Nature 2006 August

Fruits of the day, creatures of the night

I am writing the day of the Wimbledon Ladies Final, dark clouds have come and gone without a drop being spilt. There was a time when gardeners looked forward to the tennis as it coincided with plenty of rain, just when the flowers and ‘veg’ needed it most. Well it’s true by the first week of July we had nearly an inch and a half of rain. But as all of this fell on one day (5th) with over an inch of that in just 30 minutes, not even a thirsty succulent could soak much of the excess up. But then contrast this with June when a mere quarter inch fell in the whole month. Temperatures over the past two months have been creeping above the average, peaking at a smidgen below 33 °C just 3 days before the downpour. The Met Office are being very cagey about the longer term weather outlook for Summer. For the south-east they are predicting above average temperatures but less rain that usual. Then the health-warning follows:- “It is important to recognise that particularly during summer, the distribution of rainfall can be quite variable, with some locations experiencing heavy rainfall whilst others remain dry.” Then again even at a local level this is also borne out. Comparisons by weather-watchers of rainfall at both ends of the parish suggest slightly more rain falls month to month in St Leonards than in Hawridge. Not enough to cause a mass migration though. A reminder that current weather information is available at www.cholesbury.com

Fruits (which include nuts) add much colour to the countryside during the days of late Summer. Their attraction to animals and birds is vital for the distribution and their abundance or scarcity for these next two months determine how successful animals will be surviving the next winter and beyond. Invertebrates, particularly wasps, beetles and second generation hibernating butterflies; birds of all types and mammals large (foxes) as well as small (field mice) which all rely in part at least on a fruit diet. If you note what fruit is around during late August and September in these parts it becomes clear how important it is for local wildlife. A list of those you might encounter on a walk around here is almost endless: with soft and fleshy fruits such as: blackberry, black bryony; blackthorn; bittersweet; crab apple; dog rose, dogwood; elder; hawthorn; honeysuckle; rowan; and spindle; and nut fruits such as: acorn; beech; hazel; hornbeam; sweet and horse chestnut to name but a few. Why not see how many you can spot yourself next time your walk takes you along a mature woodland path or hedgerow? By the way folklore suggests you should not consume blackberries after Michaelmas (29th September) because the devil then spits on them. Leaving the mushier ones for the insects might be a wise move!

When habitat change has occurred resulting in the reduced the availability of a specific fruit on which a bird or animal is dependant means that particular population dies out or shifts elsewhere. Take just one example, the elimination of thistles and other perennial wild flowers in field margins has had a devastating effect on the goldfinch. Nineteenth and early twentieth century naturalists often remarked on coming across a charm of goldfinches harvesting thistledown moving on like a regiment from meadow to meadow. In a modest way the trend can be reversed by planting plants such as teasel in your garden and leaving the seed heads to mature on plants such as goldenrod, and regularly providing a wide variety of birdseed off and on the ground.

August is the height of the bat flying season, coinciding with the nights beginning to draw-in but evenings remaining warm attracting moths and other night-time insects. Here is a different example of how habitat change can knock-on to other species. Again the conversion of hedge-bounded meadows, into prairies, most notably in East Anglia has reduced the availability of night-flowering plants. This in turn has reduced the available moth population the staple diet of bats which have also suffered from a loss of roosts as farm buildings are replaced by or converted into residential housing. Bats have not suffered so badly in the Chilterns. Having a selection of night-scented flowers will draw more insects to your garden at twilight and in turn enhance the spectacle of bats performing aerial displays. Four out of a top 10 list of plants to invest in for this purpose (as advised by the RHS) are Buddleja davidii ‘White Profusion’, Hebe ‘Great Orme’, Oenothera fruticosa, Fyrverkeri sp ‘Evening Primrose’ and Nicotiana sylvestris ‘Tobacco Plant’. The most likely bats you will ‘see’ in the garden are the pipestrelle bats, small as a sparrow, and may hang-out locally being small enough to squeeze under wall tiles or roof slates. The serotine bats are much larger with broader wings and will occupy the roof space of old buildings. Taking this one stage further an excellent gismo designed with children (and adults) in mind to identify which bat is which is a bat box, such as the very reasonably priced Microbat (available via www.batbox.com).

Keeping with crepuscular creatures (those active at twilight), a most interesting sighting was passed on to me by a keen ‘naturewatcher’ in Hawridge Vale of a solitary eponymous glow-worm (female) displaying for all her worth to attract a male over the period of a week or two. These are now pretty rare. I think the last reports in these parts were following surveys of H&C Commons in the 1970s and ‘90s. Adults may still be around during early August so look out for the female’s bright yellow/green trademark beacon in damp flowerbeds and verges in the late evening.

Droughts put stress on plants which become susceptible to diseases and the damage to tissues encourage garden pests such as mildews aphids and mites to flourish. Bad news for gardeners but good news for ladybirds which maybe seen en masse in August. There are 24 British species of which four are vegetarian, hence the mention of mildew, and nearly all known by the number or colour (which can vary) of their spots:- look out for the 2, 7, 10, 24 all red 14, 16, 22, all yellow plus the cream spot and orange spot!

Leaving for the southern hemisphere during August will be the swifts, swallows and martins. September signals the first sign of Autumn as leaves begin to change colour. Once again the BBC and Woodland Trust have some excellent information. To learn more about the changing seasons see www.bbc.co.uk/autumnwatch.