A dash for home

It has been rather dry recently, something that is underlined by the slow growth of the vegetables in my raised beds and the dust that comes up from the forest tracks with my passing. These dry conditions are likely to have had an effect on some of our wildlife, with soil-dwelling invertebrates moving deeper into the soil profile in order to find the moisture that they need. The knock-on effects of this may be felt by the thrushes and Starlings which probe our lawn for worms and leatherjackets (the larvae of craneflies). The dry conditions might also explain the large number of Moles being seen above ground over recent days.

I encountered my first wandering Mole whilst out doing a bird survey, the first of the season’s visits to my Breeding Bird Survey square, operated by the BTO. It follows the line of the Peddar’s Way (fortunately just a short section and not the whole 50 mile route). Coming out of one of the smaller Breckland villages on a minor road I spotted what I first took to be a couple of Starlings in the road, distant as they were. As I approached it dawned on me that one of the Starlings was actually a Mole, a not unusual casualty of a passing car I thought. It was only when I got to within a few feet of the Mole that it moved; a first tentative sniff of the air then a full-throttle run towards me and away across the road. Such a turn of speed is wholly unexpected in a creature more suited to a subterranean existence. I managed to follow the Mole for a couple of minutes, even capturing it on my phone’s video camera, before I had to be on my way again, counting birds.

Later the same day, while out nest recording with the county’s mammal recorder, Dave Leech, I commented on my Mole sighting and we both remarked on how uncommon it was to get such a good view of a Mole in this way. Imagine our surprise then, when barely 20 minutes later we came across another two Moles foraging above ground. This time, however, they were foraging in the leaf litter and somewhat less easy to view. Since then, I have heard of a number of similar sightings from across the county. Moles are more commonly seen above ground during the period when the young disperse away from where they were born. Since this dispersal does not normally begin until late June, I rather suspect that the Moles we saw might have been having a hard time of it. Some rain would be good, both for the Moles and my vegetables. 

Scratchy songster of the nettlebeds

The scratchy song of the Whitethroat can be heard from many of the county’s nettle and bramble beds at this time of the year. Numerous pairs haunt the rough cover of the forest’s snag lines – the tree roots and timber waste dragged into rows once a conifer plantation is clear-felled. Other pairs deliver their sharp ‘tchack’ alarm calls from patches of waste ground, where their delicate nest of grass stems is placed low in thick cover (usually between 30 and 60cm off the ground). A male Whitethroat will build several nests, each unfinished. Known as ‘cock nests’, these platforms of grass are often decorated with plant down or other ornamentation. The female will then select the nest site and help to finish the nest, lining it with hair and fine grasses, before initiating egg-laying. The buff-white eggs, of which there are usually four or five, have yellow-green markings overlaid by darker spots, the latter often forming a zone towards one end of the egg. Incubation begins once all the eggs have been laid, with most of the incubating being done by the female; the male does some but only the female incubates during the night.

This robust warbler does well here and the United Kingdom supports the fourth largest Whitethroat population of any European country. In favoured habitats the density of breeding pairs can be staggering but more typically numbers five or six pairs per kilometre square. Two of the nests that we are monitoring this summer are just 30m apart, with both birds at about the same stage of their nesting cycle. Most of the Whitethroats that are singing now will have arrived during the second half of April, with many discovering that the vegetation cover was somewhat late in developing. This will have placed early nesting attempts at greater risk of predation, with these nests easier to spot and hence more likely to be found by crows and other predators. Most Whitethroats are on eggs and the first chicks will not be far off, the only brood that most will produce this year.

Come the autumn and these birds will head south to wintering grounds in the Sahel region of West Africa. This part of Africa has been prone to devastating droughts in the past, the most significant of which produced a massive crash in the Whitethroat population. Numbers breeding in Britain fell by 77% between the 1968 breeding season and that of the following year, purely as a consequence of failure of the rains. Numbers have not yet recovered to anywhere near their former levels and continuing problems in West Africa, notably habitat degradation, suggest that they probably never will.

A tale of two plants

Some of the trackways that criss-cross the Brecks are currently smudged with red, an apparent stain that might suggest some grisly occurrence has recently taken place. When viewed more closely it soon emerges that the stain is actually formed by a small plant, a nationally scarce species called Mossy Stonecrop. This tiny annual is a poor competitor and so only occurs on ground that is kept free of other vegetation by regular disturbance. The compacted ground of forest rides and paths suits the plant, especially here on the light Breckland soils. It also occurs on the Goodsands of northwest Norfolk and, sporadically, at a small number of other sites across the county. The range extends south into Suffolk and there are also populations in the New Forest and at a handful of sites elsewhere.

As I have noted before, the Brecks are dominated by light sandy soils, of varying depths, that sit on top of a deeper chalk geology. The climate also exerts an influence on the nature of the vegetation, with high summer temperatures and low rainfall, combining with sharp night-time frosts. Many authors have commented on the nature of this climate and its similarity to continental or more maritime conditions. Some of the many and insects found in the Brecks reflect this, with a number of the plant species found here being more typically found around the Mediterranean.

Of course, the distribution of many plants is the result of our activities rather than a consequence of climate and other natural factors. The history of bringing interesting and attractive plants into our gardens is one that goes back generations and it can often be difficult to determine whether a particular species is native or has been introduced. A good example of this is another plant that can be seen in Breckland at the moment. This is the Star-of-Bethlehem, a plant which, to be honest, has the appearance of being a non-native quite simply because of the way that it looks. A white-flowered member of the lily family, it has Bluebell-like qualities and seems exotic when viewed alongside our more familiar flowers. The species is most likely an introduction, albeit a rather old one. Some botanists consider the Breckland populations to be native but it was not recorded from the Brecks until 1772. It was certainly being cultivated in Britain by 1548 and the first record from the wild followed in 1650. That it should be considered native probably stems from its Mediterranean origins and that certain other species from this area are considered to have native populations in the Brecks. Either way, both Star-of-Bethlehem and Mossy Stonecrop are now part of the botanical richness of this part of Norfolk.

Semi-colonial finches

It’s been a tough day and I’m still picking the bits of dead gorse out of my clothes, shoes and skin. It has been worth it though, a day spent looking for nests so that we can monitor them over the coming weeks and feed our observations into an important national scheme. The effort has been targeted at the BTO’s Nunnery Lakes reserve, which lies to the south of Thetford and runs parallel to the Bury Road. The diversity of different habitats on the reserve means that it supports a wealth of different bird species, many of which also nest here. Much of today’s effort, however, has been aimed at the gorse which dominates the ridge above the old gravel workings. It is here, within these dense and spiny bushes, that the Linnets choose to nest.

Linnets are semi-colonial breeders, which means that several pairs will nest in close proximity, often in neighbouring bushes. Rather than actively searching each bush in turn, we seek to target our efforts most effectively by first watching the bushes and the Linnets to see if we can narrow down where we need to search. Having so many pairs in close proximity complicates things and it requires a good period of patient watching in order to pinpoint the nests from afar. The males like to use prominent perches, many of which will be a little way away from the location of the nest. Sometimes, however, the male will call the female from the nest and the two birds will leave the reserve to feed on the set-aside land on the neighbouring estate. Watching their subsequent return can be particularly helpful.

There are times when unexpected events can help to reveal the location of a nest. One of the males had been perched on a bush for some time but then moved off. Just after he had left, a Great Tit appeared and proceeded to forage near where the male had been sitting. Just then, a female emerged from the bush to chase the Great Tit away. Satisfied that she had done her job the female Linnet entered the bush again, just a few feet from where she had first emerged. Somewhere in between those two points would be her nest. Needless to say, we found it straight away when we went to check the bush.

Subsequent visits to these nests, made briefly some seven to 10 days apart, will enable us to record the fortunes of each nesting attempt. They will reveal the number of eggs and chicks and how many young fledged successfully. In turn this will enable the BTO’s researchers to establish how Linnets are doing, providing conservation advice that will help us look after this, and other, species.

Addition to an urban soundscape

The town has its own soundscape. Not always pleasant, and often mechanical in origin, it lacks the fluid, lyrical quality of a piece of rural woodland or southern downland, rich as they are with the many and varied notes of different birds and insects. Nevertheless, this human landscape has its avian songsters: the rich warblings of the Blackbird, the more wistful notes of the Robin and the high-pitched rambling song of the Dunnock. I have come to treasure these songsters; best heard during the relative stillness of evening or the dawn of a fresh day, they are a proclamation that nature is still here, living within earshot and going about its business with little heed to our activities.

Interestingly, the last two weeks have seen a different songster holding court – a Blackcap that has established its breeding territory across the collective piece of green space formed by our row of long and narrow back gardens. I first heard the bird early one morning while laying in the bath, the window open and the bright blue sky visible overhead. After a brief pause of disbelief, ’can it be a Blackcap, here?’, the bird picked up its tune. Rich and melodic, the song stands out above all the other songsters, drawing the attention it deserves. Of course, Blackcaps have been here before in the form of brief visits, presumably made by inexperienced males who’ve dropped down into our patch of green but singularly failed to attract a mate. Most were gone with a day or two.

This bird seems different, more assured and with a clearly defined series of song perches used over many different days. Some of the gardens have changed since our last visitation. The now mature patches of nettle and dead willowherb stems next door could provide the sort of nesting cover favoured by this delightful warbler and I peer at them from time to time. It would be rather special were we to discover the birds breeding. Most of the Blackcaps on the nearby nature reserve are already on eggs, as are the pairs breeding by the river just through town. All of this bodes well for our male.

On some mornings the Blackcap is the first sound that I hear as I wake; its melody punctuating my breaking dreams and I feel that I must be out on the borders of some scrubby woodland edge. It no longer sounds, or for that matter ‘feels’, like an urban existence. That these few notes should transport me elsewhere serves to underline the power of bird song. To the Blackcap these are notes that communicate a message of ownership and suitability as a mate; to me they are so much more.

Fishy business

It is good to be out on the water, sat in a large inflatable and at eye level with the dashing forms of Swallows and occasional passing terns. We are here to ring nestling Cormorants, a colony of which breeds in the trees that fringe Abberton Reservoir. There are five of us in all, split between the two boats which we paddle slowly around the reservoir, assessing the stage of each nest in turn before determining which ones should be approached for ringing.

Cormorant ringing in a previous year, before we had boats!

These inland breeding Cormorants are part of an expanding inland population, a relatively recent development set against a longer history where virtually all of our Cormorants were coastal in their habits. Part of the reason for this change is the establishment of colonies of the continental race, known as sinensis. This race originates from breeding colonies in France and the Netherlands where it breeds almost exclusively alongside inland freshwaters. Unlike our own race, known as carbo, the continental birds are migratory in their habits and their arrival here appears to have had an influence on the establishment of these inland breeding colonies. The colony at Abberton started with just nine pairs in 1981, growing rapidly to a peak of 551 pairs in 1996, since when numbers have fallen; we recorded just 160 pairs during our visit.

Ringing Cormorants is hard work. Not only do you have to paddle around the reservoir but you also have to spend a lot of time in the water, wading up to the partially submerged trees used for breeding, before erecting a ladder and climbing up to the nest. Then there are the birds themselves. Any adults in the tree, of which there are usually a few, retreat out onto the water to form a scattered raft of sleek black shapes with alert, periscope heads watching our activities. The chicks are relaxed in the hand but will invariably relieve themselves all over you and, occasionally, bring up a lump of partially digested fish. It is smelly but important work. Each of the chicks receives both a standard metal ring and special colour ring, the latter marked with three large digits that can be read at a distance using binoculars. These colour rings enable researchers to collect far more information on the movements of the birds than they would otherwise be able to.

Our visit to each small cluster of nests is brief, just 10 or 15 minutes on a warm day like this, allowing the adult birds to return to feed their chicks with minimal disturbance on our part. I know that Cormorants are not the most popular of birds with fishermen but there is something truly endearing when you encounter them as soft-feathered youngsters.

Semi-colonial finches

It’s been a tough day and I’m still picking the bits of dead gorse out of my clothes, shoes and skin. It has been worth it though, a day spent looking for nests so that we can monitor them over the coming weeks and feed our observations into an important national scheme. The effort has been targeted at the BTO’s Nunnery Lakes reserve, which lies to the south of Thetford and runs parallel to the Bury Road. The diversity of different habitats on the reserve means that it supports a wealth of different bird species, many of which also nest here. Much of today’s effort, however, has been aimed at the gorse which dominates the ridge above the old gravel workings. It is here, within these dense and spiny bushes, that the Linnets choose to nest.

Linnet nest, by Mike Toms

Linnets are semi-colonial breeders, which means that several pairs will nest in close proximity, often in neighbouring bushes. Rather than actively searching each bush in turn, we seek to target our efforts most effectively by first watching the bushes and the Linnets to see if we can narrow down where we need to search. Having so many pairs in close proximity complicates things and it requires a good period of patient watching in order to pinpoint the nests from afar. The males like to use prominent perches, many of which will be a little way away from the location of the nest. Sometimes, however, the male will call the female from the nest and the two birds will leave the reserve to feed on the set-aside land on the neighbouring estate. Watching their subsequent return can be particularly helpful.

There are times when unexpected events can help to reveal the location of a nest. One of the males had been perched on a bush for some time but then moved off. Just after he had left, a Great Tit appeared and proceeded to forage near where the male had been sitting. Just then, a female emerged from the bush to chase the Great Tit away. Satisfied that she had done her job the female Linnet entered the bush again, just a few feet from where she had first emerged. Somewhere in between those two points would be her nest. Needless to say, we found it straight away when we went to check the bush.

Subsequent visits to these nests, made briefly some seven to 10 days apart, will enable us to record the fortunes of each nesting attempt. They will reveal the number of eggs and chicks and how many young fledged successfully. In turn this will enable the BTO’s researchers to establish how Linnets are doing, providing conservation advice that will help us look after this, and other, species.

The Great Arrival

More than one author has conjured up the image of a Great Arrival, the 16 million or so migrant birds all heading north to summer on these northern breeding grounds. Most recently, in his excellent book Say Goodbye to the Cuckoo, Michael McCarthy speculated on how we would react were all these birds to arrive in a single flock. Such a flock would fill the sky; people would stop what they were doing in order to take in the spectacle and it would become an important signal that spring had reached our shores, celebrated with street parties and a public holiday.

Of course, our summer migrants do not arrive all at once in some grand flock; instead they turn up in small numbers or individually, with many arriving at night when the energetics of migration are better balanced. These overnight arrivals do provide one thing however; they deliver a sense of the unexpected to us birdwatchers, the thrill that the night just gone might have delivered some exciting find to an early morning trip to a patch of coastal scrub or waterside reedbed. Even those who would not describe themselves as a birdwatcher derive a thrill from seeing the summer’s first Swallow or hearing May’s first Cuckoo.

While these individual encounters act in some small way as a talisman for a wider arrival, the movement of this mass of birds, streaming out of Africa and up across Europe, goes largely unnoticed. Taken for granted, we find ourselves unaware of the problems faced by these many and varied travellers, problems which have resulted in dramatic population decline for some species. We only know of the changing fortunes of our summer visitors because of the work of organisations like the British Trust for Ornithology (BTO), whose partnership between researchers and birdwatchers provides regular monitoring of the birds breeding across Britain and Ireland. Yet even with this information we only know that something is wrong, we don’t fully know why. Are the numbers of Wheatears, Cuckoos, Turtle Doves and flycatchers falling because of difficulties here or is it because of problems on their wintering grounds or along their migration routes?

Recently, the BTO and RSPB have launched projects in Africa to look at our migrants on their wintering grounds, seeking to understand what is happening to the habitats they use during our winter. This work is only the start of a wider process which, ultimately, will need to feed into conservation action targeted at the different species across their whole range. The scale of this work also serves to bring home the message that while we view these birds as being ‘ours’, they are only ours for part of the year.