Friday, 15 August 2014

Common Ringed Plover!

After countless hours studying and reviewing the finer details of Common Ringed vs Semipalmated Plover ID it has all finally paid off.

This morning I joined 4 other local birders to check out the shorebirds at Bellevue beach. The small tidal flat is rich in mussels and other invertebrates and attracts hundreds of shorebirds at this time of year. I was hoping to get an accurate count of the birds and do a bit of teaching to show the others how to ID some of them down to species and age.

Within 2 minutes of starting the first scan of the shorebirds I happened upon a surprisingly pale Semipalmated-like plover. Then the bird turned towards me and showed off its wide black breast band and I could see the evident white supercilium. The next 1.5 hours was spent trying to study and photograph this bird while it tirelessly ran around the flats at a distance. Eventually it roosted for 10-15 minutes at a reasonable distance allowing us to get some photos.

The bird was never very close, so we never got the full frame photos we were dreaming of. But I do think the photos I got should make a strong case for CRPL. Hopefully Lisa & Frank got some photos to help prove the ID (keep an eye on Lisa's blog for her photos).


While the bird was roosting the wide breast band was more compact and was often not noticeably wider than that of a Semipalmated Plover (SEPL). When it was feeding the breast band stood out as being very broad and even in width.
The white supercilium (white eyebrow) stood out to all of us and was usually the best feature to look for to find the bird when scanning the plovers.

The bird can be found in this picture by looking for that strong white supercilium and relatively pale back.


The CRPL is an adult (and I think it's a male) and is to the left in the following photo. In the middle is a female adult SEPL, and on the right an adult male SEPL. 2 Ruddy Turnstones and a Black-bellied Plover as well.

Note the slightly paler back (which was more noticeable in real life), the much stronger and straight white supercilium, the bird seemed larger at times than nearby SEPLs but that isn't very obvious in these photos. The slightly longer bill can be seen in the below photo if you enlarge it.

Although the right most SEPL seems to have a wider breast band in the following photo than the CRPL, you can see that the breast band is wide along the sides of the breast and narrows towards the centre of the breast - very typical of SEPL (in fact, the breast band is often incomplete and is divided by white along the centre of the breast). Although not visible in this photo, the black breast band of the CRPL was a more even width across the entire breast.

The above photo is the best one I got to show the difference in the lores. On the CRPL the lore is not pinched before the bill, instead it meets the gape of the bill. Whereas in both of these SEPLs you can see that the lore is pinched just before the bill and only meets the bill above the gape. A very fine detail, but an important one in the ID of this species as it is consistent across all ages (beware that some SEPLs do have lores that meet the gape of the bill - I have photos to prove it!!!)

After enlarging all the photos I took I could see no sign of a yellow/orange ring around the eye - another indication for CRPL, and despite the distance it was faintly visible on some SEPLs. However, with the distance the lack of yellow/orange around the eye was difficult to confirm.

The shape of the black cheeks is a useful feature in my opinion to separate the two species (especially for juveniles). The CRPL has a black band that is more even in width across the face, whereas the black band on the SEPL widens just behind the eye.

The breast band was much wider when the bird was feeding, than when it was roosting (didn't get any photos of it front on while feeding). But this photos shows that the breast band width was very variable depending on its position.


Circumstantial evidence for the CRPL:

It rarely associated with the SEPLs. Preferring to stay away from them when there was enough space. Eventually when the tide rose, it was forced to be in the company of SEPLs (as in the above photos) but never flew off when all the surrounding SEPLs flew away - it was one of the last plovers to leave the area when the tide finally forced all the shorebirds away.

The date (August 15) is right on time for previous CRPL records in Newfoundland. I think there are about 15-20 records for the island. One was found at the same location on August 14, 2001, and another last year on August 16 (2013) in Renews. Adults have been found as late as Sept 17, and as early as August 7.

Unfortunately we did not hear it vocalize. And we were never close enough to see the webbing between the toes (or lack thereof).
The lack of a yellow/orange ring around the eye was never easy to confirm from the distance that we were at.


I welcome comments on the ID of this bird. Leave them below, or email me privately (alvanbuckley AT gmail.com).

3 comments:

  1. Great eye Alvan. You're lucky the bird is a male. Female Semis are known to have a white supercillium too. It does look like your bird has black down to the gape. Too bad you couldn't get some closer shots for some good views of the eye-ring.

    I've only seen Common Plovers in England. I'm from Nova Scotia and bird frequently on Cape Sable Island and nearby Cape Light (a.k.a. The Cape). Common Plovers have shown up there before but not since I've been birding.

    I've also got a blog and a Flickr account if you're interested is seeing some Nova Scotia birds.

    http://alixdentremont.blogspot.ca/

    https://www.flickr.com/photos/alixd/

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  2. Thanks for the comments Alix!
    Just checked out your photos - your Flickr page is amazing!
    Lots of great shots worth studying :)

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  3. Great identification study of these two species.

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