ID Help: Common swift Vs Pallid swift ? (1 Viewer)

[C.Andres]

Hello everyone!

I have these tricky species, maybe Apus apus or Apus Pallidus, or one of each ?
Note they are not siblings, as they were rescued from different sites in the province of Sevilla (south of Spain), where both species are present.

I'd love to hear your thoughts, and especially the criteria you base on.

Hope you like the photos, I'm attaching some more in the next post.

Carlos Andrés.

 

[C.Andres]

Here, you can see in detail the head of the brownish bird (I don't have close-up pics of the darker one).

Sorry, I forgot to say, this pics are from birds rescued in May last year. All were cared and fed properly (diet based on only insects), and succesfully released.

 

[gerdwichers8]

Not to go by the book; I will do that later but I think the Pallid Swift at the lefthand side (right in frontal view) seems to have a bit broader forehead which may be only so because of less accentuated eyebrow and forehead. I don't know from the heart how it is with the white moustache to the Common Swift at the right side (left in frontal view) whether that is individual or 2nd year but, I may listen to the input of others or go by the book.
(which I will do anyway after this post)

 

[C.Andres]

Hello, Gerdwichers8, thank you very much for your suggestions. I know it is not easy to tell these species apart, especially from photos.

The birds were fledgings, fell from the nests when they still couldn't fly. In the pics they were around 40 days old., and they were released a couple of days after that.

 

[skbirder]

Looks like a Common on the left and a Pallid on the right in the first two photos. The Common has a more contrasty head, with the lores being noticeably paler than the cheek and a well demarcated throat patch. The Pallid shows typical more homogenous colouring, with the cheek being similar in tone to the lores and the throat patch diffusely demarcated. Nice comparison!

 

[C.Andres]

Thanks a lot skbirder for your reply. I totally agree with you.

It just that a couple of ornithologists suggested that the browninsh bird could also be a common swift, because the fork of the tail is quite deep, and also it doesn't show a clear eye mask. However, for me it's obviuos that both birds in general have a different colour, and more contrast in the lores of the common swift (bird on the left), just as skbirder have said.

But when it comes to IDing by photos, colour is always tricky. What if we were to ID the birds with grayscale pictures and only use features not based on the colour tone? Please, what do you think, would it be still clear that these birds are of each species?

 

[tconzemi]

according to the metadata of the pics they were taken on June 30th 2017. Is it even possible to have fledglings of Common Swift that early, it would be a normal date for first brood fledglings of Pallid?

 

[Nutcracker]

Get a copy of the June issue of British Birds . . . major article on ID of juv Common & Pallid Swifts, just out :t:

 

[C.Andres]

Thank you, Nutcracker, it's cool there is an article exactly on this issue. Has anyone read it already?

Hello, Tom, thank you very much for your comment. Yes, it is a normal date for chick swifts to fledge, I think the reproductive period in northern Europe starts later, probably because of the temperature: here, first swifts arrive in March, and start breeding between April and May. So 30th of June is normal for both species to have fledgings.

 

[Nutcracker]

Thank you, Nutcracker, it's cool there is an article exactly on this issue. Has anyone read it already?

I had a look today; it supports what skbirder gives :t:

Looks like a Common on the left and a Pallid on the right in the first two photos. The Common has a more contrasty head, with the lores being noticeably paler than the cheek and a well demarcated throat patch. The Pallid shows typical more homogenous colouring, with the cheek being similar in tone to the lores and the throat patch diffusely demarcated. Nice comparison!

 

[C.Andres]

Great! Excellent, Nutcracker, for having a look at the article and confirming the ID. And thanks everybody who commented on the post, especially to skbirder that had it clear from the beginning.

Also, this is my first post on Birdforum.org. Indeed great birding community!

ID solved!!

Carlos Andrés.