ID seabird - Portugal (West Atlantic coast) (1 Viewer)

[Luís Vieira]

Hi everyone,

I photographed these 2 birds on 02/20/2022 in Cabo Raso, the most western location in mainland Portugal on the Atlantic coast. The birds passed a few hundred meters from the coast, at moderate altitude, in the North>South direction. At the time it seemed to me to be juvenile P. carbo, because of the white on the chest, but when I looked at the photos I see that the birds have a lot of white on the neck also and the legs seem to be very projected backwards. I asked for other birders opinions which included Gavia sp. and M. serrator, but I am not very sure about these IDs. Can you give your opinion about the ID of these birds?

Thanks a lot in advance.

 

[Alexander Stöhr]

Hello Luis,
a bit late, but: welcome to birdforum from me!

First, your birds a Loons Gavia. Please note uniform dark upperwings and jizz, that you have aleady noted.

But which species? There are others with more experience here, but they are either Red-throated or Great Northern Divers imo.

Good for (immature plumaged) Red-necked Divers is the washed darkish head and neck, contrasting with a whitish chin. Thats is enough to ID them in Germany against Black-throated Divers with a very high degree of confidence.
The right bird has a slender head-neck profile (called snake neck in ID-books) that gives this bird the flat and elongated shape of a RTD (whats the english name for Waschbrettbauch?)

I just realized that this post comes out more confident than I am and its intended to be, but I am in the Red-Throated Divers camp for both birds.

 

[RafaelMatias]

Agree with Alex, these are Gavia sp., no doubt about that part. As for species, shape and proportions best suggest G. immer (GND) to me, as does (visible) chromatic pattern (note I'm not saying "colours" on purpose). There is not much detail in these photos, unfortunately, but the neck looks a tad too robust and horizontal, as well as too dark for this time of the year, for Red-throated, imo. I'd expect to see a neck or head pointing slightly upwards at least on some of the photos, and much more white on the ventral side of the foreneck. But it's obviously difficult to be sure here, and I'd personally keep them as Gavia sp. which is not too bad.
All Gavia are rare in Portugal, though G. immer is the most common (and regular), followed by G. stellata; G. arctica is very rare, probably not recorded even every ten years.

PS: Luís, note that the westernmost spot in Portugal is not Cabo Raso, but Cabo da Roca, which is also the westernmost point in Continental Europe
PS2: Welcome to Birdforum!

 

[Luís Vieira]

Thanks a lot Alexander and Rafael for your comments on these birds. Given your opinions and available photos of Gavia species in eBIRD, I tend to favor the "Gavia immer" hypothesis, but I'm not entirely sure, so I'll leave these observations as Gavia sp.

And yes, Rafael, you are absolutely right about Cabo da Roca being the westernmost point in Continental Europe. I should know this already!

Best regards.