Thursday, 22 July 2010

Summer heat

July's heat drives me to seek out the shade offered by our young stand of Hazel. These adolescent trees, still untidy in habit, are one of the greenest things left in the garden; everything else looks faded and listless, the bone-dry soil holding little relief for thirsty plants.

It is easy to overlook the impact of the summer heat on our wildlife. While we can retreat to the cool of the thick-walled cottage or the deep shade offered by a patch of woodland, other creatures remain exposed to the full intensity of the sun. This is certainly the case for the Reed Warblers whose reed bed nests often lack covering shade. The females will actively shade their helpless young, perching above them in the nest during the hottest part of the day. The females obviously feel the heat themselves, panting with bill wide open in an attempt to keep cool. Quite suddenly one of the females will 'collapse', tipping from her sitting position onto one side as if in a faint. The bird will then raise a wing high to the vertical. This seems to do the trick, perhaps exposing veins close to the surface under the wing and reducing her body temperature through heat exchange. Just as suddenly she will recover. It will be the youngest chicks - those still naked and helpless - who will suffer most in this incessant heat.

Some creatures clearly revel in the sun's rays; a female Blackbird in the garden basks on the warm slate path, her wing feathers spread and her body feathers fluffed up. Such basking helps to drive out feather parasites but comes at a price, the bird panting heavily in the heat and only able to remain in the open for short bouts before retreating to the relative cool of the summer borders. I have seen other birds indulge in this means of feather maintenance, including one of the local Robins, but others prefer the bird bath or make use of the now dusty soil to bathe. House Sparrows, in particular, seem rather fond of a dust bath.

Many of the insects seem to be doing well and Norfolk's moth traps positively bulge with hundreds of specimens caught on these sultry nights. This bodes well for the local bats, providing an abundance of prey, and presumably for the Nightjars nesting just a few miles away in the forest. Of course, such tinderbox conditions place all of the forest creatures at risk should a careless cigarette butt or piece of discarded glass bring about a forest fire. It is a time for us to be considerate, to keep our bird baths full (and clean) and to think of the consequences of lazy behaviour.

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