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I've heard it said out here in northwestern Nevada that this ain't much of a river.
It's the East Walker River, and you'd probably have a hard time finding it on a map.
You can't compare it to the Colorado or the Rio Grande,
but in fact it's of vital importance to this corner of the United States.
Hi, I'm George Page for Nature, and the East Walker here is a lot more important than it looks.
It's one of the very last healthy riparian habitat systems left in our great western deserts.
Riparian simply means river and all the plant and animal life that flourishes along its banks.
The East Walker is a symbol of our continent's desert rivers.
There's never much rainfall out here, but for as long as anyone can remember,
the East Walker has never failed to provide its life-giving waters.
And so our film this week on nature celebrates yet another little natural piece of America
it would be mighty nice to save for future generations.
This is a story about water where you'd least expect to find it,
about life where one might think it shouldn't belong.
This is a tale of two worlds, one lush, one blistering dry,
and how together they are exploited by many lives,
connected by common needs, bound together in a singular purpose.
This is not an uncommon harmony, a bizarre occurrence on the frontier.
Rather, it is a theme of all life, the struggle to find water in a land of sand and rock,
man and animal's recurring quest.
The need for water is at the heart of all existence, even where survival seems assured.
Boisterous but fragile, subtle yet obvious, generous while merciless,
the hero of this story is simply water, desert water.
This is the river that shouldn't be.
It is late winter, banks, flood plains, cottonwood groves, and desert
seem united by a monochrome gray of lifelessness.
Soon all this will change, this river prospers because of its extreme seasons.
The Great Basin Desert is 5,000 feet above sea level and therefore cold.
It's a desert because in the rain shadow of the Sierra Nevada Mountains,
little precipitation reaches this country.
But moisture it does receive arrives most years as winter snow in the mountains.
Even now there is a stirring at the river edge.
Three weeks ago, a nest abandoned long ago by magpies was appropriated by a great horned owl.
She isn't fussy, she didn't even make one repair before settling in and laying her three eggs.
This owl of all creatures is the harbinger of spring.
Across the river a week later, one plume silhouette appears in an old colony of nests
established a decade ago by great blue herons.
They have returned.
These residents of River, Lake, and Marsh have resumed their life in this desert oasis.
On the spire of the river's forest at the crown of a cottonwood tree,
the year's breeding season is heralded by a display of somewhat equivocal courtliness.
A male heron removes a branch from the nest of an unsuspecting neighbor to take it to his own mate.
This year the snow and the Carson spur on the skirts of the Sierra Nevada mountains has begun to thin as early as March.
The waters of the East Walker, a mere 65 miles between destination and source, were born at 6,500 feet,
in country where cottonwoods are scarce and seasonal nesters few.
Here, a thousand feet above the flood plain, gravity will launch a snowflake on a journey that will modify a desert.
A river is but a multiple of a drop of water.
In early spring, only a skiff of snow from last night remains.
By afternoon, it will be gone, adding to the heavy belly of the river and rushing the catkins on the cottonwoods into bloom.
One tree may distribute over a hundred thousand seeds a year.
Seemingly overnight, the cottonwoods are girded with a heavy canopy of summer.
Several hundred yards from the river on the desert floor, there is another fleeting celebration.
Proof that out here, the Promethean secrets of wildflower seeds can be kept for two, five, sometimes even fifty years.
The patient alchemy of heat and sun and just right rain.
Desert flowers, however, may be like a mirage.
The constant here is the tight-fisted drainage of the East Walker River.
When it cuts a wide meander across bottomlands, it distributes its bounty with largesse.
The river is not nature's fence. It is rather this country's heart.
And last year's coyote pups, all brothers, have access to a territory which crisscrosses the river and whose limits are too subtle for the human eye.
Spring floods revitalize the river, replenishing the floodplains with sediment from the mountains, sowing seed beds for summer and recharging the water table against drought.
Last year the floods were high. Today, their progeny of cottonwood seedlings are putting down roots that one day will prevent this bank from eroding further.
The Fremont Cottonwood is the symbol of the river's abundance.
For the early settlers, this tree symbolized essentials, water and fuel.
Today, in this habitat, one of the most endangered in North America, the cottonwood is a high rise of reproductive activity.
But they are not stable shelters, for a cottonwood grove consists of a single generation, germinating together and an old age dying together.
The death of one may be a whisper that others will soon follow.
In a cavity beneath the cottonwood, a desert pack rat has established his midden.
No one yet knows why this rodent is driven to collect the flood's debris, bottle caps, bones, juniper berries.
In doing so, he leaves behind an archaeological record of his life and times.
Meanwhile, at the pinnacle of the high rise, there's only one survivor of the clutch of three great horned owl eggs, an average survival rate here.
This year's first born is one week short of fledging.
No matter how abandoned it may at first appear, this thin riverine forest is remarkably rich as a nursery for vertebrates.
Late in spring, a recently rebuilt stick nest of the western red tail hawk is top heavy with young.
In one 13 mile stretch of the East Walker, there were this year 15 red tail nests, all second hand accommodations built by other species or other red tails in other years.
Lured to the cottonwoods for their height, the red tails can fan out from this nesting base on the river to exploit the vast, arid shrublands of northern Nevada.
At four weeks, their talons, essential hunting weapons, have far outgrown the rest of their bodies.
Today, the prize might be a pocket gopher or a jackrabbit, even a rattlesnake, prey that almost invariably comes from the surrounding desert.
These youngsters are symbols of how prey from thousands of square miles of desert contributes to the life concentrated along this narrow riverine forest.
Equally, the cottonwoods are testament to a convenient coincidence for the red tails, a high wetland perch at the center of a desert food source.
By depending on two worlds, the high cottonwoods of the river and the high protein of the desert, the red tail has found a brilliant way to exploit a food source that otherwise might be overlooked.
The red tail spots its prey not so much by color, but by movement. The beachy or California ground squirrel.
The only poisonous snake of this cold desert, the Great Basin rattlesnake.
The pocket gopher, above ground only fleetingly.
The whiptail lizard.
And for only four months each year, the towns and ground squirrel is available to the red tail as prey. In winter, it hibernates. In summer, it sleeps two or estivates to avoid the heat and lack of water.
For each, vigilance is the only protection against red tails.
The highest elevation of this river canopy is occupied by great blue herons.
These have kept to themselves during the winter. In spring, with the breeding season, they exhibit a temporary colonial instinct.
Such sociability may appear out of character, for the majesty of this waiter seems to lie in the art of solitude.
If any large bird has mastered the multitude of wetland habitats in North America, it is this elongated waiter.
Alongside the river, the colony has prospered. Now, in mid-May, the young are eight weeks old.
This parent, with three to feed and food close at hand, transforms a very simple family errand into a monument to flight.
This marsh is temporary.
It's no more than a depression, which at present lacks any drainage into the river.
But for eight halcyon weeks after the spring floods, it attracts some special migrants and becomes a miniature fiefdom along the greater kingdom of the river.
Some eight species will nest here. Another sixteen will bivouac in these quiet waters on their way further north.
Accurtained by forbs and sedges, cattails and bulrushes, the marsh's first arrivals are American coots, born to dive, reluctant to fly.
The young are still unable to retrieve vegetation from the marsh bottom. They must make do with surface flakes while awaiting their mother's help.
The sedges throughout the marsh attracts the yellow-headed blackbird.
Here, life emerges, clinging to the cattails.
The male takes more than one mate. At this time of the year, his major role is boasting through exuberant song that his minute territory is more productive and impregnable than any other yellow-heads.
And as he sings, the several mates of his heron must doggedly provide for their young so they can be flying before the marsh dries up.
Man's hand is everywhere, it seems, even in the still waters of the marsh.
Many years ago, we thought he was doing the right thing by introducing the eastern bullfrog west of the Rockies.
Today, they've proliferated by feeding on resident frog species, and their chorus is often the most powerful sound on the river.
On the last day in May, a solitary pair of migrant black-necked stilts return.
And today, on the first of June, the population of these migrants has swelled, their long pink legs distinguishing them from all other waders.
They've been lured to the marsh by its rich load of insect larvae and worms.
An unlikely pair of white-faced ibis towers above this dowager.
This diminutive wader will pause only briefly before flying north to the subarctic to breed.
The arrival of the ibis is a good omen.
Fifteen years ago, its population was severely threatened by insecticides and wetland degradation.
Today, its numbers here have begun to grow.
The great blue heron competes with none of these transients.
While it raises its young in colonies, as a fisherman it remains a solitary figure, preferring almost always the stillest of still waters.
Its technique is living slow motion.
For hours it will stand and wait, unblinking as a rock, anticipating the approach of unsuspecting prey.
Otherwise, it will stalk so delicately as to leave barely a ripple on the surface of the water.
There is no marsh fish too small for the great blue heron, and herein lies its success.
When large fish vanish, the modest great blue will still prevail and celebrate.
On the East Walker, the shortest distance between two points is generally not a straight line.
The river needs the wide meander to remain productive.
On the outside corner of every bend, there's a cut bank.
On the inside, a point bar where sediment is deposited.
The meandering allows erosion and deposition to stay in balance.
Where man has straightened the bend, such rivers have often become essentially deep canals,
which in turn increase erosion, lower water tables, and ultimately threaten the riverine forest with desertification.
Each year, the East Walker defies map makers and farmers alike by carving new banks, plotting new courses.
Here in this cut bank cross section, we can see just how limited are the effects of a desert river.
Not two feet above the water's surface, the capillary action of the loamy soil ceases.
Desert shrubs like sagebrush could live above the line, but cottonwoods need their root systems and the damp soil below,
the soil that predominates on the point bars of the river.
One clear advantage of the spring floods is their knack of exposing a ground squirrel's tunnel.
That means something, especially for a barn owl, which might have preferred to nest in a cave,
but found all such residences on the East Walker already accounted for.
Before long, she has improvised the almost perfect alternative.
The first of eight was hatched in mid-June.
And the others emerge, one every two days, the same interval at which the eggs were laid.
The enormous size of the clutch gives yet another clue to the wealth of the East Walker.
By the 20th day, the vast inequality between the youngest and the oldest nestling is glaring.
And on the 25th day, five are now adjusting their eyes to light and movement and the erratic swarming of insects.
To the newly hatched chicks, the eldest appear to be of another generation,
and the little ones look to them for nourishment.
Today, they hear a new sound above the roar of the river, the drumroll of thunder.
This midsummer storm, smelling of raw earth and new shoots, is characteristic of the desert's boomer bust cycle.
Here, annual rainfall may vary from seven inches to only half an inch.
The livelihood of the desert rides on the whimsy of summer storms.
The flood replenishes the river plain with organic debris and rich sediment from upriver.
It also threatens to cut into riverbanks, but cottonwoods with their long, shallow root systems stabilize these banks.
While some nests in the existing marshes have been flooded, new marsh habitat has been created.
Floods make possible the propagation of the cottonwood.
These saplings were laid down last year, and if they survive future floods, they may one day provide shade,
as another generation reaching the end of its life still does.
Now, at the onset of July, the moist habitat in the cottonwood shade, the nearby wetlands,
and the irrigated fields of alfalfa have set the stage for an insect explosion.
And with a sudden multiplication in the number of insects, there's a corresponding increase in the number of birds which feed on insects.
The Bullock's Oriole uses the cottonwood limb to suspend its nest.
The Western Tanager finds the cottonwood bark infested with larvae.
And the Western Kingbird, king because of its commanding nature.
But of all these birds on the river's edge, the most brilliant is the Western Bluebird.
It exploits the insect bounty of these abbreviated wetlands with as many as two clutches of young in a good year.
The male and female take turns hunting and feeding.
This year, in this nest, the domestic arrangement was quite remarkable for bluebirds.
A second male, perhaps unable to find a mate of his own, volunteered to help with the feeding,
praising the odds that all three eggs might graduate into fully-fledged Western Bluebirds.
The result takes its turn cleaning the nest and grooming the young.
For the parents, insect collection absorbs 16 hours a day, before dawn to after dusk.
At dawn, the mother saw the first-born leave the nest.
And now, the second-born sees the river for the first time.
The speckled chests of the youngsters are evidence of their kinship with the thrush family.
Eventually, these bluebirds will disperse far beyond the East Walker.
As summer progresses, undisturbed stretches of the East Walker are hopscotch by stands of milkweed, which attract vast populations of insects.
And now they are going to join the
Also on the river's edge and soil disturbed by the flood, sunflowers grow before one's
eyes.
In the adjacent desert above the reach of the river's water, flowers must contain their
growth.
Barely will they stand over a foot, and as soon as they bloom and set seed, they wither.
Deserts make for economy.
Here both flowers and the insects that depend on them can live all of life in one day.
The desert is not always that innocent of water.
A flash flood in the mountains a week ago created a spring.
It lasted for only two days, but it produced a minute and fleeting subculture of regeneration.
When it vanished, it left no trace of its passing.
A mountain stream that flushed into the East Walker actually lasted for two summer months.
When it dried, the impact of its passing was felt by the vegetation 20 feet to either side.
But even bone dry, the desert is hardly a wasteland.
One of its most prolific residents is the antelope ground squirrel, so called because
it shares with antelopes a bright white patch beneath its tail.
This is one ground squirrel which hardly restricts its movements to the ground.
Like many desert residents, the small rodent lives where there is no drinking water.
It survives by obtaining moisture from its food, succulents, insects, and carrion.
Even when its body temperature reaches 110 degrees, it will not sweat or pant.
Instead, it retreats underground for instant air conditioning.
While the antelope ground squirrel may be a delicacy for the coyote, the energy required
to take one is hardly worth the protein reward.
Coyotes generally have more substantial quarries in mind.
Much maligned, this predator is the desert's great leveller.
Rotting mostly at night, it adapts its lifestyle to whatever prey is most numerous, thus keeping
a very necessary check on the rodent and jackrabbit populations.
In late afternoons, heat rising from the desert sand and rock creates a myriad of fluky updrafts.
Ravens ride these thermals for hours, seeming to play, pushing the wild abandon of flight
to its limits, dogfighting with a precision denied to anything mechanical.
One human would mosquitoes too, throughout the world.
This is not a land of compromise or subtlety. Where the desert ends, the river
begins, and in between there is no transition zone. Because these two
ecosystems exist shoulder to shoulder with each other, two different plant and
animal communities, those which depend on the river and those which don't, are
integrated. In the final analysis, the desert river is the enduring
stability in a land of boom and bust.
A coyote pup recently emerged from his den near the river will probably live
his entire life within a four-hour trek from the East Walker.
But the red-tailed hawks, a species that contributes over a nest each mile along
much of the river, represent in a sense that filigree bridge between river
regeneration and desert protein. Late in this desert summer, the young are nine
weeks old. For the last three days, they have been testing their wings. Today,
their preoccupation with leaving the nest is intense. As soon as they set foot
outside the nest, they discover one of the primary nuisances of being an adult.
It appears the fate of such raptors is to be forever mobbed by Western kingbirds,
bullocks, or eels, and any number of songbirds. Goliath against an army of
Davids. In this case, Goliath doesn't fight back. Each fledgling has a personal
style of preparation for its first flight. For the watching oriole, there
seems to be a triumphal ceremony of raised tail and quivering wings when it
scores a direct hit upon such an uncertain bird of prey. This one isn't
taking a chance. His test flight takes place in the nest. At last, at 430 on an
August afternoon, the first red tail launched itself from the place of its
birth, heading for the bountiful desert.
Even this journey was not without its hazards.
As summer advances and with hardly any rain in the Carson Spur for the last two
months, the East Walker falls, exposing even more of its cut banks. The eight
barn owls have excavated a labyrinth of chambers beneath this bank, and the
family has dispersed into nooks of their own. The oldest are now very close to
fledging, but the age differences are still dramatic. Barn owls are among the
most nocturnal of all owls. Their eyes will be able to detect movement in all
but the blackest of nights, and their ears are like no others. By now, the
parents must provide for this large growing brood with as many as ten rodents
a night. Even the caverns they have excavated are now too small for these
youngsters. And between each nocturnal hunting foray, there is no time for rest.
Present the prey and away to the desert. More than likely, the parent located
this pack rat by listening. Barn owls are gifted hunters because of their
extraordinary ears, adapted for pinpointing sounds and their soft feathers
rigged for silent flight. Each one of these barn owls will one day roost not
far from this site along the river. Like the red tail, they too will find much of
their food on the desert floor. The river, on the other hand, will always mean
sanctuary.
Every day in high summer, snowy egrets fly 50 miles each way to fish the East
Walker.
Late in the afternoon, these snowies perch on willows and cottonwoods, drying
their feathers for the long flight home.
But to say the East Walker is an undisturbed oasis in the desert would be
denying the awesome influence man has exerted over this river since he started
admiring it 130 years ago.
He admired it but damned its flow and then released it to improve on natural
seasons. He admired it but diverted it to country which he thought nature had
overlooked. And because he admired it so much, he divvied it up, building fences
often at cross purposes to the river. And then, thanks to fences, he undertook to
buy and sell the desert. He needed these fences for the exotic cattle he
introduced. Good producers, but the price of high yields was a kind of
high-handedness with the river. Cattle broke down the riverbanks and then
overgrazed and trampled cottonwood seedlings and in some cases threatened
the regeneration of the forests. In the end, the desert broke most men. The river
might have seemed provident to newcomers but it was only provident on its own
terms.
The minds and hopes, the wealth and dreams came and went like occasional
desert springs.
During the
last two decades, man entered into an even greater partnership with the river
and its delicate water table. By pumping water, not just diverting the stream, he
could achieve magic. The cost was steep, more than ten gallons of water per acre
a minute, but the results were remarkable. Overnight, the desert was
yielding no less than two valuable crops a summer.
Almost always, the farmer and the rancher cared deeply about this river. He never
intended to abuse it, just improve it from time to time. And indeed, in the
very constancy of its flow, the river seemed beyond destruction. Because of
irrigated ranch lands, species previously unknown in the desert, like the
brown-headed cowbird and the blackbird, now fill September skies. This time of
year, the waters of the East Walker are low and timid. Normally, the young
kestrels would have fledged by now, but their first nest was destroyed in a
summer storm. The parents were left to start again. And just before they leave
the nest, their mother goes in search of a final offering.
The last lizard of summer.
Such a scene is part of the ancient continuity of the East Walker. Kestrel
numbers, it would seem, have not been affected in this region by man's
presence over the last 130 years. By early October, the East Walker has once
again retreated into privacy. The red-tailed hawk nest has now been vacant
for several weeks. The cottonwoods are turning, and snow has reappeared on the
Carson Spur of the Sierra Nevadas. For the rancher, it's a time of change too.
Cattle are brought in from distant pastures to the aftermath of hay lands
and the security of river bottoms. All over, the first frost has supercharged
every color along the river drainage. This outburst of clear waters and
brilliance will last a mere month. Here, winter comes early.
Out of the mountains, across a flat plain, and finally into its destination,
Walker Lake. Not a long journey as rivers go, but in this desert country, a great
and vital journey. Today, it is complete. The year of the East Walker is at an end.
For all its virtuosity, for all the country it replenishes, the East Walker
is, after all, a little river, and the mark it has made on the West, at least in
man's terms, is fairly modest. But looked at another way, it stands shoulder to
shoulder with the rivers that are the very stuff of legends. The Green, the
Dolores, the Humboldt, the Yantla, the Rio Grande, the Colorado. Man has had a love
affair with these rivers, the Desert River. He used them to open up otherwise
inhospitable country. He rhapsodized about their sweet water, the abundance of
their game, the shade of their great trees. But in loving them, he despoiled
them. He fell the trees, dammed the narrows, fought others over the water,
redesigned the channels, and then was surprised, even outraged, when these
rivers were no longer provident, and the bounty of the deserts verged on
wastelands. Most of these lessons, man's had time several decades to learn. If
anything, he has found the rivers forgiving.
So it is with the East Walker. Once dammed, often squandered, it still survives.
Indeed, it prospers, because at the eleventh hour, we learned just how much we
needed this little, boisterous, fragile, generous, and merciless flowing oasis.
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