Sunday 8 March 2015

v-nigrum Common Eider

Today (March 8) Sir Edmund and I found a Common Eider that best fits the Pacific sub-species (S. m. v-nigrum) off St. Shott's on the southern shore to the Avalon peninsula. This sub-species has previously only been seen twice in the Atlantic ocean:

And, last month, Bruce found what looks like it could be a hybrid between the Western and one of the Eastern sub-species.

Having never seen this sub-species I was surprised by how quickly it stood out from the flock of eiders it was with. It was easily detected in my first pass of the flock that was about 200m away. What stood out was the beaming orange bill:

I knew right away what it could be and quickly got Ed on the bird so that we could study it closely.

There was no problem seeing that this bird was quite a bit larger than the other eiders around it:

But the large size and bright bill aren't enough to confirm this sub-species. The clinching feature is the black "V" lateral stripes under the chin.
Thankfully, within 10 minutes the bird raised its head upwards to choke down a mussel and the black chin-stripes stood out. There was absolutely no question about the black V - it was a thick and unmistakable dark line that followed the contour of the lower mandible!

It was difficult to capture the black V with my camera, but it was partly visible when the bird was swimming away from us:

Some other key features:

One last feature that is hard to see on todays bird is the border between the green hind-neck and white face. On v-nigrum there is a faint extension of the green along the lower border of the black cap. This is not present in our regular S. m. borealis eiders.

In S. m. borealis the green hind-neck does not extend onto the face, and has a straight and distinct border with the white face:


A beautiful bird! I won't be surprised if we start to see more of these beasts over the next decade. With the melting icecap, the Atlantic ocean will continue to be accessible to them. The question is, what else will follow the same journey? More eiders? ;)

And some more shots of our regular S. m. borealis Common Eiders:

Note the variation in bill shape and colour!

Interesting to see that other sub-species can also have black markings under the chin....

The Pacific Eider back on:

Black Guillemot at the same location was in nearly full breeding plumage:
(there was a lot of glare!)