Northbound again

We've been busy with field work during the last few days, but out of the corner of my eye, I've noticed impressive flights of Pacific Loons (Gavia pacifica) fairly close to shore.  The loons are migrating north to their breeding grounds, e.g., Arctic tundra lakes.  I often think of seeing large numbers of loons a little earlier, around mid-April.  Perhaps I haven't noticed, but these were the first really big flights that I've seen this spring.  

I took a few pictures for the record.  First, a distant shot.  [Click on the photos for larger versions.]

 

I don't have a big enough lens for this distance, but this group came a little closer: 

 

 

And here's one showing the striking breeding plumage of Pacific Loons:

 

 

 

There were occasional Common Loons and Red-throated Loons mixed in with the Pacific Loons.  Can you find the Common Loon (with an all black head) in the photo below?

 

(The Common Loon is the fifth bird from the left.)

The pictures in this post were taken off the Mendocino coast on 2 May 2017.  On 30 April 2017, flocks of loons were streaming by Bodega Head.  

P.S.  I've written about loon flights before — check out earlier posts: "Northbound" on 11 April 2013 and "Early morning flight" on 17 April 2014.