Sunday, November 4, 2018

California Waters: The Deserts ---Guest Post---

“Strolling on, it seems to me that the strangeness and wonder of existence are emphasized here, in the desert, by the comparative sparsity of the flora and fauna: life not crowded upon life as in other places but scattered abroad in spareness and simplicity, with a generous gift of space for each herb and bush and tree, each stem of grass, so that the living organism stands out bold and brave and vivid against the lifeless sand and barren rock. The extreme clarity of the desert light is equaled by the extreme individuation of desert life-forms. Love flowers best in openness and freedom.”

Preserving space
There’s a fence. So we turn our car to the right and go around...and around. Miles drag on desert roads of a certain quality. It’s wonderful that the Desert Tortoise Research Natural Area has expanded to encompass nearly 40 square miles, I just wish they had told our maps program.

A Longnose Leopard Lizard (Gambelia wislizenii)
in front of the interpretive center
Other than the dirt road, the fence, and the occasional pile of trash dumped by some fool, there is little evidence of human presence. The parking lot we eventually reach is empty save for a leopard lizard. It lies prostrate against a rock, soaking up the early sun.

Good omen.

As I shared in the first installment, we had set out on a journey across California to see how the state’s most vulnerable herp populations were coping with the pressures of the 21stcentury. My fellow-traveler for the desert stage of this odyssey is Matt Dagrosa, a wildlife surveyor from Oregon who has traversed nature with me since childhood. We want to witness the effects of ongoing drought and development on desert herptofauna – myself as someone who spent a fair amount of time here back in the years before drought conditions peaked, and Matt as a first-time observer of this unique desert assemblage.

We enter the preserve and loop in opposite directions to scan the landscape from as many angles as possible. Flat, sparsely vegetated desert gives way to more desert, beyond which sprawls yet more desert as far as the eye can see.

It takes patience to find the jewel in all this space
Diligent attention reveals life scattered amid the space. We come across side-blotched lizards, tiger whiptails, zebratail lizards. The first find worthy of a shout is a Desert Horned Lizard (Phrynosoma platyrhinos) camouflaged against the sand. If not for a nerveless dash it would have remained undetected. Then, to our delight, Matt spots a Mojave Desert Tortoise (Gopherus agassizii).

Not content with one tortoise, we loop opposite routes on another trail. I take a wrong turn and end up on a longer path. Soon I lose sight of Matt. Pushing on, scanning in every direction, I look to expose a tortoise, a rattlesnake, some interesting denizen of the dryness. Lizard life appears here and there. Habitat sprawls out into the distance. My eyes tire in the sun.

“Gaze not too long into the abyss, lest the abyss gaze into thee.” 
 

There is a color theme here

Alone in this land, I should appreciate Edward Abbey’s “great stillness of the desert.” But my mind dwells on how the hunt is dragging. I am desperate to score a find, my impatience a mismatch to the abiding landscape. A horned lizard reveals itself here, another there, but no more tortoises emerge in the hour it takes to navigate the abyss and return to Matt.

Something doesn’t quite fit
Of course, while Matt was looping a shorter trail he ran into the preserve manager, who showed him two tortoises failing to mate. I’ll leave their obstacle to your imagination. Matt is giddy with the dopamine rush of a once-in-a-lifetime herping moment. I am weary with the space, and wish to move on. 

“We are preoccupied with time. If we could learn to love space as deeply as we are now obsessed with time, we might discover a new meaning in the phrase to live like men.”

Danger when constrained

Three hours of driving brings us to the Coachella Valley. Famous for retirement communities and rock concerts, this desert valley also hosts considerable herptofaunal diversity. Our goal for the afternoon is an empty lot of sand on the overdeveloped valley floor, dunes that host a fascinating endemic herp – the Coachella Fringe-toed Lizard.

Coachella Fringe-toed Lizard (Uma inornata)
spotted on a pre-development visit
The fringe-toed lizard has a range of striking adaptations – fringed toes, shoveled snout, ear flaps, valved nostrils, and more – that are necessary to thrive in the dunes. Golf courses, retirement homes, and palm plantations have wiped away over 80% of this dune habitat, leading in 1980 to the designation of the Coachella Fringe-toed Lizard as a Threatened Species on the Endangered Species List. Of the habitat that remains, only nineteen square miles are considered “optimal”. 

So you can imagine my horror when we arrive at our destination and find construction vehicles breaking ground. A mile-square of desert dune is being turned into a residential development. One more project in a valley full of homes looks normal to Matt, but I remember my walks here and am aghast.

“This was nothing but dunes before! All of this was habitat! It was full of sidewinders, kangaroo rats, fringe-toed lizards...they’re an endangered species! We notified the state of their presence here! I can’t believe it’s all being developed!”

On the remaining undeveloped edge,
the dunes stretch out...and stop.
At the lot’s edge are trees and buildings, nesting 

and resting spots for predatory birds
We drive halfway around before finding the point at which construction stops. Hoping to verify that not all is lost, I enter from an intact corner and begin my search. It isn’t long before a familiar shape darts from a sandbank into a bush. Still here! I spot a second fringe-toed lizard, then a third. I am pumped to see them holding on. Yet only a few hundred meters of dunes remain. 

Kestrels hunting on the sand
Reduced habitat is tough for any animal. But in this case there is an ominous undertone to the constricted space. Historically these dunes were sweeping landscapes of wind-blown sand interspersed with brush, nothing rising to the height of a man...and no perches from which predators could survey the land. Birds of prey such as the American Kestrel can hunt from flight, but they prefer to spot their prey from the rest of a perch, and their nests must be placed in tree cavities or building nooks. In the open desert the fringe-toed lizard is relatively safe. But set a power line or ornamental tree in that same habitat, and it becomes a killing zone. 

So the conversation about desert conservation revolves around space. I may underappreciate the open expanses that define the desert, but for reptiles they are a defense from the kestrels, shrikes, and owls that otherwise decimate their numbers. One study found that Flat-tailed Horned Lizard populations decline within 1500 feet of human development, apparently due to an increase in depredation. Desert tortoises are eaten by coyotes and ravens, which once struggled to persist in the barren desert but now make inroads by feasting on the trash of human presence, waste that no one thinks will be a problem because “it’s just the desert.” Every campground and dump is an oasis from which predators branch out, and the tortoises suffer. 

It will get worse. The average size of a new single-family home in America has grown from 983 square feet in 1950 to over 2,500 square feet today, even as the number of people per household has dropped over the same period. Larger homes lead to larger plots, leading new suburbs to leach away from the original cities. To some degree it is a product of vast central planning; “An economic system which can only expand or expire must be false to all that is human.” But it is also the result of millions of individual decisions, every family that moves further out to get the big yard, every speculator or vacationer who buys a second home in the desert. Suburban sprawl has maxed out the LA Basin and now reaches to the north and east. Is this constant growth necessary? Inevitable? Sustainable?
Exactly the right amount...

“Water, water, water....There is no shortage of water in the desert but exactly the right amount, a perfect ratio of water to rock, water to sand, insuring that wide free open, generous spacing among plants and animals, homes and towns and cities, which makes the arid West so different from any other part of the nation.”

If you travel to the Anza-Borrego Desert Visitor Center this year, you may see a remarkable notice. The paper stapled to the wall states that only 1.12 inches of rain has fallen on the desert, and 0.99 inches of that was in one day in early January. With virtually no rain, the park’s famous spring wildflower bloom was a dud. 

So dry you can feel the brush crackle
Many of us assume that the desert doesn’t need water. And it is true that its inhabitants are adapted to persist on limited rain, just the right amount. But that amount is essential. Water brings life to plants, which are fed upon by insects and rodents, which provide nourishment for lizards and snakes, which are eaten by owls and kit foxes. Every form of life is part of a chain for which water is at the core.

Take the water away, and life diminishes. Thus goes desert vitality in California’s ongoing drought, labeled a “hot drought” due to rising temperatures that exacerbate the situation. Research shows that this changing climate has a negative effect on some populations of Mojave Desert Tortoises and Coachella Fringe-toed Lizards, and anecdotal reports by herpers suggest the same for many other species. We see their numbers ebb and flow with the climate.

Anza-Borrego is one of my favorite wildlife spots in the world, but Matt and I are disappointed. No lizards move on the dunes, few snakes cross the roads. One particular expanse usually riddled with desert iguanas now fails to produce a single one. The highlight for the day is a palm oasis with an array of frogs and canyon lizards. But even that stream is deficient, its famous waterfall dry.

A California Chorus Frog, Western Chuckwalla,
Granite Spiny Lizard, Desert Pupfish, Banded Rock Lizard,
and Baja California Collared Lizard enjoy the last reservoir of
remaining moisture in the palm oasis
We had planned to spend two days in Anza-Borrego. But a tangible depression overcomes us as we miss out on one target after another, the dryness of climate change an intimidating foe. Less than 24 hours in, we throw our hands in the air and move on to the next desert. 

An altered valley
“there is method at work here, method of a fanatic order and perseverance: each groove in the rock leads to a natural channel of some kind, every channel to a ditch and gulch and ravine, each larger waterway to a canyon bottom or broad wash leading in turn to the Colorado River and the sea.”

This Desert Blind Snake (Leptotyphlops humilis), found
 in moist sands below the dry desert surface,
was uncovered on  an earlier trip to the river's shores
The Imperial Valley is a fertile desert laid down by floods. Over millions of years the Colorado River cyclically surged and dried here, draining water and sediment from seven western states to deposit in the valley’s flats. Flora and fauna adapted, some species utilizing the arid desert and others the unique niche where the sands and waters met, making use of the “just enough” water that all desert life craves.


It all changed in 1900. The California Development Committee dug irrigation canals to divert water to Imperial Valley and create farmland from the rich deposits. But the engineers failed to account for silt loads which the Colorado continued to bring from the Grand Canyon and beyond. Soon the canals blocked up and a new intake was cut too hastily without the necessary gates and flow regulators. Heavy rains hundreds of miles upriver increased water volume, and the entire output of the Colorado River burst over the levees and poured across the landscape. A dry lakebed called the “Salton Sink” filled with the overflow and became the “Salton Sea”, now the largest lake in California. 

In a rocky canyon west of the agriculture, one productive night
 with our friend Jeff Nordland yielded Speckled Rattlesnake,
Red Diamond Rattlesnake, Leaf-toed Gecko, 

Colorado Desert Shovelnose Snake, and Granite Night Lizard

It took a few years to recover from the debacle, but the water was eventually brought under control. Today the world’s highest capacity irrigation aqueduct, the All-American Canal, carries 3.1 million acre-feet of water away from the Colorado River every year. Thus the lifeblood of the parched Southwest is routed into a network of agricultural fields from the Mexican border to Mecca, redistributed at human discretion. Much of America’s lettuce, broccoli, carrots, and dates are now grown it what was once desert. And the herptofauna of the region has changed forever.

Before the irrigation revolution, an ecosystem existed at the edges of the Colorado River and in the pools and creeks that periodically flowed off of it. Checkered Garter Snakes and Sonoran Mud Turtles hunted in the mud. Lowland Leopard Frogs floated in the small streams. Sonoran Desert Toads, Woodhouse’s Toads, Great Plains Toads, and Couch’s Spadefoots bred in the pools, spreading out into the desert whenever the rains accommodated. 

Woodhouse's Toad (Anaxyrus woodhousii) hopping across
 a city road. Nearby a lively breeding chorus emanated
from a manmade pond
Irrigation shifted the balance. Those species constrained to water now have a more consistent source, not so dependent on the year’s rain. They have expanded their range along the network of canals and across the valley. Checkered Garter Snakes and Woodhouse’s Toads now roam irrigated orchards up to the northern tip of the Salton Sea, fifty miles or more from their historic range.

Unfortunately, not every species could adjust to hard-edged canals, a poor facsimile of the well-vegetated natural shallows that the region’s aquatic life was adapted to exploit. The introduction of pesticides and invasive fish also posed an issue, especially for tadpoles. And in the 1940s the Imperial Irrigation District sprayed oil and burned over 8,000 miles of ditches and canals in an attempt to control muskrat populations. That may have been the final blow for several native species.

Variable Ground Snake (Sonora semiannulata)
found a footstep away from the Colorado's waters
By the 1950s the Lowland Leopard Frog (Lithobates yavapaiensis), Sonoran Desert Toad (Incilius alvarius), and Sonoran Mud Turtle (Kinosternon sonoriense), ancient denizens of the Colorado’s overflow, had disappeared completely from California.
Not that there aren’t herps to be found. On one bank we flip a board to reveal a Variable Ground Snake, on another a Sonoran Gopher Snake basks in the evening sun. Purple-backed Spiny Lizards and Colorado River Tree Lizards utilize riparian brush, while invasive American Bullfrogs and Rio Grande Leopard Frogs sit just off the shore. 


Our highlight comes when we stumble upon a ‘Yuma’ Kingsnake, deep black with thin white bands, beginning to consume a gopher snake it has just killed. 

A Yuma Kingsnake (Lampropeltis californiae “yumensis”)
devours a Sonoran Gopher Snake (Pituophis catenifer affinis)
in a ditch near the Salton Sea
But even that was found...on the edge of an irrigation canal. There’s something missing from the wonder of the valley when so much of its life can now only be found in these unnatural wounds on the landscape. Matt tires of it, not wanting to herp roads and farms. I struggle to imagine the natural overflow, wondering what habitat looked like before dams were king.

The ongoing drought that plagues Anza-Borrego has impacted the valley as well. Flows in the Colorado River have decreased by about 20% since 2000. It is estimated that they may drop another 35% through the rest of the century. And the demands of household water consumption have been increasing. Caught between climate change and domestic overconsumption, the future of not just the river but the agricultural system it supports is tenuous.




We had entered the Imperial Valley at its northwest edge, stopping when a Woodhouse’s Toad hopped across the road to a manmade pond. We exit the valley at its southeast corner, photographing a dead Checkered Garter Snake (Thamnophis marcianus) hit by a car in its attempt to move from one irrigation canal to another. This valley is millions of years old, and these new changes began only a century ago. But you feel they cannot be wound back.
This Couch's Spadefoot (Scaphiopus couchii), found
during a dry night on the edge of agricultural fields, was likely
only active due to the moisture from sprinklers

We cross the river and race through the Arizona desert. The Lowland Leopard Frog, Sonoran Desert Toad, and Sonoran Mud Turtle, all extirpated from California, have receded from the Arizona side of the Colorado River as well. We have to go forty miles east to reach one of their last domains in western Arizona. 

Near alfalfa fields surrounding a small town we find a dead Sonoran Desert Toad, its unseasonal May surfacing likely brought about by the pitter-patter of irrigation water. Not to be outdone, a Couch’s Spadefoot has also emerged, similarly confused by the fake rain.

A young Lowland Leopard Frog sits
in the shallows of the creek
Miles of highway followed by country road followed by dirt road followed by hundreds of meters of  bushwacking finally bring us to a stream small enough to be jumped across in spots, the first natural stream we’ve seen in days. Here Lowland Leopard Frogs persist and Sonoran Mud Turtles still roam, along with a dozen other species unique to the riparian zone where water and desert meet. It reminds us of what once existed to the west, and what we hope will remain in those rare spots where we have not yet drained God’s natural work away.

May your trails be crooked, winding, lonesome, dangerous, leading to the most amazing view.

References

All quotes from Edward Abbey, primarily drawn from his 1938 classic, Desert Solitaire.

Thomson, Robert C.. California Amphibian and Reptile Species of Special Concern. University of California Press. Kindle Edition.

“Indirect Effects of Development on the Flat-tailed Horned Lizard”, a report submitted to the Arizona Game and Fish Department by Kevin V. Young and April T. Young

“Boundary processes between a desert sand dune community and an encroaching suburban landscape”, paper published in Biological Conservation by CW Barrows, MF Allen and JT Rotenberry

“Struggle for survival: some animals moving, vanishing as deserts grow hotter”, article published in The Desert Sun by Ian James

“Desert Tortoise Threats: Predators”, from the Desert Tortoise Preserve Committee, Inc., http://tortoise-tracks.org/threats/predators

“A Few California Farmers Have Lots of Water. Can They Keep It?”, article published in Bloomberg by John Lippert

“Preparing for a drier future along the Colorado River”, article published in The Desert Sun by Ian James

Special thanks to Brian Brenhaug for his insight on the water management history of the Imperial Valley.

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