Friday, October 10, 2014

American Bittern

I still don’t know how John Holden saw this American Bittern. On Wednesday morning, we drove slowly across the 180th Street Marsh in Dakota County, Minnesota. “Stop the car!” shouted John, “I think that’s a bittern!” “Where?” I asked. “Right in front of us,” he exclaimed. “Where?” I asked again, “In the green grass?” “No, in the corn field.” Only when the bittern finally moved, did I finally see the bird.
I never thought to look for a bittern in a corn field—they usually inhabit wetlands. They favor marshes with tall reeds or cattails, where they cryptically blend into the background. Bitterns usually do not pursue their prey, but wait motionless for the prey to come to them. They are usually most active at dawn or dusk. In a previous blog post, I wrote about the bitterns’ declining numbers due to wetland degradation and destruction.
But the bittern was not finished with us. The bird casually strolled out of the cornfield and walked towards us across a dry, grassy patch. Now and again it struck and consumed prey—what appeared to us to be either grasshoppers or perhaps small frogs. (They also eat other insects, amphibians, crayfish, small fish, and even small mammals.)
When disturbed, bitterns sometimes freeze or even play dead—but this American Bittern walked right up to our car, so close I could no longer take photos. I got out of the car and took more photos.  The bittern did not move, though occasionally it puffed up its neck feathers. Only when I turned around to my side of the car did the bittern fly the short distance back to the cornfield. 
Lowther et al. (2009) comment that “remarkably little is known about basic aspects of [bittern] biology.” They are usually too secretive and their habitats too inaccessible. Erika and I marveled at the last photo—the eyes clearly afford the bittern with binocular vision, and the eyes are oddly placed on the bottom half of the head. Perhaps this placement allows the bittern to keep its eyes on you while it points its bill skyward to further blend into its environment. 

2 comments:

  1. Wow, very cool eyes! Great photos and sounds like a marvelous encounter.

    ReplyDelete
  2. Thanks Lorrene. The encounter was very cool, better even than a bittern that played dead in front of me years ago, when I just started birding.

    ReplyDelete