knowledge required

[Ray Cox]

Kestrel hovering over school field near Unity Academy at 4pm. Used to see them regularly in Park End, but much less regular since Sparrowhawks moved in. Is this coincidence or does one just out compete the other?

Acklam Cemetery 11.30 am Pheasant perched on gravestone. Mistle Thrush feeding on berries with mixed flock of Green and Goldfinches, Also two Gulls "dancing" (Pink Feet). Is there a proper name for this display/feeding behaviour?

Originally posted in sightings (still learning site).....

[IanF]

An interesting topic about which I'd like to hear other opinions as well.

My thoughts rather than direct knowledge.

Regards Kestrel v Sparrowhawk I recall reading an article some years ago that in some areas Kestrel had disappeared whilst Sparrowhawks have thrived. I think there is some overlap between habitats albeit Kestrel prefer rural open areas whether fields or grassland. Sparrowhawks can be urban, rural and woodland. Sparrowhawks generally take small birds up to Dove size though I've often seen them take mice as well. Kestrels generally take small mammals like mice and voles though again I've seen them take small birds as well.

Locally Sparrowhawk seem to be much more prevalent than they were a few years ago. For the last couple of years up to a few months ago we've had one almost daily in the garden often perched for several hours. Lately we only seem to get fly throughs. We seem to have a decent number of Kestrels still.

I don't know if there's a term for the 'dancing' by the gulls, but it sounds like the behviour that several birds use to entice worms and insects to the surface. I've read that the behaviour maybe be to mimic rain drops on the ground so that the likes of worms are tricked to make for the surface to avoid drowning. I watched some Black-headed Gulls at the weekend from the Phil Stead Hide doing the same thing as the Little Egrets, shuffling their feet around in the very shallow water on the muddy edges to disturb food items.

[StewH]

I think Kestrels being replaced by Sparrowhawks is a difficult topic to be certain about.  My understanding is that Kestrel numbers expanded massively at a time when other raptor numbers crashed, as we created lots of habitat suitable for them in the form of motorway verges (with bridges for nest sites) and, other raptors were more affected by DDT - causing failure of their nesting attempts which Kestrels, presumably due to prey choice, were immune to.  So a set of circumstances where they could expand, with no competition from other raptors, existed and a falsely high population was created, spreading into habitat more suited to Sparrowhawk.
As DDT was banned other raptors have done better, none more so the Sparrowhawk which have recovered fantastically!  This gives the impression that they're replacing Kestrels but perhaps they've just recovered to realistic numbers and should be commoner than Kestrels, at least in many habitats.
The worry is that Kestrels may actually be declining in numbers for reasons we don't know about yet and the numbers will continue to fall...... there's much to understand!

Stew

[Ray Cox]

Many thanks for your thoughts...I remember watching a Song Thrush dance many years ago and I've seen it a number of times with Black-headed Gulls but this is the first time I've seen one of the larger species doing it, so I wonder just how many species do lure food that way.
It also makes sense with the Sparrowhawk/Kestrel population as Park End was built in the late fifties/early sixties and that was when pesticides were "flavou of the month" so what I am seeing is the balance of nature being restored.