Western or semi-palmated? Rizières de Mana, Fr. Guiana, 28 Nov 24 (1 Viewer)

[kb57]

I had a fairly steep learning curve with Nearctic waders wintering on the Guyane coast recently. The default 'peep' is semi-palmated sandpiper, present in vast numbers, but I wondered if this could be Western, due to bill length - allegedly present but under-recorded, and certainly not turning up on many eBird records.
In the same area, I had another suspected Western which I inadvertently called in whilst listening to calls on Merlin, trying to see if I could work out the difference better on vocalisations.

 

[lou salomon]

Bill shape is just perfect for a female (maybe western breeding) Semipalmated Sandpiper and not in line with the downcurved and longer bill of Western Sand.

 

[kb57]

Bill shape is just perfect for a female (maybe western breeding) Semipalmated Sandpiper and not in line with the downcurved and longer bill of Western Sand.

Thanks - the only question remaining is whether a semipalmated would respond to tape of a calling western...a bird I unfortunately didn't manage to photograph!

 

[Southern Viking]

Thanks - the only question remaining is whether a semipalmated would respond to tape of a calling western...a bird I unfortunately didn't manage to photograph!

One way to find out I've found that not only Goldcrest, but also Treecreeper respond to Firecrest song for example

 

[njlarsen]

Thanks - the only question remaining is whether a semipalmated would respond to tape of a calling western...a bird I unfortunately didn't manage to photograph!

Would the call of a western be a territorial call or one given with a different reason? and in both cases, there might be response also by other species given that shorebirds tend to flock in winter and migration.
Niels

 

[kb57]

Would the call of a western be a territorial call or one given with a different reason? and in both cases, there might be response also by other species given that shorebirds tend to flock in winter and migration.
Niels

I was listening to what I hoped were non-breeding calls on Merlin (i.e. from Florida / California rather than Alaska) - see screenshot. To my ear the 'chirrup' call of semipalmated sounded harsher than the equivalent western (as opposed to the 'trilling' calls). I got a pretty much identical response to the western call from a small peep which flew into the wetland over my shoulder, landed in front of me, then flew off again before I could take a photo. It looked to me like the relatively long billed bird I'd photographed earlier and posted above. Everything else I saw I believe was unequivocally semi-palmated, so on the evidence of my photo also being a semi-pal, and the possibility it was a semi-pal responding to the western Merlin recording, I'll take western off my eBird list.

 

[kb57]

I'll stop posting after this because otherwise it's going to start resembling a dunlin subspecies thread, but this is an example of what appeared to be a more 'typical' (male?) semi-palmated bill length (Salines de Montjoly, 02 Dec).

 

[njlarsen]

One thing to be aware of is that both western and semip. show geographical variation where eastern birds have longer bills than those occurring to the west. Therefore, some WeSa can have shorter bills than some SeSa even though the average is opposite.
Niels