Hot Bird

Every afternoon this week this blackbird has been sunning itself in the hottest spot in the garden, in our potato patch. It sits in a trance, wings spread out, panting with its beak open, eyes glazed over .... and potentially easy prey for cats. Given the risk, there must be some biological imperative for this behaviour. The favourite theory seems to be that the heat forces parasites in the feathers on its back to move around, making it easier for the bird to reach them with its beak.

Wildlife on Walls: 3. Viviparous Lizard

If you are a viviparous lizard (aka common lizard, aka Lacerta vivipara), on the lookout for food, safe shelter and warmth, then a dry stone wall has a lot to recommend it. 

The sunny side of the wall is the perfect spot to bask in the morning after a cold night, until your blood warms up....

... and those nooks and crannies between the stones are a safe retreat when dangers - like moorland kestrels, for example - hove into view. Add to that the fact that the wall is probably home to plenty of small, tasty invertebrates that you can snack on, plus the way in which the sun-warmed stones tend to act as a night storage radiator after darkness falls, and its easy to see why dry stone walls are amongst the best places to look out for these lovely reptiles.

I took these photos (which are scanned colour transparencies) a few years ago now, on a dry stone wall on the moors above Wolsingham in Weardale. Must go back soon for another look ......


More on the wildlife of walls here.


More on local reptiles here.

Wildlife on Walls: 2. Cladonia macilenta

In the beginning, when the glaciers melted, there was nothing but bare rock. And lichens thrived there. Then came the grasses and flowers in newly weathered soils, followed by scrub and finally forest whose shade cast out the bare rock-loving lichens. Then came humans with their axes and fire, cutting and burning the forest to grow crops and graze animals that often wandered away. So their owners quarried rocks and built walls. And then the lichens - like this Cladonia macilenta (I think - correct me if I'm wrong) found a new habitat on the rocks that humans piled one on top of another, in an unconscious act of habitat creation. Full circle.

Under close scrutiny, lichens are extraordinarily beautiful organisms - an intimate amalgam of alga and fungus, with each different combination producing a lichen of a distinct shape, colour and texture. The granular columns here, rising from those grey-green scales,are called podetia. They're tipped with red apothecia that produce fungal spores that will blow away, land on a rock, germinate and - if they happen to have landed close enough to a compatible alga, form a new lichen, just as they did on bare, broken rock left by the glaciers.

More on walls and their associated wildlife here

More lichens here