Spring, in Colorado’s Eleven Mile Canyon often doesn’t arrive until June. When it does, some would say it arrives with a vengeance; not with the gradual progression of wildlife activity as seems typical in most other parts of the country or for that matter, Colorado. As if made impatient by the incessant winter snows that pound through the days of March, April and sometimes May, those living for part or all of the year in Eleven Mile Canyon frantically begin their springtime rituals as if there were no tomorrow. There’s a lot to do before next winter’s snow begins to fall. Amidst this flurry of wild activity, the insects, the hawks and eagles, the ducks, the geese, a myriad of mammals and the songbirds come and go but one gray nondescript bird remains along the river, never venturing far from the boulders and rock walls contouring the banks of the South Platte River that passes through this canyon.
I am walking along the lower Platte River as it courses through Eleven Mile Canyon, looking for the nests of this aquatic songbird. Aside from the roar of the river, another dominating sound echoes between the canyon walls above the rumbling mountain torrents. It is the wren-like song of the American Dipper [Cinclus mexicanus], more whimsically called the American Water Ouzel. One of four species in the world and the only one in North America, this is the only true aquatic songbird, related to the wrens and thrushes with characteristics of both. Dippers live at elevations from 2,000 to 10,500 feet, ranging from the Aleutian Islands, north-central Alaska, south to central Alberta, southwest South Dakota, southern California, Mexico and western Panama. Two other relatives live in Europe and in the Andes of South America. We were here to try to photograph the nesting behavior of these amazing sooty-gray birds.
Having gotten their name by their habit of bobbing up and down, up to 60 times a minute while hunting along the water’s edge, the Dipper creates a comical picture. Researchers have theorized that this dipping action helps them blend in with the motion of the pulsing waves and changing light. They average from 7 1/2 to 8 1/2 inches in length with filmy blackish-gray plumage made up of nearly 6,300 outer feathers and a thick undercoat of down. The sexes are identical and solitary, except during mating and nesting season. Their wings and tail are short and stubby while their legs are long and strong with toes like any other perching bird. A large preening gland, 10 times the size of any other songbird, helps keep the feathers waterproof. A well-developed nictitating membrane protects the dark eyes from the water spray of rapids and waterfalls. The upper eyelids are bordered by short white feathers. A long slender black bill has a slightly hooked notch at the tip to better snag their prey. Immature Dippers on the other hand have pale, yellowish beaks and spotted breasts. To complete this picture, the Dipper has a movable flap over the nostrils to keep out water.
All these accessories make up a bird that swims on the surface of a icey mountain stream by rapidly paddling it’s unwebbed feet, literally flies underwater through 20 feet of water to reach feeding places, and is able to fly from beneath the water’s surface and continue out over the river in a quail-like buzzing flight. Dippers can dive into water directly from flight, from a boulder or from the surface of the water and may remain submerged up to 30 seconds.
Be it a stream or pond bed, the Dipper can walk underwater in search of food. They are so well insulated against the cold that the American Dipper has carved out a niche for itself in the upper reaches of most of our wild mountain streams, challenged by few competitors and it is here the Dippers stay throughout the year, leaving for lower elevations only when the stream freezes over completely.
The abundance of food in a swift moving mountain stream is remarkable. Dippers fish a 1/2 to 1 mile stretch of river territory; an area vigorously defended by the breeding pair during nesting season. The Dippers I watched rarely surfaced without a beak full of caddis fly larva, of which they seem especially fond, mosquito, midge, mayfly, or stone fly larvae, water bugs and beetles, small fish, clams and even snails. Whether the prey is floating, frozen or underwater, it makes no difference.
Anytime during March through June, the American Dipper leaves it’s normal solitary existence to find a mate. Once accomplished, as a pair they will defend their section of the river against any interlopers. All the while, the female works on building a bulky nest of yellow and green mosses and fine grasses, approximately 1-foot-wide in diameter, with a side entrance. The nest may be on the ledge of a rocky cliff, on the upturned roots of a fallen tree, on a beam under a bridge, behind waterfalls or sometimes but least often on a rock midstream. In all cases, nests are situated near the water.
Once the usual four to five white eggs have been laid, the female incubates them for 15 to 17 days, while the male tends to her needs. The young will fledge the nest when they are about 24 to 25 days old.
We have arrived in mid-May and although there has been a lot of snow this spring and snow still remains on the north facing slopes, there are fledglings out on the river boulders demanding to be fed by their attentive parents. Still, further up stream another Dipper pair is busily tending the gaping mouths of three nestlings which are poking out of the arch-shaped entrance of a nest precariously wedged in a fissure of a rock wall. Bundled in our winter attire, doing our best to blend with our environment, we quietly position cameras and selves across the river to watch and photograph.
As with most bird species, the nestlings remain silent until they hear an adult returning with a beak full of river potluck. Long before I hear the parent bird, their open yellow mouths are thrust out the nest entrance in anticipation. As fast as my camera shutter opens and closes, the adult Dipper has swooped in, popped a morsel or two into the mouths of the hungry nestlings and flown off without missing a wing beat. Both parents, while taking time to eat and rest, share the duty of supplying food to the babies until they are old enough to venture out on their own.
A fastidious bird, the Dipper parents washed the food before feeding it to the youngsters or eating it themselves. At regular intervals, the adult Dipper would call to the youngsters from below the nest, who upon this apparent demand would expel a fecal-sack from the nest. The adult would retrieve and sometimes even wash it as if to recycle some usable portion and release the remainder into the river. Occasionally, a parent would fly into the nest and do some additional housekeeping.
At about 25 days of age, the juveniles tentatively leave their nest, stepping out onto the nearest reasonably level ledge where they will perch and dip until they develop enough curiosity and strength to explore the immediate area. Since a young Dippers’ flying and swimming skills are limited, they stay close to the nest and are delivered shipments of food by their ever-vigilant parents.
Each day, we would arrive to find the three fledglings farther and farther from the nest and as we would soon see, this was not always intentional. They would try out their wings with short trips back and forth to nearby boulders. As the river beckoned, they would wade in and out, then stand dipping while waiting for their parents to return with food. With each passing day the juvenile Dippers would become stronger and braver. Their wading attempts became swimming attempts and while swimming in protected pools became easy, the fast-flowing river was another matter. A fledgling would find itself swept downstream if it ventured out into the water too far or misjudged its landing. The Dipper parents were constantly on the go, tending increasing food demands while keeping track of their young spread out along the river.
By the end of their first week out of the nest, we were pleased to see the trio swimming and finding some of their own food, although their underwater skills were still a bit lacking. But as they became more adventuresome, I became increasingly anxious as I scanned the river for the three youngsters each morning upon our return. Once accounted for, I would expel a sigh of relief like a doting parent. Afterall, they had become my own.
The Dipper trio grew, learned and thrived. When, after week number two they became nearly impossible to keep up with, we ended our foray into the lives of these young Dippers, confident that they would go on to become the amazing little gray aquatic songbirds their parents are. The American Dipper is truly one of the dominating features of a cold mountain stream and Eleven Mile Canyon.