Nature 2003 December

The Sound of Silence at this time of year is truly deafening!

Measuring the fall in water level (as much as 10 inches per week) from the garden well in mid November confirms the obvious that the water table in this part of the Chilterns is now worryingly below normal levels. With only an inch (25mm) of rain in October, the prospects for our woodlands, farm crops and wildlife is a particular concern this winter and next year. The signs of this can be seen all around us. The Indian Summer has meant that trees remained in leaf much later than usual but also drew on even more ground-water than usual. Hence the spectacular display of reds and browns. However we can also expect to pay for this with a severe dieback over the months to come and regular loud thud of boughs falling from over-stressed trees, so take care on your winter walks.

The winter season is an excellent time to look and listen out for, our local wildlife. For mammals and birds, there is a necessary trade off between conserving vital body heat and braving exposure to the cold air to participate in feeding frenzies during the reduced daytime hours. With shortening day lengths and night-time temperatures falling to below -3°C from the start of November, animals have been preparing for winter by building up their body fat, storing food away and insulating their nests. It is often and mistakenly thought that many of our mammals like ‘cold-blooded’ fauna (amphibians and reptiles) and many invertebrates also hibernate over the winter period. In fact whilst several become less active, only three of our resident mammal families actually hibernate; the hedgehog, the dormouse (including our notorious ‘local’ the Glis glis) and all sixteen of our native species of bat. So what are the reasons that distinguish these three very diverse mammals from all the others who may be less active but do not hibernate? Well the most likely reason is that their diet is primarily insects which are not available in winter.

If parts of your lawn look like a pincushion this is the work of the green woodpecker with their characteristic shrieking call as they probe for invertebrates including the leatherjackets (cranefly larvae) I spoke of last time. Not all species of flora lie dormant at this time of year. Many mosses take the opportunity of the moist atmosphere which condenses on their leaf tips to put on a growth spurt and put up their spore capsules on long stalks which noisily discharge their spores from capsules ringed with shark-like teeth as the air dries at day break on frosty mornings. For the early riser the opportunity for a prize-winning photograph at next year’s Hort Soc Summer Show.

With bountiful quantities of beech ‘mast’ and hornbeam seeds in our woodlands look out for birds such as the brambling, a winter visitor from the continent particularly in hard winters. Meanwhile bullfinches will be chattering as they busy themselves finishing off the sloes and other berries and thrushes smashing snail shells on their favourite stone. Over-wintering starlings flocking as darkness falls can deafen the unsuspecting evening walker as they squabble over the most desirable roosting sites. Badgers will make only rare forays before mid February when their cubs are born but listen out for their tell-tale grunts and snuffles after dark. Both foxes and muntjac make their presence felt this time of year with their distinctive high-pitched cries which may account for a somewhat spooky story I unearthed about Cholesbury Camp a while back. Ever heard of the ‘Screaming Pigs of Cholesbury’? Well the story is told of strange ‘unearthly noises’ emanating from Camp and the reluctance of even the most fearless of the men of the village to enter the Hillfort after dusk. So if anyone fancying a stroll as darkness falls is welcome to test out this theory let me know what happens!