- Author: Cameron Barrows
A "Natural History Note" From UC California Naturalist's lead scientist, Dr. Cameron Barrows.
“It is that range of biodiversity that we must care for - the whole thing - rather than just one or two stars.” – Sir David Attenborough
That range of biodiversity includes the panoply of life occupying a region. Everything from charismatic species (those one or two stars), bighorn sheep, collared lizards, wolves, and mountain lions, to microscopic soil organisms. Everything from diaphanous-winged butterflies and damselflies to the parasitic wasps that keep insect populations from becoming so numerous that they would otherwise consume all plant life on earth. Everything from towering sequoias to pond scum. Those microscopic soil organisms are essential for helping plants convert inorganic minerals to the building blocks of life and for capture moisture in an ever more arid desert. That pond scum is an organic factory converting sunlight and carbon dioxide to oxygen.
In 1798 Thomas Malthus, an English economist, published an essay on the principle of population growth. Malthus' math was elegant, and its conclusion undeniable. In the absence of factors that limit population growth, populations will grow geometrically until some critical food resource was exhausted and then the population would crash into oblivion. Malthus was thinking humans, but his conclusions are applicable to all species. Arguably no other document was as inspirational to both Charles Darwin and Alfred Russel Wallace for their independent development of the Theory of Natural Selection. Malthus' math was clear; based on any species' reproductive capacity, we should be neck-deep in lizards, spiders, voles, wrens, bighorn sheep and coyotes. Obviously, that is not the case, but from those two conclusions, what the math predicted and what we can see with our own eyes, Darwin and Wallace deduced that species underwent a struggle for existence. That struggle included within and between species competition, avoiding predation, parasitism, disease, and natural disasters. That struggle was real and intense enough that only those individuals that could survive those challenges would ultimately survive and pass their genes on to the next generation. So, species are being subjected to an on-going gauntlet of threats, as are the parasites and viruses and predators, ensuring that species do not reach such numbers that their populations would then crash into oblivion.
Aldo Leopold, in his essay “Thinking like a Mountain”, acknowledged that early on he too fell into the trap of valuing species as “good” or “bad”. “Good” species were those charismatic vegetarians like deer and sheep and squirrels. “Bad” species were non-human carnivores, wolves and coyotes and mountain lions. Leopold, in his early years, sought to rid the rangelands of predators to ensure that deer and other “good” species could proliferate. Proliferate they did, so much so that they ate all the available palatable plants, the forests and rangelands were degraded, and the deer began to die of starvation. It was a mistake people have repeated and continue to repeat to this day. Mountain lions and wolves are now gone from eastern North America, and the deer populations have exploded causing widespread starvation and disease. Not long ago I heard a local bighorn sheep biologist celebrate the death of a mountain lion because it meant more sheep would survive, but he did not include the reality that “his” sheep now face hillsides incrementally devoid of palatable food and flowing springs because of climate change.
A few years back I attended a lecture by a young biologist telling of his efforts to explain to cattle ranchers why their animals were faced with food shortages. The ranchers were convinced that the bison, who shared the grasslands with their cattle, had become too abundant and needed to be “culled”. The biologist patiently explained that, based on his analyses, that the bison and cattle were selecting different plants to eat. The ranchers argued back that the bison must be to blame. The biologist again patiently explained that it was not the bison, it was jackrabbits that were competing with their cattle for food. The ranchers stared is silence, trying to identify where the biologist's analysis and logic had been in error. One of the ranchers finally spoke, not to the biologist but to the other ranchers, and said that perhaps they (the ranchers) had been overzealous in killing coyotes. A healthy coyote population would have kept the jackrabbit population from a Malthusian population trajectory, and so would have left sufficient forage for bison, jackrabbits, and the ranchers' cattle. Attenborough's call for to care for and protect biodiversity, all species (including humans), is the only sane path forward.
- Author: Adina M. Merenlender
Guest author Adina Merenlender is the founding Director of the UC California Naturalist program, and writes about the North Coast Biogregion for California Biodiversity Week 2021.
California's Northern Coastline is a refugia where the local climate is relatively stable compared to rates of climate change in other parts of California. This is particularly true if we continue to experience a drier future under climate change. The resilience to immediate rapid change is due to the influence of the Pacific Ocean and the topographic diversity of the coastal mountain ranges.
Steep coastal watersheds provide an escape route for species to move up to higher elevation or down to cool air drainages to escape the heat. Summer fog buffers terrestrial plant communities from extreme heat and freezing temperatures and frost is rare close to the ocean, making for more mild winter temperatures. The mild temperatures and higher humidity year-round are ideal conditions for plant growth and the Northcoast harbors very diverse plant communities.
For many, redwoods, the charismatic mega-flora, that create unparalleled cathedrals filled with majestic qualities may come to mind. But those towering trees leave little sun or nutrients for the plants below. The real biodiversity hotspots are coastal prairie and scrub communities where rare flowering plants can still be enjoyed. Whereas interior woodland wildflowers come and go over a short Spring season, coastal prairies offer a seemingly ever-changing wildflower show from January through September. The show starts with manzanita and Lupin and ending with pearly everlastings and Dudleyas.
These coastal refugia might provide endemic plant communities time as temperatures rise, but we need to act now to curb greenhouse gas emissions so that these cooler moist areas can persist over a longer time horizon.
September 4-12, 2021 is California Biodiversity Week. Join us in celebrating the unique biodiversity and renewing our commitment to stewarding the state's incredible natural heritage! During the Week, CalNat is posting blogs authored by members of our community, ending in our September 14th CONES event from noon-1:00 PM. Be sure to also check out a list of activities and resources online from the CA Natural Resources Agency!
Guest author Blanca Villalobos is a certified UC Riverside Palm Desert Center California Naturalist, and writes about the South Coast Biogregion for California Biodiversity Week 2021. You can follow more of Blanca's work at www.blancasvillalobos.com or on Instagram at @blanca.s.villalobos.
Tecolotlán & El Totole, nahuatl names given to the lands from which my parents were raised in: their origin meaning place of owls and turkey hen, respectively. My parents are therefore birds, who eventually migrated north in the 1970s across colonial borders until settling as guests on Cahuilla & Yuhaviatam/Maarenga'yam ancestral lands to raise their family. I grew up in the San Gorgonio Pass in Southern California surrounded by the Peninsular & Transverse Mountain Ranges, craving stories about my ancestors, cultural practices and post Mexican revolution folk tales. Lucky for me I was blessed with amazing storytellers for parents who compliment oneanother's approach to storytelling through performance & wit.
In 2018 I landed my first environmental job working at a local nature preserve after years of social work & organizing. Due to this new field of work, I quickly learned to drive slowly through the desert canyon out of concern for wildlife like bighorn sheep, rattlesnakes and the usual gambel's quail. Never did I expect to spot & identify a bird unknown to me except from the stories I had heard over the years from my dad.
On my way out of the canyon one evening, I spotted something drab & not much larger than a robin in the middle of the road. Red glowing eyes fixated on my car, I approached the relative slowly until it haphazardly took flight only to quickly rest their body on the asphalt once again. I smiled upon realizing who they were: un tapacaminos, one who covers roads. I grew up hearing my dad tell animated stories about this nightjar, how he'd be traveling in Jalisco and how he'd come across them on his path “¡No se mueven! They don't move!” he would say grinning.
Still in my car, I noticed that the illumination from my headlights helped this nocturnal bird locate their dinner: a plethora of insects under a crepuscular desert sky. Once they had their fill they eventually flew out of my path, allowing me to reflect on the metaphor of their Spanish common name while I made my way out to the Coachella Valley.
It is critical to understand the connection between the migratory paths of these birds across North America with those of my parents and other migrants. Every year I look forward to seeing the monarch butterflies journey between Canada & Mexico and just recently I became aware of the black bear in my neighborhood that travels up and down the Sand to Snow National Monument for water & refuge. What I would like folks to consider during this year's California Biodiversity Day is a compassionate & intersectional reflection on the absurdity that is a border for all living beings.
With love & in solidarity,
Blanca S. Villalobos, they/she
September 4-12, 2021 is California Biodiversity Week. Join us in celebrating the unique biodiversity and renewing our commitment to stewarding the state's incredible natural heritage! During the Week, CalNat is posting blogs authored by members of our community, ending in our September 14th CONES event from noon-1:00 PM. Be sure to also check out a list of activities and resources online from the CA Natural Resources Agency!
Guest author Chloe Van Loon is a certified Grassroots Ecology California Naturalist, and writes about the Mojave Desert Biogregion for California Biodiversity Week 2021. You can follow more of Chloe's writings posted on Chloe Van Loon's Nature Blog.
For most of the past year and half I have nomadically roamed around California, chasing nature's “blooms”. That meant spending the winter in Mendocino County finding fungi, and springtime in the Bay Area wandering around for wildflower displays. Between these two Northern California spots, Joshua Tree was my home. For two months my husband and I searched for flowering annuals, prickly cacti, quick-footed reptiles, jumping rodents, and magnificent nocturnal moths.
Many California Naturalists may already know the desert ecosystems of California are incredibly diverse. I was well aware of this myself before spending time in the Sonoran and Mojave deserts. But a weekend trip really isn't enough, a week isn't enough, and two months isn't enough to fully grasp the ecology of desert ecosystems! I think it takes multiple years of visiting at different times. I think it's equally important to visit during a super bloom year as it is to visit in a non-super bloom year to see the diversity of species that have adapted to the extreme temperature fluctuations, long dry spells and the winter rain deluges.
This year, 2021 wasn't a super bloom year as the winter rainfall was pretty poor for much of the state. So we had to get smart about where and how to search for angiosperms and accompanying insect visitors. One resource that was super valuable was Tom Chester's Bloom Reports (tchester.org) for the Anza-borrego Desert, located about an hour and half south of Palm Springs. Unlike the alpine meadows of the Sierra mountains where at peak bloom my senses are overwhelmed with color, textures, and scents, iNat-ing the California deserts is a treasure hunt: it takes time for the human eye to hone in on the often cryptic and small plants amongst the desert floor. Having a general sense of the area's plants before heading out for a hike really helped in order to spot the common plants, rarities and lifers. Fellow California Naturalist, Colin Barrows' iNaturalist observations were also very helpful study tools. His Coachella Valley Wildflower iNaturalist Project was a great photo reference source. Projects like these are a fantastic resource and fortunately exist in similar forms all across California. Doing your homework by brushing up on what's been recently observed before heading out is totally worth it. You might be surprised how diverse the desert is.
Depending on the time of year - really even the week! - will dictate what might be blooming. Will the common Brittlebush (Encelia farinosa) still be producing its wonderful yellow compound flowers? Will my personal favorite the Desert Globemallow (Sphaeralcea ambigua) finally produce its glorious apricot orange petals? Will the gorgeous Sand Blazingstar (Mentzelia involucrata) have Sweat Bees visiting? But how will these plants, associated insects, and wildlife that use them for food or shelter cope with rising temperatures, altered rain regimes, and all the other compounding effects of climate change? A recently published study by Hantson et al. (2021) from UC Irvine suggests climate change is to blame for recent “strong” declines in vegetation cover, and these hardy dryland ecosystems are more at risk than previously thought to the effects of climate change. Oh no.
The Western Joshua Tree (Yucca brevifolia), the charismatic, long-limbed Dr. Suess-like trees of the Mojave desert, are the first plant species reviewed by California's Endangered Species Act to attribute climate change as a primary threat. Among other reasons like habitat loss, developments, and invasive species, the Western Joshua Tree's habitat may be almost totally gone by 2100. What other vulnerable species should be citing their primary threat to existence as climate change? For myself it's hard to imagine that any native California species escapes the negative effects of human induced climate change. Throughout my time in the desert I saw a Ladder-backed Woodpecker checking out the flowers of the Joshua Tree, Northern Mockingbird and Loggerhead Shrikes perched up high while LeConte's Thrasher and Gambel's Quails run between its shadows. Turn over a fallen branch and you might find beetles or weevils scurrying on the ground, or Giant Water Bugs crawling around if the branch had fallen in a creek. How will all these species fare with altered or absent Joshua Tree populations?
How will the biodiversity of California's desert's change in the near to distant future? Is the future only one round of Ocotillo's flowering? Will the Desert Bighorn sheep at lower elevations become locally extinct like Eeps et al. (2004) predicted? Both these species along with the other incredible flora and fauna of California's deserts evolved over time to produce the mosaic of biodiversity we see there today. How climate change is going to change this assemblage is perhaps predictable for some species, but I'm sure surprising for others. So I encourage everyone to visit, learn and appreciate how the species you see while visiting the deserts of California, and to ponder what adaptations they evolved over time to flourish there, and most importantly what you can do to keep it thriving in perpetuity.
September 4-12, 2021 is California Biodiversity Week. Join us in celebrating the unique biodiversity and renewing our commitment to stewarding the state's incredible natural heritage! During the Week, CalNat is posting blogs authored by members of our community, ending in our September 14th CONES event from noon-1:00 PM. Be sure to also check out a list of activities and resources online from the CA Natural Resources Agency!
Resources:
Hantson, Stijn, et al. "Warming as a driver of vegetation loss in the Sonoran Desert of California." Journal of Geophysical Research: Biogeosciences 126.6 (2021): e2020JG005942.
EPPS, C. W., McCULLOUGH, D. R., WEHAUSEN, J. D., BLEICH, V. C., & L. RECHEL, J. (2004). Effects of Climate Change on Population Persistence of Desert-Dwelling Mountain Sheep in California. Conservation Biology, 18(1), 102–113. doi:10.1111/j.1523-1739.2004.00023.x
Center for Biological Diversity. “Court Upholds Protection for California's Western Joshua Trees.” Center for Biological Diversity, Center for Biological Diversity, 22 Feb. 2021, biologicaldiversity.org/w/news/press-releases/court-upholds-protection-for-californias-western-joshua-trees-2021-02-22/.
Olalde, Mark. “Joshua Trees Can Be Legally Protected in California, Court Rules.” The Desert Sun, Palm Springs Desert Sun, 25 Feb. 2021, www.desertsun.com/story/news/environment/2021/02/24/joshua-trees-can-legally-protected-court-rules/4552210001/.
Guest author Siera Nystrom is a certified UC Merced Vernal Pools and Grassland Reserve California Naturalist, and writes about the Sacramento and San Joaquin Biogregions for California Biodiversity Week 2021. You can follow more of Siera's writings posted on Notes from a California Naturalist.
September marks the beginning of a great awakening across California's Great Central Valley. As summer fades quietly into the warm, golden tints of autumn, long-absent birds begin to return, filling sleepy wetlands with sound and color and motion, the throbbing pulse of life.
Scattered up and down the Central Valley, carefully engineered wetlands, many of which are managed by the U.S. Fish and Wildlife Service as National Wildlife Refuges, provide pockets of protected habitat, humble but precious remnants of what was once an extensive system of freshwater marshes, sloughs and riparian corridors, linked together within a mosaic of arid upland habitats stretching the length of the Valley.
Native Yokut people, who have long called this beautiful valley their home, make wise use of the natural abundance found here, their lives intertwined with and dependent on the bounty of the wetlands. Tule reeds, which grow in the still, freshwater marshes and sloughs once so characteristic of this region, provide plentiful food and fiber, while the marshes themselves afford valuable habitat for a seasonal abundance of waterfowl, a rich and reliable food source for the Yokut.
The majority of the Central Valley's freshwater marsh habitat has long since disappeared – and with the wetland, her people. Diked and drained, paved and plowed beyond recognition during the nineteenth and early twentieth centuries, the once abundant freshwater marshes of the Valley vanished at the hand of progress.
Like the coming of the first autumn rains, the mid-twentieth century once again brought change to the Valley's wetlands: change and hope. Through the Herculean efforts of both government and private organizations, with the cooperation of conservation-minded landowners, wetland restoration began in earnest.
Three quarters of a century later, the Central Valley wetlands of today are a far cry from the wild places they once were before European settlers arrived. Though highly fragmented and intensively managed, freshwater marshes in the Central Valley persist as functional blocks of priceless habitat for the wide array of plants and animals that rely on them. And, most importantly, they are protected in perpetuity.
Though the damage to Central Valley wetlands can never be undone, it can be somewhat mitigated: water can be redirected to fill dry sloughs and sinks, native plants can be regrown. The tules themselves breathe new life into rehabilitated wetlands, drawing wildlife into their sheltering thickets. Migratory birds are drawn by instinct to the mild winter climate of the Central Valley, following ancient flyways to return each autumn to their ancestral overwintering grounds.
Yes, hope remains for the diverse assemblage of species that rely on Valley wetland habitats.
A cursory glance across the Central Valley landscape from the highway belies its true value. What the casual observer sees are rural communities, sprawling towns and cities, and the intensive farming operations of one of the most productive agricultural regions in the U.S. But tucked away, hidden within the rigid patchwork blocks of almond orchards and corn fields, are the sinuous curves of meandering sloughs and marshes, painstakingly carved out of the landscape and set aside for the birds – and for the future.
During the short, gray days of winter, waterfowl overwhelm the wetlands: ducks and geese swirl through the air like avian confetti, and blanket open water like drifts of snow; Tundra Swans glide through dense tule fog like apparitions, emissaries from the Arctic.
With the coming of spring, the animated chatter of Marsh Wrens, buzzing notes of Song Sparrows and rollicking songs of Common Yellowthroats fill wetlands with a joyous chorus, the sound of life reveling in a landscape that has suddenly cast off her somber winter tones in exchange for vibrant green finery.
But spring is fleeting, and all at once Valley wetlands are plunged into the heat of yet another seemingly endless summer, the lush growth of April rapidly fading to the dry, muted shades of August. Pools of water shrink before drying completely to reveal basins of cracked mud. All is still and quiet in the wetland, save the soft droning of dragonfly wings and the rustling of dry reeds in a hot breeze.
After sleeping through the long, dry days of summer, tule marshes awaken in the autumn with the return of countless millions of birds, from raptors and songbirds, to waterfowl and shorebirds. And with them come perhaps the most iconic Central Valley bird of them all, the Sandhill Crane.
From late September through the end of March, these elegant, three-foot tall birds grace Central Valley wetlands with their stately presence, bestowing on the tule marshes a certain dignity that is lacking in their absence. Large flocks of Sandhill Cranes spend the winter months in the gold-and-gray landscape of Central Valley marshes, dancing and grazing in fields of grain grown especially for them. In a scene that has remained unchanged for countless generations, trailing skeins scrawl across the sky, silhouetted against the sunset as the cranes fly in for the night, seeking refuge in the wetlands.
With autumn on the way again, the marshes know that change is coming: change and hope. Slowly, quietly, imperceptibly at first, the seasons begin to shift. Morning mist lies heavily over the water; a cool breeze stirs; cottonwood leaves fade from green to gold. With any luck, the autumn rains begin.
And once again, the birds return to this special place, the place their ancestors have relied on for millennia. Once again, the cranes' bugling cries sound across foggy marshes, haunting echoes of the prehistoric heart and soul of the Great Central Valley.
September 4-12, 2021 is California Biodiversity Week. Join us in celebrating the unique biodiversity and renewing our commitment to stewarding the state's incredible natural heritage! During the Week, CalNat is posting blogs authored by members of our community, ending in our September 14th CONES event from noon-1:00 PM. Be sure to also check out a list of activities and resources online from the CA Natural Resources Agency!
