Saturday 25 July 2009

Foxgloves


I spent some time the other week watching a bumblebee as it worked its way around the tapering tubular flowers of a Foxglove. This particular plant was one of a number which have become established within the garden, their spires of colourful flowers recalling the shady woodland of my youth and a welcome addition to the garden. Each flower has now faded and shrivelled to a thin papery brown ball and the bees have moved on to other opportunities.

The Foxglove is one of those plants which has a strong folk tradition and I often see reference to the plant in the context of fairies and other wondrous woodland folk. Some authors have gone so far as to suggest that the origins of the name ‘foxglove’ are rooted in a corruption of ‘folks glove’, alluding to the fairy folk. However, this association is almost certainly incorrect, since the association in Old English is clearly with the fox, with ‘glofa’ being a glove or mitten. Perhaps the link with the fox comes from the shady woodland habitats which both the plant and fox favour.

Regardless of its origins, the Foxglove remains a very interesting plant and most readers will know that it is the source of digitalin, a drug used in the treatment of various heart conditions. All parts of the Foxglove plant are poisonous and contain compounds known as cardiac glycosides, which act to both slow and strengthen the heartbeat. However, the dosage is critical; get it wrong and the heart will stop beating altogether. Worryingly perhaps, the plant is mentioned in many old herbals and it was widely used as a treatment for various ailments, from sore throats and ulcers to dropsy, the latter treatment often proving either dramatically effect or fatal. It was not until the late Eighteenth Century that the workings of the drug became more fully understood. William Withering, a doctor working at Birmingham General Hospital and a member of the Royal Society, established how the active ingredients in the plant worked and calculated the rates at which doses should be applied. It is because of this work that Withering is now regarded by many as the grandfather of pharmacology.

Today the drug is derived from the Woolly Foxglove, a closely related species found across much of Eastern Europe. During the Second World War, when access to overseas supplies of the plant were greatly restricted, we turned to our native Foxglove, which was harvested in vast quantities by members of the Women’s Institute. The drugs derived from the humble Foxglove have an important role within modern medicine and some readers may be using them without even knowing it, making this a plant worthy of our affections.

Friday 24 July 2009

Woodpigeons keep on nesting


The Woodpigeons are nesting again, this time back in the Holly tree above the chicken run. It seems to be a never ending process; nesting attempt follows nesting attempt, with most doomed to failure, a seemingly dismal cycle of poor parenting. That the Woodpigeons should fail so often could reflect the density of cats, many of which stalk this urban area, but I don’t think that this is the whole story. With just two eggs per nesting attempt and a pitiful excuse for a nest, these birds just don’t seem to have it in them to make a proper go of it. While other species build well constructed and intricate nests deep within cover, the pigeons seem to just sling a few small twigs together somewhere obvious and hope that this will suffice. More often than not, I find the eggs smashed on the ground beneath the nest, the result of a windy day, a lack of robustness in the nest’s construction or a clumsy parent.

The surprising thing is that these birds are doing so well, with a population that has gone through the roof over recent years, thanks largely to changing agricultural practices. You cannot move for Woodpigeons; even here in town they dominate the bird community, hoovering up food from bird tables or delivering a monotonous dawn chorus with their ‘take two cows, taffy’ call. It would be fine if they were attractive, elegant even, but they come across as clumsy, overweight and, let’s be honest, rather dim. To see a Woodpigeon attempt to perch on a hanging feedeer reveals a triumph of determination over brains. However, there is one thing that Woodpigeons do which does suggest some initiative. When it rains they line up on the fence and each bird raises first one wing then the other high above their head, allowing the raindrops to wash the underside of the wing.

The increase in Woodpigeon numbers may be having a knock-on effect on another monotonous songster, the Collared Dove, whose numbers locally seem to have taken something of a dip over the period that the Woodpigeons have been on the increase. The doves are a rare visitor to our garden feeding station these days, seemingly ousted by a succession of pigeons that waddle around on the ground beneath the feeders or clamber in a most comical manner over the Hebe in search of fallen seed. I guess that I have a grudging respect for them; that they have been able to increase their numbers despite their seeming inadequacies suggests they must be doing something right. I think it must be a combination of persistence and adaptability that has served them so well.

Thursday 23 July 2009

Urban birds are lazy


The divide between town and country is one that you often see mentioned in the news. Be it a story about economics, social attitudes, crime or even quality of life, the differences between town and country are much trumpeted. One difference that you might not expect, however, is the difference that has been found between how particular bird species behave in towns and how they behave in the wider countryside. Research that I have been involved with has just revealed that urban birds are lazy, at least when it comes to getting up in the morning to visit garden feeding stations! Urban-living populations of Robins, Greenfinches, Blackbirds and many other species arrive at garden feeding stations, on average, a few minutes later after first light than their country cousins.

Of course, this is not really a case of lazy birds but the result of different factors operating in each of the two habitats, influencing the birds’ behaviour. On cold winter nights (the time of year when we carried out our study) many small birds struggle to survive the low temperatures and long nights without access to food. In order to keep warm, many of these small birds will burn off much of their body’s fat reserves, reserves that need to be replenished as soon as possible after dawn. It is these energy losses that prompt the early arrival at garden bird tables and hanging feeders, the birds arriving as soon as it is light enough for them to see what they are doing.

Now you might think that with all the street lighting that exists within our cities, urban living birds would be able to start feeding earlier because of the extra light available to them. That this is not the case suggests that another factor is operating on our urban birds, working in the opposite direction. This factor is temperature. Because of all the heat that escapes from offices, shops, factories and houses, our urban areas are typically several degrees warmer than the surrounding countryside. In fact, some of the largest urban areas (think of London, Birmingham and Manchester) may be as much as eight degrees warmer than the surrounding land. This is known as the urban heat island effect and in winter it can counter the effects of lower ambient temperatures. If it is less cold overnight for urban-living birds then they will not have to use up so much of their energy reserves keeping warm, meaning that they are not so pressed to replenish fat reserves come first light. This allows them to make a more leisurely start to the day than hard-pressed relatives who happen to be living in rural areas. Sometimes an urban existence pays dividends.

Wednesday 22 July 2009

Transformation


I have been fascinated by the transformations of butterflies, moths and dragonflies since childhood; that one body form can be turned into something completely different is amazing. While the changes in butterflies are striking enough, it is those of the dragonflies that I have always found the most interesting. The transition from an aquatic larva to a winged, non-aquatic adult is truly remarkable. In some ways the metamorphosis of a butterfly appears to be a passive process, the larva settling down in a sheltered location to become a pupa from which an adult will ultimately emerge, often many months later. In dragonflies it feels so much more active and immediate, the adult emerging from a larval form that has itself only recently emerged from the water. Of course, this is an illusion in the sense that it is the adult itself, held within its old larval skin, which drags itself from the water to clamber up a suitable stem.

Many of the British dragonfly species (and I include damselflies under this broader title) emerge from mid- to late-morning, which offers the interested observer with the opportunity to witness the breathtaking series of behaviours which deliver the winged adult into the world. A few of the larger species, however, leave the water at dusk, completing their emergence by the early hours. Most individuals select an emergent plant as their place of transformation, clambering up to a position well clear of the water. Once a suitable position has been found, the larva attaches itself head up and then proceeds to swing its body about in a characteristic and jerky manner. It is thought that this behaviour, which also includes various circling leg movements, allows the dragonfly to determine that it is securely attached to its support and also that there are no obstructions close by that might hinder the expansion of its wings. If the wings push up against an obstruction during their expansion phase then they can be severely damaged.

The first stage of the transformation involves a switch from aquatic respiration to aerial respiration. The cuticle then splits and the head, legs and thorax are pulled clear of the larval skin. This appears to be a demanding process because it is invariably followed by a long period during which the insect remains immobile and resting. The abdomen is then withdrawn from the skin and the process of expansion begins, with both the wings and abdomen very slowly increasing in size. Once the process of expansion is complete, the now fully formed adult remains on its support until it is ready to take to the air for its maiden flight, leaving behind the larval skin and all evidence of its once aquatic lifestyle.

Tuesday 21 July 2009

The last Corn Bunting?


It was Kate who picked it up first, the soft, distinctive ‘jangling keys’ song of a Corn Bunting. Despite his rather drab appearance he was easy to spot, a dumpy little bird sat on a telegraph wire above an arable field margin, repeating his characteristic song at steady intervals. Males sing incessantly throughout the breeding season and are highly territorial, even to the extent of making regular visits to the breeding territory during the winter months. These levels of song production may be one reason why male Corn Buntings often attract multiple female partners, although the quality of the territory in which he is singing also has a major influence on his ability to attract and support a mate. One male, holding a high quality territory on the South Downs, was found to have six different females nesting in his territory at the same time.

This was a good bird to see, a species in retreat and now missing from much of the county. It is only here, on the chalky soils of northwest Norfolk, that they seem to be hanging on in any numbers. The demise of the Corn Bunting is part of a wider decline in the breeding populations of many of our farmland seed-eaters, with species like Tree Sparrow, House Sparrow and Reed Bunting in documented decline. It is a story that we have heard all too often; changes in the way in which we manage the land impacting upon the other creatures with which we share our fields and woodlots. The desire for cheap food necessitates a particular form of land management which, in turn, determines how much space there is for birds like the Corn Bunting.

The changing status of the Corn Bunting has had a knock-on effect on our appreciation of it as a bird. Once described as being ‘lumpy, loose-feathered’ and ‘spiritless’ the Corn Bunting is now growing in our affections. One author wrote ‘He is a dull bird and seems to know it’, something which would surely be countered today with the response ‘He is an understated bird, not brash but subtle in his charms’. And that’s the thing really; here is a bird with old world charm, a species whose song would have been familiar to a generation of birdwatchers but whose future now looks uncertain. We could lose the Corn Bunting from Norfolk and with its loss would go one of the true sounds of arable farmland. I know that, at present, I can come to the chalk around Ringstead and Chosley to see Corn Buntings but what I really want us to have them return as a backdrop to farmland walks elsewhere in the county.


Monday 20 July 2009

The last leg


The going is easier today. After yesterday’s 22-mile dash from Castle Acre, the final leg of our walk along the Peddars Way is a gentle stroll over the seven remaining miles to the coast. With our heavy packs left behind at our last overnight stop, it feels more like a normal walk through the Norfolk countryside. This part of the Peddars Way runs through some of the county’s most beautiful countryside. At times the route is a wide green lane, straight and showing its Roman origins, that slips through gently rolling hills and cuts between small woodlots and arable crops. In places the path is alive with butterflies; clouds of newly emerged Small Tortoiseshells (a welcome sight after several difficult summers for the species), a profusion of Meadow Browns, the odd Small Copper and the occasional Painted Lady, the latter tattered remnants from the extraordinary influx of earlier in the summer.

Seen on a map, the original path of the Peddars Way is undeniably straight, deviating just twice (and then only very slightly) along its length but our modern route takes a less direct path thanks to the accumulation of land into private hands. The straightness and position of the Peddars Way suggests that it was a military road, established through the heartland of Prasutagus’s Iceni kingdom in the aftermath of Boudicca’s revolt. A show of strength by the occupying Roman Army perhaps but also facilitating the movement of troops should the need arise to quell further uprisings.

A great deal has been written about the Peddars Way and its purpose, with many authors seemingly frustrated by the lack of any obvious destination – ‘roads must go somewhere’. There is no hill fort at Holme or any major settlement, leaving some authors to suggest that it might have ended at a ferry, which crossed the Wash into Lincolnshire. However, there is no evidence for this and there is no reason to suppose that the road did anything beyond allowing troops to move quickly through potentially hostile terrain. The road avoids most of the known Iceni settlements by passing to the east of the more ancient Icknield Way.

Dropping down towards the sea from Ringstead we can see our destination, the village of Holme and the signpost that I know awaits our arrival just beyond the golf course and before the dunes. ‘Knetishall 46 miles’ it will say, with its wooden finger pointing back along our route to where we had set out just two days before – just beyond a small ford on the Little Ouse. This last leg has been a pleasant way to bring our journey to its end, delivering a sense of connection with an ancient landscape and those who travelled its highways.