Yellowstone Reports

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Late Summer Magic

Life of the aspen grove
by Dan Hartman

Aug. 10, 2015

     As seems to happen every year, my owl nests keep me busy until mid summer.  Then I find myself scrambling to salvage what is left of summer.

     I headed straight to my favorite aspen grove hoping there was still some magic left.  I could hear hairy woodpecker chicks the moment I stepped out of the car.  Within minutes I had located their nesting cavity.  While I was waiting for the adults to feed, I heard a purring sound.  Below and to my right a red-napped sapsucker arrived with a beak full of insects.  I watched as he flew into a low hole in an aspen snag.  In a cavity just below the woodpecker nest, a green tree swallow was bringing food to its' mate.  I heard a mountain bluebird and soon spotted him perched high in an aspen.  He knew I spotted him and didn't want to give away the location of his nest.  I turned away and saw him disappear into a cavity in a dead aspen.  Suddenly, a commotion errupted upslope. A flicker was feeding it's young.  Their heads were completely out of the nesting hole, meaning they were only days from fledging.  A wren made regular visits to a hole just above my heard and another swallow nested to my right.

     The next day I noticed a williamson sapsucker passing by me from time to time.  He always disappeared in the aspens just above, over a step hillside.  When I was done photographing the woodpeckers, I went looking for the williamsons.  Just over the hill, I found an eight foot aspen snag.  A cavity was near the top.  I backed off and sat down to wait in a cluster of saplings.  Suddenly a flycatcher flew in to a grass nest beside me and fed chicks.  Soon after, the williamson male arrived with a beak full of bugs.  Sure enough he entered the cavity in the snag.

     I'm always amazed how aspen groves come to life every summer.

     During winter one might hear a woodpecker or maybe chick-a-dees foraging in the aspens.  If you should knock on a tree cavity, a flying squirrel may pop out to say hi. Then as spring rolls around, one by one, songbirds arrive to select a cavity and begin house keeping, (carrying out the trash and bringing in fresh material to line their nest cavities).

     Aspens not only supply cavities for nesting, but also shade the lush undergrowth which becomes food for a large variety of insects.  Then these insects become food for nesting birds.

     As climate change accelerates, aspen groves are disappearing.  I personally have witnessed the demise of four aspen groves in the Tower to Lamar Valley region.  I can even remember photographing flickers, sapsuckers and bluebirds in those aspens back in the 80's and 90's.  Take a close look at the aspens still growing in Yellowstone.  You'll see large mature trees and small saplings but very few teenagers.   When the big aspens eventually, one by one, die and fall, all that will be left is a patch of aspen shrubs.

     Where will the birds nest?


View slide show

Red-Naped Sapsucker

Hairy Woodpecker

Red-Naped Sapsucker

Red-Naped Sapsucker

Red-Naped Sapsuckers

House Wren

Green Tree Swallow Chick

Williamson Sap Sucker


Fly Catcher Nest

Female Mountain Blue Bird

Male Mountain Blue Bird

Blue Bird