Nature 2012 April

Pimping reaches the Hilltop Villages!

Needed something along the lines of a tabloid heading to get your attention this time! Not of course what it sounds like. However, the more frequent occurrence of red kites over us these days is starting to create some competition for territories. As numbers increase each year the younger birds need to move further and further afield to find suitable roosts.

Pimping is the characteristic behaviour of some raptors whereby the two birds do acrobatic tricks in mid air, often interlocking their talons and spinning around or passing on food scraps or roost materials. The gymnastics are normally accompanied by a cacophony of “wee-ooh” sounds. March and April are the two months when this nest refurbishment activity is at its height. Apparently later inspections of nests reveal all sorts of plundered material including flags, toys and clothes including gloves and underpants!

Aside from my father and David Attenborough, who coincidentally bought all his blue shirts and safari slacks from him, my other inspiration for an interest in natural history was a much more obscure one. I can first recall seeing David Bellamy appearing on a programme in 1972 called Bellamy on Botany. For those who remember him, his approach involved much gesticulation, usually whilst bouncing up and down on peat bogs and much, largely unintelligible, grunting and guffawing, interspaced with gems in natural history. It was his expression “the importance of Hacid Eths” of which I was reminded the other day when coming across a report by the Chilterns Conservation Board about how rare acid heathland habitats are in England and that they remain under threat in this part of the Chilterns.

We are lucky enough to have such an example on Hawridge and Cholesbury Commons. With grateful acknowledgement of the Heritage Study I note the key indicator species for such habitats, in this area at least, are: heather, pill sedge and rushes. In times not so long past, commons such as ours would have been grazed by domesticated animals: cattle and in particular sheep. Until even more recent times, periodic burning by Commoners also managed the habitat in a less sustainable way. Gorse, which is another indicator species, is interesting in that it would have been carefully managed by Commoners to avoid it becoming a weed on the heathland.

One of its older and colloquial names is furze, which was harvested by furze-cutters and used for making fires for baking bread. I recall Winnie the Pooh also had a tangle with gorse when looking for honey, but this was not in Cholesbury or Hawridge! However, in the absence of these ruminants (I’m excluding the Commoners from the definition here) heather, in particular, is quickly suffocated out by bracken, which flourishes when not beaten out by animal activity. Mechanical crushing of the bracken fronds achieves this end today. The benefit of protecting the heather and other heathland plants spreads far wider than just protecting a desirable habitat. It also helps conserve other species which depend more exclusively on these landscapes. Go back 75 years and above the heather and gorse by day might be seen hen harriers and at night might be heard nightjars and nightingales. Probably neither seen nor heard but still there amongst the thickets would have been the odd woodcock. Last seen in 1973 and now extinct in the UK, was the red-backed shrike.

Many invertebrates occupy this habitat. Some are partly and some exclusively dependent on it, such as the lesser yellow underwing, which may not have been seen since 1990. Other moths such as the metallic coleophora feed on a wide variety of herbs but rely on the rushes to make neat little cases in which the larvae pupate. The trickle down effect of sensible conservation is the real value and bonus rewarding hard work. Whether or not the Commons are your usual stalking grounds, it is worth taking a closer look next time you go for a stride or two.

Are foxes bigger these days? This was the gist of the news report on the BBC website the other day. Turns out it related to a 38lb male fox killed for attacking sheep in Aberdeenshire. Typical male rural foxes might weigh up to a max 16lbs whilst those living in the smart sophisticated urban areas come in at a svelte 13lbs. But then there are also plenty of bijoux animals around too: in all habitats at 9lbs it seems.

The helping hand of man leaving out scraps, or hobby farmers laying on ready-made chicken dinners in the foxes’ territory has an effect. But the main reason for the weight difference is the abundance or otherwise of earthworms from year to year in July when the young are out foraging. A wet summer brings out a plentiful supply of the fox’s favourite meal, which come to the surface in these conditions. By October foxes have put on their maximum weight for the season. So a dry summer followed by a harsh winter produces slightly smaller foxes which may fail to survive to the next year. Meanwhile, a wet summer and mild winter provides the conditions for heavier foxes to make it through to the following year with an advantage over other males with which they ferociously compete for territories.