Saturday, December 22, 2018

California Waters: Salamanders In The Cracks -- Guest Post --

Part I and II.


A young Panamint Rattlesnake (Crotalus stephensi).
At a distance the old mining route unfurls above us like an M.C. Escher painting; all drops and climbs and precariously tilts to the side. There is no ledge and you can imagine sliding off into oblivion. I check the map. The potential salamander habitat Matt had located on Google Earth will require four miles of that, to be followed by at least a mile of steep hiking.

There is a beauty in these mountain roads, not least because you can roll on for hours without seeing another vehicle. At one point Matt and I stopped in the middle of the road for a gorgeous rattlesnake, crouching down on elbows and knees to get the best shot, oblivious to the fact that cars were sanctioned to drive there at fifty-five miles an hour. Other people with cars is an abstract concept for now.

Matt in the Inyos, with Owens Valley and
the Sierra Nevadas in the background.
But the rule of eastern California is that no matter how remote the road you’re on is, the road it leads to is even worse. Matt stops when we get to the mining turnoff. Our target species may be a few miles down.

“This is the road?”

“Yeah.”

“I don’t know if I’m willing to do that.”

“Haha – no way man.”

So this is herping in the Inyo Mountains. How do you even know whether salamanders are there when it becomes too hard to find them?

Unlikely desert denizens

Much of our three-week expedition to observe California’s rarest species covered familiar ground, providing me an opportunity to note changes to populations and habitat in the intervening period. But I also wanted to check out remote locations that I had never been able to visit. And nothing was higher on my list than getting to herp the Owens Valley and especially the Inyo Mountains that form its eastern border.

The Black Toad (Anaxyrus exsul) is known from
a single spring complex surrounding an alkaline lake
on the north end of the Inyo range. It is common
within its extremely limited habitat.
The Inyos are a high-elevation desert, shielded by the Sierra Nevadas and thus receiving no more than nine inches of rain a year. Isolated from other mountains by the Owens Valley to the west, Saline Valley to the east, Great Basin Desert to the northeast and Mojave Desert to the south, this range has developed a unique herptofaunal assemblage. Several of its residents are found nowhere else on Earth, including the Black Toad, Panamint Alligator Lizard, and Inyo Salamander.

Wait, a salamander?

In defiance of everything you know about amphibians, the dry and desolate Inyo Mountains have a salamander. It is possibly the only surviving desert salamander in the world.

 Though the wash is dry and vegetation on the slopes is sparse,
 those patches of dark green in the distance indicate a spring
pulling together enough water to
support the salamanders.
Salamanders need water. Deserts don’t have much water. Thus salamanders and the desert don’t mix. A casual hike in the Inyos doesn’t suggest that such a dilemma would be resolved here. These mountains are dry. The reptiles are scattered, even the cacti are thin, making their homes with the wide spacing that scarcity of water requires.

But hike far enough in the right direction and you will get to a mountain spring. The spring is created by hundreds of acres of slope which funnel water into a depression. Rain is rare but when it arrives it soaks deep, gravity pulling the moisture through rock and soil to create a persistent trickle in one spot. The varying distances that the water travels to reach this spot spread its arrival over the course of the year, ensuring that the spring flows months beyond the latest rains. Surface water may appear for no more than ten feet, or as much as half a mile.

Tucked away along that trickle in the right crack between the right rocks under the right fern, a species of salamander can be found that knows no other way to live. Only 17 springs, spread out across 20 miles of mountain on the east and west slopes of the Inyos, constitute the entire known range of the Inyo Salamander (Batrachoseps campi).

Matt and I used satellite images to locate many potential salamander springs, but our attempts were often thwarted by dangerous approaches, washed-out roads, and hikes that simply drug on too long in difficult mountain terrain. Outside of a few snakes on the road we didn’t see much herp life on the slopes, possibly in part due to a cold front that limited reptile activity.

But we persisted, and on a few of the hikes we reached beautiful springs, two of which revealed a total of nine salamanders.

An Inyo Salamander on the left and their typical spring-in-the-desert habitat on the right. 
The limited water and vegetation that the salamanders manage to subsist within is remarkable. 
Habitat photo courtesy of Gary Nafis.


Defying the desert, defying California’s ongoing drought. The Inyo Salamander lives on in its wet little niche as it has for hundreds of thousands of years.

While it appears to be living on the edge, the Inyo Salamander may be able to maintain that edge for thousands of years to come. The Inyos are hot and dry, but the salamanders’ shaded microhabitats are fed by cool underground spring water trickling in from mountain slope stretching up to 10,000 feet elevation. Thousands of mining operations that pepper the hillsides may once have been a threat to their survival, but 90% of those claims are now closed and protecting the limited number of occupied salamander sites from further impact is doable. In the forty-five years since the salamanders were first discovered, a few of the original springs have dried, but most remain robust. So long as the water sources are left untouched and wild burros are kept away from the crucial vegetation, the salamanders are probably safe.

In another region of Owens Valley Matt and I found Mt. Lyell Salamanders (Hydromantes platycephalus) 
at the edge of snowmelt streams running off the east side of the Sierra Nevadas. This distantly sourced 
water supports just one salamander species in otherwise dry and inhospitable terrain. Photo courtesy Matt Dagrosa.
Victims of warming

San Joaquin Fence Lizard (Sceloporus occidentalis
biseriatus) on the Kern Plateau. 
Excited to have observed what appear to be secure populations of Black Toad, Inyo Salamander, and Mt. Lyell Salamander, Matt and I headed south and west across the valley to scout areas where climate change has taken a deeper hit.

Small creeks in the oak, pine and fir forests of the semiarid Kern Plateau are less unlikely-looking salamander habitat than the desert springs of the Inyo or the rocky canyons of the eastern Sierra Nevada. But parts of this range are just as dry as the other two habitats we had surveyed, and many of its scant creeks only run seasonally. Once again, a single salamander species has turned this inhospitable terrain into a home.

Unfortunately, Kern Plateau Salamander (Batrachoseps robustus) populations may not be as stable as the other two dry-habitat salamander species we’d located. As drought and rising temperatures reduce the seasonal persistence of moisture in southern California, some previously occupied sites on the eastern and southern portions of this salamander’s range have not produced in some time.

A Longnose Snake (Rhinocheilus lecontei) crawls along
 the valley’s edge at at night while a Red Coachwhip
(Masticophis flagellum piceus) makes
its appearance during the day.
Matt and I first investigated an east-flowing creek on the southwestern edge of Owens Valley in what should have been prime salamander habitat. Desert reptiles such as the Red Coachwhip, Desert Horned Lizard, and Long-nosed Leopard Lizard were prevalent along the route.

But salamanders were nowhere to be found.

As we proceeded westward and climbed higher into the mountains, the operative word was dry. It is clear that drought conditions have done a number here. The largest creeks flowed only in their central channels, the small annual creeks which often provide the best robustus habitat lay parched to the bone. The highest-elevation reaches of the plateau were closed off to vehicular traffic, so we began to worry whether we would see any salamanders at all.

At over 6,500 feet elevation I finally spot a heavy log sitting in a moist grassy hollow in the center of an otherwise dry ravine. Beneath that log was a solitary Kern Plateau Salamander.

A combination of shade, a slight depression in the soil, and a heavy log allowed the retention of 
just enough moisture for this Kern Plateau Salamander to remain near the surface in a dry May landscape.
It would be the only one we saw.

We took care to leave her perfect little niche exactly how we had found it, and prayed that she would continue to find moisture until the next rain. We were excited and proud to have found such a salamander during the drought, especially after learning that many of our peers had failed to see one that season. But the uniqueness of the find highlights the struggle they may be facing in many of their historic haunts.

The waterfall on the left suggests the presence
of salamanders near the surface. Thick green
vegetation on the right indicates water below the surface...
and salamanders below as well?.
“May” is an essential word. Are the salamanders actually struggling, or are just we struggling to find them? With creatures as secretive as these, how can you tell whether they are becoming rarer or are simply retreating to more difficult-to-survey cracks in the rocky landscapes that make their home? Even when a Inyo spring dries on the surface its salamanders can persist in underground waterways. Perhaps when a Kern Plateau stream dries out the salamanders dig deep enough to find the point at which the soil stays moist, waiting to emerge again in the wet years.

Or perhaps, as climate change heats and dries their landscape past anything they’ve seen in thousands of years, they are beginning to disappear from much of their historic range.
The relatively long-limbed San Gabriel
 Mountains Slender Salamander.

Either way, the Kern Plateau Salamander is in no danger of extinction. While much of the low-lying and east-facing portions of its habitat are drying out, it can be found as high as 9,200 feet and parts of its range include west-facing slopes which draw thirty inches of rain a year. But its total range is small, and if drought conditions and warming persist, many locations which once held the species will no longer support any salamanders at all. 

Other salamanders in California are becoming similarly difficult to find, especially among the Batrachoseps genus. The San Gabriel Mountains Slender Salamander (Batrachoseps gabrieli) of the warm and dry Transverse Ranges has shown up less frequently in many of its known locales in recent years. The Lesser Slender Salamander (Batrachoseps minor) and San Simeon Slender Salamander (Batrachoseps incognitus) of the San Luis Obispo coast have become harder to locate and may be failing to adjust to a gradual drying of the region. The Kern Canyon Slender Salamander (Batrachoseps simatus) is now rarely found in open terrain, being seen only in its more sheltered seeps. And the Desert Slender Salamander (Batrachoseps major aridus), previously known from just two desert canyons in the Santa Rosa Mountains, has not been seen since the 1990s and may be extinct.

 Sierra Nevada Ensatina (Ensatina eschscholtzii platensis)
 from the wetter region just to the west of the Kern Plateau.
Some of these changes may have been accelerated by anthropomorphic global warming and man’s habitat alterations, but to a degree they are also natural processes related to the cyclic nature of climate and a 12,000-year-long transition in California’s precipitation patterns. As the southern half of the state dries, certain species which rely on moisture are going to be forced into smaller and smaller microhabitats, and some of those microhabitats may blip out. Other than retaining and breeding a few examples of the species for posterity, it may not be a process we can stop.

Of course, there are other situations for which we cannot declare ourselves so uncertain, or so innocent.


The remnant

A mule deer stopped to watch me as I crossed the road. I moved off and descended an untrailed ravine that dropped, dropped, dropped into a lower creekbed, picking my way through brush and treefall. On one fallen tree a hawk had picked clean a squirrel’s carcass and left the skin inside-out, hooked onto a branch.

For the first time in our trip I was in a place that looked like typical salamander habitat. The mountain was green, the trees were thick, and the ground was wet. A late afternoon storm had rolled in, blocking the sun and dropping temperatures into the low 40s. For this search I hiked alone. The issue of exposure crossed my mind as I headed a long ways off the beaten path.

You could write out every living person who has seen a Relictual Slender Salamander (Batrachoseps relictus) and might not get to the end of a page. Originally discovered among a series of springs and streams in the Lower Kern River Canyon in 1968, none of the original populations have been seen since 1971. Highway construction along the canyon appears to have altered local hydrology in a manner that the species could not survive.

A decade later, Robert Hansen discovered a new population of Relictual Slender Salamanders near an isolated mountaintop meadow some distance away. Unfortunately, the discovery of that new population coincided with the building of a logging road. Once again the hydrology changed, and the new population disappeared as quickly as the previous ones had.

For 20 years the species was not seen again, until a remnant of that mountaintop population was found to be hanging on in the same meadow. As I suggested earlier, being unable to find a thing doesn’t mean it is not there! A second population was discovered in a nearby creekbed, and just last year surveyors located a third population. Those three populations persist to this day. The total occupied habitat of the species might fit within a football stadium, and it is all contained on one mountain.

One of several Yellow-blotched Ensatina
(Ensatina eschscholtzii croceater) found in the forest. 
On first impression there appears to be a lot of habitat here. Indeed, other salamanders like the Yellow-Blotched Ensatina reside throughout these mountains. But the Relictual Slender Salamander is unique among slender salamanders in that it is semiaquatic, and thus it rarely strays far from water. This otherwise fossorial salamander even possesses a dorsally flattened tail which may help propel it across the creek. As I navigated the steep hillsides, occasionally casting concerned glances skyward to see if the darkening clouds were bringing a storm, I realized that the waterlogged edge habitat preferred by relictus comprised only a small proportion of the landscape before me.

Relictual Slender Salamanders
lurking at the creek's edge.
 So it was with some excitement that I saw a promising spot where water met land in just the right way...and indeed there were two slender salamanders there. They persist. I pray they may persist for many years to come.

I’ve asked myself what it means to hold out hope for a salamander reduced to three tiny populations. It is true that whether the salamander survives or not, few humans will ever see it. But whether or not many of us notice, what does it say that a species has been diminished to this state? The Black Toad, Inyo Salamander, and Mt. Lyell Salamander persist despite limited habitat in part because their localities are so inhospitable and undesirable to humans. The Relictual Slender Salamander was just a little bit too close to places we wanted to change and so it teeters, reduced to an ecological island that could be devastated by a few degrees of global warming or a shift in precipitation. Should it take an utterly remote habitat niche for any interesting species to remain unimperiled from human development?

Who is responsible for bringing the situation back from the brink? Well, ask who builds the highways, and the logging roads, and the cities and tourist traps that such roads and logging operations support. The honest answer is that to some degree nearly all of us have played a part.

Is there another way, one in which we reduce our own footprint so that other species can maintain theirs? Do we care enough to look for the options and commit to them?



References:

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

Nafis, Gary. California Herps: A guide to the reptiles and amphibians of California. http://www.californiaherps.com/

I want to thank Ben Witzke and Robert Hansen for insights into these salamanders, and Shanti Mathias for editing and suggestions on this article as well as the previous ones.

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