Sunday 11 August 2024

Adult Semipalmated Sandpiper, Pagham Harbour, Up Close

The adult Semipalmated Sandpiper (now present for it's 9th day) finally showed well on Ferry Pool this morning. The bird has mainly been out in the harbour showing distantly so it was fantastic to finally see the bird close. Thanks to Andy House for putting out the news.  A few photos below in homage to this first for Pagham Harbour and second for the Selsey Peninsula. 

Adult Semipalmated Sandpiper- a full summer adult. No contrast in the mantle/scapulars with the remiges/coverts so the bird is at least in it's third calendar year. Early autumn adult American waders are often birds that have arrived in previous years and now caught up in the Palearctic migration system, moving south with Palearctic wader migrants. This bird either arrived as an adult in last year's epic American invasion or more expectedly as a juvenile in a previous autumn. Alternatively it's fresh across the Atlantic this autumn although not much in the way of other arrivals in the west to support that. 
Raised wing showing the relatively fresh remiges- a first-summer would have more worn and contrasting remiges
Even the greyish looking scapulars are not winter feathers as they have dark internal markings so presumably just slightly different ages as it moulted into summer plumage. Basically it's still in full summer plumage. 
Maybe a hint of the semipalmations in this photo. Other photos show these better HERE. The semipalmations are usually more distinct between the middle and outer toe as shown in the link photos. Western Sandpiper also has semipalmations- I think the only other stint to have these.
The relatively short primary projection (about 2-3 exposed primaries beyond the tertials) is shown well here. 


Adult Semipalmated Sandpiper and Juvenile Dunlin (above and below). This Dunlin seems to have become the American celebrity's UK agent - these two birds have been largely inseparable and also seem to be doing their own thing from the main Dunlin flock. I often associate vagrant waders with keeping away from the madding crowd (where they are presumably at risk of being targeted for being a bit odd).  
I've not seen many adult Semipalmated Sands (seen stacks of juvs in Azores and found one on Scilly in the late 90s) so nice to see this age class.. It's such a different looking bird to a juvenile (below) with adults having heavy breast streaking (a pec band), flank markings, extensive dark centred scaps and mantle feathers but similarly to juvs lacking rufous tones (particularly in the tertails) and similarly structured distinguishing them from Little Stint. Typically juv Semi-p shows 'anchor-marks' in the scapulars shown beautifully in the photo below. 
A juvenile Semipalmated Sandpiper (August 2014 from the Azores)

2 comments:

Jonathan Lethbridge said...

Excellent. Posts like this remind me that Autumn is well and truly underway and that I should get off my backside and go and experience some of it. Lapwing in Wanstead today, in clear blue sky!

Peter Alfrey said...

Plenty of waders on the move now. Good luck Jono!