Friday, July 27, 2012

Who's That Dipping Under My Bridge?

"He is the mountain streams' own darling, the hummingbird of blooming waters, loving rocky ripple-slopes and sheets of foam as a bee loves flowers, as a lark loves sunshine and meadows.  Among all the mountain birds, none has cheered me so much in my lonely wanderings, none so unfailingly." - John Muir, The Mountains of California

Who's under the bridge?  No, it's not a hungry troll... it's an American dipper, one of our most unique and specialized local birds.  Specifically adapted to live in and around mountain streams, dippers spend their days swimming and foraging in the clear, cascading waterways that give life to the Colorado high country.  Here's a short list of adaptations that make dippers special, as chronicled by Janis Huggins in her field guide
Wild at Heart:
  • dense plumage for feeding underwater without excess heat loss
  • stout, strong bill for foraging between rocks
  • waterproof feathers
  • short wings for easier maneuvering, used like flippers
  • large strong clawed feet for walking in strong currents
  • nostril flaps to keep water out
  • elevated hemoglobin for more efficient oxygen consumption in water
  • vision that compensates for the refractive index of water
  • dark plumage for camouflage.
Watching dippers has been a favorite pastime of naturalists from John Muir to Matt Reed, a fellow ACES summer naturalist, who tracked down an active nest in the Maroon Bells - Snowmass Wilderness Area.  The mossy nest and its inhabitants seem much more in tune with the spray of West Maroon Creek than with the clomp of hiking boots on the bridge above them.

Last week I snuck under the bridge to see what was dipping!  How many of the dipper's special adaptations do you see in the video?



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