Goldfinch with abnormal plumage

This Goldfinch has been visiting the garden over several weeks. In place of the black heading markings is an area of white, meaning that this bird is suffering from some form of plumage abnormality. The BTO is running an Abnormal Plumage Survey and wants to hear from you if you have seen a bird with unusual plumage, perhaps a Blackbird with some white feathering. You can access the BTO pages on abnormal plumage here.

Networks

In this land of large fields and monster blocks of plantation woodland, it is the rivers that provide the all-important linkage across wider spatial scales. These are lowland rivers, more often than not a steadily flowing meander that shifts its liquid bulk across the broad, barely perceptible valley floor. At various places along their length these rivers are controlled, forced into channels that meet our needs: the neat, concrete-sided river that flows through town; the high banked channel into which the drains feed to keep the low lying land dry.

If you could see a natural river from above over a period of many decades you would see a river that is alive, its course shifting over time as it throws out new meanders, splits into multiple channels and reforms. These shifting courses underline the power of the river, brought about by the volume of water that is carried ever seawards.

My local river forms part of my own natural rhythms. It is my guide as I walk to work; it is my companion when I seek somewhere quiet to pause. In summer it is clear, the green of countless waterweeds gently moving in the current, but come winter it turns dark and brooding. The river annotates the seasons, catching the blossom of spring and the spent leaves of autumn. At times it is tranquil, its surface a flat reflection of bright skies and white clouds. On other occasions it is fierce, the rush of water over the weir gates into the plunge pool below, whose depth you can only guess at.

It is the wildlife that brings the river to life, the other creatures with which I share its watery environs. An egret hunting in one of the shallow feeds that drain into the main river; the electric blue of a Kingfisher as it rushes upstream piping alarm, and the rare glimpse of an Otter as it slips silently into the water in the shade of the far bank. These creatures make use of the river along its length, a pattern repeated on other rivers in other places. It is a corridor that connects many different habitats, providing linkages that would not otherwise exist.

There is a flip-side to this connectivity, however, in that damage done in one place may be felt elsewhere along the river’s length. The plastic bag carelessly discarded here may choke a creature many miles downstream. Sample a river upstream of a town and compare this with what you sample downstream of that same town and you’ll gain true measure of our impact. The river is not about the here and now; it is connected and we must understand that if we are to care for it properly.

Roads take toll on Barn Owls

The surprisingly mild conditions that we have seen this winter are likely to have been beneficial for the county’s Barn Owls. Cold weather, in particular periods with snow cover, high winds and prolonged rain, can all cause major difficulties for Barn Owls which, unable to find favoured small mammal prey, soon succumb to starvation. One of the reasons for this is that Barn Owls carry little in the way of fat reserves, something that limits their global breeding distribution to those parts of the World where the winters are less hostile. The northern limit of the Barn Owl breeding distribution falls, for this reason, in northern Scotland. Even here, the species only just hangs on, restricted to lower altitude sites and the population quickly knocked back by a particularly poor winter.

Another major cause of Barn Owl mortality is collision with traffic on our increasingly busy roads. Roads fragment Barn Owl hunting ranges, leaving the birds no choice but to cross them; flying characteristically low they are often hit by a passing car or lorry. One estimate suggests that as many as one in three of the Barn Owls born each year will end up dead on a road. This statistic was brought home to me the other morning when, driving south into Suffolk I came across the corpse of a freshly dead male Barn Owl. This proved to be a young bird, the talon comb on its foot scarcely developed. It is thought that this comb is used in older birds to maintain the plumage, particularly that on and around the all-important facial disk.

It appears that some young Barn Owls may actually be drawn to roads by the small mammal populations supported within the roadside verges. On quiet country roads, these verges can provide important hunting opportunities, particularly where the wider landscape is dominated by more intensive arable. I have seen birds working these verges at various sites across the north of the county, often with great success, judging by the numbers of Field Voles and Wood Mice taken. However, where these verges sit alongside busier stretches of road, then it is often only a question of time before a bird is killed.

With so much bird-ringing activity directed to increasing our understanding of Norfolk’s Barn Owls it is likely that many of the Barn owls found dead on our roads will be carrying a numbered ring. If you come across a dead Barn Owl, please do stop (if you can do so safely) and check. The number of the ring will almost certainly link the bird to a local breeding site and help researchers to build up a picture of where these birds face the greatest risks from our road network.

Jack Snipe

The presence of a Jack Snipe on the local nature reserve last week, once again highlighted the value of birdwatching a local patch. The finder, a colleague from work, visits the site on a regular basis throughout the year. Every now and then one of these visits turns up something unexpected or unusual, just reward for the amount of effort put in to watching the same site and its visiting birds on many occasions throughout the year.

Although the Jack Snipe is a smart little wader, it is rather secretive in its habits and rarely strays far from damp, well-vegetated cover. If you are fortunate enough to see one from a bird hide then you may well be treated to its furtive, crake-like feeding behaviour. The bird will tend to pick at food items on the surface, probing less often than its more familiar relative, and sometimes bobbing its body up and down like some peculiar clockwork toy. Your more typical view of a Jack Snipe is to see one launch itself from the piece of vegetation next to which you have just placed your foot. Once in the air, the Jack Snipe tends to stay rather low, flying in a straight line (Common Snipe zig-zags and gains height rapidly) before quickly dropping back down into suitable cover.

While the nature of its escape might suggest the Jack Snipe to be somewhat weak when it comes to flight, it is actually a long distance migrant, with some birds from the Siberian breeding population known to winter in sub-Saharan Africa. Others, from the western end of the breeding range, pass through Britain in the autumn, with some overwintering here. Arrivals here tend to begin in mid-September, increasing through October then dropping before the return movement in April.

The migratory nature of the species, coupled with its somewhat secretive habits and choice of feeding habitats, mean that we have a very poor understanding of this species. Of particular concern is the degree of uncertainty surrounding estimates of its population size. If we do not know how many Jack Snipe occur in Europe (or beyond) then how can we reliably determine if their populations are in difficulty, perhaps declining with the loss of favoured habitats to afforestation or land drainage.

While both Woodcock and Common Snipe are familiar birds to me, often seen on my ramblings around the Brecks, the Jack Snipe is a bird that I have seen only on a handful of occasions. I might just make a few more visits to the reserve over the coming week to see if I too can strike it lucky. Even if I don’t, there is always the chance that I might stumble across something else equally fascinating.

Pink-footed Goose will have a tale to tell

It is amazing to see so many Pink-footed Geese out on the marsh. The numbers here today are significantly greater than I have seen on the site before and are more reminiscent of the North Norfolk coast. I am, instead, far inland, walking the marshes that border the River Yare not far from Norwich. Admittedly, the numbers of winter pink-feet on these marshes have increased over recent winters, so the presence of such a large flock should not be that unexpected.

As I have remarked before, the ‘grey’ geese can represent something of an identification challenge for the birdwatcher, testing skills on dull, late-winter afternoons. It doesn’t help that this particular site often holds several different goose species, individuals of which may mix together. This flock of pink-feet is straightforward enough though. With the sun behind me, and the advantage of a flood bank from which to scan, I steadily work my way through the flock, tally counter clicking away in my hand as the numbers steadily increase.

There is one particular individual that catches my attention, however, because it is sporting a silver-grey neck collar on which are written three large letters. This is a bird that has been caught by researchers, either somewhere within Britain or elsewhere in Europe, perhaps even in Iceland. While the use of these neck collars does not do the birds any harm, it is carefully regulated, remaining a tool for those studying the movements of these birds between different sites, or indeed different countries. I know that I will be able to send this record off and, by doing so, add another piece of the jigsaw to help researchers understand which wintering sites are important to which breeding populations. If we are to protect and conserve these geese then we need to know as much as possible about where they go and when.

Britain is a particularly important wintering destination for these geese, with virtually the entire Icelandic breeding population, and most of the east Greenland population, spending the winter here. While many favour coastal saltmarshes, many more now move onto arable land, where they can feed on sugar beet, waste potatoes and barley stubble. The switch to these new food sources highlights the adaptable nature of these geese, something that can also be seen in their wintering strategy. Individual birds have large feeding ranges but still have a favoured core area within this. The geese will move between sites, especially as the winter progresses and they disperse away from the places at which they initially staged upon arrival. This approach means that they can respond to local food availability and, by doing so, presumably increase their chances of getting through the winter in good condition.

A tree of damp places

At this time of the year the riverside alders often hold chattering flocks of siskins and redpolls, noisy affairs that pull your gaze to the outermost branches and to the fidgety silhouettes of these small finches. The tree itself has a ‘twiggy’ silhouette and, with its characteristic female cones, can appear somewhat fuzzy around the edges.

Alders are often encountered in riverine surroundings, either along the river banks themselves or on the damp ground that occurs where fen and carr sit nearby. You might think that this suggests an association with waterlogged ground but this is not the case. Alder is more particular in its habits and favours ‘flushed’ soils, i.e. those where there is a movement of water through the soil. Riverside soils provide these conditions, as do spring-lines and similar features elsewhere.

We have a fair bit of alder on the Nunnery Lakes Reserve in Thetford, where it is sometimes cut as part of the wider management of the site. The timber is white when freshly cut but quickly takes on an orange-red colouration through the process of oxidisation. Interestingly, it made ideal charcoal for the production of gunpowder and this may explain the presence of planted alder woods close to sites where gunpowder used to be produced. The timber has also been used in the framework supporting the banks of canals, in the handles of farm and garden tools and as lure for woodworm. Although found across the whole of Norfolk, alder is more common in the east of the county, where it has traditionally been viewed as the first coloniser of early successional habitats.

Alder is a tree whose shade I enjoy in the summer, when sat by the river, or whose rough bark I scour for insects and spiders throughout the warmer months. During the winter it is the crown of the tree that I watch, scanning for finches that have come to feed on the tiny seeds, held within rather delicate and open-looking cones. I can remember cursing these cones as a child as it was all too easy to leave a fishing line entangled within their grasp. Compared to other trees (think of oak, yew and elm) the alder does not attract that much attention and it remains a largely overlooked part of our countryside. This is a real shame because I think that the alder has a strong character, in part defined by its waterside habits but also by its twisting branches, thick mass of smaller twigs and rich-coloured catkins. The tree did catch the news a few years ago, however, when a Phytophthora fungus was found to have killed roughly one in ten trees over parts of Wales and southern England.

Fenland in all its glory

It is a glorious morning to be out for a walk, the sky a bright expanse of blue tinged with the softest wisps of fine cloud. Such a dramatic sky is enhanced by the dark, peaty flatness of the fenland landscape, the land reduced to a narrow band, linear beneath a great and vibrant canvas. The ultimately circular walk will take me along Burwell Lode, north towards Adventurer’s Fen (with Wicken beyond) before looping back around to follow smaller ditches and fenland drains.

The going is easy, the land flat and the tracks relatively free from mud. My progress, however, is slow, such are the distractions of this vast expanse over which I can scan with my binoculars. The fields that sit neighbourly with the village are farmed but, while they hold partridge, Brown Hare and (surprisingly) a good number of Roe Deer, it is the distant wet fens that draw my gaze. It is these that will hold the hunting Short-eared Owls, wildfowl and waders.

Small parties of winter thrushes, Starlings and finches pass overhead, as do larger groups of Black-headed Gulls and the occasional swan. Even with the unseasonal warmth you can tell it is winter by the light and the calls of the birds that pass overhead. Spaced along the lode are groups of fishermen in their twos and threes, their large ‘Day-Glo’ floats sitting high in the dark water, unmoving. Despite the unseasonal warmth, the water must be cold and I wonder just how active the fish will be. From the reeds that line the far bank comes the harsh scolding chatter of a Wren. Holding a larder of insects, these waterside habitats can prove a lifeline for Wrens and other small birds in winter. Such is their importance that many Wrens will establish and defend feeding territories here for the duration of the winter.

A couple of miles in to the walk and I leave the arable behind, the ground becoming rougher and I sense that this is the place for hunting owls and harriers. Almost immediately, a Short-eared Owl catches my eye. It is quartering the ground, dropping down periodically onto unseen prey, though often unsuccessful in its strike. This is the first of several owls that I see over the course of the morning, the best of which comes within 40 m of me, perching on a post and staring with its intense yellow eyes. I never tire of these birds, such is their charm and character.

This winter, the fen is proving a reliable site for the owls, with up to six birds in the air at a time. Their presence draws birdwatchers, most of whom drive to fen but for me the walk is more rewarding.