Friday, May 31, 2013

A Long Bike Ride Around Eastern Denver

May 30, 2013

I started an hour before sunrise to take a 40-50 mile bike ride to Cherry Creek Reservoir, Rocky Mountain Arsenal and Barr Lake.  It turned out to be a miscalculation on distance.  My final trek was 72.6 miles.  At the start, winds were only 6 mph, temperature was 44 °F.  By 11:00 am, temperatures were 60 °F; however, winds had increased to 22+ mph, gusts to 31 mph.

My plan was to arrive at the Prairie Loop mudflats, Cherry Creek Reservoir by 7:00 am to look for the Least Tern reported yesterday.  Another miscalculation, I arrived at about 7:20 am.  It took another hour to reach the mudflats because of "distractions".

The willow patch along Parker Road, just north of the eastern entrance to the Park was quite birdy.  A Wilson's Warbler, Yellow-breasted Chat and several Common Yellowthroats were all singing.

At the eastern sand spit inside the Park, a Whimbrel walked the distant mudflats (halfway between the sand spit and the bird observation platform).  No Least Tern was here.

Finally arriving at the Prairie Loop mudflats, no Least Tern was around.  An interesting Gull occupied the next 45 minutes or so.  It was far enough away to make size estimation difficult.  It was a non-adult bird (black on tail tip).  A black spot behind the eye indicated a young Bonaparte's Gull. 

However, two field marks were strange.  The Gull had a dark blackish top of head and nape (more like was expected by a first winter Little Gull).  It also appeared to have a bold dark carpal bar and many white feathers above it (Little Gull like).

I really did not believe it was a Little Gull because possible size and length of legs (longer than expected on a Little Gull) indicated a Bonaparte's Gull.

Eventually it started to walk closer.  I pulled out my scope but because I was biking, I only carried a foot long tripod.  This only allowed looks limited looks through the cattails between the bird and the scope.

After 45 minutes or so, the Gull was close enough that I could see it was a Bonaparte's Gulls molting from first winter to 1st summer.  What I thought was a bold dark carpal bar was the wider dark flight feathers.  The wide white feathers were the molting flight feathers expected on an older Bonaparte's Gull.

I walked my bike along the path that runs from the Prairie Loop to the Mountain Loop (too muddy to ride the trail). 

As I passed a rather thicker area, I was thinking about a Long-eared Owl I had found several years ago.  There right in front of me, a Long-eared Owl was looking at me!

Nine Western Wood-pewees were counted between the Prairie Loop and the Lake Loop.  Another six were seen between the Lake Loop and the Mountain Loop, with another five around the Lake Loop.

An Olive-sided Flycatcher was a surprise between the Prairie Loop and Lake Loop.

A walk around the thick area at the Mountain Loop added another surprise.  A Yellow-billed Cuckoo called from one of the taller cottonwoods.  If he had not called, I would not ever found him.

Before leaving the Park, I biked down to the southwestern sand spit.  No Least Tern there either, only a dozen American White Pelicans and a few Ring-billed Gulls stood around.

Several dozen Western Grebes swam close to the dam.  A Clark's Grebe was among them.  A Rock Wren called from the rocks above.

It was time to bike back toward home.  The strong winds and expended time changed my plans; I skipped Rocky Mountain Arsenal and Barr Lake and rode home by way of the eastern side (outside) the Arsenal.

Five Burrowing Owls were encountered along Buckley Road (between 56th and 88th avenues).  Three inside the Arsenal (Adams County) and two outside (Denver County).

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