Monday, August 3, 2015

Regurgitated beetles and cherry stones

We found this regurgitated pellet, full of cherry stones, near some wild cherry trees in a field beside the river Tees near Egglestone, at the weekend. I'm pretty sure it was produced by a rook, as there is quite a large rookery nearby and I've often seen them feeding in this field.

Regurgitated pellets of indigestible food held in the gizzard are usually associated with raptors and owls but many other birds produce them, including rooks, crows, magpies, gulls, herons and even oystercatchers, which expel pellets of sand grains swallowed with their food onto the seashore.

When I took this pellet home and soaked it in soapy water it fell apart almost immediately, revealing eleven cherry stones, plus ....

..... the remains of at least ten ground beetles. 

Strangely, each of the beetle heads was perfectly intact and snipped off from the rest of the body at exactly the same point. A ground beetle's jaws are quite powerful and I imagine that they would grip the bird's throat as it tried to swallow its prey, so I wonder whether this rook had leaned to detach the heads and incapacitate its victim before swallowing it.

The other debris included fragments of wing case, plus ...

..... lots of legs.

So how did the bird come to be eating cherries and beetles in the same meal? It might be because the ground under the trees was covered in rotting cherries, which might have attracted soft bodied invertebrates like slugs and worms, which might in turn have proved a fatal attraction for the beetles.

Sunday, August 2, 2015

Goosander chasing fish under water

We encountered this goosander family when we were out walking in the Derwent Valley Country Park near Gateshead this afternoon. They were swimming under the Butterfly bridge on the river Derwent at Winlaton Mill just as were were walking over it.

This provided an unusual opportunity to watch them diving and chasing fish under water. By flicking that broad, fan-shaped tail downwards and kicking with those big feet they can dive in an instant and have an impressive turn of speed under water, chasing fish relentlessly.

There are three underwater in the picture above, and several more emerging under the other side of the bridge in the picture below.

In winter goosander are wary birds, difficult to approach, but in summer family parties like this are much more accommodating and rarely fly unless severely threatened.

Monday, July 27, 2015

Mystery Beetle

My thanks to Richard Jones @bugmanjones for identifying this little beetle that was feeding on a bracket fungus growing on a willow, in Grantchester meadows beside the river Cam near Cambridge last week. It's Diaperis boleti "Once exceedingly rare. Scarce, but spreading or increasing? Mostly E.Anglia and SE England", says Richard.

Colour scheme looks like a sexton beetle but too small (only 4-5mm) and no clubs on the tips of the antennae.

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