Tuesday, June 14, 2016

Meadowlarks at Rocky Mountain Arsenal

June 13, 2016

Richard Stevens:

It was another superb morning in Colorado.  Winds were negligible and temperatures around 57 degrees at 5:00 am.

Rebecca Kosten and I sat outside the Rocky Mountain Arsenal (Adams) at 5:00 am.  A Barn Owl was perched on the entrance fence.  We were "allowed" to watch him for a good five minutes before he took off into the Arsenal!

The gate opened up on time (at sunset 5:31 am) and we drove to Lake Ladora.  We could hear the reported Eastern Meadowlark when we stepped out of the car. 

The meadowlark was about 500 yards to the north at the extreme north side of Lake Ladora.  He continued to sing and we approached within 22 yards (measured with laser after the bird flew away).

We captured 728 photos and two 1-minute videos with audio.

My notes on the "Eastern Meadowlark" during and when seeing photos and listening to video/audio later at home.  The bird clearly lacked yellow on its malar area.

It sounded "weird", not anything like a Western Meadowlark but not exactly like an Eastern Meadowlark.  Its call note was also a little strange.  We thought closer to an Eastern Meadowlark.

The flank of the bird was spotted on its right side; however, they were streaked on its left side.  Again, we thought that strange.  Its head had quite strong, contrasting head stripes (would this be so on a Western Meadowlark)?

Eugene M. McCarthy writes in "Handbook of Avian Hybrids of the World" that hybrids between Western and Eastern Meadowlarks are common and difficult to recognize due to similarity to parents. 

Lanyon wrote that 90 percent of 158 eggs between Western & Eastern Meadowlark breeding in his study were fertile (comparable to pure matings).  I.e. hybrids maybe common. 

This bird looked like an Eastern Meadowlark and sounded close to one.  We will wait to see what other birders think.

Later we drove around looking for a reported Blue Grosbeak (not found).  The Eastern Phoebe was perched along the canal below the north side of 6th avenue.  Several times, he flew with a beak full of bugs into the drainage below 6th avenue.

Just outside the entrance is Gateway Open Space.  A large pond is north of the road.  We counted 16 American Avocets, which have been recorded nesting around the pond.

As we drove past the pond, two adult American Avocets were making quite a racket.  The reason quickly become obvious when a young Avocet jumping onto the road.

He just would not leave.  I had to get out of the car and chase him off the road.  All the time, the two adults dove at me (coming quite close to my head).  COOL!   

We then retreated to home before the rain and big hail hit the area.

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