The American dipper appears as a small nondescript bird found along the west coast from Panama to Alaska. Take another look. Sometimes big surprises come in little packages.
What makes this species special? Why is this nondescript, dark brown to gray bird amazing? It doesn’t look amazing, but don’t judge too quickly… several things make them very special.
Indicator Species
Think of the old reference to a ‘Canary in a Gold Mine.’ Canaries were used as an indicator species for the mining industry. Canaries are very sensitive to methane and carbon monoxide. Early mines did not have ventilation systems and could be very dangerous. As long as the canaries were singing, it was safe.
American dippers are very sensitive to pollution and are only found on rushing, unpolluted streams. They look for streams with rocky bottoms and overhanging banks, and areas with adequate nesting locations.
If you were thirsty and lost, the sight of an American dipper near or in a stream is a sure indicator of good water quality.
Diver Extraordinaire
American dippers hang out near stream edges, bobbing up and down on long legs, and foraging aquatic insects and larvae, crayfish, and caddisfly larvae. They will also eat fish, tadpoles, mayflies, mosquitos, dragonflies, worms, and midges.
Suddenly, the dipper dives into the cold, rushing stream. The bird bobs up and down searching for prey. American dippers are great swimmers and will wade and move small rock as it hunts.
Diving gear
Moments later the dipper pops up very close to the dive location. How can it do that?
Dipper species have their own built in ‘diving gear.’ They have an extra eyelid membrane that allows the bird to see underwater. In addition, the bird can also close off the nostrils (with special scales) when submerged. Finally, their extra oily feathers may keep them warmer when underwater and help shed water quickly.
Diving makes dippers prey for large trout.
Migration
American Dippers are permanent residents for an area and do not migrate. They will move around an area to take advantage of insect hatches and find unfrozen water. Indicator species typically focus on animals that do not migrate.
Huge Song
Both sexes of this species sing an elaborate song year around. The song includes high whistles and trills that can be heard above the chaotic rushing water.
Nests
The American dipper builds an interesting rounded nest as well. The globe-shaped nest is built by male and female birds. It usually on or near a rock ledge, river bank, under a bridge, or even behind a waterfall. The nest will usually have a side entrance near the water.
The birds dip grass and other materials into water before adding them to the nest. The outer mossy layer is 8-10 inches in diameter and absorbs moisture. Coarse grass helps keep the inside 2-3 inch in diameter chamber dry. The inside chamber also includes leaves and bark. The female typically incubates 2-4 white eggs. The male helps to feed the young which fledge in about six weeks. Streamside territories are fiercely defended.
REFERENCES:
–Oregon Department of Fish and Wildlife (https://www.myodfw.com)
–Wikipedia, American dipper (https://en.wikipedia.org/wiki/American_dipper)
–All About Birds, American dipper (https://www.allaboutbirds.org/guide/American_Dipper/)
