Saturday, 20 October 2007

An eye for detail

Regular readers of this column will know of my great passion for experiencing the natural world first hand; getting out into the countryside and immersing yourself in the world around you. Of course, it is not always possible to do this and, with so much countryside out there, even those of us who spend a lot of time out of doors cannot experience everything. That is why nature writing, wildlife filmmaking, sound recording and art (in all its forms) can offer us the experiences of the natural world one step removed. In some cases, the countryside and the wildlife it contains are captured in a way that simply relates their true form; in other instances, the picture we see has been interpreted by the writer or artist and they have left an echo of themselves on the object that we ultimately view.

I have a huge amount of respect for those who can deliver views of the natural world that most of us do not have the time, patience or opportunities to witness. As such, I enjoy seeing a painting or photograph that captures an inspiring piece of wildlife action, or reading a piece of prose that adds to my sense of wonderment at the depth of beauty that exists within the natural world. There are photographers whose work captures the interplay between wildlife and the Norfolk landscape so completely that I am deeply moved by what I have seen. One of these is Chris Gomersall, a photographer whose impressive portfolio of work has graced many books and magazines. His photograph of a rook, which appears in Birds Britannica, shows the bird levering a bin bag from a dustbin; the crisp and striking image bubbles over with the mischievous resourcefulness of this bird and serves to illustrate an important piece of behaviour. At the same time, other images captured by Chris show barn owls and pink-footed geese silhouetted against soft-toned Norfolk skies, evoking memories of my own trips to Norfolk’s north coast. Such images blur the line between straight photography and art. They have an integral beauty of their own, derived not from the subject matter but from how it is portrayed. One particular image of Chris’s stands out for me and, perhaps surprisingly, it is not a bird but a simple portrait of a wood blewit mushroom, its rich purple tones set off beautifully by the ochres and browns of the dead leaves that carpet the ground around it. For those interested, Chris Gomersall has an exhibition of his work running at Brancaster Staithe Village Hall from 26th-28th October and I, for one, will be dropping in to share his experiences of Norfolk’s wildlife.

Friday, 19 October 2007

A new sound in the forest

There is a new sound in the half-light of early morning, a deep intonation that carries well across the otherwise silent forest. This is the roar of a red deer stag, one of at least three on my local patch who are taking part in the annual rut – a seasonal proclamation of ownership of a harem of females. Although typically described as a roar this challenge to other stags recalls the deep bellow of a bull. Unlike their upland cousins these sylvan red deer usually utter a single resonant groan, with long intervals in between each roar. It is an unsettling sound in the half-light, an echo of a time when the woods of Britain were truly wild and inhabited by a range of large mammals now extinct.

The seasonal cycle of sexual activity in red deer is primarily driven by changes in photoperiod (the daily pattern of light and darkness) but it can also be influenced by the condition of the stag. Rutting is a draining experience and a stag may lose up to a fifth of his body weight, predominantly because of his greatly reduced intake of food during the rut. Beginning in late September, the rut itself is initiated by the largest and oldest stags who seek out traditional sites. Male red deer tend not to hold harems of females until they reach five or six years of age but they may find it easier to establish a harem in woodland than on the more open uplands of Britain, where red deer densities can be much greater.

As with many other animals, the act of attracting a mate (or mates in this instance) has become a highly ritualised process. During the rut a stag will not only roar but will also thrash the vegetation, wallow and adorn himself with his own urine. In high density populations, individuals of comparable rank and size may end up fighting. After a roaring contest, the closely matched males may walk side by side, each presenting their bulk to his opponent. Then one individual will lower and turn his antlers, interlocking them with those of his rival. A pushing and twisting contest then follows which, not uncommonly, results in serious injury or even death. The prize in all this display and aggression is access to one or more females and the opportunity to secure parentage of the next generation. While woodland red deer tend to have small harems, with seven or eight hinds in attendance, those on the open uplands will typically hold more females. The rut will continue for several weeks, ending sometime in November. Until then, my morning walks will be blessed by this new soundscape, the roaring of stags.

Thursday, 18 October 2007

The winter geese arrive

The first of the winter’s geese have arrived, the end of a journey that has brought them south from breeding grounds in eastern Greenland and Iceland. These are the pink-footed geese, harbingers of the approaching winter, and a welcome addition to the soundscape of bleak November and December days. They are our very own spectacle, vast flocks that fill the early morning sky as they set out from overnight roost sites to feeding grounds scattered along the North Norfolk coast. Changes in hunting pressure and wintering grounds have led to an eight-fold increase in the numbers wintering here since 1950 and there are now some 250,000 using Britain between September and the end of April. This represents over 85% of the total world population, making Britain an incredibly important place for these birds.

Historically, the pink-feet would have wintered on saltmarsh, feeding on the mixed grass and short herb swards, but over the last century there has been an increasing tendency to feed on arable land, particularly on sugar beet, waste potatoes and barley stubble. Such opportunities last through into February, when the fields are ploughed, and then the geese move on to utilise pasture. Their numbers are monitored through the Wetland Bird Survey (WeBS), coordinated by researchers based at the British Trust for Ornithology. Vast flocks can be difficult to count and an expert eye is needed to work out the numbers of birds present.

Other geese species may be seen feeding alongside the pink-feet, including rare visitors from further afield. The breeding grounds used by the pink-feet overlap with those of other species and, on occasion, birds may migrate with the wrong group, ending up many thousands of miles from where they should have spent the winter. This year, for example, a snow goose, which normally breeds from Arctic North America to north-west Greenland and winters south to Mexico, was tracked down the east coast, arriving with the pink-feet in Norfolk at the end of September. This may well be a genuine vagrant but there is also the possibility that the bird belongs to the small feral population that has arisen due to individuals escaping from private collections here in Britain. That genuine snow geese do reach Europe has been demonstrated by bird ringing, with an individual ringed in Manitoba turning up in the Netherlands three years later. Another unusual visitor to Norfolk has been the lesser Canada goose, one of which spent the 2005/06 winter in the company of pink-footed geese at Holkham. This species breeds in northeast Canada and is noticeably smaller than the naturalised British Canada geese. While these vagrants excite twitchers it is the scale of the pink-feet flocks that enthral more casual birdwatchers.

Wednesday, 17 October 2007

Jays on the move

There appears to be a definite shortage of acorns this autumn, something that is not just restricted to the county of Norfolk and which is already having an effect on some of our bird species. Most notable among these is the jay, one of our most resplendent birds and so beautifully described by Mark Cocker and Richard Mabey in Birds Britannica. With its “… electric blue patch on the pied wings and a body colour of warm greyish-pink, set off by bold moustaches, black crown freckles and a striking white rump” this is a stunning, though secretive bird. Such is the beauty of the blue wing feathers that jays were targeted by milliners, the feathers often gracing the hats of well-to-do ladies.

Over recent days I have seen or heard any number of jays, and many of these have been in open country which suggests that they are having to work hard to find the acorns that they favour. The acorn crop would normally form a key part of the diet for many months, with individual jays caching some 5,000 or so acorns in a normal year. The bird will collect three or four acorns in one go, transporting them to favoured locations to be stored in natural cavities or in damp ground. Amazingly, the jay is able to memorize the locations of most of the buried acorns, with those missed contributing to the regeneration and spread of oak woodland. A shortage of acorns in one area will prompt the jays to move elsewhere and this leads to periodic irruptions, with individuals from some northerly populations moving en masse into south-eastern Britain or the near Continent. Although one of the largest movements took place in the autumn of 1964, when 35,000 birds were counted moving over Gdansk in a four-week period, other significant irruptions have taken place more recently. For example, some 173 were noted passing Titchwell in October 1983 and smaller numbers have been noted arriving in off the North Sea since then.

A lack of other tree seeds, most notably beech mast and conifer seed, may well signal the arrival of greater than usual numbers of other bird species, including brambling, chaffinch and siskin. This is likely to lead to busier than usual bird tables and those monitoring garden bird populations are predicting a good winter for garden birdwatchers. No doubt, some of our rural gardens will be visited by jays, arriving early in the morning to feed on peanuts, bread and other scraps. Although not welcomed by everyone – jays are still controlled on many game estates – they are great fun to watch, full of character and brimming with a mischievous intelligence.

Tuesday, 16 October 2007


To me, autumn is the season of decay; much of the luxuriant growth of summer is broken down and utilised by a host of unseen organisms. Included with these are the fungi, hidden for much of the year and only now evident as their fruiting bodies push up through the ground. Perhaps the most well-known of the autumn-fruiting fungi is the fly agaric, it’s red cap – speckled with white – instantly recognisable to even the most casual of observers. This is the toadstool upon which gnomes are pictured, which is featured dancing by Disney and which has a folklore extending back into the antiquity of many cultures.

The fly agaric belongs to a genus of fungi known as the Amanita, which contains not only some of the most beautiful fungi but also some of the most deadly. The Amanita are cosmopolitan in distribution and the 30 or so examples in Britain include species that are also found on the sun-bleached hillsides of North Africa and the Arctic tundra of Alaska. The various species typically form close relationships with trees and all of the British species are thought to be mycorrhizal. This means that instead of occurring loosely in the soil, their underground structures (known as hyphal threads) accumulate around tree roots. Some of the threads penetrate the roots and help the fungus to receive moisture and nutrients from the tree; in return, the tree gains an enhanced ability to compete with other plants for soil nutrients. These relationships are complex and this may be why fly agaric is usually found associated with birch and, to a lesser extent, pine, rather than other tree species.

The name ‘fly agaric’ comes from the formerly widespread practice of using the fungus as an insecticide. The chopped fungus would be sprinkled with sugar or placed in milk, killing the flies that it attracted. The main toxic ingredient in fly agaric is concentrated in the red skin of the cap but with ageing, permeates into the cap itself. The toxin attacks the central nervous system causing lethargy and nausea and, depending upon the dose, a hallucinogenic high. As such, fly agaric was regularly used to induce a state of spiritual exaltation in primitive cultures. Needless to say, messing around with such potentially dangerous toxins is not to be recommended, particularly when this group of fungi contains species that can kill. The aptly named death cap has been responsible for 93% of the European deaths caused by fungus poisoning; just half a cap is sufficient to bring about death. Strangely, several members of the genus are edible after cooking but, given the potential costs of a misidentification, I don’t think I will be trying them.

Monday, 15 October 2007

A nightly gathering

The other afternoon, on my way to give an evening lecture, I made a brief stop at Waitrose in Swaffham. The crisp, clear day was coming to an end, as the sun slowly slipped towards the horizon, dipping behind the cathedral-like spire of the wind turbine that now dominates the local landscape. From all around me I could hear the loud ‘chis ick’ flight calls of pied wagtails, as individual birds moved between the young trees that dotted the car park. Others stood, silhouetted against the sky on the roof of the supermarket, marking the beginnings of a gathering that would, most likely, be repeated each night throughout the coming winter.

Pied wagtails are well known for their communal roosting behaviour, perhaps because such roosts are often formed on or around man-made structures. These small, insect-eating, birds can find winter a difficult time; food is scarce and energy expenditure is high. In the short-days of mid-winter they may spend 90% of the daylight hours feeding, collecting a prey item every four or five seconds. Even this high rate of feeding is only just enough to balance their energy expenditure. In particularly cold winters, many individuals will move further south, deserting southern and central Britain, to winter in France and Spain. Even so, winter mortality can be very high.

It should be no surprise then, that pied wagtails gather to roost communally, seeking out the warmest sites. These include factories, hospitals, commercial glasshouses and trees along major roads or in supermarket car parks. Not only do such roosting sites provide much-needed warmth, they can also act as information centres. Birds that have not fed that well during the day are able to spot individuals that have been more successful; the following morning they will follow these individuals out of the roost and, with luck, have a better day. One final benefit of roosting communally is safety in numbers. While the presence of many small birds at a roost might attract predators, the individual’s chances of being taken by a predator remain lower than they would be if the bird were alone.

Most pied wagtail roosts within Norfolk number just a few tens of birds but roosts in excess of a hundred strong are not uncommon and a small number have been known to hold over 1,000 birds. For example, a roost in Brigg Street, Norwich, was reported to have held 2,213 individuals on the night of 12 January 2001. Pied wagtail roosts lack the frenetic energy of starling roosts and, because of the choice of roosting site, are often more readily viewed. Next time you are out shopping late afternoon keep an eye out for these delightful little birds.