Weird Sparrow Hawk Behaviour

[Manders]

Weve seen her dive at the aviary in the past, feet first and wings outspread, like they do in hedges to pull out sparrows, of course she couldnt get her feet through the wire.

In this case she was just prowling around the floor outside the aviary. Recently she has just taken to flying and landing straight on the floor and prowling around.

Our cat went for her once and scared her off but doesnt seem to have kept her away for long.

[Ukwildlifeo]

Originally Posted by Jim Ford

I thought it did it to shade the reflection of the sky, so it could see below the surface.

Hmm, made me think! I wonder if any birds that fish have evolved eyes that polarise the light to some extent, in order to help them see their prey better? I wonder if it's been researched?

Jim

I vaguely remember reading a paper where little egrets had adaption in thier eyes to see into water (with a polarising effect I think) which was much more developed when compared to that of a cattle egret which obviously needs the adaption much less or not at all.

[Hobjob]

Continuing off topic conversation

Originally Posted by Hobjob

At a complete tangent ............

The Black Egret (Egretta ardesiaco) in southern Africa does a shading trick with its wings.

Only it does it whilst fishing to hide its presence.

Originally Posted by Jim Ford

I thought it did it to shade the reflection of the sky, so it could see below the surface.

Hmm, made me think! I wonder if any birds that fish have evolved eyes that polarise the light to some extent, in order to help them see their prey better? I wonder if it's been researched?

Jim

You are right Jim! Or maybe you are not!

I have a hand written note in my Newman's Field Guide that says "shades water to attract fish", information which I presume I was given by a guide, but on checking in an old edition of Roberts (vs 4), that says that this behaviour improves visibility of food (not a direct quote, but that is the gist).
But then I thought I would check further
and Wiki says

"The Black Heron has an interesting hunting method called canopy feeding—it uses its wings like an umbrella, and uses the shade it creates to attract fish. This technique was well documented on episode 5 of the BBC's The Life of Birds. Some Black Herons feed solitarily, while others feed in groups of up to 50 individuals, 200 being the highest number reported. The Black Heron feeds by day but especially prefers the time around sunset. It roosts communally at night, and coastal flocks roost at high tide. The primary food of the Black Heron is small fish, but it will also eat aquatic insects, crustaceans and amphibians."
Black Heron = Black Egret = Egretta ardesiaco

I will check the latest 'Roberts', the Bible of Southern African birding, in a few weeks when I again have access and report back.