Monday, July 30, 2012

A Tale of Two Nests

Nests of Brandt's Cormorant and Double-crested Cormorant
Nesting cormorants--upper left Double-crested; lower right Brandt's.
Photographed at Newport, Oregon on July 21, 2012 by Greg Gillson


Take a close look at the cormorant's nests. Do you note that they are constructed differently?

According to The Audubon Encyclopedia of North American Birds, the Brandt's Cormorant (lower right in front) builds a nest of marine plants, mosses, and grasses in a circular nest. On the right hand side of the upper piling are two fuzzy brown Brandt's Cormorant chicks.

On the left side of the upper piling is a nest of Double-crested Cormorant. Notice that is is built of "sticks and weed stems, lined with leafy twigs and grass."

There is actually a third species, Pelagic Cormorant in this photo. See the dark form up on the bridge just above the upper right hand Brandt's Cormorant? That's where they build their nests. On natural substrates they build nests on "remote and precipitous cliffs" of seaweed, grass, and rubbish.

2 comments:

  1. How amazing to find and photograph all three species on one set of pilings! I'm in awe of this capture, thank you for posting it. I've seen various nesting sites of cormorants, but never fully knew about the nuances in nest structure. A great education for me.

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  2. We pass this piling on our pelagic trips. Before I get there I tell passengers that the cormorants perching on the top will be Double-crested, the Brandt's will be on the crossbars, and the Pelagic Cormorants will be clinging to the side or in the water below--that's niche specificity!

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