December 2009
The Holly and the Ivy
The Holly and the Ivy and their pagan associations with Christmas have a much deeper meaning for one of our prettiest butterflies. The Holly Blue is the “blue” butterfly that you are most likely to see in your garden; the only other blue butterfly around Rushcliffe is the Common Blue which is found mainly on short-cropped lime grassland and poorly vegetated railway tracks where its food plants, mainly members of the pea family grow.
Holly Blues have good years and bad (like most butterflies) and they may be absent in some years. These fluctuations are believed to be caused by a parasitic wasp which lays its eggs in the Holly Blue larva, its sole host. The adult wasp emerges from the butterfly pupa.
Holly Blues are unique among British butterflies in having different food plants for their two generations. If the attentions of the wasp have been avoided, the adult (or imago) emerges from the over-wintered pupa in April and can be on the wing until June. This generation lays its eggs on Holly and these result in the late-summer generation which is on the wing from July into August. These imagos lay eggs on the tips of developing Ivy flowers. Whereas the spring pupal stage lasts only a few weeks, the autumn equivalent spends seven months or so near the foot of the Ivy before emerging.
The adult is a spotted pastel blue beneath and is a less brilliant blue above than the Common Blue.
November 2009
Deer
There are seven species of deer in the UK, only two of which are native, these being the Roe and the Red. The easiest place to see them is, of course, at Wollaton and Bradgate Parks where feral herds of Red and Fallow Deer are kept. The latter, perhaps the prettiest with its dappled markings, is a native of southern Europe and was probably introduced by the Romans. Of the natives, only the Roe Deer lives in the wild in the county and until recently they were not found in Rushcliffe, but they do now occur locally, having crossed the Trent from their stronghold in the Dukeries or moved northwards out of Leicestershire.
Seeing deer from a distance, as is usually the case, they seem much bigger than they really are; Red Deer stand about four feet high at the shoulders and Roe deer about three feet. However, our other wild Rushcliffe Deer, the Muntjac, is just eighteen inches and seems hardly bigger than a Hare. It was introduced from China onto the Woburn estate from whence it escaped in the mid 1800s and it is now found over much of England.
There are thought to be more deer in Britain now, than there have ever been but they are notoriously difficult to see, even where they are numerous, as they are nocturnal and secretive; my only rendezvous with a Muntjac being during a late night moth-trapping session at Keyworth Meadow.
With Christmas approaching, a mention of Reindeer seems appropriate: There is now a feral herd in Scotland, but they disappeared from the wild not long after the ice age retreated and Scotland became just too warm for their specialist diet of lichen to support them. The final two introductions are the Sika from Japan, numerous in Wareham Forest in Dorset for example and the Chinese Water Deer, which is doing well in the Fens.
October 2009
Harvest Mice
Harvest Mice have been a pet interest of mine since I was introduced to them at Fairham Brook nature reserve at Clifton in 1999. At that time I was quite unaware of their status in Britain and intrigued that they were present in Rushcliffe.
They are extremely secretive little creatures and still, next to nothing is known about them in the wild; most of what is known comes from studies of captive animals. What can be determined, with patience and effort, is how numerous they were during the previous summer by searching for their fist-sized, spherical breeding nests when the vegetation has died back in the late autumn.
These diminutive creatures, about the size of my thumb, excluding their prehensile tail, and weighing the same as a twenty-pence coin, weave a nest from growing grasses a few feet above the ground, to rear their litter of 3-6 babies in. My pet interest has recently taken a twist as I’ve acquired a pair of Harvest Mice and I can tell you that they are more charming and cute than the most flattering portrait can suggest.
In the wild they are known to have a very brief life expectancy and a boom and bust population cycle. In some years I find little or no evidence of successful breeding and in others I find nests in most suitable habitat, including field margins, lane verges and marshes, but the one thing they seem to depend on, at least locally, is rank grassland growing up through stiff herbage such as bramble.
September 2009
Oaks
There are two native species of oak tree in Rushcliffe, though the Sessile Oak (Quercus petraea) is naturally more typical of north-western Britain; planting has blurred the natural ranges of the two species. Our native species is the English Oak (Quercus robur) – the same as the famous oaks of Sherwood Forest.
As the last ice sheets slowly began to melt around 12,000 years ago, Rushcliffe developed a tundra-like landscape colonised by birches and grazed by mammoths and wild cattle. As the climate warmed still further, forest developed over much of the landscape (though there is doubt now that this was unbroken) and this was dominated by oaks.
Because of the tree’s long-term presence, it has associations with a great variety of insects and other invertebrates – more than any other tree; the variety of galls alone is considerable and includes the gall wasp, Biorhiza pallida which causes the oak-apple gall.
Among butterflies, the Purple Hairstreak is totally dependent on them for completion of their life cycle. Their eggs are laid on the leaf buds in late summer and the tiny caterpillar overwinters inside the egg. As with the other hairstreaks, these are really difficult to see as they spend most of their time in the canopy sipping honeydew.
August 2009
Hedges
Most of the hedges that we see around the south Notts countryside were set out by surveyors at the time of the enclosures. Various parishes were converted from the open field systems to the pattern we see today at different times during the late 18th century.
Keyworth for example was enclosed in 1791. There are some hedges dating back to a period before then and careful inspection of maps or aerial photos for the less straight boundaries give a clue to these. Hooper’s rule is a system for dating hedges based on the number of woody species in the hedge over a random 30 yard length. So, if a hedge has hawthorn, elder and field maple it would be 3x110 = 330 years old (approximately!) and the rule seems to hold true when tested against documentary evidence.
Our enclosure hedges, being around 200 years old now would have died off long ago had their longevity not been prolonged through the traditional management practice of hedge-laying which promotes new growth from the old rootstocks. An unmanaged hedge develops gaps and will eventually become unsuitable for laying and would need to be coppiced.
With so few farm labourers at work today, hedge-laying has become a rare indulgence for farmers without grant aid where previously it was a job for the winter months when other work was slack. As well as revitalising the hedge, laying provides a dense barrier which provides perfect shelter for many nesting birds whereas an annually flayed, open, hedge provides neither nesting sites nor berries for their winter sustenance.
July 2009
Grass
Grass, to many people means a lawn, and to gardeners it can also be both a pestilential weed and a specimen, variegated plant. To most people, including most naturalists, grasses are so similar, with some exceptions, that they are carefully avoided and left to specialist botanists with a dissecting kit and a microscope. Yet those who lived off the land, throughout the middle ages, knew their grasses intimately, without resource to books, because the different kinds, and their unique qualities, meant making or losing a living.
And they really can be very beautiful and diverse if the right places are looked at. Sadly, the ubiquitous Rye grass and roadside False-oat Grass dominate most of our despoiled grassy areas, but Keyworth Meadow is a great place for spotting relatively natural meadow or pasture grasses. With a little practice and reference to basic picture guides, the soft, downy Yorkshire Fog and the coarse, stiff Cocksfoot are easily distinguished, but the Timothy and Meadow Foxtail resemble each other and to tell these apart with confidence, a good botanical key and a lot of practice is needed.
The flowers are fascinating in themselves and have a whole new vocabulary to describe the components accurately but grasses are another field of natural history where specialisation will pay dividends and surveys will reveal new distributions and tell a lot about the geology and soil condition.
June 2009
Pond Dipping
Children love going pond-dipping and if the truth be known so do grown-ups. The fun is a bit like that from tombola; not knowing what might come out next.
Since water is essential to life, and water is where life first life began, it is not all that surprising that there is such richness, both in diversity and numbers in a jar-full of unpolluted pond water. A 10x hand lens or, better still, a low power microscope is needed to see the smaller creatures clearly such as Cyclops and Daphnia, but there are many easily observed beetles including of course, the backswimmers and Great Diving Beetle and even a spider, Argyroneta, that spends most of its time submerged - in a bubble of air that it collects from time to time. It is also called the Diving-bell Spider.
One of the more common creatures is the freshwater shrimp, Gammarus, which swims on its side, but the three-tailed mayfly larvae should also be present. Perhaps the most spectacular are the nymphs of the dragonflies and damselflies which are all aquatic prior to their climb up an emergent plant stem and their metamorphosis into the jewelled aerial form.
Even the 99p nets from toy shops will serve the purpose providing they are treated gently. The technique is to tip the strained contents into a white dish (an old ice-cream container will do) containing a couple of inches of water. Wait for any silt to settle and the creatures should soon be detectable by their movements. The Field Studies Council produce some inexpensive waterproof guides to aid identification and different ponds and stream will turn up different creatures because of the varying pH, oxygen levels and chemistry.
May 2009
Wildlife Gardening
Our gardens have the potential to be marvellous refuges, not just for us, but for wildlife too.
As in many nature reserves, it is the diversity of habitat that ensures a variety of species will find it to their liking and if they can be designed to resemble miniature versions of their natural habitat then so much the better. The space available determines how much variety can be incorporated but the most immediate benefits can be had from a pond and even a small one may quickly attract, frogs and newts.
If not too shaded, a closer look will reveal a diverse assortment of crustaceans, such as daphnia and cyclops. Dragonflies and damselflies will visit and may breed and it will always double up as a bird bath.
Planting with native species is a golden rule but there are many plants that give year round benefits and ivy, given space to flower and fruit is one of the best. Holly Blue butterflies lay their summer eggs on the tips of the buds, the flowers in October pull in Red Admirals and a humming bevy of hover flies and honey bees. Then in March, the berries provide for thrushes and perhaps Blackcaps whilst in April it gives a secure nest site for Blackbirds.
Next on design options, might be an untidy corner incorporating a log pile (for beetles and fungi) an open compost heap which a grass snake might like for a warm hibernaculum or a border with nectar-rich flowers to invite the summer butterflies (honeysuckle may even entice a Humming-bird Hawkmoth). There are many options that can be incorporated to create a pleasing variety of aspects and seasonal interest and although a wildlife garden is not maintenance-free, they generally benefit from a policy of minimal intervention: It’s just as well, as the free time can be spent taking pleasure from watching those sharing it with you.
April 2009
Swallows
Forty or so years ago, during autumn, the overhead telegraph wires around Keyworth were often shoulder to shoulder with hundreds and hundreds of Swallows and House Martins gathered together and preparing to migrate. Nowadays even a dozen is notable and this must be a reflection of the decline in the availability of aerial insects – their sole food. Farmyards certainly seem far tidier and even sterile, compared to how they once were.
Although their numbers are down, their reliability to return here from their wintering grounds seems undiminished and between now and the beginning of May almost all breeding sites will be occupied – usually by the same pair as previously.
Whilst Blackcaps and Chiffchaffs only move as far south as southern Europe and North Africa, with many lingering here all winter, the Swallow’s winter stronghold is in South Africa, and yet the strategy of migration is a risky balance – negotiating sea crossings and the Sahara Desert sees lots of casualties and it’s a two-way journey.
Most cross the narrow point of the Mediterranean at Gibralter but the English Channel is navigated on a broader front with birds arriving in-off the sea from Cornwall to Kent. Given the risks, perhaps it’s not surprising that individuals do occasionally attempt to overwinter and a bird in Cornwall seems to have managed it successfully for what appears to be the first time as it survived to late February at least.
Reminding oneself of the utterly fantastic journey just completed, when the first chattering and excited birds arrive, it’s easy to see why they seem so elated to be back.!
March 2009
Ladybirds
Ladybirds are mostly an easily identifiable group of beetles and everyone is familiar with the 7-spot which will be emerging from hibernation during the warmer days of March.
There is an invasive species which can resemble the 7-spot, and that is now common in Rushcliffe; the Harlequin Ladybird is about the same size but very variable. Both the 7-spot and the Harlequin are voracious predators of greenfly but the latter is undesirable as it resorts to eating other ladybirds when the greenflies have gone. They have spread rapidly across England in just a few years and it appears we’re now stuck with them. Originally from Asia, in the US it has become the most widespread ladybird having only arrived there in 1988.
There are 46 species in Britain, and the UK ladybird survey has chosen 26 species and produced a photographic guide to their identification. Several are restricted to pine trees (a pine tree in my garden has held Pine and Eyed ladybird) and others to grassy meadows (Keyworth Meadow has 14-spot, 16-spot, 22-spot and 24-spot).
All in all, they are an easy group to get to know and with the threat from the Harlequin, now is an important time to document their populations. Visit www.ladybird-survey.org for more information.
February 2009
Winter Thrushes
Two species of thrush spend the winter in Rushcliffe, the Redwing and the Fieldfare. Both arrive in October and depart in April back to their breeding grounds in northern Europe.
They are both charismatic species; Fieldfares are big and resemble Mistle Thrushes somewhat but are more patterned and have a loud chacking call as they circle in often large flocks. Redwings are smaller – the size of Song Thrushes and often accompany Fieldfares. They have a distinct creamy stripe above the eye, the supercilium, and red patches beneath their wings. They are often noticed by their “tsweep” call as they migrate into the country nocturnally.
Both occasionally enter gardens to mop up fallen apples but spend most of the winter in the fields feeding on berries and soil invertebrates. Although both species winter here annually, many Fieldfares stay close to their breeding grounds from Scandinavia eastwards whilst Redwings, which also nest in Iceland, are not at all loyal to this country and ringed individuals that have spent one winter here have been known to spend subsequent winters in Italy, Syria and Iran. Both species nest in northern Britain in small numbers, Redwings since 1932 and Fieldfares, as far south as the Peak District, since 1967.
A more striking bird is spending this winter with us; Waxwings, another Scandinavian breeder comes here in small numbers most years but when the berry crop is poor, as this year, they arrive in big numbers and congregate, often in urban streets to mop up rowan, pyracantha and cotoneaster berries. They are wonderfully attractive and confiding birds. A large flock was present in Gamston in January but they can turn up anywhere.
January 2009
Bird Ringing
Amongst the bountiful information contained in The Natural History of Selborne is the reference to a duck (species unspecified) that was shot in England in the winter of 1708-09 and that bore a silver collar bearing the arms of the King of Denmark. This was proof for Gilbert White that birds can cross the North Sea and if ducks could manage it, then so could other species.
Bird ringing is now pursued internationally and continues to provide insights, not just into birds’ movements, but also their longevity. The rings are of lightweight but very durable metal fastened to the bird’s leg.
The South Notts Ringing Group is overseen by the British Trust for Ornithology and they ensure that ringers are properly trained before a permit is issued. A recent result made the headlines when two Common Tern chicks, flooded from their nest in at Attenborough in July 2007 and feared to have drowned, were “controlled” in Senegal, 2,793 miles away in Spring 2008.
More fascinating findings include a Blackbird ringed at Bingham in November 2005, found dead in Sweden in May 2006, a Long-tailed Tit ringed at Attenborough, still there and still going strong 7yrs 209 days later, a Grey Heron, ringed as a chick at Barton in Fabis, enjoying some winter sunshine in the Canary Islands, 3,000 kms away in December of the same year and Black-headed Gull ringed in Finland and found at Holme Pierrepont five years later.
If you are interested in taking up this fascinating activity, contact me on 0115 9144896 and I’ll put you in touch with the group.
