Nature Notes 2007
Partridges and Pear Trees
With the exception of Turtle Dove, the precise species referred to in the Twelve Days of Christmas is unclear, but I thought it might be of interest to see how they have fared since the song was written, or at least since the first BTO Atlas of breeding birds was published in 1976. It’s a fair bet that the Partridge was Grey as the song is reputedly 16th century and there were no Red-legged in England then. Between the first and second atlas (1993) there was a significant reduction in both Grey Partidge and Turtle Dove’s breeding distributions with patches appearing in their stronghold areas of lowland England; a trend that is believed to have continued and that will be established through the current atlas project, just begun.
French hens are domestic breeds and as far as I’m aware, are as rare in Britain as they’ve ever been - unlike Blackbirds which are widely distributed throughout the country and whose population showed little change between 1976 and 1993. Why am I mentioning Blackbirds? Because “calling” is a corruption of “collie” – old english for coal (hence collier). So the 4 calling birds are actually Blackbirds – a strange gift, though no more so than the others.
At least you can eat geese and swans, though you’d need a large freezer or a lot of friends to do justice to a cumulative thirteen over two successive days! The population of our resident swan, the Mute, was fairly static between the atlas years but has since increased due, it is believed, to the mild winters and replacement of angler’s lead shot with non-toxic alternatives.
England’s only breeding geese are both introduced species and are both increasing in numbers with Greylag lagging behind Canada. The latter has been increasing at around 10% a year and is well known for its “consequences”.
Profuse ivy blossom has a faint honey-like aroma and on mild autumn days hums loudly with the activity of myriads of insects. Most are hoverflies and the majority of these are the species known as the Drone Fly which closely resembles a honey bee. Drone flies have a larval stage which survives well in heavily polluted water with low oxygen levels, through their being equipped with a breathing tube, several times longer than the larva itself. This reaches up into the air above and earns it the name of rat-tailed maggot. Amidst the humming and commotion there is often the flash from the opening wings of a Red Admiral, imbibing of the late supply of nectar.
There is another species of butterfly which has become regular in Nottinghamshire in the last couple of decades that is dependent on ivy as a host for the larvae: Holly Blues lay their eggs on the tips of the flower buds in the summer and the young caterpillars munch away on the flowers and young leaves before pupating. They over-winter on the ivy and upon emergence in the early spring (before the other species of blue butterfly) mate and lay eggs on Holly. These become the generation that lays on Ivy, so completing the cycle.
Grasshoppers & Crickets
There has been a remarkable expansion in the range of several species of grasshoppers and bush-crickets recently. Keyworth Meadow holds just one species of grasshopper, the Lesser Marsh, which only established itself in Nottinghamshire in 2000 but is now the most widespread species in the county. Whilst trying to see if others are present I discovered a Long-winged Conehead in August – the first record of this species in the county and following hot on the trail of Roesel’s Bush-cricket, discovered near Clifton in 2006, but which now has several more colonies nearby.
Incredibly another first, this time for the Midlands, was found in a garden in Bilborough in September. This is the Southern Oak Bush-cricket, a flightless species, which is known to have colonised Britain recently but was known only from the vicinity of London.
These extraordinary records are mirrored by expansions and colonisations of damselflies and dragonflies, with Small Red-eyed Damselfly reaching Notts in 2006 and now present at many sites including Cotgrave CP. These are all sun-loving species and it is difficult not to connect the changes with climate change.
Keyworth Meadow has a web-site at Keyworth Meadow
Fifty or so years ago, Stoke Bardolph sewage “farm” was nationally famous for the birds it attracted; the most memorable of them being Black-winged Stilts. Those were the days when the treatment process involved the spreading of sludge over large areas of land. These expanses of deep, insect-rich mud attracted the waders following the Trent Valley migration route, and also bird-watchers from all over the country.
Nowadays the availability of wader habitats in the Trent valley is much reduced and the sewage works is a complex of concrete tanks and enclosed steel chambers. Redshanks, Green Sandpipers and Greenshanks do still drop in on to the margins of gravel pits such as those around Holme Pierrepont especially at this time of year, but in vastly reduced numbers, and there’s always the chance of a surprise. However Black-winged Stilts are not a realistic prospect. Amazingly, two pairs nested and reared 3 young at Stoke Bardolph in 1945 but there have been none since. The species is the emblem of Nottinghamshire Birdwatchers – if Nottinghamshire’s birds interest you, contact the membership secretary, Lynne Demaine by email to email@example.com.
Bird watching along the Trent Valley is set to improve immensely with the RSPB’s initiative, in conjunction with Tarmac, who are developing 170 hectares of reed bed and open water habitats at a site north of Newark.
Since this date, Wall butterfly has become extinct in Nottinghamshire. It was already in decline in 2007 and there is still a thriving population in some Derbyshire dales. They also remain reasonably common around southern coasts.
There are seventeen species of butterfly that can be seen readily by the observant wanderer in Rushcliffe during an average summer. Indeed most if not all, will at some time visit the average garden. But to see additional species it is necessary to be in the right place at the right time.
During late August a good venue is Bingham Linear Park where Brown Argus, Small Copper, Small Heath and Wall should be on the wing. This site also has a population of Grizzled Skipper but these fly during May and June. Green Hairstreak and White-letter Hairstreak are other Rushcliffe species that need to be targeted, though the latter is thought to be more widespread than the records imply, and it is worth careful observation of any roadside elms during July.
A further two species, Clouded Yellow and Painted Lady, are migrants and may be present in some years but not in others – the latter sometimes in big numbers. If seeking butterflies at Bingham LP, visitors should concentrate their efforts on the section south-east of the A52, where the old railway goes into embankment.
Congratulations to Howard Broughton and helpers on the Rushcliffe Barn Owl Project on the fledging of 100 young Barn Owls in the borough this year!
There are around four million square metres of roadside verge in Rushcliffe. That equates to 560 new Wembley Stadium pitches and that’s a lot of wildlife habitat – far more than is managed intentionally as nature reserves. For our most common plants, such as Cow Parsley and False Oat Grass, verges are the only habitat available since they are not permitted in our gardens and cultivated land. In amongst the abundant species are less-common plants and where soil conditions are favourable, small swathes of diverse flora.
The County Council maintains verges and they are generally cut twice a year - or more where safety dictates it. A few notified verges, of recognised importance for their plants are managed sympathetically but it is not practical or affordable to apply this practice everywhere. However, I sometimes see the first flush of late-spring flowers beginning to decorate and embellish the lanes only for them to be laid low before they have had a chance to be pollinated, let alone set seed.
Gotham by-pass (Gypsum Way) runs along the alignment of an old railway and has a variety of plants which look as though they would benefit from a more considered regime; If you know of others, please inform the County Council, and maybe they will qualify for notification. Let me have a grid reference and description and I’ll happily collate them and pass them on – firstname.lastname@example.org or 0115 9144896.
Around 2,500 species of moth have been recorded in Britain of which 800 or so are loosely described as “macros”. The latter are the group with which the beginner begins. In five years of trapping in my garden I have recorded 220 species of macro, many of them just once or twice, but I considered that to be sufficient experience to host a moth-trapping session in Bunny Wood in May. Although the weather on the evening was less than ideal, woodlands have their own climate, insulated as they are from the winds, and twelve species of moth were recorded. They included the “cuddly” Pale Tussock” as well as a couple of species that were new to me.
Two days later, in perfect weather, the open day at Keyworth Meadow attracted many visitors including many well-informed naturalists. Plants are not my strong point and it is a pleasure to have more expert botanists share their skills. I was shown Rough Chervil by one visitor which I would otherwise have missed. Click beetles proved entertaining, by obligingly showing how they got their name: upon being turned upside-down they recover themselves explosively with an audible ‘click’.
The events run by the trust are usually hosted by volunteers wanting to share the delights of a place or a particular branch of flora or fauna and are normally free. All ages and ranges of experience are welcomed.
Wilwell Cutting, to the north of Ruddington was excavated in 1895 for the Great Central Railway and abandoned around half a century later. It is now among Nottinghamshire’s best sites for wild flowers with more than 250 species recorded. Many plants that are rare in the county are to be found here and they include several species of orchid with Southern Marsh Orchid a speciality. It is both a Site of Special Scientific Interest and a Local Nature Reserve. But had it not been for vociferous protests by local people it would have been destroyed in the early seventies as it was planned as a landfill site!
It is often the case that such “brown-field” sites are rich in scarce plants and at Wilwell, this is because the rich, fertile soils that cover Rushcliffe have been removed and the less fertile sub-soils or underlying strata exposed. This means that the plants that thrive on high-nutrient soils, notably grasses, are stifled and those that thrive on nutrient-poor soils find a niche. And where there is a variety of plants there are the associated insects. Pick a sunny day at this time of year, arm yourself with a field guide to wild flowers or butterflies and Wilwell will not disappoint.
As I write, there is a sense of spring in the air and the expectation of coming warmth and sunshine. It seems that the birds are thinking that way too, for amongst other signs of nesting activity, a Robin has built a nest and laid an egg. This wouldn’t be so strange except that it is now incubating the single egg. Robins normally lay 5-7 in early April in the south. Those are the facts, now the speculation: has the warmth promoted breeding activity ahead of the physiological conditions that determine it? Day length is the factor for much hormonal activity in birds and presumably in other groups, so is this asynchrony a threat to breeding success?
Well, robins breed as far south as northern Africa, and a migrant population that winters in Europe, moves into central Scandinavia and western Russia to breed. These must have adapted to the day-length and temperatures typical of those regions and I suppose that our birds will do the same given time. The worry is that fluctuating conditions (an “Arctic blast” is forecast) will confuse their metabolisms. And it is certain that if Robins attempt to raise just a single young each spring, they are on the road to an early extinction since their life expectancy is around twelve months and one young bird replacing two adults will not keep the species going.
Barn Owls numbers declined dramatically during the latter half of the twentieth century. The intensification of agriculture drove their dwindling population to hunt along roadside verges where they were commonly killed by passing vehicles. They readily breed in captivity and there used to be quite a lot of releases of captive-bred birds into the wild in well-intended but unsuccessful attempts to boost their numbers. Far more successful results have been achieved by the Rushcliffe Barn Owl Project, through the provision of Barn Owl nest-boxes. This initiative is run by volunteers with the help of donations and has as its mascot, “Speedy” who is a small and now aged Barn Owl who visits schools and shows to promote the project’s work. Speedy won the Mayor’s Special Achievement Award (along with Clive James) in 2006. 130 boxes had been erected by 2005 and in that year alone, fifty young owls were fledged.
Tawny Owls hunt amongst trees and their numbers remain constant. Their song is the well known “tu-whit-to whoo” associated with graveyard scenes and they also deliver a high pitched “ke-wick” contact call which may be heard at night, almost anywhere in Rushcliffe. Our two other native owl species are the Long-eared and Short-eared which nest, respectively, in woodland and moorland and are quite scarce in Rushcliffe, and there is a fifth species which was once very common in the area. The Little Owl was introduced to this country in the 19th century and established itself very well, becoming one of very few introduced species that seemed to find a niche in the ecology without unfavourably affecting our indigenous species. Its stubby posture, undulating flight and cat-like calls are becoming very scarce in many parts of the country and no-one is sure why.
Our woodland plants have adapted to their habitat by flowering early in the year, before the shade of the leafy canopy cuts out the light. Violets, Wood Anemones and Primroses typify these early blooms and provide the earliest butterflies with nourishing nectar. Red Admirals, Small Tortoiseshells and Brimstones all hibernate and emerge when the first flush of spring warmth sweeps the country. At least, that is normally the case, but the record-breaking mild winter that we have just experienced, saw some Red Admirals in flight throughout December causing concerns that they may have suffered in not being able to find nectar supplies on their forays.
Our wildlife has adapted, since the last ice-age retreat, to fairly consistent climate patterns and the recent changes present both opportunities and challenges to the way in which wildlife responds. A principal difficulty is the synchrony in timings such as that described above. It will be interesting to see if the willow and sallow blossom coincides with the emergence of the early spring moths that depend on that resource. The mildness of January is likely to advance the blossoming season – will the moths respond?
The Woodland Trust manages a scheme that documents the timing of ‘nature’s calendar’ through a network of volunteers. Contributing to the study is easy and educational with many of the observations being ideal for getting children involved in field biology by noting the date of the first ladybird or frogspawn. Visit Nature's Calendar for how to enrol.
Birding at Holme Pierrepont
There are three country parks in Rushcliffe, but for winter bird-watching, Holme Pierrepont is undoubtedly the best. This is because of the large areas of open water and their attractiveness to the wintering ducks and other water-birds: Amongst the ducks, Wigeon, which, in common with most of our species, breed across northern Europe and Asia, reach around 1,000 across the complex of gravel pits and grassland. Gadwall, Teal, Goldeneye, Pochard and Tufted Duck often number more than 100 and there are lesser numbers of Pintail and Shoveler.
Great Crested Grebes and Cormorants occur all-year round, but this wasn't always the case, with the former verging on extinction at the turn of the last century. It was saved through the establishment of the RSPB, whilst Cormorants have only populated Nottinghamshire in the last thirty years or so, when the continental race colonised the country. The British race is restricted to the coast.
The Little Egret is another species that has spread northwards through the country and can now be found in Rushcliffe though mainly in the autumn, rather than winter. Like the grebe, the threats to this species from the hunting for head plumes to decorate ladies hats, prompted the inception of the RSPB.
The enticement of bird watching is the unexpected: Whilst counting the regular ducks is essential in documenting their welfare, it is the surprise species that make the day memorable, and even the rowing course can have such species as Red-necked Grebe or Common Scoters early in the day.