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.

Look out for abnormal birds

Every now and then I come across a bird sporting some white feathers. Perhaps it is because these white feathers stand out most on a bird that is otherwise black, that the species involved is often a Blackbird, Jackdaw or Carrion Crow. Such plumage abnormalities are, however, likely to be more widespread than this and this is why the BTO is carrying out a study to examine the incidence of abnormal plumage across a range of species.

The presence of one or more white feathers often results from some non-heritable cause, such as disease, food deficiency or trauma. In other cases, the cause may be under genetic control. Perhaps the best-known of these is albinism or partial albinism. However, the definition of what constitutes an albino or partial albino is rather precise and most of the cases involving aberrant white feathering in birds are usually either a form of leucism or result from some non-heritable cause.

White feathers can occur where the normal colour pigments (e.g. melanin) are missing. The resulting feathers are often weaker because of this and, therefore, more prone to wear and damage.

In some instances, the process works the other way and too much melanin is produced, resulting in feathers that are far darker than usual. There is, for example, a population of Great Tits in southeast England that have completely black heads, the white cheek feathers turned black by abnormal levels of pigment.

Other aberrations can produce feathers that appear washed out or, alternatively, more strongly coloured with a particular pigment. In some cases these may result from diet; I can recall a case from a few years ago where House Sparrows that had been feeding on fish pellets at a Salmon farm in Scotland had feathers that were a muddy shade of pink! The pellets contained a natural pink dye, used to give the Salmon a stronger colour, favoured by customers.

One of the main problems with understanding the different abnormalities is that the naming of aberrations is based on the relevant gene action on the pigmentation process and not on the appearance of the final plumage colour. As observers, we see the final result not the process that brings it about, making it difficult to interpret which abnormalities occur in the wild. The BTO survey will provide some useful background figures but it will require detailed work to more fully understand the processes operating on individual birds. If you have seen a bird with abnormal plumage then the BTO would like to hear from you. You can either complete the survey online (www.bto.org/gbw) or request a paper recording form from, BTO Plumage Survey, The Nunnery, Thetford, Norfolk, IP24 2PU. Alternatively, email gbw@bto.org.

From the bottom to the top

You may well recall that I’ve been involved in something of a challenge this year. Along with colleagues at the BTO in Thetford, I have been attempting to record as many different species as possible on the Nunnery Lakes Reserve in Thetford. This is part of a challenge with RSPB and their reserve at Sandy in Bedfordshire. While light-hearted, though in some quarters rather competitive, the challenge has the underlying aim of identifying the species we have on our respective reserves, particularly beyond the large and more obvious groups like birds, butterflies and mammals. An inventory of what we have on the site is the starting point for targeted conservation measures.

Last week, we turned our attention to the offices themselves, seeking out the creatures with which we share our daily lives. The BTO offices are centred around an old nunnery and chapel; with such a long history we hoped that they might support some particularly interesting species. We have a small population of Wall Bedstraw, for example, a rare plant nationally that is found on very old walls. Our population is centred on the 12^th Century ruin in the grounds that was once used to accommodate visitors and treat the sick. It is not an impressive plant, unless you happen to like your plants small, unobtrusive and best viewed from a ladder!

Perhaps unsurprisingly, the offices themselves have not turned up a great deal in the way of species new to our growing list. Last week, however, we decided to investigate some of the more tucked away parts of the building, the first of which was the cellar. I have always had something of a romantic notion of what our cellar would be like: a bit damp, rather dark and hosting some interesting spiders, woodlice and slugs. To say I was disappointed would be something of an understatement. The cellar was very dry, shockingly clean and there seemed little chance of finding anything of interest. The one creature that seemed to be doing well down here was the Daddy-Longlegs Spider Pholcus, several individuals of which hung from loose, fragile looking webs. Quite what they were living off was difficult to comprehend. Thankfully, they were not the only spider present and Iain, our spider expert, soon had several specimens to take away and identify with the aid of a microscope.

We then turned our attention to one of the attics, where there were more signs of invertebrate life. The attic was clearly the hibernaculum of choice for the dozens of lacewings that were perched on most surfaces and the presence of several large wasp nests hinted at several summers’ activity.  It was good to see so much life making home alongside us.

Bullfinch

It is one of the coldest mornings of the year and I am glad to be on the move, working my way around the local lanes and tracks for Bird Atlas 2007-11. I have written of this national stock-take of Britain’s (and Ireland’s) birds before, a periodic mapping of their distribution and numbers. It is the last leg of the Atlas, with two winter visits over the coming three months and then two summer visits next year, and I find myself in an area of open farmland and small woodlots up near Shipdham. This is a place that I have not visited before.

As my two-hour mapping exercise continues so I come to realise just what an excellent piece of Norfolk countryside this is. A large flock of Yellowhammers and Skylarks is feeding on some stubble, a rare sight these days, and Lapwings lift from a piece of damp pasture upon my approach. It is the hedgerows that surprise me most of all. Although they have been cut back hard, they rise to a decent height and hold a larder of berries and fruits, attracting in Fieldfares, Blackbirds (by the dozen) and various finches. They also carry last year’s nests, including a surprising number of Chaffinch and Goldfinch nests, neatly constructed in the forks of the taller shrubs, alongside those of Wren, Blackbird and Wood Pigeon.

A soft whistling note alerts me to the presence of a Bullfinch, old billy black cap, and then I spot him just ahead of me above the bramble. He is not alone; two other Bullfinches slip from the hedgerow, their striking white rumps evident as they fly. The Bullfinch is a wonderfully engaging bird, with its little black cap, pinky-red breast (in the male) and stubby little beak. I used to watch them as a child, feeding on the seed heads of dandelion and sorrel with delicate precision. They are birds of scrubby woodlots and thick hedgerows, often overlooked despite their colourful attire. Both the song and the call are subtle and easily missed.

Our Bullfinches are largely sedentary in habits but they will make small local movements out from favoured woodland sites to search for seeds in nearby farmland. These movements are more pronounced in those years when Ash seeds, their staple food, are in short supply. Interestingly, the larger Scandinavian birds can make substantial movements in some years. This is such a year and several have been reported around the Norfolk coast. Bullfinch numbers have declined since the 1960s, most notably within farmland, and they are one of the birds that is often missed when doing Atlas fieldwork. To stumble across this trio of billy black caps has made my morning.

Changing waterfowl require greater understanding

The latest review of waterbird populations in the UK makes interesting reading. At first glance it suggests contrasting fortunes for many of the species with which we share these islands. The review, jointly published by the BTO, RSPB and JNCC, stems from the efforts of some 3,000 volunteer counters. These volunteers participate in the synchronised monthly counts that take place across our many inland and coastal waterbodies.

While some species reached new ‘highs’ in terms of their population levels, others reached all-time lows. An examination of the ‘winners’ and ‘losers’ reveals that many of the ‘winners’ are introduced species whose naturalised populations continue to expand. These include Egyptian Goose, Mandarin Duck and Barnacle Goose. However, in with these are genuine colonists like Little Egret, a species expanding north on the back of global climate change.

The numbers of some species reflect breeding conditions elsewhere, the UK being a wintering ground with little or no breeding population of its own. A poor breeding season elsewhere may see fewer birds available to make the journey to our shores. The recent downtown in wintering numbers of Bewick’s Swans was once thought to be linked to a contraction eastwards in the wider European wintering range. However, recent research has revealed a decline in the overall population rather than just a shift in distribution. In contrast, our population of wintering Whooper Swans has continued to increase, with most of our visiting Whoopers arriving from Icelandic breeding grounds. The nature of the survey also enables the volunteer counters to gather information on breeding success for some species. In the case of the Whooper Swan, cygnets accounted for 16.8% of the birds present, slightly up on the previous winter.

The estuaries around Britain & Ireland are important wintering sites for many wading birds and these are also surveyed by the volunteers. Again fortunes appear mixed, with some notable increases seen in Avocet (a real conservation success story), Grey Plover and Sanderling. Balanced against this is the apparent news that Ringed Plover and Dunlin have both hit all time lows. Britain has eight sites of international importance for Ringed Plover but, while the decline might seem worrying, news of increasing numbers at sites elsewhere in Europe (notably The Netherlands) suggests that what we are actually seeing is an eastward shift in the core wintering range, perhaps linked to a run of mild winters.

Taken as a whole, this report highlights the need to monitor the changing fortunes of these birds at a much wider spatial scale, since a decline here may not mean that the population is falling, merely that it is now wintering elsewhere. Fortunately, our knowledge of waterbirds is increasing, placing our understanding into a wider context.

Nesting neighbours

It has been something of a slow start to the year and you may well have noticed how behind some of the spring flowers have been. The same is true for birds, with fewer early nesting attempts reported than is usually the case by this time of the year. Following a mild winter I might expect to have heard about 16 or 17 different species with active nests by Valentine’s Day; this year, however, there were just nine and even now things have not really picked up a great deal. Although early nesting attempts often fail, the birds caught out by a return to colder conditions, there are some species that always nest a bit earlier in the year than others. Tawny Owl (recently fledged Tawny Owls are on the wing in Kensington Gardens, London) and Mistle Thrush (a brood of young Mistle Thrushes is being fed in Manchester United Old Trafford stadium) are two for which nesting typically begins early.

For certain other species there are just a few early nesting attempts; these often take place in towns and cities, where it is warmer and where there is food available to help get parents into breeding condition. Interestingly, the urban habitat and in particular the gardens within it, are the one place where we lack a thorough understanding of the size of breeding bird populations. It makes sense really, in that people carrying out surveys of nesting birds can’t very well go and peer into privately owned gardens! This lack of knowledge has prompted the BTO (British Trust for Ornithology) to launch a new survey under the banner of Nesting Neighbours and they are looking for householders to keep an eye out for nesting birds.

Of course, finding nesting birds is not always easy. If you have a pair of Blue Tits using your nest box or a family of heavy-booted Starlings in your roofspace then you are likely to know about it. However, you try finding the Greenfinch nesting in one of your conifers or the Dunnock tucked away in a quiet corner. These are just the sorts of nests that the BTO wants to hear about and to help you with your efforts they have produced a wallchart, detailing the different types of nests and eggs and explaining where and when particular species nest. I, for one, will be out there, poking through the Ivy that adorns the end wall and searching through the climbing rose. You can get your free wallchart and survey pack by calling the BTO on 01842-750050 or by emailing nestingneighbours@bto.org. Make a difference to their work by finding out which birds are your nesting neighbours this breeding season.

A bird in the bush

I’ve been out nesting a few times over recent weeks, squeezing in visits on those days when the sun has shone and the wind has stilled. This is not the sort of nesting to be confused with that of uncaring individuals who, with criminal intent, seek out nesting birds to steal their eggs, robbing the potential of a future generation for the sake of a collection arranged like stamps. Instead it is the collation of information invaluable to nature conservation and part of a national scheme.

My trips out have been in the company of nest recorders participating in the British Trust for Ornithology’s Nest Record Scheme. Experts in finding nests (though always learning, so they say), my guides have shown me how to find the carefully hidden nests of warblers, finches and thrushes. It has been a tremendous privilege and I feel that I am developing a skill that I will be able to put to good use in future years, sending in my own contributions to the scheme.

Nest finding involves a range of different approaches, a combination of skills that come together to reveal a hidden nest. One of the most often deployed of these skills is cold searching an area in which the species of interest has set up its territory. This involves a careful and steady search of each bramble bush or nettle bed, looking for the nest, while at the same time minimising the amount of disturbance. Ideally the nest will be found at an early stage, while the birds are still building. Its position can then be noted and a return visit planned for when the birds have started laying their eggs. Several more visits follow, carefully spaced to provide the maximum amount of information with the minimum of intrusion. Each visit contributes to a bigger picture, providing information on how many eggs were laid, how many of these hatched and how many chicks survived through to fledging. Visits can also reveal if a nest has been predated, at what stage and, sometimes, by what sort of predator.

Collectively, the information from many hundreds of nest recorders, delivers a powerful overview of how a species is faring, addressing the question of whether or not it has had a good breeding season and, importantly, alerting Government and the conservation agencies to any sudden declines in breeding success that might signal a wider problem. Nest recording is one of those skills that is being lost, the generation of practitioners an ageing one and with few youngsters coming in to replace those lost to old age. Efforts are being made to engage with a new generation of nest recorders and I hope to be one of them.

In awe of snakes

The other week I visited the garden of Dave Shearing to take part in some filming we were doing to promote a new survey of garden reptiles and amphibians. The garden was a wildlife haven, a formal area stocked with bird feeders and then a gate through into open woodland complete with nestboxes, wildlife pond and corrugated tin plates. The tin provided shelter for Grass Snakes and Slow-worms, both of which proved to be present in the garden in good numbers.

With a careful approach and lifting of the tin it was possible to take a close look at these two less commonly encountered creatures. While some of the snakes made a swift retreat into one of the many woodpiles that dotted the garden, others remained and seemed just as inquisitive about us as we were of them. By being able to watch the snakes in this way I was really impressed by the range of adaptations they displayed.

Snakes are not unique amongst the reptiles in being limbless but this feature does form the cornerstone of their anatomy. The long thin body places constraints on its internal structure and many of the internal organs are highly modified (or absent - most snakes have just a single functional lung). Many organs are elongated and paired organs are often arranged one behind the other, rather than side-by-side; the left kidney, for example, sits behind the right. Each of the vertebrae (and there are usually between 160 and 400 of these) has a pair of ribs attached to it. The ribs themselves articulate and can be swung forward, allowing the snake to flatten out its body to soak up more of the sun’s warmth (I often see Adders doing this) or to allow the passage of a large prey item down the digestive tract. The skull is also adapted to aid the passage of large prey, the two lower jaws not joined at the chin and allowing them to move independently of one another as well as pull apart. This is why even some of the smaller individuals we watched could have tackled an adult frog.

The survey of garden reptiles and amphibians is being organised by the British Trust for Ornithology, Froglife and the Herpetological Conservation Trust. The researchers want to find out which factors influence whether or not particular species of reptile and amphibian will use a garden. As such, they want to hear from anybody who has a garden, regardless of whether or not it contains any reptiles or amphibians. A free survey pack and identification chart can be requested by calling the BTO, by emailing gbw@bto.org or by writing to Reptile Survey, BTO, The Nunnery, Thetford, Norfolk, IP24 2PU.

Has the cold weather hit our Wrens?

There is a chill to these bright mornings, the clear skies overnight allowing the mercury to dip below zero and delivering a brushstroke of silver frost to the short heathland turf. Even so, such bright mornings bring with them the hope of spring, lifting my spirits, and it feels good to be out at such an hour. The change of season appears to be having a similar effect on many of the woodland creatures, including the birds, and the ranks of conifers echo with bird song. The Robins have been singing right through the bleak days of winter but now their wistful song has a more strident tone. Blackbirds too, are delivering a purposeful chorus and many pairs will have already started to build nests or lay eggs.

There are other singers; the thrice-repeated call of the Song Thrush strongly sung, the ‘teacher-teacher’ of the Great Tit and, here and there, the less often heard songs of Siskin and Crossbill. What is missing, however, is one particular component of this early season orchestra – that delivered by one of our smallest songsters. In recent years, this part of the forest has been alive with the metallic ringing trills of the Wren. This species has fared well over recent years because of a run of mild winters and I fear that this year’s cold snap may have hit the Wren hard.

The Wren is one of our most numerous breeding birds but its numbers can fluctuate quite dramatically from one year to the next if the winter weather goes against it. The severe winter of 1962/63, for instance, resulted in an 80% decline in the breeding population nationally the following year. Another study, carried out in a Nottinghamshire woodland, saw virtually the entire adult breeding population lost after the very cold winter of 1985/86. In both cases, it took several years for the breeding population to recover to former levels.

While the most recent winter may not have been as severe or long-lasting as these, it might have been sufficient to reduce the number of Wren territories locally. One other characteristic impact of a cold winter on the Wren population is a noticeable change in habitat preferences. In the year that follows a cold winter, breeding Wrens are often absent from formerly favoured hedgerow and garden habitats. Those territories that remain occupied tend to be in woodland or alongside riparian habitats, suggesting that woodland is a high quality habitat, while hedgerows and gardens are less suitable and the last to be filled with breeding birds. We will have to see what long-term monitoring programmes, such as the BTO’s Breeding Bird Survey, reveal later in the year. Have our Wrens been hit by the cold?

Can you help House Martins?

The house martin is a familiar summer visitor, more suburban in habits than its country cousin the swallow. Although it once commonly nested on cliff faces, including the chalk cliffs at Hunstanton (where it last bred in 1967), the species has adapted to the opportunities provided by modern housing, choosing to place its characteristic nests under the eaves. However, it appears that the house martin is in trouble, a large-scale decline in abundance prompting researchers to place the species on the amber list of birds of conservation concern. House martin populations at the local level, for example colonies on a particular house or bridge, are known to fluctuate over time and this makes it difficult to untangle any underlying change in abundance that may be masked by such short-term fluctuations. It is clear, however, that even within Norfolk the characteristic large colonies at favoured sites have been lost. Saddlebow Bridge at King’s Lynn used to have a colony numbering 150 active nests but no longer. Nationally, the highest densities tend to occur in villages and small towns across East Anglia, so we should be concerned about the changes seen in Norfolk.

In an attempt to increase our understanding of how house martins are doing, and to add more records to Bird Atlas 2007-11, the British Trust for Ornithology (BTO) has teamed up with BBC Radio 4, to launch a house martin survey. Through the survey, researchers hope to establish where colonies of breeding house martins are to be found and to assess the size and success of individual colonies. If you have a colony nesting on your house, or are aware of one nearby, then visit the British Trust for Ornithology website (www.bto.org) to access the survey.

Despite its familiarity there is still a great deal that we do not know about the house martin. While we know that they tend to arrive here from the middle of May and depart again from September or October we know very little about exactly where they spend the winter. We know that they winter in Africa, south of the Sahara, and some 90 million house martins from Europe cross the Sahara each autumn. However, they are very rarely seen in Africa during the winter months. Unlike swallows and sand martins, they do not gather together in huge winter roosts in reedbeds or other accessible sites and it has been suggested that they actually winter above the thick jungles of central Africa. This, at least, might explain the paucity of sightings and recoveries of ringed birds. We also need to know more about the reasons for the decline seen across Europe. With luck, the new BBC/BTO project will shed some light on this particular mystery.

A walk with a purpose

My early morning walks through the forest have taken on a new purpose. In addition to exercising my dogs (and indeed myself) I am now helping to chart the distribution and status of our birds. Along with many thousands of other birdwatchers I am participating in Bird Atlas 2007-11, a mammoth undertaking to map breeding and wintering bird populations within Britain and Ireland. The last time that this was done was nearly 20 years ago and much has changed since then. Buzzards have expanded their range to the east and are now breeding in Norfolk, making them a far more familiar sight in our skies than they were just a decade ago. Other species are known to be in decline and it is likely that we will see a contraction in the range that they occupy within the county, or a thinning in their numbers.

The project is being coordinated by the British Trust for Ornithology (BTO) and has two different components. First, a series of survey squares have been selected across the country and these will receive intensive survey visits from volunteer birdwatchers, twice in the winter and twice in the summer. I have taken on two of these squares, one where I walk my dogs and the other out near East Harling. Information from timed visits to these survey squares will be collated and then used to determine the abundance of different species across the country. We might find, for example, that Norfolk’s corn buntings are now concentrated in the fens or that our green woodpeckers are most abundant on the sandy soils of the brecks.

The second component has been termed ‘roving records’ and involves collecting simple records of birds from anywhere in the country. The song thrush or bullfinch that you see in your garden could prove to be an important record and can be submitted on a simple roving record form (available from Bird Atlas 2007-11, BTO, The Nunnery, Thetford, IP24 2PU). A record in winter of a fieldfare or a redwing will help the BTO to map winter distribution, while a summer record of a nesting long-tailed tit will reveal the breeding range. These roving records should be particularly useful for supplementing information from the more intensive, but time-restricted, counts made in the selected survey squares. Taken together they will supply the information needed by those addressing the conservation needs of our birds, providing an audit of bird populations and highlighting those species in need of additional conservation resources. So if, like me, you get out into the countryside (or a town or just watch the birds in your garden), why not get involved and make your contribution to Bird Atlas 2007-11.

Birds count cost of awful summer

It has been a poor summer for many of our breeding birds. The appalling weather that dominated from May through into July caused problems for nesting bitterns and lapwings, both caught out by rising water levels, and made life very difficult for nesting tits. It had all started so well, with the fine weather in April favouring early nesting species, like the long-tailed tits which had a bumper season. However, those birds nesting later in the year were caught out.

Species like blue tit and great tit time their nesting attempts to coincide with the annual peak in the abundance of caterpillars. They need to do this because each chick (and there may be up to 12 in a nest) requires something like 100 caterpillars per day. The arrival of heavy rain literally washed many caterpillars off the leaves, making food more difficult to locate for busy parents. Short on food, the growing chicks were also hampered by the fact that their parents were returning to the box wet. With far fewer body feathers than their parents, chicks quickly became damp and chilled and many a brood was reported dead in the nest.

Information from those with nest boxes in their garden made it apparent fairly early on that it was not going to be a good breeding season. These anecdotal reports have now been supported by the recently published results of systematic monitoring work carried out by the British Trust for Ornithology (BTO). Through the Constant Effort Scheme (CES), bird ringers working for the BTO collect vital information on movements, survival rates and productivity. Every summer, teams of CES ringers catch birds by using a system of special nets, with each net used in the same place and for the same length of time from one year to the next. This enables the researchers to look at the numbers of adult and juvenile birds that have been caught and, from this, establish a measure of breeding success. The 2007 breeding season has proved to be the worst on record for a number of species: blue tit productivity was down by half, that for great tit was down by a third and two migrant species (reed warbler and whitethroat) were down by a quarter. While a good breeding season next year may enable some birds to bounce back quite quickly, for others the poor summer is yet another thing that has gone against them. Some of the migrant species, like whitethroat, are facing problems on their wintering grounds in Africa and a poor breeding season here only serves to exacerbate their plight. We need to keep our fingers’ crossed for a better breeding season in 2008. 

Take on the challenge

The British Trust for Ornithology (BTO) and the BBC have just launched a major new project, seeking to follow the fortunes of our nesting birds. Called “The Nestbox Challenge” the scheme forms the centrepiece of this year’s National Nestbox Week (an annual event initiated by the BTO and Jacobi Jayne). Tradition has it that songbirds pair up on February 14^th and National Nestbox Week, running from 11^th-17^th February, provides the focus for a host of nestbox-related events up and down the country. Many of these events are being coordinated by BBC local radio or television and are geared towards children, often providing the opportunity to build your own nestbox.

The Nestbox Challenge itself is what the Americans would call a “Citizen Science” project, where you (the “citizens”) collect information that can make a valuable addition to our scientific understanding. The Challenge is an online survey (visit www.bto.org to access the survey), so you will need a computer and access to the Internet. In addition you will need a nestbox – either one that is already in your garden or a new one that you have just put up. I have already visited the website to register the robin nestbox in our garden and found the whole process very straightforward. Asked to enter some basic details about my garden, such as where it is, how big it is and what sort of plants it contains, I could then log details about my robin box. Once I had entered this information, I could then view its location by using a built-in satellite view of the earth. Now all I need to do is keep an eye on the box, watch to see if nesting birds are using it and then log the details of how the nest is progressing. Guidance is given on how to monitor the nestboxes without disturbing the nesting birds and what information is needed by the researchers.

It is hoped that results from the Challenge will enable researchers based at the BTO to examine the nesting patterns of familiar species like blue tit, blackbird, robin and spotted flycatcher, and to find out how nesting success may be influenced by location, garden type, the presence of predators (like cats) and weather. Understanding such interactions is important if we are to determine the effects of a changing environment (and climate) on our wildlife. The project also serves to engage people with wildlife, providing you with an opportunity to discover new things. Being part of an army of citizen scientists also means that you are making a valuable contribution to conservation science within Britain. So go on, put up a nestbox (or register one already in place) and take the Nestbox Challenge. 

Become a plover lover

Mixed flocks of lapwing and golden plover will be a familiar sight to those who venture into the Norfolk countryside at this time of the year. On dull autumn days, the hunched silhouettes of these medium-sized wading birds can be seen on freshly ploughed fields or areas cleared of sugar beet. Both species make less extensive use of mudflats than other wading birds and, as such, they can turn up almost anywhere across our largely agricultural county. While some of the lapwing will be birds that have bred locally during the summer, perhaps at Holkham or within the Brecks, most will be drawn from breeding populations elsewhere, including Fennoscandia and the Low Countries. All of the golden plover will be winter visitors – the species does not breed in Norfolk – drawn from upland areas spread across northern Europe.

Because the wintering populations of these two species make use of inland agricultural habitats they are not well-monitored through existing monitoring schemes, such as the Wetland Bird Survey (WeBS); paradoxically, though, Breydon Water supports an internationally important population of lapwing. The use of inland habitats means that the size of their wintering populations has to be determined through a special wintering plover survey. This is organised by the British Trust for Ornithology (BTO) and, with concerns of a potential population decline and a suggested shift in wintering range, the latest survey is taking place this winter. Most of our wintering lapwing arrive between late September and the end of November, with peak numbers of golden plover noted in November. Later into the winter, birds may become more mobile as freezing temperatures force them to move south or west to find areas free from frost, where they can feed. Both species prefer to feed on areas of permanent pasture, rich in earthworms, a habitat that is scarce within Norfolk. Instead they make use of winter cereals, oil seed rape and sugar beet stubbles, feeding at night on beetles and earthworms.

Sizeable mixed flocks can literally ‘carpet’ fields but smaller flocks, of 50 or so birds, often go unnoticed. If you are out and about in the countryside this month, make an effort to scan the fields for these two plovers or offer to take on one of the BTO’s survey squares. While the bulk of the survey work will be carried out by BTO volunteers, visiting the randomly selected survey squares, information is also needed from other areas. Records of lapwings or golden plovers seen anywhere within the county are especially welcome and can be submitted on a casual records form. Copies of the form can be obtained by downloading it from www.bto.org/goto/winter-plovers or by phoning the BTO on 01842-750050.

Audit of our bird populations

Last weekend saw the launch of “The State of the UK’s Birds 2005”; a now regular publication charting the changing fortunes of our bird populations. Published by the British Trust for Ornithology, RSPB and the Wildfowl and Wetlands Trust, in association with the four Country Agencies, the report provides a very valuable measure of how our birds are fairing. Knowing that a species is in decline can help to trigger appropriate research and plan effective conservation action. Similarly, evidence that a species has begun to recover from a previous decline is a valuable yardstick by which the success of conservation work can be measured.

The information presented in the most recent report comes from a wide range of surveys, some covering multiple species, others targeted at single species or particular sites. While figures for individual species provide the best level of detail for conservation efforts, they can also be used collectively to stimulate appropriate policies for Government. One way in which such an approach has been adopted is through the use of indicators, such as the “farmland bird indicator” which summarises what has been happening to farmland birds as a whole. This particular indicator demonstrates that, as a group, farmland birds underwent a period of sustained decline during the 1970s and 1980s, from which they have yet to recover. Government sees indicators as a useful tool for communicating the state of the natural environment and for measuring the success of Government policy. However, some researchers feel that they are of limited value, not least because they may hide all-important differences between individual species. Nevertheless, thanks to work carried out at the British Trust for Ornithology, the UK has led the way in developing these useful tools, demonstrating the role they can play in conservation.

One underlying message within the report was the essential role that volunteers play in collecting the information upon which much of our understanding is based. The report presents long-term information for many widespread species, monitored by volunteers who give up time each year to go out into the field and collect information in a standardised manner. Without these volunteers, we simply would not have the information that is needed. A similar message emerged from the recent run of programmes on BBC Radio 4 looking at “citizen science”. This American term is used to describe the way in which ordinary “citizens” participate as volunteers in projects organised by scientists to collect information at a scale that could not be achieved with paid professionals. If you are out in the countryside, collecting information on plants, bugs, birds or bees, then you are doing your bit of citizen science and helping the nation’s conservationists and researchers.

Birdwatchers highlight partridge decline

Norfolk is partridge country, the one English county where the grey partridge retains something of a stronghold. Yet, even here, it is under threat and populations have continued to decline. New figures, just published for the Breeding Bird Survey, highlight a 40% decline since 1994 and an 87% decline since 1978. The species is now found on just 9% of the 2,879 sites covered as part of the survey, fewer than for red-legged partridge or pheasant.

The causes of the decline are well known, thanks to the vast amount of research carried out, making this one of the best studied of English birds. The grey partridge favours lowland farmland, using areas of mixed arable and grass leys, with uncultivated margins and hedgerows. Although the hens produce more eggs than any other British bird, typically 12-18, productivity has declined massively since the 1950s because of increasing pesticide use and decreasing amounts of predator control. In particular, the use of herbicides has reduced the availability of those invertebrates taken by partridge chicks after leaving the nest. By understanding what has driven the population decline it has been possible to develop prescriptions to manage farmland in a manner which favours the grey partridges. However, such prescriptions have only really been employed on traditional shooting estates, such as Holkham (which, incidentally, boasts the title of Britain’s premier partridge estate), with the wider countryside far from suitable. If we are to halt the decline in partridge numbers then we need to re-establish the network of hedgerows and field margins that are so important for this species.

That we are able to chart the changing fortunes of this and many other species, is down to the efforts and hard work of the thousands of birdwatchers who give up some of their time each year to participate in long-term surveys. One of the most important of these is the Breeding Bird Survey, administered centrally by the British Trust for Ornithology (BTO) and organised by voluntary regional organisers. Although the survey only began in 1994, the data collected can be compared directly with a previous BTO survey – the Common Birds Census – thanks to a period of overlap between the two, which allowed calibration of the two sets of information. Collectively, the surveys provide a long-term dataset, which can be used to monitor the changing populations of many bird species over a forty year period and across a wide range of habitats, something that is unique within the United Kingdom. For the grey partridge, the efforts of those birdwatchers participating in the Breeding Bird Survey provide a means by which we can evaluate the effectiveness of the conservation measures that are being put into action.

Scheme charts nesting success

On a Saturday, by accident, I found my first yellowhammer nest of the year, situated just above the ground in a hawthorn bush and surrounded by rank grass. The presence of the nest was revealed when a female yellowhammer shot out of the bush I had just tapped with my butterfly net. Tapping bushes is a useful way of discovering hidden butterflies and other insects.

The nest was made of grass stems, woven together and lined with fine grass and hair. The front edge sported a ‘doorstep’, often characteristic of the species, and inside were three off-white eggs. Each egg was beautifully marked with a mixture of thin and thick squiggles, almost as if some child had taken a fine pen to a blank egg and added a random design. Having counted the number of eggs and checked that they were warm, I moved away to let the female back on. From a distance, I made a mental note of where the nest was located and jotted down a few notes in my field notebook. This would enable me to make further visits to the nest over the coming weeks and to collect information of value to the British Trust for Ornithology’s (BTO) Nest Record Scheme. Through the scheme, the BTO is able to gather essential information on breeding success and productivity for a large number of our breeding species. This information is then used alongside that from other BTO surveys to help find out why particular species are in decline or on the increase. The network of Nest Recorders operates under a strict code of conduct. This governs the way in which nests are visited and standardises the way in which information is collected. Recorders typically make a number of visits to each nest throughout the nesting period, in order to collect information on the number of eggs laid, the number which hatch and the number of chicks which survive through to fledging. Perhaps the most important information concerns the outcome of the nesting attempt: was it successful or did the nest fail because of predation, weather or desertion?

The timing of my visit, coupled with the presence of an incubating female, suggested that the clutch was complete at three eggs (yellowhammers may lay up to five eggs but don’t start incubating until the final egg has been laid). This will enable me to plan the timing of my next visit so that I can collect information on hatching success and gain a better indication of when the first egg had been laid. Two more visits will follow this and then I will send in my completed Nest Record Card to the BTO to add this important dataset.