Occurrence of pale phase Common Buzzards? (1 Viewer)

[MJB]

In our neck of the woods, my observations since 2006 in the area (ranging from c650m asl up to 1600m, mixed habitats) have only logged one really white CB in the breeding season (paired with a classic 'brown job') ,though some very pale birds are seen heading south in late autumn at the migration watchpoint by the Rhône (so, birds from more northern populations).
Not wishing to put a spanner in the works, but is it correct to be talking of a pale phase? The French name for the species is Buse varaiable and in my (lengthy!) experience the name is appropriate as the variations in darkness/paleness are many and fluid (photo of a local bird from last year attached).

Richard, I think your spanner technique has merit. Given that pale individuals occur widely, is this 'form' simply an example of a case of within-brood colour differences? Such was finally proven for the 'Altai Falcon' when broods contained 'normal' Saker Falcon chicks and an 'Altai' form; usually one of the parents was confirmed as an 'Altai' form. Also, such broods were found outside maps of the putative breeding distribution of 'Altai Falcon'. (Nittinger et al 2007)
MJB
Nittinger, F, A Gamauf, W Pinsker, M Wink and E Haring. 2007. Phylogeography and the population structure of the saker falcon (Falco cherrug) and the influence of hybridization: mitochondrial and microsatellite data. Mol. Ecol. 16: 1497-1517.

 

[KenM]

In our neck of the woods, my observations since 2006 in the area (ranging from c650m asl up to 1600m, mixed habitats) have only logged one really white CB in the breeding season (paired with a classic 'brown job') ,though some very pale birds are seen heading south in late autumn at the migration watchpoint by the Rhône (so, birds from more northern populations).
Not wishing to put a spanner in the works, but is it correct to be talking of a pale phase? The French name for the species is Buse varaiable and in my (lengthy!) experience the name is appropriate as the variations in darkness/paleness are many and fluid (photo of a local bird from last year attached).

Ok pale face 😄....”Collins” seems to have seen fit to comment on the “pale” variant to the point of generalising their distribution in Europe and less face it aesthetically they are more attractive than the brown jobs? Certainly one that I would go out of my way to image given the chance locally.👍

 

[Richard Prior]

I’ll put my spanner back in the tool box then Ken, I’m having enough trouble with sparrow ‘variants’ at the moment!

 

[Jeff Woad]

Ok pale face 😄....”Collins” seems to have seen fit to comment on the “pale” variant to the point of generalising their distribution in Europe and less face it aesthetically they are more attractive than the brown jobs? Certainly one that I would go out of my way to image given the chance locally.👍

Hi Ken,
Agree the pale variants are attractive birds that catch the eye.

But note they are referred to as just that, variants, which I take to mean variation within the general Buzzard population. I guess you are wondering if the pale birds you are seeing locally originate from the area stated in Collins, where this variant is more common. Maybe this area is indeed expanding, maybe some birds do come here, but purely based on my own observations over 40+ years, I'd say I've occasionally encountered pale birds in all parts of the UK at all times of year, and the variant is just part of our resident Buzzard population. Pale pigmentation tends to be recessive to darker pigmentation, so presumably that explains why their frequency remains low.

Though maybe we notice them more as the Buzzard population increases?

Just thoughts really.

 

[KenM]

Yes thanks for your thoughts Jeff, the thrust of my thread was as you’ve implied.
Knowing the origination points of these variants measured against my (since the expansion locally) experience from the early ‘90’s onwards.
Previously being a description species, then fast forward to 2016 for my first local “pale” variant (amongst the scores of dark birds). Followed by another three occurrences since and up to April this year, therein you have the context for my thread.👍

Cheers