Carrion Crow

There’s often a carrion crow on the old felled sweet chestnut trunk near the Lower Lake bridge, feeding on grain that’s been left there and frequently being photographed. You can see in my photograph that it’s stuffed its crop with grain.

A few rooks feeding alongside jackdaws on the turf in Obelisk Park also have full crops, but they are more likely to be feeding on earthworms and insect larvae, such as leather-jackets: the caterpillar-like larvae of the crane fly.

grey squirrelUnder a yew near the Menagerie seven grey squirrels have gathered. They’re turning over the leaf litter and stopping to nibble at frequent intervals. One appears to have found half a nut, probably an acorn that it – or another of the squirrels – had hidden during the autumn.

We disturb the adult grey heron yet again. This time it was hoping to be left in peace at the top end of the lake beneath the Cascade Bridge. It takes off, clearing the clapper stones of the Druid’s Bridge with inches to spare.

 

The flock of fieldfares are still around. Wigeon have left the now completely ice-covered field pool. There’s a pair on the Middle Lake, along with two pairs of gadwall, tufted, the usual mallards and swans and an increasing number of goosanders, some swimming in pairs.

There are more wigeon on the ice-free Upper Lake, which isn’t accessible from the Park.

As we walk along the edge of Top Park Wood, a kestrel wheels from tree to tree ahead of us.

Pleurococcus Algae

On the northern half of the trunk of an oak by the Lower Lake a coating of powdery green algae shows up in the morning sunlight. It is absent from the sunny south side of the tree so, if you’re trying to do a bit of natural navigating and you’re lost deep in the forest this could help you to orientate yourself.

This is probably Pleurococcus or a very similar-looking species of green algae. Seen through a microscope, Pleurcoccus is a globular single-celled alga with a thick cell wall to help it resist desiccation. The individual cells are slimy and stick together to form the powdery coating.

Green algae contains two kinds of chlorophyll: Chlorophyll A and Chlorophyll B. The two molecules work together; Chlorophyll A absorbs blue-violet and orange-red light while B extends the spectrum by absorbing blue light. The green that we see is the light that doesn’t get absorbed.