Category Archives: Climate change

Winter in the Wash

One of the ‘must see‘ natural events in the UK occurs in the winter when hundreds of thousands of ducks, waders and, in particular, geese spend the season on the mudflats of the Wash. The Wash is a huge bay on the east coast of England into which the rivers Witham, Welland, Nene and Great Ouse all drain into the North Sea.

When the tide recedes, like Morecambe Bay in the previous post, enormous areas of mudflats are exposed which provide sustenance and a roost site for colossal numbers of birds. Every morning at dawn thousands of geese take flight to head inland to feed, and the geese are what everyone goes there to see.

Multiple skeins of pink footed geese at Snettisham at dawn (Anser brachyrhynchus, Dansk: kortnæbbet gås)

I arrived at the coast at Snettisham on the north Norfolk coast around 6am when it was just starting to get light. Already sizable flocks of geese were in the air and I was concerned that I’d missed most of them. But then as the sun rose higher gargantuan flocks started to pass overhead and it was a truly incredible sight!

I don’t know how many thousands of geese were there but at the end of the day I went back to the same place to see them return. It was getting dark and all was still, so, as in the morning, I thought I’d missed them. And then they appeared, quite suddenly in their tens of thousands. I tried to estimate the numbers by counting small numbers of each wave and multiplying up, and I estimated there were between 30-40,000 birds returning.

Skeins within skeins, I like this formation

And if you’ve ever spent any time near geese you’ll know that they’re not afraid to announce their presence, so the other thing that I hadn’t expected, but maybe I should have done, was the noise. It was a magnificent cacophony! And not just the squawking, but the sound of them flying when they came over lower to the ground.

These birds breed in the summer up in the Arctic, in Greenland, Iceland and Spitsbergen and then head south to the relatively balmy conditions of the UK coast in winter (!).

Another skein of pink footed geese passing low overhead

It’s unknown why geese fly in skeins, but it’s thought to provide an aerodynamic advantage to the ones behind as they slipstream in turbulent air generated by the bird in front. Which makes me wonder if they constantly switch the pacemaker or if the biggest and strongest bird is always the one at the front.

I estimated there were around 500 birds in this huge flock, but even that was a tiny proportion of the total

To see this meant getting up and out at 4am which is never my favourite thing to do, and it was ferociously cold, but it was worth it to see such a unique spectacle. And as the sun rose and it got lighter, it soon became apparent that the geese weren’t the only seabirds in the area:

A shelduck (Tadorna tadorna, Dansk: gravand) on final approach past a lone dunlin in the foreground

Small flocks of shelduck and dunlin were mingling and feeding close in to the shore

The Wash is now not the only significant area of coastal mudflat in East Anglia. In order to attempt to mitigate some of the anticipated ravages of climate change, flood defences protecting areas of farmland on the coast further south in Essex have been deliberately breached. This has allowed the land to be reclaimed by the sea and to regenerate the tidal mudflats that were there before humans originally interfered. The new habitat  was created with the millions of tons of earth removed the ground under London in order to build the Crossrail tube train tunnels. And as soon as this happened the wildlife started to recolonise, and even though it is still fairly barren in comparison to established habitat, I hope that in the near future it will also provide refuge to hundreds of thousands more birds, and lots of other wildlife too.

Dunlin (Calidris alpina, Dansk: almindelig ryle)

But more of dunlin in the next post, and plenty more species of sea birds both at Snettisham and after that at the RSPB coastal reserve at Titchwell.

Advertisements

The glimmer got a little brighter

Following on from my post from yesterday, in todays news on the BBC News website:

UN climate summit: China pledges emissions action

These are the two countries which really need to take big action on emissions and it looks as though they may be serious.

Let us all hope so!

A glimmer of hope

Yesterday on the BBC News website there was an article entitled:

‘Rockefellers to switch investments to ‘clean energy”

I think this one of the best pieces of news I’ve heard for a very long time and that it may signify that people who’s opinions and actions can influence government policy are finally taking steps to curb what has the potential to be the greatest global disaster in modern times.

The Rockefeller family, who made their vast fortune from trading in fossil fuels, have announced, on the eve of the next climate summit, that they are to divest themselves of all their investments in fossil fuels and reinvest them renewable energy!

If this is as true as it appears then huge respect to them and I hope that many other businesses, banks, investment houses etc. follow suit and send a very powerful message to the UK, US and all other governments who are in thrall to the fossil fuel industry that there are other ways to fuel the world that don’t need to involve wrecking it.

I don’t really have any appropriate images to illustrate this post so I thought a singing whitethroat was as good as anything.

Isle of Wight 2013

Part 1 – Lepidoptera

I’ve already grumbled in earlier posts about how the weather over the last three years leading up to 2014 was cold and unpredictable here in the UK, and how it had a very bad effect on our wildlife. In particular, overall numbers, and numbers of species, of butterflies, which are very sensitive to environmental change, seem to have been dramatically affected over those three years here in Cambridge at least.

But last year whilst on holiday on the Isle of Wight I took a walk from Shanklin up to the old WW2 radar station which is the highest point on the island, and apart from a flypast by a peregrine falcon, the most eyectaching natural phenomena were the butterflies, which seemed to be in direct contrast to the previous three years.

Comma – Polygonia c-album

The first part of my route took me through a wooded area bound by sea cliffs on one side and farmland on the other. A huge buddleia bush overhung the pathway which was hosting numerous species of butterfly, including the comma, above, and a painted lady, of which I’d seen plenty in 2010 but virtually none in the intervening years when the weather had turned bleak.

Painted lady – Vanessa cardui

The comma is resident to the UK and in recent years its numbers and range have actually increased and this has puzzled the entomologists as it is bucking a general trend amongst all butterflies here in the UK. in contrast, the painted lady is a handsome migrant which, according to my field guide, may or may not show up in the UK, consequently the entire population depends on immigration from Africa. But that raises the question what happens to the adults that are born here?

But since my guide was published, some research has been published where populations were tracked in and out of the UK on their migration routes by radar, and it revealed that painted ladies leave the country at high altitude – 500-1000m – where they can’t be seen by eye. The application of technology is revealing many hitherto unknown phenomena about many species and it’s interesting that up until now it was thought the whole UK population of painted ladies died out each year simply because they fly back just out of visual range.  And even more amazingly, it has now been discovered that this species takes up to six generations to make a circular 14000km (9000 miles) round trip from the Arctic Circle to Sub-Saharan Africa!

Which raises another mind boggling question: how is it hard wired into this tiny creature to make successive steps of this awesome migratory feat, covering half the globe, all in the same direction, at any one time? Unbelievable! But on the other hand, if populations on a previous leg of the journey take a hit for whatever reason it may be the explanation of why population size can vary so much from year to year in the UK.

Common blue male  – Polyommatus icarus

After emerging from the woods I climbed a steep incline, crossing the main Shanklin to Ventnor road and up the chalk downland of Boniface Down towards the WW2 radar station. Consequently, the terrain and the vegetation changed and so did the butterflies. The common blue is another species which I sighted frequently before the three year cold snap of 2011-14, but this male was the first one I’d spotted for a while.

Silver Y moth – Autographa gamma

The silver Y – it’s easy to see how it got its name – is a migrant moth which isn’t peculiar to chalk downlands and can be seen in most habitats, including the farmlands here around Cambridge, and this one was soaking up the sunshine on the down.

Marbled white  – Melanargia galathea

But the real gem of this trip was the marbled white, of which there were numerous examples fluttering around the down, and this one was sipping nectar from a greater knapweed flower. The marbled white is a UK resident and its favoured habitat is chalk downland.

Emerging on the top of the downland the vegetation changed to primarily low scrub consisting of acres of thistles which were home to more gatekeepers than I’ve ever seen before in one spot, I’m not exaggerating when I say there were literally hundreds of them. The information board at the entrance said that small coppers were also in residence but I only saw one and unfortunately it didn’t settle, which was a pity because they’re beautiful little brown and orange chaps and I wanted to get a photograph of one to share. Oh well, next time.

Gatekeeper – Pyronia tythonus – this one is a male, identifiable by the brown patches on the forewings, the ‘sex brands’

During the winter of 2013-14 and so far through this year the weather has warmed up, the cold, the rain and the high winds have all abated allowing many species to start to recover. It’s been a good year so far for butterflies and dragonflies, and hopefully lots more insects and the other creatures that predate them. The resilience of the natural world is astonishing, but I’m hoping we get another couple of mild years so the recovering wildlife can consolidate its numbers before the next big change in the weather.

The views from the top of Boniface Down were lovely. The cliffs on the southern edge of the island falling away to the English Channel were to the left, and when I looked north I could see mainland England. It’s not discernible in this photograph but the Solent and the south coast of the mainland are in the distance:

The only bird I managed to photograph up there was this little fellow who I think is a meadow pippit:

The pippits were very busy feeding youngsters, toing and froing across the scrub with beaks full of insects.

And the other reason I hiked up the hill was to see the old radar station at RAF Ventnor at the top of Boniface Down. This was one of the original installations set up before WW2 and was instrumental in detecting and reporting the massed attacks on southern England by the Luftwaffe during the Battle of Britain.

The remaining pair of radar towers at RAF Ventnor – there were originally six

The station was twice bombed by the Luftwaffe and I believe it holds the dubious distinction of being the only radar station to be destroyed by the enemy!

Down on the farm in July

Summer was late arriving in  2013. The weather was cold and wintry up until June and that had a profound effect on the wildlife. Breeding seasons were knocked out of kilter by it, and the numbers of many species have suffered as a result. But it seemed that once summer did arrive the wildlife got very busy very quickly to make up for lost time.

The skyline on my regular dog walking route is dominated by a magnificent poplar tree which makes a wonderful sound when the wind blows. It’s right on the pathway where many walkers pass every day and there is a bench underneath it which folk sit on occasionally. But despite all the human activity in such close proximity a pair of kestrels (Falco tinnunculus, Dansk: tårnfalk) were brave enough to build a nest in it about 20-25 feet up.

Kestrel fledgling taking it easy and apparently unfazed by me pointing a telephoto lens at it

I posted about the adults taking up residence in the poplar in August last year. Their decision to nest in this exposed location paid off in spades as the kestrel pair fledged three youngsters who could be seen in around the poplar into the later months of 2013.

And a pair of the fledglings sheltering in the poplar

I made a point of not lingering too long around the poplar to avoid disturbing the birds, but because of the constant human presence there I think they were relaxed about me taking pictures as long as I didn’t try to stay too close for too long.

All the pictures in this post were taken on one summers evening stroll in July, and as well as the kestrels there was lots of other wildlife.

Also breeding in the field adjacent to the poplar tree were numerous skylark (Alauda arvensis, Dansk: sanglærke). I’ve been trying unsuccessfully to get photographs of skylarks for a long time but on this particular evening this one perched on top of a low bush and sang for England. I called the dog to heel and using an adjacent bramble as a shield I crawled as close as I could, which was less than 10m in the end, and poking my lens though the bramble I finally got some pictures:

A singing skylark lit by the low, late evening sun

The resident corn buntings (Emberiza calandra, Dansk: bomlærke ) usually vacate the fields around Histon with the harvest at the beginning of August, but in 2013 they stayed much later. I don’t know if that was coincidence, because there was still cover in one of the fields, or if it was a result of the enforced delay in the breeding cycle due to the cold spring weather. But they were here in much greater numbers and much later in the year than normal. According to the British Trust for Ornithology the corn bunting is so sedentary that individulas only 30km apart sing in different dialects, but I’d love to know how that was discovered.

Corn bunting on a regular perch in the late evening sunshine

Corn bunting are red listed in the UK due to rapid decline in numbers as a result of habitat destruction for agriculture. Despite that, and decreasing numbers in Central Europe for the same reason, it’s not considered under threat as a species in mainland Europe… yet.

Another songbird which is also red listed in the UK, also as result of rapidly declining numbers, is the yellowhammer (emberiza citrinella, Dansk: gulspurv).

Male yellowhammer with his striking yellow head plumage

The yellowhammer has suffered catastrophic decline in numbers over the last few decades and over the last 2-3 years I’ve noticed the numbers in my locality seem to be on the wane too. I think it hasn’t been helped here by the farmer who recently took a flail to all the hedgerows and a lot of the drainage ditches and stripped most of the winter cover and food away. I just don’t see the sense it that – it wasn’t impinging on the crops or impeding access to farm machinery. Seems completely pointless to me.

Yellowhammer and corn bunting are both species of bunting and prefer arable farmland, but due to the intensive nature of arable agriculture and the resulting lack of seed, either natural or crop, both species are under dire threat in the UK. I’ve seen evidence to show that rates of decline can be slowed by changes in farmland management such as set aside or organic cropping, but I think attempts to conserve need to be applied in more holistic fashion to ensure survival of the wildlife.

One species which appeared to be abundant last summer was the hare. They’ve been ever present on any summers evening stroll across the fields in 2013. And I’m still seeing them through the winter too.

And as I headed home there was a spectacular sunset:

…one of many through the summer of last year.

The way it should be

My last post showed some random weather at the end of March and in this one all the photographs were taken during the following weekend when the weather was rather more in keeping with the season, the way it should be.

Another of the great British bird of prey success stories over the last two decades has been the resurgence of the buzzard (Buteo buteo, Dansk: musvåge). Up until the mid 1990’s I’d only seen buzzards on summer holidays in Denmark and the occasional sighting on the western periphery of the UK, in south Wales or in Cornwall. But then I noticed they were creeping further eastwards up the M5, year by year, and now they can be seen all over England, and it’s not at all surprising to see them over my garden. I think a major contributory factor to the increase in raptor populations has been the ban on the use of DDT.


A buzzard soaring over the farmland on the edge of Histon.

DDT, or dichlorodiphenyltrichloroethane…

…was originally extremely effective in the control of insects but is very persistent in the biosphere, and because of its chemical properties it accumulates in the fatty tissues of apex predators such as raptors. The toxic effect was to cause thinning of the eggshells which would break before the chicks were ready to emerge. The consequences were devastating for many species inclusing sparrowhawks in the UK as well as peregrine falcons and bald eagles in the USA. The systematic use of DDT has been outlawed for many years  now, although restricted localised use for the control of malaria is still sanctioned, but here in the UK the long term benefit of the ban has been dramatic with these magnificent birds once again a relatively common site in our skies.

Other birds species were making the most of the change in the weather at the start of April too, including this female reed bunting (Emberiza schoeniclus, Dansk: rørspurv):

Reed buntings have been a common site in the fields to the north of Histon since the weather has warmed up and the males with their black and white heads cling to the top of wheat stems proclaiming their availability. The females are more reclusive but can often be seen perched in bushes

A less common visitor to the fields is the golden plover (Pluvialis apricaria, Dansk, hjejle). I love to see the plovers, because when they do arrive they come mob handed, and on this occasion there was a flock of approximately 500 birds which looped round at high speed in extended skeins which was great to watch!


Skeins of golden plovers

Golden plovers are amber listed in the UK but not of concern in Europe so I hope that means that the overall population is stable and we continue to see them over the UK. An amusing little factoid about the golden plover which I’ve unashamedly borrowed from the British Trust for Ornithology is that a question about the flight speed of the golden plover raised by a member of a shoot in Wexford, Ireland, prompted Sir Hugh Beaver to found the Guinness Book of Records in 1955.  And if you’re keen to know, the speed of the golden plover is around 60mph (100kmph).

The rook, Corvus frugilegus, Dansk: sibirisk allike

All the photographs in this post were taken during a walk in the fields adjacent to my home the weekend after the snow, except the rook. This miscreant had lifted the fatball feeder from the branch in the crab apple tree and dropped it to the floor where it commenced to single handedly empty it. But as it posed for several portraits in the process I reasoned that it earned it’s fill. I like crows and especially the rooks, they seem to have a sense of devilment akin to a childs… if not even a tad more sophisticated. Through history though, alas not everyone had such a benign attitude to the rook (and just about every other creature!), which you can read about here.

Less predictable ramifications of global warming

This all seems a mite anachronistic now, but at the end of March when things appeared to be warming up and becoming rather more in keeping with the calendar this happened:

Snow capped post box at the front of my garden on March 23rd!

I often here folk grumbling that global warming often doesn’t feel that way, and, of course, the reason for that is that the average global temperatures are rising which can result in higher highs, but also lower lows, as more heat energy is sequestered in the atmosphere and the oceans causing altered patterns and much greater unpredictability. ‘Climate change‘ therefore seems the more accurate description.

From the point of view of the UK, our weather system is complicated because we are at the edge competing systems, from the south and west Atlantic, east from Europe and north from the Arctic. A major determinant of which of these systems dominates is the jet stream. This is a ribbon of fast flowing air, around 100mph (160kph), formed at the barrier between cold arctic air and warmer mid-latitude air, around 6-6.5miles (11000m) up, and moving from west to east. It’s position can wobble northwards and southwards and in the winter it tends to be south of the UK so we are dominated by cold polar air and in the summer it migrates further north so warmer conditions can predominate. But due to climatic variability in recent years the position of the jest stream has not conformed to tradition and has remained much further south so our summer weather has been much colder and wetter in the last few years.

Hence snow at the end of march…

A male great tit, Parus major, wondering what’s going on!

The unseasonal weather over the last few years has caused real problems for wildlife. Numbers of bees and butterflies have been down and hibernating creatures such as hedgehogs can struggle to find food when they eventually arise from the winter slumber.

A male blackcap, Sylvia atricapilla, nibbling on frozen fatballs

The blackcap pair which arrived in my garden in January made their last appearance during the March snow and then disappeared. I think they must have been overwintering here in the UK and when the really cold weather finally ended they headed back on their long flight to central Europe in time for the breeding season.

We’re now at the end of June and the jet stream has moved north allowing high pressure systems to move in from the Atlantic to the west and bring some warm weather. Long may it last!