What is this bird in my garden?!

RockDesk

Hi,

I've had this bird come into my garden for the past few months. It seems that it could be a "black and white" blackbird but I'm just going by looking Google images.

Could anyone confirm that this is a blackbird? Or is it something else?

The beak is orange (doesn't seem to be as orange as a "black" blackbird. It's ground feeding.

Thanks

ytpe2r5bxkn0c1

It's a partially leucistic Blackbird

Alun

Looks like a leucistic blackbird.

https://www.bto.org/news-events/press-releases/when-blackbird-not-blackbird

RockDesk

That's really interesting! Thanks for the replies, and for posting the link

recedite

Just looking at that photo, its actually not a bad camouflage pattern in a modern suburban environment. I wonder if there would be evolutionary pressure in favour of this "abnormality".

There was a moth that adapted to the industrial revolution by having a darker colour pattern.

Blackbirds like robins, are originally a forest bird. The females have better camouflage. The males are the posers

RockDesk

I never thought of that, you're not wrong! Looking at this 2nd picture definitely adds to that.

I've actually lost sight of it a few times in the garden before as it just stops moving so it's hard to see it.

ytpe2r5bxkn0c1

recedite wrote: »

Just looking at that photo, its actually not a bad camouflage pattern in a modern suburban environment. I wonder if there would be evolutionary pressure in favour of this "abnormality".

There was a moth that adapted to the industrial revolution by having a darker colour pattern.

Blackbirds like robins, are originally a forest bird. The females have better camouflage. The males are the posers

Leucism is usually the regressive gene and leucistic birds, if they find a mate at all, have been shown to not find the strongest or healthiest mates. As white feathers reflect heat significantly more, leucism leads to more deaths in winter here.

recedite

Recessive genes can still become common, for example the gene for blue eyes became common among humans in northern latitudes.

As for the white feathers reflecting away solar heat and being colder, I'm not sure there is any evidence for that being a disadvantage. You would think that gulls and swans would be at a disadvantage in that case. If a bird is going to freeze to death, it would probably be at night, and not when they are sitting in the sun.

ytpe2r5bxkn0c1

recedite wrote: »

Recessive genes can still become common, for example the gene for blue eyes became common among humans in northern latitudes.

As for the white feathers reflecting away solar heat and being colder, I'm not sure there is any evidence for that being a disadvantage. You would think that gulls and swans would be at a disadvantage in that case. If a bird is going to freeze to death, it would probably be at night, and not when they are sitting in the sun.

Look, I'm just posting what surveys have shown and the reasoning behind the lower survival rates among leucistic passerines. You are great for theories, and that's fine but the research is out there and leucistic passerines have weaker offspring and shorter lives, including much greater mortality in cold weather.

Eddie B

Troy Wailing Farmyard wrote: »

Look, I'm just posting what surveys have shown and the reasoning behind the lower survival rates among leucistic passerines. You are great for theories, and that's fine but the research is out there and leucistic passerines have weaker offspring and shorter lives, including much greater mortality in cold weather.

I'm not being smart or anything, honest question. Would ptarmigan, mountain hare etc suffer loss of heat during the winter so as to remain camouflaged with their surroundings, or are they just better equipped for the cold, so colour really isn't a factor for them?

ytpe2r5bxkn0c1

Eddie B wrote: »

I'm not being smart or anything, honest question. Would ptarmigan, mountain hare etc suffer loss of heat during the winter so as to remain camouflaged with their surroundings, or are they just better equipped for the cold, so colour really isn't a factor for them?

Good question. They are adapted to it. Many factors like more downy feathers for insulation and even their bones adapt in winter to help cope with the cold. Leucistic or albino blackbird has no such compensating adaptations.

snipey

there's a Leucistic Hen Harrier up close to where I'm living, it's the male and has no black tips on his wings