“We must risk delight. We can do without pleasure, but not delight. Not enjoyment. We must have the stubbornness to accept our gladness in the ruthless furnace of this world.”
Yosemite Valley dogwoods in bloom.
I rolled into Yosemite Valley on a Sunday evening in early May. All along the route, the dogwoods outstretched their boughs of blossoms through the pines, as if welcoming visitors along the winding path.
We don’t deserve this, I thought to myself.
All the ways we’ve just about loved this place to death, and it exudes beauty nevertheless. Stubborn gladness embodied.
I’m here to study frogs; an administrative campground in upper Yosemite Valley will be my home for the next month and a half. My campsite is cradled in an elbow of the Merced River; the high flows rush up at night and drown out all the campground noises, lulling me to sleep. Bears walk past the campsite regularly—three different individuals I’ve counted so far—donning the radio collars and brightly colored ear tags the park biologists use to keep track of them. Lumbering along in the tiny creek that flows past my camper, they are oblivious to the racket they make stomping in the water, crushing sticks with each step in the woods, pulling apart logs to look for grubs. Making oneself scarce is not a necessity here.
A tried-and-tested campground food storage locker helps keep human food away from bears.
“We’ve created this unique situation in National Parks,” a Bear Crew biologist told me one day, after firing a shotgun blank to haze yet another bear out of the campground. “Outside, there are hunters; here, they have no fear.” She says the average life of a black bear living outside of the national parks in California is about 8 years; in Yosemite, it is closer to 30. The Bear Crew is responsible for keeping bears away from food and people, and training humans to make sure it stays that way. These days they mostly haze bears; in the 1990s, at the pinnacle of the “bear problem”—actually a human problem caused by careless food storage—it was the demoralizing job of the Bear Crew to euthanize a disturbing number of bears. The extraordinary efforts of National Park staff to fix the human problem has resulted in far fewer human-bear conflicts and set an example for managing these conflicts all over the world. (Recommended reading)
Living in Yosemite Valley is about as nice as it sounds. At 4,000 feet, it’s usually cool at night, and warms up for swimming weather during the day; an occasional afternoon thunderstorm will settle in, providing a welcome change in the weather. After a long, hot day at work, I jump in the icy Merced. Cold plunge therapy is gaining in popularity for everything ranging from depression to obesity; while Scandinavians and alpine backpackers have quietly known the life-changing effects of fresh, cold water for a very long time.
Wilderness stalwarts and horde-avoiders alike are apt to denounce Yosemite Valley if you ask them whether they visit. “Too crowded for my taste,” they will say, often bitterly. I was among these before I first came to work here in the fall of 2019. Upon my arrival, my colleague gave me a tour of what would be my field sites for the next few months. We drove the loop around the Valley, dodging cyclists and strollers, distracted drivers and habituated deer who couldn’t care less about what the humans are doing. Everywhere there were people—on the trails, off the trails, on the roads, in the corners, under trees, in the trees, in the meadows, on the beaches, in the river—everywhere.
“How do you get work done here?” I asked.
“What do you mean?”
“There are…just…so many people!”
“You get used to it,” he said, adding, “This isn’t a place for purists.”
Half dome and meadow, Yosemite Valley
He was right, of course. Working (or living) in Yosemite Valley requires a radical change in perception. Many have wasted a lot of time wishing Yosemite Valley could be something it is not—pristine, unaltered, less-visited, quiet. But it hasn’t been that way since before 1890. The Valley has been blasted, built upon, invaded, paved, poisoned, and generally trampled for well over a century. The fact that it still stands as an internationally-renowned symbol of natural beauty is a testament to what the National Park Service has done right to take care of it—from piping all of the sewage from millions of annual visitors several miles downstream to El Portal for treatment, to all of the wildlife research and management that ensure the visitors aren’t destroying the landscape, the hard work shows. It is always easy to find what’s wrong; but what I’ve loved most about working in this park is learning about, and appreciating, what is going right.
Like the monumental efforts to reduce human-bear conflict that set an example for the rest of the country and the world, reintroducing frogs to the Valley is another effort that is going right. In 2016, the endangered California red-legged frog (Rana draytonii) was first introduced to Yosemite Valley from a private pond in the nearby foothills. Since then, they have been doing well—migrating to new habitats, breeding on their own in the wild, and taking up residence in the quiet backwaters of the Merced and adjacent meadows. It still amazes me, but despite all of the people around, the frogs seem to be thriving.
California red-legged frog with radio transmitter in Yosemite Valley, 2019.
I had the opportunity to conduct research with some of these introduced frogs in 2019. I would spotlight for them at night in the river, ponds, and meadows, nestling down in the dewy grass to sample them for Bd while the visitors slept. On a full moon, the light reflecting off of El Capitan was so bright I didn’t need a headlamp. I made peace with the visitors during the day, accepting crowds as just another part of the landscape, and at night it was just me, the frogs, an occasional field partner, and the deer that I occasionally pissed off by disturbing their evening meadow respite. One night, two bucks bedded down next to a pond we were working in suddenly got up and bounded directly toward us. After they passed—fortunately without skewering us with their antlers—my field partner said, her voice shaking, “That is the most afraid of an animal I have ever been,” while I climbed down from the tree I had just leapt into.
On this spring research sojourn, though I’m living in Yosemite Valley, I’m working outside the park in Stanislaus National Forest, where foothill yellow-legged frogs (Rana boylii) are still present. Yosemite Valley had foothill yellow-legged frogs once, but they haven’t been seen here since the 1970s. It’s likely that they were extirpated by the invasion of the amphibian chytrid fungus (Batrachochytrium dendrobatidis; Bd); and by the introduction of non-native American bullfrogs (Rana catesbeiana) in the 1950s. Bullfrogs, native to the eastern United States, are voracious predators and competitors of their more diminutive, native counterparts, and the local frogs often disappear when bullfrogs show up.
Foothill yellow-legged frog, Rana boylii.
The timing of my visit is aligned with the Rana boylii breeding season. Reintroducing frogs back to the Park might be possible, but before we can do that, we need to know if there are enough to go around. So, I came to count the egg masses, which serve as a fairly good proxy for the number of individual adult females in a population. Because an adult female will usually lay just 1 clutch of eggs every spring, we can take that number and multiply by 2 (because of an assumed 50/50 sex ratio) to estimate the total number of breeding adults. Are these frog populations outside the park barely hanging on, or can they spare some eggs for restoring the species in Yosemite? That is what we are hoping to find out.
Rana boylii egg mass.
Egg masses are tightly clustered eggs sealed in a protective jelly. Because foothill yellow-legged frogs lay their eggs in streams, the jelly is pretty tough—somewhere between silicone and your grandmother’s Jell-O mold. The female attaches the egg mass to a rock, where it remains until the embryos hatch out into tadpoles, which swim free to start their next phase of life. Rana boylii egg masses can have 400-1000 individual eggs; and perhaps half of these will successfully hatch out into surviving tadpoles; 50 or so will metamorphose into tiny frogs; and statistically only 1 of those baby frogs might live to a fully breeding adult. So really, to get from a tiny fertilized egg to a fully grown, breeding adult laying her own eggs is nothing short of a miracle. Egg masses are tiny packets of possibility—on the roulette wheel of evolution.
Tuolumne River.
Tasked with counting these egg masses, I identified all the places where we think the species is still present in the Tuolumne and Merced River watersheds. We based this on information from colleagues at the Forest Service, Bureau of Land Management, and other land management agencies; as well as from environmental DNA (eDNA) samples taken in the streams last year. Everything living sheds DNA into the environment—like our skin cells that can be used for forensics. We do wild animal forensics in the same way—by taking a water sample and using molecular techniques to determine whose DNA is in that water sample.
The sites I’m visiting are very unique from one another—from large and medium-sized rivers with giant boulders and deep pools, with old-growth trees fallen across them, to tiny creeks, that even in early May weren’t much more than a trickle, thick with alder and Himalayan blackberry vines. I walk upstream, looking under rocks, in crevices, and especially on the sides of boulders and cobbles for egg masses. Sometimes, in the larger rivers, I snorkel—a survey technique I am new to this year but am planning to take up as a sport, because it is so much fun. While snorkeling, I can cover a large area much more quickly, and see the rocks so much better. I also get to see what all the other underwater creatures are up to—beds of freshwater mussels tucked under the edge of a boulder, filter feeding. Large trout lurking in the deepest pools. Suckers appearing to play in the swift of water at the base of a waterfall, attaching themselves to a rock. Thousands of caddis fly larvae, each in their own unique cocoon of found items.
Rana boylii egg mass (left) with newly hatched tadpoles.
The breeding season has now wound down—the egg masses counted, the tadpoles hatched out. This year’s severe drought is likely to be hard on them; some will probably get stranded in small pools before they have time to fully metamorphose into air-breathing frogs. This is part of the program in a drought year, unfortunately.
For the next month or so, field crews will do another round of eDNA sampling in streams where we are still looking for more Rana boylii, hoping to find additional populations we didn’t know about before. Even though the species has declined from 70% of its range, the places where it still hangs out can teach us a lot about what the species needs, and how it can persist in the face of invasive pathogens, invasive predators, and climate change.
Though the frogs may be thrown into Jack Gilbert’s “ruthless furnace of this world,” there is reason for pragmatic hope. There are frogs left in the Stanislaus. They are still breeding. Next year, we will take action to give them a leg up, holding egg masses in rearing pens to protect them from their natural predators, so that each egg mass has a chance to produce more than one adult frog.
With their tiny packets of possibility, the frogs have given us a way to help them out. We can make amends for the diseases and predators we humans have spread around; the habitats we have altered. Just as the dogwoods have forgiven us, we can forgive ourselves and move on, helping a disappearing species recover, and delight in the work itself at the same time.