By ABA Young Birder, Mackenzie Hollender
It was a strangely cold and gloomy May morning in Nevada City. All around the small mountain town, the glowing greens of spring were woven through a layer of late snowfall. Nevada City has the privilege of hosting a part of Deer Creek as it runs from the alpines and winds its way through the Sierra Nevada before emptying into the Yuba River. When walking over the stream’s bridge, I noticed that the gushing of the journeying water is almost louder than the gushing of the journeying people on the adjacent highway. The creek appears shallow, and clusters of small rocks rise above the current, causing the water to twirl as it travels around them. The shore is blanketed with ferns and saplings, creating the illusion that this part of the creek is as wild as the rest. But shortly up the slope, restaurants are packed together, jostling to see which can sport the best “streamside view” advertisement. Concrete encloses the creek like plastic encloses a toy. On a street adjacent to the bridge, construction vehicles lie still. Development threatened to encroach on the water. A concrete wall with a broad pipe sits a few feet into the stream, causing the water to curl unnaturally.
I had my back on the creek, when suddenly, an unfamiliar, buzzy trill sounded. I turned around and peered over the bridge. My face lit in a pleasant shock when I spotted a small, silvery bird moving on the bank– an American Dipper. I had always associated dippers with pristine mountain streams in an untouched forest– not with noisy, cramped city creeks.
The dipper walked energetically where the water met up with the thin gravel shore. I gazed at its almost monocolored, dark silvery plumage. I noted how its head was more brown than the rest of its body by a few slight shades. Its metallic thin legs give off a hint of pink. I watched as the dipper paused on its shoreline stroll, and did a few quick stationary squats. It bent its legs, moved the tips of its wings out as it went down, and as quick as it went down, it energetically popped back up into its straight, compact posture. I watched as the dipper repeated this pattern of walking and dipping. Then, the dipper moved onto a patch of rocks rising from the creek. Here, the dipper repeatedly stuck its head under the water, and resurfaced, sometimes holding an insect in its bill. While hunting, it faced the opposite direction to the stream’s flow. Perhaps that was the easier way for the bird to collect insects. It could snag them as they glided past, instead of trying to keep up with the stream’s current to chase them down. The dipper hunted until it had a bill full of many flimsy legs and glinting wings. It then performed a few quick dips while making rapid, bouncy trills. Abruptly, the dipper lifted from the rocks and perched on the rusty pipe sticking out from the cement wall.
I was puzzled at first. Why would the dipper choose such an unnatural, high perch instead of the streamside rocks it knows and loves? Then I took a closer look. Sitting atop the pipe, was a circular mound with an entrance at the bottom. The small mound was made of moss, dirt, and flimsy hay-like material. As the dipper landed before the mound, I could hear, just above the roar of the cars and the water, fainter trills coming from inside the mound. Offspring! Not only was this dipper able to find food at this small stream trapped by development, but it also, miraculously, was able to rule this spot as suitable to breed. Here, in the center of a construction site in the heart of a busy town, this dipper was able to find a mate, build a nest, and start raising a family. I pondered this with awe.
Pausing atop the pipe, the dipper carried out a couple dips. The begging nestlings continued their celebratory trills as the dipper entered half of its body into the mound. I imagined the dipper shoving each insect into the gaping, energetic mouths of the youngsters, and the growing chicks being satisfied enough to briefly close their bills. Moments later, the dipper backed out of the mound carrying a bright, soft looking small ball. A fecal sac. With the sac in bill, the dipper flew down to a half-submerged rock. It then gently placed the sac in the water. The sac floated smoothly down the current, away from the nest. I marveled at the dipper’s cleverness in using the stream’s strong current to ferry away the fecal sac so that it doesn’t have to spend that energy flying a distance away from the nest to hide it. The dipper flew a short distance to another outcropping of rocks to repeat this cycle of hunting, announcing itself with trills, feeding young, and disposing of a fecal sac.
I noted the birds’ different approaches to hunting. Along with hunting perched on a rock with only its head in the water, it would leap off the rocks to dive swiftly into the current. The bird would also land atop the water, and scoot around its surface like a duck, then abruptly dive from there. I watched the dipper swim against the current with seeming ease, and I was amazed by its strength. The dipper visited around four clumps of rocks on each hunting outing, none of which were very far from the nest, and it always hunted until its bill was near overflowing with the smushed bodies, limbs, and wings of insects.
Under the water, the sunlight had been altered, and as the hunting dipper passed below its surface, its sooty gray plumage became lighter and shiny. Its wings became flippers underwater, and I noticed that it motions its wings to swim in a similar way the Mourning Doves flies- each wingstroke is a quick snap. When the dipper flies, it zooms with rapid, unfaltering wingbeats, and its flight path is inches above the waters’ surface. The visions of the silvery bird slipping quickly under the stream stayed in my mind for the rest of the day. The light reflecting off the water as the bird passed smoothly underneath seemed to blur the two- [1] the dipper became one with the flow of the sparkling Deer Creek.
Throughout the rest of the day, I wondered about that family of dippers. Why did they choose to settle at such an exposed site? To feed my curiosity, I opened my old reliable bird knowledge lifelines- Cornell’s All About Birds and Birds Of The World websites. I was eager to dive deeper into the physiology of the American Dipper to enhance my understanding of its relationship with the sparkling mountainous streams. And it turns out, the stream is beautifully intertwined with every aspect of the life history of the American Dipper. There are many examples in the dipper’s physiology that show how bird and stream are woven together in a grand tapestry of silver and blue.
From the very moment a dipper fledges from the nest, its entire life is served by the stream. Adult dippers construct the nest so that the entrance faces the water, meaning that the offspring fledge straight into the stream. Their first vision of the outside world is a speeding, sparkling stream, the all providing natural feature where their entire lives will play out. Immediately after leaving the nest, the fledgling dippers start learning how to be in time with the infinite current. As the dipper fledgeling makes its way on its own, it will learn to perfect the art of hunting under the water. It will pick up swimming and diving pretty quickly-it instinctively knows how. It will learn how to propel itself against the flow while foraging on the streambed, and will find that it can stay submerged for fifteen seconds at a time. It will master using outstretched wings as its only defense to the rushing torrent. In turn for becoming well acquainted with the flow of the stream, the dipper will be able to acquire all of its food. I can picture the river whispering to the newly fledged dippers as they make their first plunge into the frigid water. If you learn how to keep in tandem with my flow, I will provide for you all the tasty caddisflies and mayflies you will need.
The dippers will learn the stream also provides protection from the speedy accipiters that hunt it. When in danger, it will figure out to dive under the water, or lay flat along its surface. There, it is sheltered from the talons of those hawks that are specialized for the woods, but nearly useless when it comes to aquatics. Every year, the dippers will undergo a simultaneous loss of all its flight feathers, assuming a stage of flightlessness- a type of molt uncommon in birds. During this flightless period, the dipper will find that it is able to rely on the stream’s flow for transportation and escape. I will be your protector, whispers the stream. With my flow, I will provide an alternate locomotive, so that you may go flightless in order to have a quicker molt.
Once the fledgelings understand the ways of the stream, the male dippers disperse to find their own territories. They may find that another dipper also occupies the territory– a female that can be tolerated. At first the two birds will simply exist in the same space, hunting independently of each other. But over time, the female may come a little closer, and beg the male for one of his prize catches. The male may ignore her, or he may feel it in him to deliver her request. Maybe she comes back again and asks for more, maybe he continues to feed her as the two go from tolerated individuals to something more. And then, the feeding is replaced by a bedazzling display. One of the dippers will droop its wings, start strutting on the streamside rocks, and tilt back its head so that its bill is angled straight up to the broad sky. Out from the skyward bill comes a bubbly, melodious warble, rising above the roaring water and melting back into the stream. Both the male and female may sing to each other, signifying their satisfaction with this territory, and this developing relationship. Finally the two birds will journey onto the final stage of courtship. Following the course of the stream, the male will pursue the female in a fast, fierce, and frankly romantic chase, their feathers barely out of reach of their fast, fierce, and forever flowing creek. All day the two birds may race just above the water, tracing the sunlight’s wavy glistens. There is no specific isolated act that cements a pair bond, rather, dipper pairs develop and strengthen over time, just like our own. Once a pair is together, they will stay together for life, only splitting up if their territory fails. As long as their stream keeps providing, they will stay together. The water is the bonding factor between the two birds. As long as my water is unpolluted and my rockbed is filled with tasty treats, I will keep your mateship intact forever.
As the days start to warm, the dippers will find that nesting material is among the stream’s many gifts. Along the stream’s rocks, they will be provided with moss, bark, fallen leaves, and grasses. Both birds construct the nest. Once done, the female will lay 4-5 eggs, which both parents incubate for about two weeks. Then the eggs will hatch, and the cycle of the life of the American Dipper will begin anew, nurtured every step of the way by a different but equivalent cycle taking place in the shiny creek below.
Even the smaller details add so much depth and grandness to the ecological relationship between stream and dipper. I think back to my observation of the adult using the stream to dispose of its young’s fecal sac. I will hide the fecal sacs far away for you, keeping the nest site unnoticed by predators, saving you valuable energy. I think about how dippers always fly following the stream, even if it ends up being the longer route. I will be your roadmap, the path that will guide you to new destinations. Dippers are served in so many ways by this land form, it’s no wonder they never seem to want to be distanced from it. Dippers are known to place their nests in spots that continually get sprayed, so that even inside of the terrestrial nest, bird and stream can always be a part of each other.
The stream is everything to the dipper, but what is the dipper to the stream? How could the stream benefit from associating with dippers? Like all creatures, American Dippers have habitat preferences. The stream could have the right depth, temperature, and velocity to be sustainable for dippers, but all of that will not matter if the stream’s water is unclean. Since dippers will not engage with a polluted stream, scientists can rely on the presence or absence of American Dippers to determine the quality of a stream’s water. If you will provide me everything I need, the Dippers whispers back to the stream, then I will be your water quality tester. My presence along your shore will let everyone know that you are pristine and beautiful, and if the time comes, my absence will serve as alarm bells, letting the world know that you need to be helped.
Centuries of living completely off the stream have evolved dippers into something unlike anything else that exists in the world– a merge between two polar opposites of the avian world. American Dippers are a masterful blend of the densely feathered, water bound ducks, and the territorial, melodious songbirds. In the same way the water carves shape into the land it travels through, this bird has had its genetic makeup sculpted by the rushing creek. A multitude of adaptations aid their ability to keep up with the currents- an extra coat of feathers for the freezing water, a lower metabolic rate, and larger sphincter muscles, allowing dippers to accommodate for underwater visual changes. We all understand that adaptations exist for survival. But what if adaptations could also be looked upon as a love letter to place? If you provide for me all of the things I need to thrive for generations and generations, the dipper whispers to the stream, Then I will let myself be changed by you. I will evolve to be your perfect companion, so that we may remain side by side for millennia.
When looking for territories, the surrounding vegetation is unimportant to dippers. That’s the piece of information that answers my question about why the dippers were able to find a home on a creek enclosed by human activity. It’s simply because the cars on the highway, the squished restaurants above, and the concrete walls are of no importance to the birds. From the clean water beneath their feathers, they are given everything they need for life. Perhaps the American Dipper and the stream show us that it matters less where we are, as long as our all providing lifeline is present and well, we have all we need to be fulfilled. I think about what that is for me, what is the stream to my American Dipper? My loving parents, closest friends, and mother earth herself come to mind.
The Nevada City Deer Creek spot will host dipper families for generations of birds. Each individual life that plays out within that stream will strengthen their intertwined roots. Or, that was supposed to be the case. Such an engulfing experience with wilderness can mask threats that are mere feet away. The towering construction vehicles that lay dormant just up the slope were bound to stir into wakefulness and descend on the dipper’s whole world.
I returned to Nevada City in August, looking forward to seeing the family of dippers, and watching their ecstatic squats as they contemplated entering the creek. But, as I peered over the Deer Creek bridge, I was thrown into a bewildering dismay. The wall where the dippers had built their mound was gone. The ground where the stream traveled was covered in broken cement. The shimmering, wild Deer Creek was reduced to a small, stagnant brown puddle. No remnant of the majesty of a bird family thriving in the city remained. What had happened?
From research I learned Nevada City had been preparing a stream diversion. The city was going to divert the water of the stream down a different route, in the process uprooting the home that the dippers had found. The stream diversion was to take place in order for new construction on the Nevada City bridge, which was set to end in November of 2025, and Deer Creek would remain diverted until then. How did the American Dipper family react at the halting of the background noise that had meloded their entire life? What were their reactions to, for the first time, hearing only the roar of highway cars, the piercing beeps of construction vehicles, and realizing this place was no longer theirs to live off of? The male and female pair, who were set to live out their days along this humble stream, likely parted ways for good. I can only hope the offspring fledged long before the stream went quiet at the hands of man. I hope the chick’s first glimpses of the world were of the sun dancing off the creek as they dove straight into their life of catching currents and building homes with the wild water, rather than a desolate, concrete mound, with nothing left to offer.
This is why I love the study of Ecology. Because we need it. We need it so the novelty of a relationship between two parts of the natural world doesn’t go unnoticed and destroyed, but rather, appreciated and sustained. If the construction facilitators had paused and noticed the dipper nest, and had taken some time to understand its relationship to Deer Creek, maybe the stream and the American Dippers would still be thriving together today.
Sources Cited:
Cornell, “American Dipper”, All About Birds, https://www.allaboutbirds.org/guide/American_Dipper/overview, Accessed August 23rd 2024
Kingery, H. E. and M. F. Willson (2020). American Dipper (Cinclus mexicanus), version 1.0. In Birds of the World (P. G. Rodewald, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.amedip.01, Accessed August 26th 2024
Wikipedia, “Deer Creek (Nevada County, California)”, https://en.m.wikipedia.org/wiki/Deer_Creek_(Nevada_County,_California) last edited 2019, Accessed August 29th 2024
The Union Staff, “Updates from Nevada City: New Website, Construction over Deer Creek, short term rentals and more”, The Union, January 17th 2024, https://www.theunion.com/news/updates-from-nevada-city-new-website-construction-over-deer-creek-short-term-rentals-and-more/article_547a10ac-b4cf-11ee-afa7-0f2f8e1f9886.html, Accessed August 29th 2024
Mackenzie Hollender is a sixteen year old birder from Sacramento California, who began birding at age six, after being captivated by a stunning murmuration of European Starlings above a neighborhood park. She has gone on to become the first Student Representative on the board of the Sacramento Audubon Society, and in this position so far she has helped develop a survey for wintering Mountain Plovers. In addition, she is also the founder of the first youth-led birding organization in her region, the Sacramento Valley Young Birders Club, where she leads monthly field trips and participates in community outreach events. Outside of birding, she is a climate activist, actress, and a creative writer experimenting with all styles. In her future, she hopes to pursue a career in ornithological research, continue environmental advocacy, and continue to capture the essence of birds through writing.
