Sunday, February 5, 2012

Double Crested Cormorant in Eastern Washington

Double-crested Cormorant (Phalacrocorax auritus)

I learned a bit about cormorants after spotting the cormorant shown above in an irrigation run off pond in eastern Washington. Cormorants are common site for anyone taking a Washington State Ferry. They often can be seen in the pose of the one pictured above with their wings outspread drying off. I was a bit surprised to see a cormorant in eastern Washington. I thought they were salt water only. But apparently Phalacrocorax auritus can be found in both fresh and salt water and has recently expanded its range up the Columbia River into the Mid Columbia River area.

The two other cormorant species, Brandt's and pelagic, can be seen in the salt water along with the double-crested. I'll have to sharpen my cormorant observation skills to distinguish between these species.

Why the range expansion by Phalacrocorax auritus? I can't answer that, but it is an interesting question. Were the birds in eastern Washington in the past and are just returning to their old range? I can say that habitat areas suitable for the birds has expanded with significantly more wetland areas as a result of irrigation water and water backed up by dams along the rivers. For example, the pond pictured above was scrub steppe land 20 years ago. 

There is also a climate consideration. Even with more habitat can these birds tolerate a periodic extremely cold winter. In this regard, it has been 30 years since the Columbia River last froze over in the Mid Colombia area. How well can Phalacrocorax auritus manage long protracted cold spells with loss of access to food sources? Or will they simply head down river to open water when conditions turn bad? Something to watch for the next time eastern Washington experiences an exceptionally long cold spell. 


Dave Wenning said...

Did you spot the second Cormorant swimming just to his right? According to iBird, captive birds will strike the same pose after feeding even though they are not wet. I was equally surprised when I saw seagulls on the Mississippi between Iowa and Illinois.

Dan McShane said...

Dave: I did see the second cormorant - after I took the picture. Not the best pictuer, but the pose is distinctive. Had a birder with with that gave me the run down on the newness of the species in the area.

Randall Schalk said...


Large numbers of cormorant remains were recovered by Luther Cressman (Univ. Oregon) in archaeological excavations at the Roadcut Site near The Dalles in the early 1950s. These deposits are dated to be about 10,000 years old. Cressman also recovered quantities of California condor and gull. Channel islands of the Columbia in the Hanford Reach are to this day nesting colonies for gulls. These islands may also have been used as nesting colonies by cormorants in the past.

A more recent analysis of the The Dalles Roadcut site avifauna has been reported in a W.S.U. M.A. thesis by Victoria Hansel-Kuehn.

Dan McShane said...

Thanks for the tip Randall. Funny thing, I just saw two coromats yesterday in a lake abote 35 miles south of Spokane.