Autumn river

The river has become a different beast over recent weeks, the water levels higher than they have been for many months and the greens of summer growth now edged with brown, as water plants retrench ahead of the approaching winter. The riverside path has become slippery with fallen leaves; those from the many limes, paper thin in character, have been transformed into a delicate layer of yellows and translucent greens. Upon this layer are scattered the more robust leaves of willow which, with their silver white undersides, take on the appearance of a shoal of fish, flung up from the river and scattered in death.

The air itself smells damp and heavy with scent. The earthy smells of fruiting fungi rouse the nostrils and hint at decay. Nature is busy, breaking down the growth of summer and secreting it away in a largely unseen cycle of renewal. It seems to have been a good year for fungi and an abundance of fruiting bodies adorn the stumps of trees, cut down in case they fell unplanned at a later time. Not everyone has appreciated the fungi; several of the path-side clumps carry the impression of of a boot or shoe, too big to be that of an overenthusiastic child.

Elsewhere, other, less-obvious, fungi can be seen. Small fruiting bodies emerge from the leaf litter or grow on the litter itself. Others adorn the trunks of trees, a dozen or more feet off the ground and safely out of reach of ignorant boots. While it might feel as if nature is winding down, it is clear that there is plenty going on, even here where the river winds nonchalantly through the town. Shrubs and bushes are still festooned with berries and the trees heavy with seed. Returning blackbirds and migrant thrushes will have had plenty to feed on this autumn, so it is little wonder that garden feeders have been so quiet.

The changing of the clocks, coupled with the shortening hours of daylight, have restricted my riverside walks. While I am forced to take a less pleasant route to and from work, I know that life along the river will continue and that it will still be there, renewed come spring.

Rabbit down, deer up

Contrary to what you might imagine, our understanding of the changing fortunes of Britain’s mammal populations is far from complete. In fact, it turns out that we have very little knowledge of just what has been happening to many familiar mammal species over the last two decades. This lack of information contrasts with what we know about birds, primarily because mammals tend to be more secretive than birds and, therefore, that much more difficult to monitor at the population level. Additionally, many of our mammal species are nocturnal in habits or occupy habitats that make them hard to observe.

The information that we do have tends to come from periodic national surveys, but these are usually expensive to run and so only tend to take place once every few decades. Annual monitoring, which can be key to understanding how and why populations change, is limited to just a handful of species, a number of which are actually monitored by birdwatchers participating in national surveys, like the weekly BTO Garden Birdwatch or the annual BTO/JNCC/RSPB Breeding Bird Survey. These birdwatchers have been kind enough to take on some additional recording of other taxa. Such surveys have underlined the decline in hedgehog populations nationally and, more recently, have flagged up a worrying decline in our rabbit population, which fell by 48% over the period 1995 to 2012. It has also been possible to detect regional declines in some of the more widespread species. For example, the fox population in England fell by 27% over the same period.

Some species have increased in number, with one group – the deer – showing a particularly pronounced increase in their populations. Living in Norfolk, we will all be familiar with the increasing numbers and distribution of muntjac, an introduced species that became established here after escaping from private collections. Nationally, its numbers have increased by a staggering 191% since 1995. Less dramatic, but still significant, increases have been charted for red deer (up 71%), fallow deer (up 89%) and roe deer (up 60%). Such increases have already had an impact on habitats and the other species that use them, underlining the importance of collecting reliable information on a regular basis to support conservation action.

Hawk

There is something quietly powerful about a hunting sparrowhawk. The compact body and short broad wings provide the strength and agility needed by this woodland predator. While it may lack the raw speed seen in the hobby, the sparrowhawk is still an effective hunter, more often than not taking its prey by surprise. Pursuits are usually made at low level, the bird twisting and turning to emerge close to where feeding birds are likely to be gathered. Individual sparrowhawks appear quick to learn the sites where favoured prey gather and birds may target roosting starlings and waders or the finches attracted to garden feeding stations.

Sparrowhawks can often be seen drifting over an area at height, perhaps hoping to pick out feeding opportunities, but at other times they show their adaptability by hunting on foot, something which may surprise observers fortunate enough to witness such behaviour. I once witnessed a sparrowhawk working the base of a hedgerow in such a manner but I couldn’t work out what it was after. It may have been a mouse or vole, or perhaps a wren or dunnock, that it was attempting to flush from cover. I have also received a few reports over the years from observers who have witnessed hunting sparrowhawks attempting to flush small birds from the thick bushes in which they have sought shelter. The hawk may fly at the bush, attempt to push its way inside or circle the bush to seek a better angle of attack. Persistence doesn’t always pay off, however, and it seems that the smaller birds often trust the security provided by thick cover and simply sit tight until the sparrowhawk gets bored and leaves to pursue feeding opportunities elsewhere.

As with many other predators, sparrowhawks may spend time loafing, perhaps dozing on a favoured perch or sitting quietly in the sun. When they do, it provides an opportunity to take in the structure and plumage of these birds, to pick out the piercing eye, the surprisingly long legs and the curving talons that so often deliver the coup-de-grace to an unfortunate victim. Hawks are part of the natural system and, while a kill can be hard to witness, these remain one of our most of striking birds.

The small white heron

Walking my regular riverside route to work the other morning, I fell into conversation with a lady who sometimes brought her dogs down to the river. Our conversation flowed through half-a-dozen or more different natural history subjects before turning to the ‘small white heron’ that she had seen here on occasion over recent weeks. Believing it to be a young grey heron because of its size, my companion commented that she hadn’t realised that young herons were white. My response of ‘they’re not; it’s a little egret that you’ve been seeing’ surprised her and underlined how often we make assumptions about what we see based on previous experience. This lady had not heard of little egrets and assumed that any heron-like bird would be a grey heron; after all, that was the one found in all but the most recently published books on Britain’s birds.

To some extent this underlines just how rapidly the little egret has colonised the country. Little egrets were once rare vagrants to Britain, with most arriving in the spring as birds that had overshot their Continental breeding grounds during migration. Then, in 1989, there was an unprecedented influx, followed over subsequent years by records of pairs breeding alongside grey herons at heronries dotted along the south coast. The population quickly expanded – both in size and distribution – with increasing numbers of little egrets seen in Norfolk and the establishment of regular roost sites at Holkham and Titchwell. The first Norfolk breeding attempts took place in summer 2002 and by 2007 (the time of the Norfolk Bird Atlas) in excess of 100 breeding pairs were breeding within the county.

Much of the little egret expansion was focussed on the coast and it has only been over the last couple of years that we have seen increasing numbers of birds well inland. The sight of one on the local river, typically during winter, used to signal a red-letter day but now you almost expect to see one, particularly as more birds now gather on Thetford’s Nunnery Lakes Reserve. Now that my companion knows about the little egret I suspect that more of those who walk the river will come to appreciate this small white heron.

A season of mellow fruitfulness

The low autumn sun still retains brightness enough to brush the tops of the birches with brilliant light, splitting the trees into two horizontal bands; the upper band of vivid gold and yellow positively burns against the dull brown of shadow below and the rich Payne’s grey of sky above. The rain has been through, a passing shower moving at speed and leaving behind it a fresh fall of leaves to float on shallow puddles or stick to the glistening path. It is a beautiful scene, truly autumnal in nature and reminiscent of the paintings that filled my Ladybird book of Autumn as a child.

Much of the autumn landscape has changed since those paintings provided my first views of the wider landscape. I suspect that were I to view them again now they would present themselves as nostalgia, glimpses of an England now lost. Gone are the teams of horses and the burning stubbles; gone too are the vast flocks of finches and buntings that would have taken the grain that the harvester was unable to collect. Something of that landscape remains however: the autumn harvest still continues, the hedgerows still hang heavy with berries – particularly so this year – and the dark, clouded skies still bring with them autumnal storms.

The autumn landscape is often beautiful, the light more subtle than the harsh glare of summer and the air carrying with it ripe scents that tease the senses. There is a real feeling of change at this time of the year and of industry, evidence that the rural landscape is alive and lived in. Tractors ferry crops from the fields, lorries heavy with beet trundle to the towering sugar beet factories and tables at the local farmers’ market are weighed down with local produce.

Arriving thrushes and finches suggest a transition. These are winter visitors, arriving from Scandinavia and beyond to tuck into autumn’s bounty and delight birdwatchers. As the days shorten, so the richness of autumn will slip away, the landscape shedding its autumnal tones to reveal those of winter. It is a time of year to be out and about, making the most of the last warming rays and the harvest that underlines autumn’s bounty.

Four birds in a bush

There is little cover within these dunes but that which is present affords shelter to newly arrived birds, some of which will be exhausted after the long sea crossing that has delivered them to our shores. I am sitting quietly on a shallow, spreading incline at the base of a large dune. Just a few feet away is a rather scrappy bush, small in size and somewhat ‘gappy’ in nature. Four small birds can be seen and heard, fluttering about within the foliage to take tiny, half-hidden insects and spiders.

It was the ‘hueeting’ call of a chiffchaff that had attracted me to this particular bush. More far carrying than the rather plaintive, needy-sounding, contact calls of the Goldcrests also present, it was this call that caught my ear as I dropped down over the dunes into this quieter backwater, away from the shushing sea and ever present on-shore breeze.

All four birds seemed undisturbed by my quiet approach and within a few minutes all were again feeding from my side of the bush. Telescope stowed away, the tripod now held my camera and the soft click of the shutter dutifully logged a record of the moment and these delightful little birds. The bush and these birds became my focus; the great dunes with all their autumn arrivals, birdwatchers included, narrowed down to this single point. It is hard to say now how much time elapsed but there must have been rich feeding opportunities for the birds, as not one was tempted to move to other bushes just yards away.

Sometimes the birds were two-dimensional, silhouetted through the bush against the dunes behind, dunes brushed with the gold of a late afternoon sun. In other moments they searched for food on the outer branches, emerging in front of me and close enough to touch. Periodically one would fix me with its gaze, intense eyes like tiny beads of shiny jet that had been washed and polished by the action of sea and sand. Eventually one bird flitted across the gap to the neighbouring bush, its contact calls more intense and prompting the other two crests to follow. I took a lead from the crests and rather stiffly regained my feet to continue my walk.