Saturday, August 8, 2015

The Wrong Branch

I watched a Great Blue Heron (GBH) land in a tree along the Patuxent.

He made a poor choice of landing sites. The raised crest on the top of his head indicates he is agitated. So does his open mouth.

It seemed the harder he struggled to correct the problem, the worse it got.

It is a good example of why large birds learn to avoid landing in trees with small branches. This could very well be a young, inexperienced heron.

I am not sure if GBH's molt twice a year or not. I couldn't find anything definitive except for one mention that they molt four times in their first two years. But that is what I would expect in an adult bird also. Feathers are the clothes they wear for six months or more before being able to change them. If they have significant damage well before molting, it could be a real problem for flight and other reasons.

That is why most large birds such as these vultures will choose trees (or at least branches) that have lost the smaller limbs that can damage their feathers. These birds had found enough trees to fit the bill, so to speak, all in one place and it became a rookery where they would gather every night. Using dots of paint, I counted sixty-two silhouettes in this picture that I am pretty sure were birds.

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