The Santa Rosa Mountains, part 2: BioMeandering

On our trips to out of the way places in Nevada, Tara and I often haphazardly identify (or at least try to identify) various kinds of plants and animals, from conifers and grasses to birds and bristletail insects. What we’re doing has something in common with so-called BioBlitzes, events where large teams of biologists and others try to record as many species as possible in a given area, often in a single 24-hour period. By comparison, though, we’re engaged in more of a BioMeander, unplanned and unfocused, drawn out over many years and many sites, and characterized, at just about every timescale, by disruption more than continuity.

In Nevada’s “outback,” we often run across species that are new to us, of course, but, beyond that, we sometimes find ones that have rarely or never been identified before by anyone in the particular place. That makes us feel a little like the early, rugged naturalist-explorers of the West (despite the fact that we rarely get more than a few miles from a trailhead these days). Part of the reason we can find novel things is that Nevada, for the U.S. anyway, is a very poorly known area, biologically speaking. But, in truth, such little discoveries (and even big ones) can be made almost anywhere.

With the unexpected especially in mind, here are some photos and rambling notes from our trips in June and September of this year to one of Nevada’s little known places, the Santa Rosa Mountains, in the north-central part of the state.

Pigmy Short-horned Lizard (Phrynosoma douglasii), a.k.a. the most baby-like and cutest of all the horned lizards. I saw two of these in the valley of Lye Creek, both looking like animated dirt clods, because they perfectly matched the beige soil. They count as surprising because (1) I had never seen a Pigmy Short-horned Lizard before (so it was a “life reptile,” much rarer for me than a life bird), (2) there aren’t any records of the species from the Santa Rosas in the giant online museum database Herpnet, and (3) I saw these lizards at over 7,000 feet, more than a thousand feet above the normal elevational range for the species.

Swainson’s Thrush, not in its environment. Photo by Matt Reinbold via Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Catharus_ustulatus_-North_Dakota-8a.jpg

On our June trip, almost anywhere near an aspen grove and at all times from before dawn to after sunset, I heard the beautiful, whistled, “upward spiraling” song of Swainson’s Thrushes. One male sang right by our campsite, and, as I lay in the tent as the darkness fell, I listened to him singing several songs, all rising spirals, but differing in pitch or the timing of the notes. In many songbird species, individuals sing several to many different songs, but I had never heard Swainson’s Thrushes doing that, or, rather, I had probably heard it, but it hadn’t registered. (It’s still, for the most part, a mystery why birds do this.)

The thrush’s songs were like a little solo flute concert for bedtime. After awhile, though, I wondered whether his singing—melodious but piercingly close—might actually keep me awake. But at some point he stopped and I fell asleep, or I fell asleep and he stopped.

According to the most up-to-date field guide I have—Sibley’s second edition, published earlier this year—Swainson’s Thrushes aren’t supposed to breed in the Santa Rosa Range, and the wonderfully detailed Atlas of the Breeding Birds of Nevada indicates only “possible” breeding of the species in these mountains. But Nevada birders who have been to the Santa Rosas in summer know that Swainson’s Thrushes breed there. I guess it could be that the birds only recently moved in, but the more likely explanation is that it’s the ornithologists and wildlife scientists who have been missing from the area, not the thrushes.

Below Lye Creek campground I got a brief look at a bird that flew, with a burst of heavy flapping, from the side of the road into some aspens. From what I could pick out—big grouse, more or less all gray, with squared-off tail—this seemed to be either a Dusky Grouse or a Sooty Grouse, neither of which is supposed to be in the Santa Rosa Mountains. When I posted this sighting on the NVBIRDS listserv, there was some skepticism, justifiable given my sketchy description of the bird and the area’s general lack of conifers, which these grouse species seem to need as winter food. But then Jen Ballard, who works (and blogs) for the Great Basin Bird Observatory, wrote to say that one of her surveyors had seen two Dusky Grouse in the Santa Rosas in 2011. So they are there after all. The maps in Sibley and other field guides will have to be changed and, more importantly, my identification of the grouse has been vindicated!

Tara and the kids found an adult Rubber Boa (Charina bottae) in the road in Lye Creek campground, not a huge surprise, but a treat for the kids. Rubber Boas are slow-moving and docile, perfect for introducing small children to snakes. A day or two later, we found a ridiculously cute baby boa, also in the campground road.

Also not surprising to find these paintbrushes—the tall, spare Castilleja linariifolia and the squat, dense C. pilosa—but the fact that these two species, at opposite ends of some axis of paintbrush morphology, were within a couple hundred yards of each other was kind of cool. Made me wonder exactly what those different morphological forms are doing for these plants.

Face of bristletail from Lye Creek campground

On our September trip, I woke up one morning and, right by my head on the tent, was the unmistakeable shadowed outline of a bristletail. (Given my hyper-awareness of these insects, I at first thought I was hallucinating.) That turned out to be the second of two species of Mesomachilis bristletails I found in the Santa Rosas, the other being in rockpiles on a bare ridge. As far as I know, bristletails have never been recorded from these mountains, and the rocky ridge species probably has never been found anywhere in Nevada before. Considering the obscurity of bristletails in general, seeing a new species for the state wasn’t shocking, but it was still a satisfying find, a little Meriwether Lewis moment.

The weird structure above, the sort of heart- or spatula-shaped thing with hairy edges, armed with what look like little black thorns or hooks, is the penis of one of these bristletails. All Mesomachilis species have some variant of this odd “spatulate” penis. They’re probably doing something interesting with it, but nobody has a clue what that is.

Eiji has some kind of creature in his fist

The kids (because they’re kids) spent much of their time in camp right by or in the creek, at least until we got a fire going and pyromania took over. Eiji, especially, was taken by the stream creatures that we caught in a bucket, including this feathery-tailed mayfly nymph (possibly genus Ameletus).

I didn’t notice it at the time, but there’s also a water mite (Hydrachnidia) in the picture of the mayfly. I have to confess that, before I looked at this photo, I did not know there was any such thing as a water mite. However, I’ve just learned that there are some 5,000 described species of these small arachnids (and no doubt many unknown ones too) and that, as larvae, they parasitize aquatic insects, and, in nymph and adult stages, they prey on insects, crustaceans, and other mites. These little round guys are wreaking some havoc in streams and ponds all over the world.

It’s been suggested that, when the chironomid midges that most water mites use as hosts underwent an explosive radiation (that is, a bunch of species formed within a relatively short time) the mites did the same. The tiny products of these evolutionary explosions are hidden all around us, and that’s a wonderful thing to contemplate. Crossing paths with these organisms is like discovering new worlds you didn’t know existed. It’s like being a kid dipping a bucket in a stream all over again. And it’s one of the reasons we love to meander.

Hana making a “nature list” (and wishing Nevada had more trees)

 

More on trees in the Santa Rosa Mts: what is and what could be

After writing the last post, I wondered whether anyone had done any research that would indicate whether there are conifer species in the general area that ought to be able to thrive in the Santa Rosa Mountains, yet don’t occur there. If such species exist, that would give more credence to the idea that some conifers are not in that range simply because they haven’t gotten there (or, at least, haven’t gotten there often enough to establish a population).

So I googled some conifer species names along with the phrase “niche model,” and one of the first things that came up was a page for the Faculty of Forestry at the University of British Columbia showing a map of the “modeled suitable climate niche for Douglas-fir.” The map showed in green the areas that the model said should be suitable for Douglas-fir populations (whether they actually exist in those places or not). And, sure enough, there was a small green patch for the Santa Rosa Mountains, including areas we visited. (The patch in question is just southwest of the three-way intersection of Oregon, Idaho, and Nevada.)

Digging a little more, I found a scientific article, by different researchers, that produced such maps for both Douglas-fir and ponderosa pine. These maps indicated that both of these species could live in the Santa Rosa Mountains.

Actually, Douglas-fir and ponderosa pine are already in the Santa Rosas—both species were planted there in small numbers. In his great 1996 reference book, Atlas of Nevada Conifers, David Charlet noted that, although these introduced trees had survived, they did not seem to be reproducing. However, I saw a Douglas-fir sapling in the area of Lye Creek campground, about a mile from the planted Douglas-firs. That’s another small piece of evidence that the area might be able to sustain a population of that species.

Finally, those maps of “suitable climate niches” for both Douglas-fir and ponderosa pine show that the Santa Rosa Mountains are surrounded by an “ocean” of environments where populations of those species cannot persist. As far as those trees are concerned, the Santa Rosas do seem to be a remote island that can only be reached by chance, long-distance dispersal, or by people carrying seeds or trees.

Biogeography in our backyard: The Santa Rosa Mountains, part 1

Once, when Tara and I were living in eastern Nevada, we went to an outdoor store in Salt Lake City, Utah, because I needed a pair of cross-country ski boots. The young woman who rang us up, finding that we were from Nevada, wondered where we could ski; she seemed to think the whole state—Utah’s neighboring state, I should add—was a giant, sweltering desert. We had to inform her, hopefully without sounding too condescending, that we lived in a valley at 6,500 feet, with mountains more than 10,000 feet high on both sides. At times, we could ski right out our back door.

No, Nevada is not all sweltering desert. Through most of the state, even the valleys are high and, in the winter, quite cold. More than that, though, Nevada is, by some measure, the most mountainous state in the country, with 314 named ranges (that’s 3…1…4, not a typo), 25 of them with peaks over 10,000 feet. (These mountains almost all run north-south, which led to a geologist describing the landscape as “an army of caterpillars marching toward Mexico.”) The high Nevada mountains can be very snowy, and the Snake Range, in the far eastern part of the state, even has a paltry but real glacier.

For Tara and I, one of the great pleasures of living in Nevada is visiting these different mountain ranges, all of them distinctive in one way or another. (Well, that’s an educated assumption—we’ve only been in several dozen ranges, a small fraction of the 314.) Having two small kids has cut way down on our pace of exploration, but this year we managed two trips to an especially intriguing and beautiful range that we’d never visited before, the Santa Rosa Mountains, in north-central Nevada, close to the Oregon border.

Granite Peak, the high point (9,732 ft) in the Santa Rosa Mountains. The rock of this peak formed in the same events that created the granitic plutons of the Sierra Nevada. Thanks to Alan Wallace for that bit of geological history.

One of the most striking things about the Santa Rosas is that, despite having multiple peaks over 9,000 feet high, the range has only two species of conifers. As you drive north up the road from Paradise Valley toward Hinckey Summit, you pass through sagebrush and bitterbrush and, where you might expect pinyon pines and junipers—the “PJ zone” so common in Nevada mountains—you find…more sagebrush, along with some mountain mahogany.

Farther along that road, at Hinckey Summit and points north, you run into dense stands of trees, but they’re not conifers, they’re aspens. My impression is that the stands are especially extensive here, which might be related to the absence of other trees (or, alternatively, could be a trick of the eye caused by that absence). Incidentally, on our trip last week, we hit the aspens at what I consider their peak—not the time of greatest brilliance, but when there’s a wild quilt of different colors, various shades of green, yellow, and orange. The “patches” in the quilt are groups of clones, with the aspens making up each clone sharing a common timing of the shift to fall colors and a common leaf hue.

Patchwork of aspens at Lye Creek campground

An orange clone

On the ridge that runs from Hinckey Summit west to Granite Peak, at an elevation of 9,000 feet or so, you would expect to find three or four kinds of conifers if this were a “typical” Nevada mountain range (which I realize is an oxymoron). However, here you find only a few scattered limber pine, the one moderately common conifer in the Santa Rosas. (The other conifer is western juniper, which is rare.) Unfortunately I didn’t get up high enough to walk among the limber pines—I had to settle for looking at them through binoculars.

Dead limber pine on Granite Peak. Photo by Tara de Queiroz, who made it farther up the mountain than I did.

I was going to try to explain in some depth why there are so few conifers in these mountains, but, in looking into the topic, I realized this would involve a lot of speculation. However, it seems that at least part of the answer is pretty straightforward: Some of the species that might thrive in the Santa Rosas simply haven’t gotten here.

For instance, Douglas-fir and white fir, which are now found in eastern Nevada mountains, do not seem to have been in the Great Basin during most or all of the Pleistocene. The subspecies of these trees that are in eastern Nevada apparently colonized the Great Basin from the east or south, and, for that colonization process to reach the Santa Rosas, seeds would have to jump over numerous arid valleys, from one mountainous “sky island” to another. A similar argument might apply to singleleaf pinyon pine, which colonized the Great Basin from the south in the last 7,000 years, but hasn’t reached this far north (although it may be that the northward spread of this species was slowed or stopped by climate).

To the degree that this argument is right, you could say that the Santa Rosa Mountains (and other Great Basin ranges) are like a volcanic island that had to be populated from elsewhere by some kind of chance dispersal. But the analogy obviously isn’t perfect, because, unlike a newly-formed island, the Santa Rosas were not devoid of life before the Pleistocene, nor were they wiped clean of trees by Pleistocene glaciers. I assume that at some point there were conifer species other than limber pine and western juniper here. So an obvious question is “What happened to those Pleistocene or pre-Pleistocene conifers?” I’ve got little to say about that. I would love to hear if someone else has any insight or information on the subject.

In any case, visiting the Santa Rosas is a great reminder of the uniqueness of Great Basin mountain ranges and how their character is connected to deep biological and geological history. It’s also a great place to see the beauty of aspens, in a pure state, unadulterated by all those conifers!