAY BE SHRUBS IN ARIZONA

BUT THEY'RE NONETHELESS THE
SAME SPECIES IN MANY CASES.

BECAUSE OF THE DENSITY OF
VEGETATION HERE

THERE IS COMPETITION FOR
SUNLIGHT.

SO, AS A CONSEQUENCE,
YOU'LL NOTICE THAT

SOME OF THE ADAPTIVE STRATEGIES
USED HERE ARE,

THAT MOST OF THE TREES AND
CACTI FOR THAT MATTER ARE

TALL AND NARROW.

THEY'RE REACHING FOR THE
SUNLIGHT BEFORE THEY GET

OVERSHADOWED BY THE TREE NEXT TO
THEM OR THE CACTUS NEXT TO THEM.

THE GROWTH OCCURS ONLY
DURING THE RAINY SEASON.

SO THAT'S THE TIME WHEN THEY'RE
STRUGGLING FOR LIGHT AS WELL.

WHEN THEY'RE LEAFLESS,

THERE'S ALMOST NO PHOTOSYNTHESIS
TAKING PLACE.

BUT DURING THE SUMMER
RAINY SEASON

EVERYTHING IS LEAFED OUT AND IS
NEARLY A SOLID CANOPY OF LEAVES.

SO THE ONES THAT GROW THE
BEST ARE THE ONES

THAT ARE IN THE SUNLIGHT; THAT'S
A FAIRLY NARROW CROWN

BECAUSE THERE ARE TREES ON
BOTH SIDES

OF ANY GIVEN TREES IN MOST
CASES.

SO THE GROWTH IS UPRIGHT,
VERY, VERY UPRIGHT.

THERE AREN'T VERY MANY
TALL, BROAD TREES HERE.

ONE OF THE MAJOR CONTRASTS
THAT YOU CAN SEE HERE,

AND THE REASON YOU CAN
TELL THAT IT'S NOT IN FACT

A TROPICAL RAIN FOREST, IS
THAT DURING THE DRY SEASON

ONE OF THE PROMINENT GREEN
THINGS IS THE CACTI,

THE COLUMNAR CACTI,
WHICH ARE QUITE TALL,

FIFTEEN TO TWENTY FEET ALTHOUGH
THEY'RE SOMEWHAT SHORTER

THAN THE TREES
IN MOST CASES.

BUT NINE MONTHS OF THE YEAR
MOST OF THE TREES ARE LEAFLESS

SO EVEN THOUGH
THE TREES ARE VERY DENSE,

THERE'S STILL PLENTY OF
SUNLIGHT MOST OF THE YEAR

FOR THE CACTI TO DO
THEIR PHOTOSYNTHESIS.

BUT DURING THE THREE
MONTHS OR SO OF RAINY SEASON

THE CACTI ARE ALMOST COMPLETELY
OVERSHADOWED BY LEAFY TREES.

BUT THEY CAN SURVIVE HERE
BECAUSE MOST OF THE YEAR

THEY DO IN FACT HAVE
PLENTY OF SUNLIGHT.

IT'S THIS MIX OF DRY AND
WET, OPEN AND LEAFY,

WHICH DRAWS SUCH A WIDE
CAST OF CHARACTERS.

THERE DOESN'T SEEM TO
BE ONE OF ANYTHING HERE

EXCEPT MAYBE
POISONOUS LIZARDS.

WE'VE TALKED ABOUT
SNAKES IN THE TREES.

HOW ABOUT SNAKES
ON THE GROUND?

WELL, THERE ARE
QUITE A FEW.

WE HAVE TROPICAL SNAKES
THAT OCCUR HERE

GOING FURTHER SOUTH THAT ARE
PRINCIPALLY TERRESTRIAL

OR FOSSORIAL MEANING THEY BURROW
INTO THE GROUND IN SOME WAY.

WE HAVE SOME, LIKE THE
SADDLE LEAF NOSE SNAKE,

WHICH HAS A BROAD SCALE
ACROSS THE FRONT OF ITS NOSE

AND THAT WORKS SOMETHING ON
THE ORDER OF A BULLDOZER

AS IT PLOWS
THROUGH SOFT EARTH, BURROWING

INTO THE GROUND, OPENING
UP OLD ABANDONED BURROWS.

THE SINALOAN
LONG NOSE SNAKE,

CLOSELY RELATED TO OUR
SONORAN DESERT LONG NOSE SNAKES

OR WESTERN
LONG NOSE SNAKES.

THEY GET THEIR NAME BECAUSE
THEY HAVE A RATHER POINTED NOSE

WHICH SERVES ESSENTIALLY
THE SAME FUNCTION

BUT IN A
DIFFERENT WAY.

IT OPERATES MORE
LIKE A PLOW.

HOW DO SOME OF THESE LIZARDS

COMPARE IN SIZE TO THE DESERT
TYPE?

WELL, ONE LARGE SPECIES WE
FIND HERE IN SOUTHERN SONORA

IS THE SPINY TAIL
IGUANA.

THEY GROW TO ABOUT
THIRTY INCHES IN LENGTH,

AND HAVE A VERY ROUGH
SPINY TAIL WHICH THEY USE

VERY EFFECTIVELY IN
DEFENSE AGAINST PREDATORS.

THEY LASH THE TAIL AND MAKE
THEMSELVES VERY UNPLEASANT.

AND, OF COURSE, THEY HAVE
A STRONG BITE AS WELL.

BUT WE OFTEN SEE THEMON,
IN ROCKY HABITATS,

ROCKY PROTRUSIONS WITHIN
THE THORN FOREST.

BUT THEY ALSO CLIMB
TREES QUITE WELL.

AND WHEN WE SEE THE ADULTS
WE SEE AN ANIMAL

THAT BLENDS MORE WITH THE TREE
TRUNKS AND LIMBS AND THE ROCKS

THAN THEY DO
WITH THE FOLIAGE.

BUT WHEN THESE GUYS HATCH OUT IN
THE RAINY SEASON,

THEY'RE BRIGHT GREEN, VERY
BEAUTIFUL EMERALD GREEN.

THIS GREEN COLOR, WHILE
THE TROPICAL FOREST

IS VARIDENT AS IT IS DURING
THE SUMMER RAINY SEASON,

GIVES THEM AN
EDGE FOR SURVIVAL.

NOW ANOTHER LARGE LIZARD
FOUND IN SOUTHERN SONORA,

REACHING THE NORTHERN
LIMITS OF ITS RANGE

THROUGHOUT MEXICO AND ON
DOWN INTO GUATEMALA

IS THE BEADED LIZARD, THE
NEAREST LIVING RELATIVE

OF THE GILA
MONSTER, A LIZARD

WHICH HAS COME TO CHARACTERIZE
THE SONORAN DESERT.

VERY CLOSELY RELATED SPECIES
BUT THE BEADED LIZARD

GROWS TO A LARGER SIZE UP TO
ABOUT THREE FEET IN LENGTH

AND IS CONSIDERABLY MORE
ARBOREAL THAN THE GILA MONSTER.

THE GILA MONSTER WILL
ACTUALLY CLIMB UP

INTO LOW GROWING SHRUBBERY
IN THE SONORAN DESERT.

BUT THE BEADED LIZARD
IS KNOWN TO GET UP, OH,

TWELVE, FIFTEEN FEET OR MORE
IN THESE DRY FOREST TREES.

BUT WE THINK THAT PROBABLY
THE BEADED LIZARD

IS A SPECIES THAT HAS ORIGINATED
IN THE DRY TROPICAL FOREST

PRETTY MUCH AS
THEY EXIST TODAY

AND THAT'S BECAUSE
THEIR DISTRIBUTION

VERY CLOSELY FOLLOWS THE DRY
FOREST AS WE NOW KNOW THEM.

THESE LIZARDS ARE OF GREAT
INTEREST THROUGHOUT THE WORLD

BECAUSE THEY'RE THEY ONLY
LIVING VENOMOUS LIZARDS.

AND THIS HAS CAUSED SOME
PROBLEMS FOR THEM

BECAUSE THEY'RE IN
SUCH GREAT DEMAND;

IN SOME AREAS THEY HAVE
BEEN EXTENSIVELY COLLECTED.

AND LAWS IN BOTH THE
UNITED STATES AND MEXICO

NOW PROTECT BOTH OF THESE
SPECIES

FROM COMMERCIAL EXPLOITATION.

IS THAT THE PRIMARY THREAT TO
THOSE ANIMALS?

WELL, IN REALITY MAINTAINING
THE HABITAT THAT THEY REQUIRE,

THIS HABITAT WE'RE IN
RIGHT NOW IN FACT,

IS THE MOST CRITICAL NEED FOR
NOT ONLY THE BEADED LIZARD

BUT ALL THE OTHER
SPECIES THAT OCCUR HERE.

MAINTAINING THIS RICH
BIOLOGICAL DIVERSITY

IS VERY IMPORTANT AND I THINK
THAT IT CAN BE DONE

WHILE MEETING THE HUMAN NEEDS
AS WELL.

HUGE GRANITE FORMATIONS WITH
EMBEDDED SILVER WERE SUBMERGED

IN THE ALAMOS AREA OVER
FORTY MILLION YEARS AGO

AND THOUGH THEY WERE LATER
COVERED EVEN DEEPER BY LAVA

AND CINDERS AND ASH,
THEY DIDN'T STAY BURIED.

THE NEXT THIRTY FIVE
MILLION YEARS OR SO

OF EROSION AND MASSIVE FAULTING
ALSO CREATED THE BAJA PENINSULA.

WITH ALL THE FAMILIAR LOOKING
CREATURES AND PLANTS HERE,

THE LITTLE PATCH OF OCEAN
NEAR THE SONORAN DESERT

MAY BE THE ONLY THING IN THE
PICTURE THAT'S UNFAMILIAR.

MORE THAN LIVING THINGS
LOOK FAMILIAR HERE.

THIS TERRAIN EVOLVED VERY MUCH
THE SAME WAY AS DID OUR DESERT

TO THE NORTH WITH GREAT
VOLCANOES

AND STRETCHING OF THE EARTH.

AND EVENTUALLY UP TO THE
SURFACE CAME A LOT OF SILVER

SO WE HAVE A COLORFUL
HUMAN HISTORY HERE TOO.

THANKS TO THE EARLY
MEXICAN MINERS,

SPAIN MANAGED TO SUPPLY
MOST OF THE WORLD'S SILVER

FOR A FEW HUNDRED YEARS.

THE TOWN OF ALAMOS HAS STILL
GOT A COLONIAL LOOK TO IT.

[MUSIC]
[SPEAKING SPANISH]

LIFE BACK THEN WAS MUCH MORE
SEDENTARY.

THERE WERE PEOPLE HERE
FROM ALL OVER THE WORLD--

CHINESE, JAPANESE, GERMAN,
AND, OF COURSE, THE SPANIARDS,

AND ONE OR TWO
ENGLISH, NOT A LOT.

WHEN I WAS A BOY, THERE
WEREN'T ANY FENCES.

WE KNEW WHERE EVERYBODY'S
LAND STARTED AND ENDED.

THERE WERE MANY
BIRDS, MANY SNAKES,

LOTS OF COYOTES, WILD
CATS, AND MOUNTAIN LIONS.

THERE USED TO BE GREAT
QUANTITIES OF JUST ABOUT

EVERYTHING OUT THERE
IN THE JUNGLE AND MOUNTAINS.

THERE WAS SO
MUCH VEGETATION.

WE THOUGHT THERE WOULD
ALWAYS BE ENOUGH.

LOTS OF TREES. SO MANY TREES.
LOTS OF WILD FRUIT.

MANY PEOPLE LIVE
OFF ALL THIS FRUIT,

EATING THEM AND SELLING
THEM.

[CHURCH BELL RINGING]

THINGS OFTEN LOOK SWEETER
IN THE REAR VIEW MIRROR,

MORE COLORFUL,
MORE PLENTIFUL.

BUT AT LEAST AS
FAR AS BIRDS GO,

THIS FOREST IS STILL A VERY
COLORFUL AND ABUNDANT PLACE.

IN THE DECIDUOUS
FOREST IN SOUTHERN SONORA

THERE ARE PROBABLY
ONE HUNDRED,

ONE HUNDRED AND FIFTY
SPECIES OF WHICH ABOUT FORTY

ARE REALLY CHARACTERISTIC
OF THAT HABITAT.

ABOUT HALF A DOZEN OF THOSE
SPECIES COME ON INTO ARIZONA.

THEY FOLLOW THE RIPARIAN
CORRIDORS NORTH

SO THEY'RE FOUND IN EXTREME
SOUTHERN ARIZONA

JUST IN THE RIPARIAN AREAS.

THE GRAY HAWK IS AN EXAMPLE OF A
BIRD THAT'S REALLY QUITE COMMON

IN THE DECIDUOUS FOREST
AND IS RATHER UNUSUAL TO RARE

IN THE SOUTHERN PART OF ARIZONA.

PARROTS, ALONG WITH MANY
OF THE OTHER SPECIES

THAT ARE CHARACTERISTIC OF
THIS DECIDUOUS FOREST,

ARE PRIMED AND
READY TO NEST

WHEN THE RAINS BEGIN
IN JUNE OR JULY.

AND ALMOST INSTANTLY AFTER
THE RAINS BEGIN

THEY'RE BUILDING NESTS,
LAYING THEIR EGGS,

THEN THE YOUNG ARE
BEING FED AND FLEDGED,

LEAVE THE NEST AT A TIME WHEN
THERE ARE LOTS OF INSECTS

AND OTHER FOOD ITEMS
FOR THEM TO FEED UPON.

THE CRESTED CARACARA
IS A KIND OF HAWK;

IT'S A RAPTOR.

IT EXTENDS ALL OVER MEXICO,
EVEN FURTHER SOUTH,

AND JUST BARELY GETS
INTO THE UNITED STATES

AND SOUTHERN ARIZONA.

THE BLACK FOOTED
MAGPIE JAY IS ONE OF

THE MOST CHARACTERISTIC BIRDS
OF THE DECIDUOUS FOREST.

IT'S A SOCIAL SPECIES
AND USUALLY ONE SEES

SIX OR EIGHT
INDIVIDUALS AT A TIME.

SOME OF THE INDIVIDUALS
ARE IMMATURE BIRDS

THAT ARE REMAINING WITH THEIR
PARENTS AND THEY ACTUALLY HELP

IN THE REARING OF YOUNG,
OF THEIR PARENTS.

WHAT WE SEE IN THE BIRDS OF THE
DECIDUOUS FOREST AND IN SONORA,

IS THE NORTHERN EXTENSION
OF A VERY LARGE GROUP

OF SPECIES WHICH
RANGE ALL THE WAY FROM THE

SOUTHERN PART OF CENTRAL AMERICA
TO SOUTHERN SONORA.

AND IN SOUTHERN SONORA THERE ARE
ABOUT FORTY SPECIES OF BIRDS

WHICH WE DO NOT FIND
IN THE UNITED STATES.

SO THE AREA IS OF
GREAT INTEREST

BECAUSE IT REPRESENTS A DIVIDING
LINE BETWEEN THE TROPICS

AND THE TEMPERATE AREAS OF
NORTH AMERICA.

FINALLY, IN-BETWEEN PLACE
HAS ONE MORE POPULATION

AS VARIOUS AS CONVENTIONEERS.

THE CATS OF THE DECIDUOUS
TROPICAL FOREST ARE MADE UP

OF FAR RANGING NORTHERNERS
AND SOUTHERNERS.

MOUNTAIN LIONS OR PUMAS ARE
FOUND ALL OVER NORTH AMERICA,

CENTRAL AMERICA AND SOUTH
AMERICA,

AND ALMOST ANY
PLACE YOU FIND DEER,

WHATEVER KIND OR SIZE OR SHAPE
YOU'LL FIND MOUNTAIN LIONS,

AS LONG AS THERE ARE A BIT
OF WILDERNESS AROUND, TOO.

THERE ARE A NUMBER OF
SMALL CATS YOU COULD FIND

IN THE DRY TROPICAL FOREST
OF SOUTHERN SONORA.

ONE IN PARTICULAR
WOULD BE THE OCELOT.

IT'S PROBABLY THE MOST ABUNDANT
SMALL CAT OF THAT AREA.

BUT THERE ARE OTHERS.

THERE ARE MARGAYS
WHICH ARE KIND OF

A SMALLER VERSION OF THE OCELOT
AND A LITTLE MORE ARBOREAL.

THERE'S THE JAGUARONDI, WHICH
IS A VERY DIFFERENT SMALL CAT,

VERY DARK IN COLOR,
DIFFERENT BEHAVIOR.

IT LOOKS LIKE A, ALMOST
LIKE A CAT-LIKE WEASEL.

THE BOBCAT BEGINS
TO FADE OUT.

THE BOBCAT'S FOUND OVER
MUCH OF NORTH AMERICA AND BEGINS

TO DISAPPEAR AND IS REPLACED
BY THESE MORE TROPICAL CATS.

THE FUTURE OF THESE
VARIETY OF CATS

WE'VE TALKED ABOUT
DEPENDS ALMOST ENTIRELY

ON THE FUTURE OF THAT HABITAT
WHETHER IT'S PRESERVED,

WHETHER IT'S, HOW
IT'S PRESERVED,

WHETHER IT'S PRESERVED IN
LITTLE BITS HERE AND THERE

OR A BROAD
CONTINUOUS FORCE.

BUT AS THAT GOES, SO
WILL THESE ANIMALS

JUST THROUGH CHANGES THROUGH
THE, THROUGH THE FOOD CHAIN

AND THE ECOSYSTEM. AS
YOU FOLLOW THE LINEAGE

OF OUR DWELLERS BACK
TOWARDS THE TROPICS,

THINGS BEGIN TO SPREAD.

THERE ARE MORE AND MORE
VARIATIONS

AS YOU GET FARTHER SOUTH.

AND THE WETTEST
TROPICAL FOREST

IS THE ONE WITH THE MOST
INCREDIBLE VARIETY.

SOMETIMES IT SEEMS
THAT DIVERSITY IS

SOMETHING YOU COULD GET
JUST BY ADDING WATER.

IT'S NOT THAT
SIMPLE, OF COURSE.

BUT IT IS TRUE THAT THE
DIVERSITY

IS THE HARDEST TO PROTECT WHERE
THE WATER'S SCARCE.

AND DIVERSITY IS PRETTY
IMPORTANT

WHEN YOU THINK ABOUT IT.

NOBODY WOULD REALLY PASS
UP A GOOD FIVE COURSE MEAL

FOR JUST FIVE HELPINGS
OF JUST THE GARBANZOS.

AND ANOTHER DRINK OF WATER

REALLY WOULDN'T HELP THAT MUCH
EITHER.

[MUSIC]

MAJOR FUNDING FOR THE DESERT
SPEAKS

HAS BEEN PROVIDED BY ASARCO,
INC.,

AN INTEGRATED PRODUCER OF
NON-FERROUS METALS

AND OTHER INDUSTRIAL MINERALS
AND PRODUCTS.

ASARCO, INC., ADDING VALUE
TO NATURE'S RESOURCES.