'dark' Barn Owl (1 Viewer)

[liverpool_bob]

A most unusual Barn Owl crossed my path recently.

It was here (East Yorks) on 23rd Dec.

At the time I just thought it was an extreme alba but having had a look for some similar images on t'internet it would seem that guttata can be fairly pale. And then there are intergrades. There's some images on Surfbirds <here> of a bird at East Ruston, Norfolk in Jan 2004 that look strikingly similar.

It was by far the darkest/greyest Barny I've ever seen but was nowhere near how guttata are shown in guides with a complete dark underside. The bird was also in the company of another Barny and the contrast was considerable.

How dark do alba get? Do integrades regularly occur in UK?

Any thoughts appreciated - cos I'm stumped!

Cheers,
Bob.

 

[rob stoff]

A most unusual Barn Owl crossed my path recently.

It was here (East Yorks) on 23rd Dec.

At the time I just thought it was an extreme alba but having had a look for some similar images on t'internet it would seem that guttata can be fairly pale. And then there are intergrades. There's some images on Surfbirds <here> of a bird at East Ruston, Norfolk in Jan 2004 that look strikingly similar.

It was by far the darkest/greyest Barny I've ever seen but was nowhere near how guttata are shown in guides with a complete dark underside. The bird was also in the company of another Barny and the contrast was considerable.

How dark do alba get? Do integrades regularly occur in UK?

Any thoughts appreciated - cos I'm stumped!

Cheers,
Bob.

Pairs of pure alba have been known to produce offspring that look just like guttata so this is a very tricky problem. there was a note in BB about this a couple of years ago that showed photos of a guttata like offspring from a pair of alba in Devon. As far as I know guttata itself has never been recorded breeding in Britain.

Rob

 

[KnockerNorton]

A pair hunting together are often a male and female, and females are darker while males are much paler, so that would have emphasised the contrast. Also, wet weather can make them look darker too. Plus, they are quite variable too.

 

[liverpool_bob]

A pair hunting together are often a male and female, and females are darker while males are much paler, so that would have emphasised the contrast. Also, wet weather can make them look darker too. Plus, they are quite variable too.

Those were pretty much my thoughts at the time too but this one was way out of range of anything I'd seen before, hence the curiosity.

As regards the weather it was a clear sky with the sun behind and an hour or so before dusk so the light was good. I watched it, together with my brother, down to a range of 20m for about 15 minutes.

I'm sure it was just a very dark female alba but the Surfbirds (and other) pictures threw me - why is that one considered 'dark-breasted'?



Cheers,
Bob.

 

[KnockerNorton]

I'm sure it was just a very dark female alba but the Surfbirds (and other) pictures threw me - why is that one considered 'dark-breasted'?

Purely because of location and date, presumably. And such 'considerations' are individual based on someone's ideas of probability, which may or may not be reasonable - if you consider your bird to be just like the Surfbirds one, then you are perfectly at liberty to think of it as such. On the flipside, if you personally feel that your bird was a dark alba, but looks suspiciously like the Surfbirds one, then no-one can disprove you if you reckon that was a dark alba too. 'Received wisdom' in this kind of thing is often based on little more than hunch and opinion, rather than fact, as facts are hard to come by.