(chiming) – [Announcer] The
following is a production of New Mexico State University. (chiming) (cheerful music) (birds squawking) – [Narrator] The Rio Grande, a river of immense
importance in a dry land. This lifeline has flowed
through the American Southwest as long as recorded time. And it has provided
humans, animals, and plants a thriving shelter from the harsh forces of the surrounding desert. Nowhere along its shores
is this more apparent than in central New Mexico, in a place called Bosque del Apache. (birds squawking) – That’s where the water is, that’s where the lush flora is, that’s where animals are. Deer, mountain lions, beaver, everything. – Well what’s really
amazing here on the Bosque is just the sheer opportunity to see just a wide variety of mammal species. – The Bosque represents
an almost undiscovered treasure trove of the human past. (peaceful music) – [Narrator] But this spectacular place is best known for its birds. They gather here each
winter in great numbers in the well-watered areas of the Bosque del Apache Wildlife Refuge. There are over 20
different types of ducks. Tens of thousands of
snow geese flock here. (birds chirping) In all the Bosque offers refuge
to over 370 bird species, from songbirds to shorebirds. But of all the winged
residents here at the Bosque, none is more captivating
than the sandhill crane. Each year, they migrate long distances to winter along the banks
of New Mexico’s Rio Grande. And they come in great numbers, 28,000 in a given year. The majority of this Rocky
Mountain population stays here. From the outlook on the farm loop, visitors can observe large
flocks of sandhills feeding. Migratory bird expert Don Caccamise explains the not so obvious
importance of this activity. – The cranes here at the Bosque spend most of their time feeding. They’ll put on 20 or
25% of their body weight through the course of the winter. That’s critically important,
because when they arrive on the breeding grounds in the spring, there’ll be very little
there for them to eat. The vegetation here in the Bosque provides vital calories and nutrients that’ll be required for
successful migration and successful reproduction. And there’s a good
selection of things to eat. The refuge managers allow
some of the local farmers to sharecrop certain areas on the refuge, and that’s a good deal for all involved. Farmers get to use the irrigated land and harvest part of the crop, and the cranes, they get
to use what’s left behind. That’s why you can see such large numbers of cranes and geese here at the Bosque. The sandhills get to feast on alfalfa, on large fields of corn, and on tender aquatic plants. With such an abundance of food, they maintain an adult weight of about 9 1/2 pounds for the females and up to 12 pounds for the males. Unlike the blue herons here, that thrive on fish in
the Bosque waterways, cranes are mainly vegetarian, but they’ll eat just about anything. Frogs and snakes and
baby birds, birds’ eggs, and a whole variety of plant material. But what they really seem to relish is a plant that grows naturally
along the Rio Grande valley. Come on, let me show you. This is chufa, or yellow nutsedge. But this isn’t the part of
the plant that the birds like. What they like are these, small chufa nodules that are
connected to the plant’s roots. These nutritious bits look
a lot like Grape-Nuts. This is where the power and versatility of the sandhill’s bill comes into use. With forceful drilling into the soil, the bird uses its bill like a garden tool. It probes into the dense valley
soil as deep as six inches to get at the chufa nodules. These nutritious nuggets offer important protein and minerals needed by the cranes to support the breeding
process later in the year. Sandhills are deft with their bills. In fact, a visitor at the
International Crane Foundation had her shining hearing aid plucked away without a scratch to its owner. This amazing dexterity helps the cranes in all kinds of situations in the wild. (birds squawking) – [Narrator] Spending time
with the Bosque sandhills allows one to witness special
rhythms that occur here throughout their day. Some of the cranes begin their
morning on the wetland ponds created by refuge staff. By sunrise, the sandhills
begin to take off for the feeding fields just to the north. (birds squawking) They have built up quite an appetite after an evening spent on the ice. While this is not the most
comfortable place to bed down, it affords these birds
protection from predators. This wide open area
allows cranes to easily see intruders during the night. (birds squawking) Even this whooping crane,
one of the few on the refuge, joins the sandhills at the roost. It too heads off for a day in the fields. (birds squawking) (duck quacking) Another group of cranes begin their day on this sandbar in the
middle of the Rio Grande. At this hour, they are mostly quiet. Some begin to pick in the
mud for the day’s first food. (birds chirping) Others simply look around and wait. For the next hour or so after first light, the cranes begin to
take off in small groups of two or three. It is a slow process,
but by eight o’clock, only a group of 20 remain. One of the larger cranes
appears to be anxious to leave. (crane squawks) He squawks at the others, as if saying, “It’s time to go!” And later, he beings to flap
his wings in encouragement. (crane squawks) Several others copy this dance. Early settlers dubbed the
sandhills preacher birds, because this activity to them resembled a preacher
leading a congregation. Scientists view this
as a courtship ritual, or as displacement behavior, one that helps release
frustration or pent-up energy. After about 10 minutes, this
group appears ready to leave. In one great moment, the flock takes off. (birds squawking) The sandbar will be quiet now,
until their sunset return. (peaceful music) (birds squawking) After arriving, the
sandhills spend most of the daylight hours roaming
and eating in the fields. But there are always several
cranes within the flock that watch out for
predators while others eat. This crane suddenly spots something at the edge of the field. Without an audible warning, the rest of the group stops eating. They watch in unison. This time, it’s no cause
for concern, however, it’s just a Rio Grande
wild turkey passing by. Once assured of their safety,
the flock returns to feeding. (birds squawking) Various other distinctive behaviors can be observed throughout the day. (birds squawking) Cranes are social animals,
and call out constantly, making the feeding fields
quite a loud, raucous place. One particular sound is the unison call. It occurs between a paired couple. Sandhill cranes mate for life,
and this call is the basis for understanding their social bonding. Biologists believe that the unison call is used for a number of functions, from establishing territory,
to a warning call, to a recognition of one’s mate. Preening, or feather ruffling, is another daily behavior
that scientists believe has a social function beyond the obvious. Some believe that this activity is used in aggressive
meetings between two cranes, allowing the threatened
crane to watch the aggressor from all angles. Sometimes, of course, this
does not deter the attacker, like here, and the passive
crane is actually run off. Another behavior is the crouch threat. This can be seen here
as another bird flies in above the heads of these two cranes. By four o’clock, parts of the flock begin to return to the Rio. (birds squawking) Here one can see the intention
pose prior to takeoff. Some cranes extend their head and neck, become more horizontal,
and eventually fly out. (birds squawking) Sandhills, along with the snow geese, make this a spectacular time
of day at Bosque del Apache. With thousands of birds in flight and an impressive New Mexico sunset, the sights and sounds overwhelm. (birds squawking) It is almost dark by the
time all the Rio flock returns to the sandbar. After hours in the dry fields, the cranes take repeated
long swills of water to quench their thirst. Soon they will gather in a group for protection during the night. The daily rhythm of the
sandhills is complete. – The greater sandhill cranes
that you see here today are involved in a rhythm of events far larger than the borders
of Bosque del Apache. These birds are part
of the northern flock, and each year, they undertake
a trek to the breeding grounds some 800 miles to the north. – [Narrator] By late February, small groups of sandhills begin
testing the local thermals in preparation for their spring migration. (peaceful music) Soon, large groups begin
to leave the Bosque. Sometimes, thousands of
cranes depart in a single day. Usually within a week, the
entire flock has exited. With the raucous crowds
of cranes and geese gone, the Bosque takes on a tranquil silence. This Rocky Mountain flock is
the largest single population of greater sandhill
cranes in North America. Estimates range from
17,000 to 25,000 birds. Leaving the refuge of
the Rio Grande Valley, the cranes fly north, following the spine of the
Rockies through Colorado. Then it is on to the
breeding grounds in the area where Montana, Wyoming, and Idaho meet. It is here, like in these wetlands at Red Rock Lakes National
Wildlife Refuge in Montana, that the greater sandhills
choose to breed and raise young. But something has dramatically
changed with these cranes since their winter days at the Bosque. They are now brown! The culprit? As the cranes clean their feathers, they literally paint themselves with the ferrous minerals
found in the water and mud of Red Rock Lakes. If you look close, a gray
neck can still be seen, but from where the bill
can touch and below, the brown mineral stain persists. As they change location,
this color fades away as the birds preen
themselves with other water. Set in front of the majestic
Centennial Mountains, a single egg is found in a sandhill nest. It is a good five inches
long, and will soon hatch. Upon approaching this well-hidden
nest, both parents fled, but the female, in hopes of
luring the intruders away, fakes a broken wing. This is a prime example of
sandhill nesting behavior. They staunchly defend their offspring. In fact, the parents are even aggressive to other cranes at this time. It is distinctively different behavior for these usually
social, gregarious birds. – Sandhill cranes employ
a range of strategies to ensure their numbers in the wild. At one end of this range are species that produce a large number of offspring, but invest very little time and energy in the survival of each individual. At the other end of this
range are species that produce very few offspring
but invest a great deal in the survival of each individual. Sandhill cranes are in this latter group. Mortality is low because
sandhills have secure family bonds that last lifetimes. They are extremely nest attentive, and defend their young vigorously. What they sacrifice as a
species is energy expended and small numbers of young. Even with these efforts, about 20% of the cranes’ nests fail. At best, a sandhill pair brings
only two juveniles south. – [Narrator] Throughout
the Montana summer, the young cranes grow
at an astonishing rate. Within a day after birth,
they begin to walk, and within two to three
more, the chicks can swim. In 10 weeks, the young begin
flying, and by summer’s end, they are close to the
size of their parents. The rich nesting grounds of Red Rock Lakes has served these sandhills well. By October, the flock is
ready for their return journey to New Mexico’s Rio Grande Valley. While migrating, cranes can
travel over 30 miles per hour. Many times, they take
advantage of thermals and strong tailwinds. Often, they just glide
with the river of air. They travel six to seven hours a day, but the 800 mile journey is not completed in consecutive days. Often the cranes stop over in
Colorado and feed for a while. Weather, of course, is
always a delaying factor. Sandhills like clear, bright days or moonlit evenings to fly. The entire migration
from Idaho to New Mexico will take close to a month. This spectacular footage
was taken by Kent Clegg, an Idaho farmer who has
a great love of cranes and a desire to see the
endangered whooping cranes established as part of the
sandhill Rocky Mountain flock. Whoopers, only a few hundred exist today, have a different migratory route than the Rocky Mountain sandhill flock. Normally they summer at Wood
Buffalo National Park in Canada and winter along the Texas Gulf Coast or in near Aransas. Kent and others believe
that by establishing an alternate migration route, the species will be ensured
of a backup population in case the main population
of whooping cranes meet an unexpected environmental
or natural disaster. To achieve this goal,
Kent has imprinted himself on a group of first year
sandhills and four whoopers. They recognize him as their parent, and follow his lead when it comes to the fall migration flight. He hopes that the flock, by following his ultralight
aircraft to Bosque del Apache, will establish this route as
their annual migratory trek. But even with Kent nearby, the journey is not without hazards. Here, one of the whoopers
is suddenly attacked midair by a golden eagle. After plunging to the ground, the young crane was recovered
with only minor injuries. It was later transported to the Bosque, where it rejoined the rest of the group. The average lifespan of sandhills ranges from 15 to 20 years, although some individual
birds have been known to live for more than 30 years. One thing is for sure, this ancient flyway over the
western part of North America has existed for millennia. Scientists claim that cranes have existed since the time of the dinosaurs. And these sandhills
continue their species’s time honored habit of migration. As humans continue to
populate and urbanize the Rio Grande Valley, the role of the Bosque as a refuge takes on a great significance
for the sandhill cranes. – By the time the cranes reach here, it is already late October or November. The importance of this ancient
flyway can’t be overstated. Perhaps Aldo Leopold captured best the wonder of the crane
migration when he said, “They live and have their
being, these cranes, “not in the constricted present, “but in the wider reaches
of evolutionary time. “Their annual return is the
ticking of a geological clock. “Upon the place of
their return they confer “a particular distinction. “A paleontological patent of nobility, “won in the march of eons.” (birds squawking) – [Narrator] As the cranes return, so do many others to feast
on the rich feeding fields. However, the birds of
the Bosque are not alone in the quest for food. One of the most resourceful
animals in New Mexico also inhabits these wetlands, sometimes at the expense of the cranes. Dr. Jon Boren explains. – I’ve seen coyotes in
about every habitat type in the Southwest, from mountain meadows all the
way down to desert grasslands. But here on the Bosque,
particularly during the winter, you’ll have the opportunity to see some of the most well-fed coyotes
in the state of New Mexico. In fact, some people truly believe that there are more
coyotes here at the Bosque per unit area than
anywhere else in the state. This is not only due to
the abundance of wild game, but also due to the fact
that coyotes are protected from hunters within the refuge borders. This resilient mammal is
constantly on the lookout for birds that don’t
survive the freeze of night, or like this sandhill crane
which died from sickness. The coyote has the same hunting abilities as other canine relatives,
the wolf and fox. Sharp eyesight, excellent hearing, and exceptional sense of smell. Refuge managers here
believe that the coyote plays a unique role in helping these birds survive the long winter. You’ll notice behind me
birds feeding on corn that has been knocked
down by Bosque workers. However, they tend to stay
out of the taller corn because they simply can’t see well enough through the taller stalks. I’ve actually seen this happen. The sandhills will stand
for long periods of time right on the edge of an open area, deliberating if they
should enter the cornfield. Usually they pass on this idea, wary of the possibility of
a coyote laying in the wait. They then just stick to the
food in the open fields. When the birds are finished,
the refuge tractors return to knock down additional rows. In this way, the year’s corn
isn’t eaten all at once, but is deliberately made
available a portion at a time so that the flocks will have enough food until they begin their spring migration. Mike Oldham from the refuge believes that the coyotes do help
the cranes in several ways. – One thing they do is
they keep the birds moving from crop to crop to crop, and they don’t let ’em
devastate their foraging areas. The coyote also picks up diseased birds, birds that would otherwise
stay in the flock and maybe litter the
wetlands with their remains. Coyotes are right there to pick ’em up. – The coyote plays an
effective management role by conserving the corn supply so that there’s enough
for the birds to eat throughout the entire winter. Although this hadn’t been
proven scientifically yet, it does provide for a unique
theory in wildlife management here on the Bosque. The coyote hasn’t been much help to the mule deer populations, however. In recent years, refuge
herds have declined sharply due to disease and coyote
predation among fawns. – In the early ’80s probably
the biggest thing was the scabies mite outbreak that
got in the population. ‘Course, the increase, overcrowding, and all these deer being social together, the mite was pretty well spread
easy through the population. It left the deer vulnerable to predation, and so that was probably what cut down the population the biggest. (coyotes howling) One thing we know about predators, and specifically speaking of coyote, is that they do take
a fair amount of deer. They take about 50% of
the fawn crop that is dropped in the summer. – The deer that have survived
are often tend to be found in areas like this. I really think this place
lives up to its name, a refuge, with an excellent
source of cottonwoods, willows, and shrubs that
do provide the mule deer with an excellent source of shelter and also a bountiful food supply. These mammals are primarily browsers, and can be seen often in small
groups around the Bosque. In the early morning hours,
they graze much like here, eating green alfalfa
left behind by farmers who use the refuge. They also eat naturally occurring grasses and buds from trees and shrubs. The mule deer gets its name
from its unusually long ears. The males have long, graceful antlers that differ from those like the whitetail. If you look closely, you’ll
see that they are forked, rather than having points
rising from the main beam of the antlers as on whitetails. Another mammal that seeks shelter
in the refuge’s vegetation is the porcupine. With a little bit of patience and time, you’ll have the opportunity
to spot one like this in the top of a cottonwood tree. Being North America’s
second largest rodent, only the beaver is bigger, the porcupine puts its teeth to work eating the soft bark of
river trees in this valley. Refuge managers have told
me that their feasting does not really hurt the trees. Their numbers are low enough, and the individuals
travel from tree to tree, reducing the impact on any single plant. The porcupine is probably
best known for its quills, its natural defensive
armor that really makes up for its slow movement. If you take a look
here, these rigid spines make a formidable deterrence
for an aggressive predator. They are loosely attached to the porcupine so that they can easily penetrate and remain within an attacker. These quills are not
shot out of the porcupine like some people believe. Rather, the animal thrashes its tail from side to side vigorously
in hopes of warding off a menacing predator. These animals usually weigh
between nine and 13 pounds, although the record is
a whopping 37 pounds. None have been seen that
large at the Bosque. They tend to lead solitary
life along the Rio here, but they have also been seen
in the desert and grasslands surrounding the refuge. (birds squawking) Coyotes, porcupines, and mule
deer are not the only mammals that you’ll find here on the Bosque. With a little bit of
patience and a keen eye, you’ll have the opportunity
to spot elk, beaver, bobcats, and even an occasional mountain lion wandering in from the
surrounding Chihuahuan Desert. These mammals, along with others, do make up for the diverse fauna that you’ll experience here on the Bosque. – [Narrator] While mammals are attracted to the lush environment of the refuge, so too are the hunters of the sky. They are the raptors, or birds of prey, those aerial masters that rely
on the abundant food supply that the Bosque supplies. The most spectacular of these
hunters that resides here is the American bald eagle. This threatened species
inhabits the refuge from December through March, and can often be seen
perched above the wetlands, looking for prey. (birds squawking) Eagles, like this immature
bald, usually eat fish, but in the wintertime,
these birds tend to eat a variety of things. In this season of shorter
days, colder temperatures, and a relatively scarce food supply, the eagles come here. The Bosque supports
waterfowl by the thousands. During cold spells when
Rio and pond water freeze, it is almost a daily occurrence that a few of the huge
flock’s weaker members don’t survive the night. The bald eagles scavenge
the birds that die. Here, an immature bald feasts on a bird. But not for long. This mature eagle chases
the younger bird away. The dead bird now belongs to him. Evidence of the kill is frequent in the fields of the Bosque. But the eagles also use
their predatory skills. (birds squawking) Often when a group of snow geese are disrupted during the day, it is the work of a bald
eagle rousting up the flock. But most of their time
is spent watching for an easy opportunity. A dead bird on the road. A slower, weaker member of the flock. There are quite a few immature
members in this year’s group. Of the 25 bald eagles here
this winter, 20 are immature. Their coloring ranges from
white and brown speckled to almost black. It takes them years to get
the distinctive white crown of their elders. Immatures change gradually
over each summer. They eventually use
their brown, spotty look, but this doesn’t occur
until after their first four to five years. Immature balds here
can be seen quite close to the visitors’ tour loop. They like this bare tree that
was put here by Bosque staff. The adults also go for this perch. For 360 degrees, the
eagles can scan the horizon over this wide pond. It serves as an idea lookout. It also serves as a resting
place for this adult to finish a meal. But the bald eagles do not
have a monopoly on this tree. This crow likes to perch here too. Soon, he is joined by several other crows, who hope to pick up some dropped scraps. But the eagle lets his
objections be heard. (eagle chirping) Finally, the crows get
the hint and fly away. The mature bald, while still
seeming a bit irritated, is finally left alone. Far more serious disturbances
can be caused by humans, and for these birds, that can be problematic during the winter. In the days of limited
sunlight and cold temperatures, eagles waste valuable
hunting time and energy flying away from people. Those balds who prefer
a more secluded roost can always choose to stay
in the limited access sections of the refuge
that receive few visitors. Bald eagles are but one
species of raptor found here. Several types of hawks also
cruise the Bosque flyway, like this northern harrier. With amazing dexterity
and use of the wind, this bird is constantly
screening the grasses for small rodents. The Swainson’s hawk is also found here. But none is more frequently
seen than the red-tailed hawk. They perch among the same
dead trees as the bald eagles in search of prey. On this small island in
the middle of a pond, a snow goose failed to survive the night. Just after first light, a
red-tail inspects the fallen bird. And then eventually leaves. 10 minutes later, a northern harrier hawk flies overhead to inspect the goose. As the day gets brighter,
the red-tail quickly returns to claim its prize. Finally, he begins to feed. Over the next two hours, the
hawk devours the snow goose. (melancholy music) Mallard ducks casually drift by, seemingly unaffected by what
is happening on the island. Finally, with most of the snow goose gone, the red-tail takes off to finish
his meal on a nearby perch. The bounty of the Bosque
has again provided for the hunters of the sky. Only feathers and a bit of
carcass remain of the snow goose. Nighttime hunters of the refuge include several families of great horned owls. This one resides in a cottonwood tree in the bottom of the valley. This nest is also located in a cottonwood, but an isolated one in the
surrounding desert brushland. This parent chooses to raise its young in the shelter of these cliffs
at the southern boundary. American kestrels are the
smallest of the raptors here. In fact, they are the
smallest of all falcons. Their sleek bodies and alert
instincts help them feed on the smaller rodents, insects,
and reptiles of the refuge. These streamlined,
powerful hunters of the sky were formerly called sparrowhawks. Just like their animal relatives, it is quite logical why
humans over the ages have been drawn to the
shelter of the Bosque. With abundant water, plants, and food, this habitat has always been full of life compared to the relatively
sparse desert surroundings. The Spanish named this
place Bosque del Apache, which means Woods of the Apache, for nomadic Mescalero
Apaches often visited here. But long before their arrival,
there existed another group, one that made this resting place on an ancient flyway their home. – The people who lived along the river in this part of New Mexico
are known as the Piro. The Piro populations who
inhabited this area of the Bosque located here because at that
period in their history, this region offered the ideal
circumstances and climate for the kind of agricultural lifestyle that they depended on. It was lush with game. (lively music) There was plenty of water. (lively music) The frost-free season during the year was long enough to
successfully produce good crops of corn, beans, and squash. (lively music) – [Narrator] In rocky area
surrounding the Bosque exists a rich visual record of the Piro. Petroglyphs, symbols
diligently etched into rock with hand tools, tell much
of what the environment was like here centuries ago. – [Pete] We see that certain
animals are emphasized more than others. These people seemed particularly
concerned with deer, mountain sheep, various species of fish, as well as the birds. We see a lot of birds in the rock art, including some of the more famous ones that draw so many visitors
to this region every winter. – [Narrator] This ancient image
outlines a long-necked bird with a strong likeness
to a sandhill crane. This piece possibly mimics
a goose while in flight. (birds squawking) And this form has the distinctive shape of the mythical thunderbird. Many of the petroglyphs around the Bosque seem to take on a spiritual quality, and speculation of what
these symbols represented is limited only by one’s imagination. However, it is perhaps better
to look at this aged rock art from a historical, rather
than an emotional perspective. – Probably the biggest problem
in understanding rock art is the fact that it represents the symbolic conceptions of
people who are long gone. Native peoples didn’t make
the kinds of distinctions between the sacred and the profane that modern industrial
populations make today. All of the birds and animals and natural places on the landscape were both sacred and of
everyday significance. There’s really no way
to effectively read it. – [Narrator] While the rock
art sites in and around the refuge serve as the
most visible reminders of the Piro past, one of the most significant finds is here. To the untrained eye, this place along the eastern edge of the Rio
looks quite unremarkable. But if you look closer, small remains of Piro greatness remain. Shards of highly decorated pots. A well-worn tool used for straightening the shafts of arrows. And finally, chipped points
used for hunting local game. Underneath this ground
lies one of the largest Piro settlements of the past. It is called Qualacu. In the 1980s, archeologists
opened part of this ancient Piro town and were impressed by the size and structure. Estimates are that over 1,200 people could’ve lived at Qualacu, but records from an
early Spanish expedition give an even more vivid
picture of what life was like for these Bosque residents. – [Man] Their houses are
of mud, built by hand. The walls like like small
adobes, a half yard wide. They contain upper and lower
floors and have bedrooms. The people climb to the upper floors by means of movable hand ladders, and the lower parts of the pueblo can be dominated from above. In each pueblo, in the
center of the plazas, are some very large
cellars, 2 1/2 estados deep, with an entrance in the
shape of a trap door and with a stepladder. They are all whitewashed and provided with stone
benches all around. Here, the people perform
their games and dances. – [Narrator] Luxan’s account
of the Espejo expedition, 1583. But by the end of the 1600s, most of the Piro culture had disappeared. Disease from the newly
landed Europeans killed many. Others moved to the northern pueblos. Later, some joined the
Spanish in their retreat from the Pueblo Revolt. In any event, the effects were dramatic. Within 100 years of their
first Spanish encounters, the Piro as a unified
culture ceased to exist. Humans have changed
the Bosque in many ways since the Pueblos’ disappearance. Spanish settlers also tapped the Rio for agricultural water, developing a sophisticated
system of acequias, or irrigation canals. Later, gigantic dams were
also built along the Rio to ensure constant water supply throughout the growing season and to eliminate flooding
from the spring runoff or summer monsoon rains. River communities expanded
into the previously vulnerable Rio Grande floodplain, and eventually, plants were introduced that were not native
to this ancient Bosque. This one, tamarisk or salt cedar, was introduced in the 1940s
to help control erosion. Since then, it has become
the dominant vegetation, causing a number of problems. Dr. Kirk McDaniel explains. – There’s nothing wrong with
a monoculture of salt cedar if you had a little bit of it. But when you have virtually
nothing but salt cedar over a large area, then you’ve created a situation where you’ve got a habitat that’s only desirable to a very limited number of species, and for a wildlife refuge,
that’s not very desirable. – [Narrator] Since the late ’80s, McDaniel has worked with
refuge biologist John Taylor on reducing salt cedar at the Bosque. They used a combination
of mechanical removal, carefully applied herbicides, and fire to get rid of
this invading plant. Here the remaining dead salt
cedar provide an environment for a popular rookery, a place where birds gather to
nest and bring up their young. Today, great egrets and
cormorants flock to this area, where just last year, the impenetrable tamarisk
groves prohibited nesting. But in other areas where
salt cedar had been removed, only open fields of dirt remain. If other vegetation was not established, the salt cedar would quickly return. The perplexing question was,
what to put in its place? Taylor and McDaniel decided to mimic the historic cyclic flooding of the Rio, which occurred here before the dams, and to reintroduce native plants, like cottonwood and willow. – We’ve kinda controlled
salt cedar on an area. The area, it’s kinda left much as if the river had just come
through with a severe flood and created a, or scoured
and created a mudflat. We’ll develop water management
capabilities all around. We’ll build dykes around, we’ll divert irrigation
water into an area, flood it up to peak levels, and during that period,
late May, early June, we’ll begin dropping our water levels and creating that mudflat. Every year in late May, early June, cottonwood and willow release
thousands and thousands of aerially borne seeds. (peaceful music) It’s timed ecologically to coincide with those flood events. It’s just like a blizzard in some days. So the seed lands on that moist substrate, it germinates generally
within about 24 hours, and you get a seedling. There is no longer that
natural function anymore, so it’s incumbent on us to recreate that, to reproduce that, or
else we’ll continue to see salt cedar dominate and
area of vegetation change. – [Narrator] Today, Taylor and McDaniel can walk through large areas of cottonwood and other native plants, much like the Piro did centuries ago. While many visitors concentrate on the riverside area of the Bosque, it comprises only 5% of the
total land area of the refuge. Flanked on both sides of
the Rio are square miles of Chihuahuan Desert
foothills and grasslands. And while the comeback of
native plants in the wetlands is quite a remarkable story, the desert also has its
share of botanical marvels. Dr. Kelly Allred explains. – Most people think of
the Bosque del Apache in terms of a place like this, a rather typical riparian habitat with cottonwoods and cattails, and indeed, this is
what most visitors see. These areas look this way
due to the abundance of water supplied by the river, and also from the thick,
dense soil found in this area, layers of rich sediment
brought down this valley over the millennia. Today, however, we’re going
to travel away from the river, to areas on the refuge
where few people go, and see how differences in soil and water change the kinds of plants
that grow in a particular spot. Right here we’re standing next to the definitive edge of the wetlands. Just behind us is the Rio Grande. However, in the matter
of a few short steps, you can see we make an immediate change from a Rio environment
to a desert environment, with absolutely no
transition zone in between. Along this dividing line, you can see an abrupt change of plants. Here we find sand sage, broom
dalea, and giant dropseed, each one adapted to living
in the shifting sands of this dune environment. One big difference here is water. We’re only a few feet
higher than the river, but far enough that the
water table is well below us. The other difference is soil. Rather than the heavy clay
soil of the river bottom, what we have here is loose sand. In this dune area,
water percolates rapidly through the soil particles, leaving a dry soil surface. Let’s take a walk now and
travel the Chupadera Trail, another place on the
Bosque where desert plants live in the extreme. (peaceful music) This is a typical Chihuahuan
Desert brush community. The refuge lies at the northern
tip of the Chihuahuan Desert which occurs mostly in Mexico, plus parts of Arizona,
New Mexico, and Texas. A dominant shrub of this
region is creosote bush. As you can see, it’s very well adapted to life in gravelly, well-drained slopes. Its leaves are covered with a varnish that reduces water loss. This is what gives creosote
bush its fragrant aroma after a desert rain. I’m standing along a distinct borderline between two plant communities
of the Chihuahuan Desert. To the south is the brush
community, with creosote bush. This is a hotter, drier environment, receiving direct rays from
the sun most of the day. By taking just a few steps to the north, we’re in a grassland community. Because of its north-facing slope, it’s more moist, has more available water, and the grasses are able to grow. What you see here is the
desert grass, black grama. This is the typical grass
of the desert grasslands, although the soil here
is basically the same as on the south slope. Black grama cover here is denser,
which reduces evaporation, along with the fact that this north slope receives less direct sunshine. Well, it’s time to continue our hike, this time to the Canyon Trail, and visit yet another plant
community on the refuge. We’re going to go back in time to a community that was here
at the end of the last ice age. Come on, let’s go! (peaceful music) Here we are at the high
point of the Canyon Trail. And what’s interesting about this place are these two junipers. Junipers give us a window into the past. Plant communities often
shift, slip and slide, change with changes in environment. During the ice age, the
climate was much different than it is today. The environment was wetter and cooler, and the plant community
was very different. Even down by the river, the dominant community was a woodland, and the chief species was this juniper. As the ice melted, the
climate shifted again, and became warmer and drier, and there was a shift
in the plant community. These pinyon trees and the
woodland plants with them had to retreat away from the lowlands up into the higher elevations. They were replaced at the lower elevations by the grassland and the
desert brush communities that we’ve just seen. The woodland communities
retreated back into the hills, back up into the mountains. Today, few junipers exist in
this area, and as we’ve seen, dessert shrubs and grasses
dominate the vegetation along the river. This arid environment
surrounds the Bosque, and ever since the ice age,
this green strip in the desert has been a welcome destination
on a very ancient flyway. (birds squawking) – [Narrator] Back in the valley, spring has returned to
the Bosque wetlands, and with it, the relentless spring winds. Many different birds travel
ancient migratory routes and use the Bosque as a resting
stop along their journey. But what is most striking
is the large number of waterbirds that come here, like this flock of white pelicans, species that you would
normally expect to see along America’s coastlines
or inland lakes, certainly not in the middle
of the New Mexico desert. These shorebirds and waterbirds are well adapted for feeding
along the wetland banks, and the Bosque attracts a
number of different species. There are American avocets, (birds squawking) and white-faced ibis with
brilliant iridescent plumage. Snowy egrets also search for food here, stirring up the wetland
bottom with their feet. (bird squawks) Another waterbird that
hunts the Bosque waters is the belted kingfisher. (birds squawking) Long-billed dowitchers
also stop to feed here. They are the migration marathoners, wintering in Mexico and
breeding in the Arctic tundra. The larger wading birds of the Bosque include the great egret and the great blue heron. Another heron species is the
black-crowned night heron. These noisy nocturnal herons tend to favor this western
edge of the refuge, where thick foliage allows
them to conceal their nests. With great flocks of
sandpipers gracing the skies, springtime marks the very special season of shore and waterbirds. Their syncopated aerial
acrobatics are indeed a wonder to watch. And as the spring birds
signal the beginning of yet another year, one can’t help but ponder
the past importance of this ancient site. Bosque del Apache is a
special place in a dry land, an oasis on the fringe of
the arid Chihuahuan Desert. It has nurtured humans for centuries, allowing them to build
great civilizations, as evidenced by inspired Piro ruins, and for millennia it has
served as a major intersect along the ancient flyway
of the Rio Grande. But perhaps its role as a refuge is even more relevant today. This remarkable place
is of utmost importance for many of the region’s animals. As human population increases
in the river valley, the role of the refuge in preserving a nourishing environment becomes even more critical. It is in our best interest
to continue this preservation for ourselves and our earth, to which we are inescapably linked. (peaceful music) (birds squawking) – [Announcer] The
preceding was a production of New Mexico State University. The views and opinions in this program are those of the author, and do not necessarily
represent the views and opinions of the NMSU Board of Regents.