Monday, 23 October 2017

Digging up emeralds


Ditching work at Holkham's marshes

Anyone glancing over the marshes at Holkham in September and October is bound to have seen a large yellow tracked digger. Many people stop and ask what sort of work is it doing? The simple answer is that it is dredging the ditch systems, yet really the answer is a lot more involved than just simply doing a bit of dredging work.  Together with a series of sluices the ditches help us manage the water levels. For the ditches to do their job a certain amount of maintenance has to be done regularly and this means dredging out silty mud that accumulates and impedes the water flow.  As you can imagine the wildlife of the dykes is varied and often prolific. For that reason we try to work on a seven year rotation so that there is plenty of time for the flora and fauna to re-establish.


The Grey Herons of the marsh become most confiding during ditching work ever on the lookout for fish and eels.

Whilst we do not actually drive the machines ourselves we are often at hand assisting the driver in clearing up rubbish that has been ‘slubbed’ out or helping replace culverts and gateways.  It can be messy work but the amount of wildlife seen can be quite astounding. The dykes of Holkham are an incredibly important part of our ecosystem and a great indicator of their health is the presence of Eels. They are always encouraging to see and form an essential part of the menu of birds such as Bitterns and Grey Herons. It is quite normal to see two or three Grey Herons or even the odd Little Egret wandering about on the ‘slubbings’ metres  away from the digger looking for rich pickings. A good number of fish are also present, Roach in particular. We are quite unaware at just how many we have, but suffice to say there must be plenty judging from the concentrations we occasionally see and the constant fishing activities witnessed by our newest residents, the Great White Egrets. They are constantly pacing back and forth through the shallows of the dykes these days in search of fish to eat.


The Willow Emerald Damselfly, a new species for the reserve


As I was helping out one day this year a flash of green caught my eye on some waterside reed. It was a small elongated yet dainty damselfly. A closer inspection revealed it to be a Willow Emerald and a new species for the reserve. This southern European species first colonised the Suffolk coast in 2009 and has been slowly pushing north ever since. This year has seen more than normal numbers appear along the coast of north Norfolk and it had been a species we were expecting to find at some stage. It prefers dykes that have overhanging willows where it lays its eggs under the bark. With some of our dykes having willows in sunny situations it really does look like we perhaps have the perfect habitat for a future flourishing population.


A fearsome looking Water Scorpion


Another interesting insect seen was a Water Scorpion. This rather fierce looking insect (unrelated to a true scorpion) has a long ‘sting’ like protuberance at its rear end yet this is actually a respiratory tube that it holds above the water thus allowing it to breath underwater. Instead of having claws on its front legs like a Scorpion it actually has scythe-like front legs that are still used in a similar fashion to catch its prey.


Water Shrew, a rarely seen inhabitant of the reserve's dykes

For me however the most exciting find of the year was a Water Shrew. Having been a keen naturalist for 36 years it was a species that I should have seen before but it had always eluded me. It is also said to be a relatively common well distributed species across the British Isles yet one that is pretty much solely aquatic and that was my excuse for not having seen one. There have been one or two sightings through the years on the reserve, yet never by me so when I saw a very dark almost black shrew, I knew my luck was about to change. It proved to be a very worthwhile learning experience. Water Shrews have Mole-like black fur above and most have contrasting white underparts; this one however was more dusky coloured below making it not so easy to identify. Certain features could be seen that eliminated the more widespread Common Shrew such as its larger size, its pale tipped ears and its hairy feet, toes and tail which have evolved to enable it to swim through the water with ease. It could well be a common species on the reserve or it could be a rarity, something we currently cannot answer.


The fresh foot prints of an Otter

Another mammal that continues to elude me on the reserve is the Otter. A regular recently told me when he was young in the early 1950s he used to ‘bunk off’ school especially to watch a family of Otters sliding into one of the ditches on the marsh. Following the species nationwide demise due to the use of organo-chloride pesticides running off into river systems it took until after the new millennium for Otters to return to Holkham. Since 2012 we know through finding foot prints that the species is now present again, but being mostly nocturnal it remains very difficult to see. I think I must now be the only member of staff who works on the reserve who has yet to see an Otter here, but I’m sure that time will come soon. Another reason they are so difficult to see is the sheer distance they travel. Between Wells and Burnham Norton the reserve’s three main areas of grazing marshes are an intricate wetland of cattle grazed fields that are all bordered and inter connected by a series of fresh water dykes and ‘drains’. This again brings us back to the management of the reserve and the reasons for dyke dredging. The basic system works like this; water accumulates, be it rain water or from in-field springs and drains into the dykes which then ultimately flow out through the fields to the sea. Some are old ‘foot’ drains used from the 1700s onwards when the fields (formerly brackish and salt marshes) were drained so that the arable crops could be grown. We are able to control this flow due to a series of dams and sluices that allows us to either hold back and retain water (giving us wetter fields) or release it (thus drying areas out).

Andy Bloomfield

Warden

Monday, 9 October 2017

The splendour of Little Egrets

 
Little Egret feeding in Wells Harbour

One of our most recent pieces of survey work on the reserve was to assist in a coast wide count of Little Egrets at their overnight roosts sites. These small white herons with gleaming yellow feet are now a common sight along the north Norfolk coast, particularly on the salt marshes. Here they can be seen in shallow pools or creeks, ever on the lookout for small fish or crustaceans to eat. This was certainly not always the case, they were once exceptionally rare.

Standing at dawn on a cool late September morning when the first white shapes (of a final total of 81) started to break cover and head off from the safety off their night time woodland residence and illuminated by the rising rays of sunlight, all my thoughts raced back to my first ever encounter with a Little Egret. Wells school in the 1980s boasted a thriving bird club and periodically trips would be undertaken to the various reserves along the coast. Strangely my first ever trip out with the club was along the coast to Cley and Salthouse to see Avocets and Black-tailed Godwits in 1981 yet the most exciting species we encountered was a Little Egret. This was big news at the time as a gathering of twitchers lined the coast road with all their telescopes and binoculars pointing north into the fields at a vivid eye catching white shape. Huddled into the reeds at a great distance it was hardly the most inspiring of sightings, yet it certainly captured my young imagination that all these people had actually arrived there from all corners of the country to see what essentially looked like a  white bundle of feathers. How times have changed, nowadays most birders (and certainly not twitchers) don’t even give these birds a second glance. So what happened in the intervening years?


Little Egrets flying to roost

In the 1980s growing numbers of Little Egrets progressed north up the coast of France from a stronghold in more southerly, warmer wetlands. A combination of milder winters, good breeding seasons and an abundance of habitats combined with greater protection allowed the species to breed in good numbers right up to the coast of Brittany. From here greater and greater numbers began to cross the English Channel and finally after several years of a growing wintering population the first breeding pair colonised Brownsea Island off the Dorset coast in 1996. Ever increasing numbers spread out across the British Isles and by 2009 over 800 pairs were found to be nesting and a far cry from the not too distant past.


Little Egrets prefer the vast north Norfolk salt marsh system for feeding

Holkham NNR actually became very much an integral part in the Norfolk story. Despite not recording its first until 1988, it actually became the first place to have a wintering pair (on the NNR’s saltmarshes at Warham/Stiffkey) and then the first breeding birds in 2002 (in a wet woodland site within the grazing marshes). From the first five pairs in 2002 their increase was swift; by 2004 up to 42 pairs nested, making it the county’s premier site for the species. Thanks to global warming we gained a new resident species that had barely been given a thought of being a potential colonist until changing times in the 1980s. Its sudden appearance and colonisation almost matches that of the Collared Dove a couple of decades before.


Shrimps are one of the main sources of food.

Little Egrets can be seen these days in any spots where there is marshy ground and suitable prey can be found although the saltmarshes and harbours still attract the lion’s share. Here the tidal rhythms ensure that there is a plentiful food supply of crabs, shrimps and fish. Take time to sit and watch an egret feeding and you will be enthralled at their various methods. Sometimes a bird might be standing rigidly still, head cocked to one side waiting for a movement below whilst another favoured technique is foot shuffling. Then the bird moves very slowly with seemingly only its feet quivering under the water to stir up the mud and water and provoke movement of any potential prey. Another method sometimes seen is the half wing cocked position when its wings are held partially aloft and spread out, thus creating shade below. This may be as much to enable the bird to see well as for fish to enter under a calmer place thus leaving them vulnerable for a fatal strike from the egret’s sharp bill. Egrets are usually solitary feeders but occasionally larger congregations may be seen when a feeding frenzy erupts with birds chasing in every direction amidst a shoal of fish.


Part of the courtship rituals during the breeding season

Always seemingly immaculate, Little Egrets take on an even more beautiful new identity in the spring and summer when they are breeding. Elaborate plumes grow on their crown and fine lace-like feathers grow on their backs. These form part of highly involved social displays and to witness such a sight instantly leaves the impression that one of the finest rituals of any European bird has been witnessed.

Andy Bloomfield
Warden

Friday, 22 September 2017

Wildlife from the window of a tractor


Early morning at Burnham Overy marshes and distant sand dunes


Working on the nature reserve has many rewarding days. That’s probably very much an understatement – nearly every day has its rewards! There is nothing better than seeing some wonder of nature whilst carrying out work on the reserve. For me, that’s as much as the changing skies that come with the contrasting seasons. Varying lights and weather means that even the same view can look totally different, in fact seldom the same and very often quite dramatic. Sightings of wildlife also seem more memorable for me when carrying out actual physical work. A glance up at the right moment to witness a specific bird or a butterfly can be enough to break up the day and enliven what sometimes might seem an unrewarding task.


A Great Snipe - photograph kindly supplied by Chris Knights

One of those ‘once in a lifetime’ experiences happened in 2005 when I was ‘topping’ the marshes by tractor not far from Lady Anne’s Drive. I had just got to the last strip of grass to cut and up popped an exceptionally rare bird from north eastern Europe - a Great Snipe. Closer in size to a Woodcock than its smaller and more common relative, the Snipe, this cryptically marked wader of almost mythical desire amongst the twitching fraternity was there right in front of me, sitting beside my front wheel! It made the memories of long days behind the wheel of a tractor getting stuck in wet fields fade away in an instance. It is also true to say I would never have seen it had I not been there working in a tractor. A similar thing happened only recently, the last strip of dyke side vegetation cut and there sat a rather regal and annoyed looking Short-eared Owl. Some naturalists say it is bad to anthropomorphise but I defy anyone to look into the eyes of a Short-eared Owl and not do so! This particular one really did look like I had ruined its day by gate crashing into its own wild world. 


A newly arrived migrant Short-eared Owl as seen through the window of a tractor !

Some birds seem oblivious to the movements of tractors and the amount of exciting species or unusual behaviour I have seen whilst working has been quite remarkable. It is not just birds either, sometimes mammals otherwise not seen can be observed. Species such as Short-tailed Field Voles are common and are often seen scurrying away before a Kestrel swoops down to catch one. Birds like Grey Herons and Kestrels seem to be in tune with our workings and soon appear once mowing commences. The same behaviour was noted with Red Kites in the Park recently too. One of the least seen mammals is the brightly coloured yet diminutive Harvest Mouse. There are undoubtedly more about than we realise as normally the only time I manage to see one is whilst topping. This year I was very lucky to see one run off and swim across one of the dykes, its bright orange coat looking like a lost sweet wrapper drifting across the water.


Newly arrived Pink-footed Geese preparing for a winter in Norfolk

So, if our fields on the reserve are all grass meadows with no crops, why do we spend so much time in tractors on the marsh? The grazing marsh meadows form part of a very valuable and declining habitat in the UK. Lowland wet grassland disappeared dramatically in the 20th century due to drainage schemes and conversion to arable fields. In doing so, many of the species that formerly thrived in them started to decline to almost disastrously low levels. At Holkham we are fortunate in having up to 535 hectares of wetland, much of which is wet meadowland. For it to remain attractive to our key breeding species such as Lapwings, Redshanks and Avocets and also our wintering birds like Pink-footed Geese and Wigeon a lot of fine tuning and effort goes into achieving the right conditions. This involves controlling water levels, extensive grazing by cattle, dyke dredging, providing scrapes, pools and islands and mechanical topping by tractor driven mowers. By using mowers, areas that the cows ignore can be topped thus preventing them turning to scrub and the correct sward height of grass can be obtained and hopefully making them the ideal habitat for nesting Lapwings next spring.


Lapwings love to nest in short wet grassland

If we have missed spots from our topping system all is not lost as this week alone we have close on 10,000 newly arrived Pink-footed Geese from Iceland on our meadows, which means quite a lot more grazing ! Typically the first few birds arrive in the first few days of September, but this year they seemed slightly later arriving but when they did appear it was in greater numbers than normal. Over 100 dropped in on 13th September and quickly increased to 1100 on 15th and over 10,000 by 21st. If you are visiting Holkham in the next few weeks take a look for the geese. In recent years we have typically seen big build ups in October before the birds disperse across the county to feed on newly harvested fields of sugar beet tops. It is still one of nature's great spectacles; masses of geese clamouring for space on the marshes, their calls reaching fever pitch amidst vast skeins often illuminated by spectacular sunsets.


Part of an early autumn mass of returning Pink-footed Geese

Andrew Bloomfield
Warden

Monday, 11 September 2017

Marvellous Mini Beasts





Two of our regular invertebrate recorders using a leaf blower in reverse to sample for spiders and beetles at Holkham Bay

This summer we were involved with two quite high profile local events at Holkham that proved very rewarding for not only members of the public but also for the members of staff involved. Firstly came the coast wide Bio-blitz. This involved enthusiasts from every branch of natural history descending into all the various habitats along the coast and trying to identify and record as much as they could find. This was open to keen specialists, experts, and County recorders alongside general members of the public. Here at Holkham alone we managed to record nine new species of fungi for the reserve (including a new species for Norfolk – a very insignificant looking ‘black smudge’ fungi), a spider only known from one other site in Norfolk, a hoverfly only previously recorded in the Norfolk Broads (the Sea Clubrush Hoverfly) and two new beetles for the site. For a site that has been a nature reserve since 1967 this was quite a selection.


Lady Anne's Drive on Bio-blitz day



Achaearanea riparia,a new spider for the reserve and a county rarity

Rarities aside the joy showed by children as they were shown moths brought out from some overnight traps was priceless. For many, moths are the poor man’s butterflies that only come out at night, are drab in colours and munch clothes in our wardrobes. Nothing of course can be further from the truth. Here in the UK there have been an incredible 2,500 species recorded. So whilst it is true many are nocturnal (hence the need to attract them and catch them aided by uv lighting) many are also day flying and many are impressive looking colourful beasts. For most children when they see something like a hawkmoth for the first time they are often overwhelmed that such a mystical looking creature can exist outside of a fantasy novel. To see a child over awed from a moth or grasshopper clinging to its finger can be quite magical.


A Long-winged Conehead, an exotic insect that always attracts attention

At Holkham we took this a step further this year by running a mini-beast hunt in Wells Pinewoods as part of the annual carnival celebrations. On two days we set up shop along with the Estate’s Education Department in the hope that a few children might pop along and find us a few insects and other creepy crawlies to inspire them and for us to identify. When the start time arrived we found ourselves under an avalanche of small children eager to hunt out, collect and bring to us for identification what they had found. Initially it seemed like a happy form of pandemonium. There were children dashing about everywhere, turning over logs, peeling off tree bark, crawling underneath bramble bushes, clutching pots and nets with wood lice, worms, centipedes, beetles, butterflies and even toads. Their enthusiasm was infectious and the event proved even more successful than we could imagine. The excitement shown was both non stop and heart-warming. On an even bigger plus side, they produced the goods too. 


The Red Longhorn Beetle

The Red Longhorn beetle is a relatively scarce insect that has its UK stronghold in the south of England, particularly the forests of Breckland. It also has an outpost along the north Norfolk coast with the conifer wood of Holkham and Wells being a known site. What we did not realise was just how many we had. In the two days at least 15 were found all within a restricted area of the wood. An adult Ant-lion was also found, a specialised insect of the woods that still very few Norfolk naturalists have ever set eyes upon. One of the strangest finds, more due to its circumstances, was the reserve’s first ever Woodlouse Spider. It fell out of a branch and straight onto the arm of one of our visitors, amidst a chorus of shrieks! It is armed with ferocious looking jaws that enable it to pierce the armour plating of a wood louse (its main prey), hence its name. No bites occurred to our visitors though! Ultimately it was great to see such interest in our natural world and left me hopeful that at least some would become the next generation of field naturalists. It also left us hoping that the next time a bio-blitz is organised we can get an army of small children with keen senses to scour our vegetation and even more might be found!


An adult Antlion - a very lucky find on our mini-beast hunt


The Woodlouse Spider, with its impressive jaws opened wide!




Andy Bloomfield

Warden

Wednesday, 23 August 2017

A Great White Summer


Holkham's grazing marshes with its newest residents

Holkham has seen many changes in its wildlife over the years. Species have been lost and species have been gained and at the moment it seems we are very much in the ‘gains’ camp. Global warming has been attributed to many of the new insect arrivals and indeed some of the birds too. Arguably the most spectacular of our newcomers is the Great White Egret, a relative of our familiar Grey Heron. Gleaming white, standing close to metre tall with a wing span up to 170 cm it makes both a striking and imposing sight in its new found North Norfolk home.


In flight and close up the Great White Egret looks truly imposing

This pretty much cosmopolitan bird of the world’s warmer climes was once exceptionally rare in the UK until relatively recent times with no sightings before 1960. With the Great White Egret it was more the case of a bird that was heavily persecuted in mainland Europe to such an extent that it almost disappeared completely before protection measures and habitat enhancement enabled its population to grow again. Unlike many birds that were hunted for food, the Great White Egret’s downfall was its beautifully elegant white cloak of fine wire-like feathers; its ‘aigrettes’. These are grown in the breeding season and form part of the bird’s elaborate courtship behaviour. It spreads them upwards and outwards like some giant monochrome Peacock ! As well as attracting a mate, the feathers attracted far more sinister admirers. Birds were killed in their thousands worldwide to supply a growing trend for fashionable hats made from the aigrettes. It took a lot of hard work by a fledgling Bird Protection Society in Victorian times (the forerunner of the RSPB) to lobby governments and finally get the practise to cease.


As with the Spoonbills and Little Egrets the watery woodland at Holkham makes the ideal home for the Great White Egret

Against such a background of persecution it could be seen to be a real triumph for conservation that such a spectacular species survived and prospered again. For much of the 20th century Great White Egrets clung on to isolated wetlands in south Eastern Europe; Austria, Greece, Hungary and Yugoslavia were its haunts. Since then it has slowly reclaimed much of Europe with France having its first breeding birds in 1994 increasing to 165 pairs by 2010. From here ever increasing numbers have winged across to England culminating in the first ever nesting at Somerset in 2012.


Great White Egret coming in to land at Holkham Lake

This brings us finally to events at Holkham. Only a few had previously been seen here before a long staying bird appeared at Burnham Overy marshes in October 2014. Here it was happy to spend over a month wandering about often eating moles alongside our herd of Belted Galloway cows. It looked a very odd combination – stately white giant bird of Eastern origin alongside short stocky black and white cows from the lowlands of Scotland! It seemed rather comical that when the cows moved to Holkham, so the egret followed. When the cows were finally taken to Warham to overwinter, so the lonely egret stayed only a few more days before departing to the west. The next autumn saw what was perhaps the same bird return and by the spring and summer of 2016 it was joined by five others. This would have seemed unbelievable only a few years previous. Following the successful breeding at Somerset, we soon became hopeful that a similar occurrence might be forthcoming at Holkham. Things moved quickly and incredibly pair nested late on in the 2016 breeding season. Despite allowing no disturbance and keeping their whereabouts a secret the pair failed only a few days away from their eggs hatching. Although a huge disappointment we did not have to wait too long as this year we were pleased to announce that a pair did breed again and this time produce three healthy looking flying youngsters. We have officially become home to the UK’s only nesting Great White Egrets away from Somerset!


Here a juvenile Great White Egret is getting ready for its maiden flight !

As well as our breeding birds we had some very other notable occurrences. Firstly in April a vagrant Black Kite from southern Europe appeared, only to be escorted away from the wood by a Great White Egret. This might well have been the first time ever in the UK that these two rarities were seen flying side by side! It was also a bit of good fortune maybe, as Black Kites are known to actively search out the eggs of egrets and herons in European colonies, so our newest residents acting as 'guard dogs' perhaps did us a bit of a favour! Another interesting sighting was that of an egret bearing colour rings on its legs. After a bit of research we found out that it had been ringed on the Atlantic coast of France as a nestling in 2013 and not been seen thereafter. As far as we are aware it is the first colour ringed bird to have been seen here in Norfolk.


Black Kite and Great White Egret, a rare sight indeed !

Currently all the birds can be seen with relative ease. They favour the dykes and pools of the grazing marshes and despite often disappearing down into the dykes to feed on fish it is not long before one emerges to fly over the marshes. Their huge size and ponderous flight makes them look rather like albino eagles from a distance! Last year up to two birds regularly started to catch fish alongside the road in Holkham Lake close to the hall. It allowed an incredible insight into their lives and behaviour as they were oblivious to passers-by. In the meantime either of our hides offers a good chance of a sighting and with autumn now approaching it could be that you might see one in the skies with thousands of Pink-footed Geese returning for the winter. Now that would be a surreal sighting!

Andy Bloomfield, Warden

Tuesday, 8 August 2017

A Kaleidoscope of woodland colours



Hemp Agrimony growing alongside the track near Meales House at Holkham

One piece of valuable work that we undertake every winter and then on a couple of occasions throughout the summer is to maintain the ride side vegetation alongside the southern edge of the main pinewood track at Holkham. This involves cutting back invasive bracken and reed to give more beneficial plants breathing space.  In doing so an incredible habitat forms for an abundance of insects that are attracted by the bountiful supply of nectar. One of the most numerous plants is Silverweed. As its name suggests it has a silvery hue (on its jagged leaves) and is always one of the first plants to emerge up in the spring. It is both abundant and subtle yet could easily be overlooked even though its small yellow buttercup-like blooms seems to be a constant feature of the rides all through the summer. Whereas Silverweed is low growing ground cover, in contrast the dainty stems of Common Centaury stand slightly taller. These pink members of the gentian family again seem to be in flower all through the late spring and summer. Not only do they grow on the ride sides but also in the older sand dunes of the reserve.


The beautiful and often numerous Peacock butterfly


The Great Pied Hoverfly, a striking looking insect

The real draw for insects however are two more very different plants. One of them, Hemp Agrimony, is impossible to overlook as it grows to just over a metre tall and has a mass of tightly knitted pink blooms. The plant has long been used in herbal remedies for treating cold, flu and high fever. For us at Holkham it is our major source of summer nectar and an absolute magnet for insects, butterflies in particular. From mid-July to mid-August take a walk past Meales House and see for yourself. On a hot day the air above the plants will be teaming with activity. Up to 27 species of butterfly alone have been recorded over the years feeding on the plant. From tiny moth-like Small Skippers up to the large and well known Red Admiral, all shapes, sizes and colours in between make up this diverse group of insects. Here on the reserve we take part in a transect organised by Butterfly Conservation to monitor trends and abundance of all the butterflies. It involves walking the same route weekly, something that has been done continuously since 1976 and is one of the longest constant effort sites in the country.   

At Holkham we have been lucky, we have yet to actually lose any species, in fact we have actually gained 11 species. Surprisingly some common species were not noted initially. The first Comma (now a common species) was recorded on the transect in 1980, the first Holly Blue in 1991 and White Admiral in 2003. All are distinctive in their looks and with patience and luck all can be seen at Holkham in July.  This year we have seen large numbers of Red Admirals, three years ago it was all Peacocks and Painted Ladies. You might even be lucky and see a scarcity such as a White-letter or Purple Hairstreak or a Silver-washed Fritillary. The latter is very large black striped orange species that has only moved to Norfolk in recent years from woodlands in the south of England. The variety of butterfly colours can be overwhelming when seen for the first time!


The Silver-washed Fritillary, once rare in Norfolk but now on the increase

Another more subtle plant that grows along the same ride, yet blooms slightly later is Fleabane. This warm yellow plant also grows in thick clumps but unlike Hemp Agrimony is lower growing (standing about 60 cm tall) and hence seems to attract a variety of the smaller butterflies such as Common Blues, Small Coppers and Brown Argus. Fleabane too had old traditional values. As its name suggests it was used as an incense to repel insects, while another use was as a cure for dysentery.


Longhorn beetles can be distinguished by their over-long antennae, this species is called the Golden-plumed Grey Longhorn

As well as butterflies the flowering plants of the woods attract an array of bees, hoverflies, dragonflies, damselflies and beetles, too numerous to mention here! Keep a particular eye out for longhorn beetles, these can truly be spectacular. With overlong antennae they can look both comical and fearsome at the same time! So if you want to witness this mini spectacle of beasts and bugs come along before the summer is out or put a date in your diary for next year.


Andy Bloomfield, Warden

Wednesday, 26 July 2017

Foxes and Tigers of the Sand Dunes


 Bird's foot Trefoil growing in a dune slack at Burnham Overy Dunes

On the nice days we have been enjoying this summer if you’re at Holkham visiting the beach why not take a bit of time to have a wander through the adjacent sand dunes? As usual for the time of year the whole stretch of the coast between the pines and beach from Holkham Gap through to Overy Harbour is awash with varying hues of colour thanks to an abundance of wild flowers. The overwhelming colour is yellow. Ragwort, so despised as an agricultural weed and renowned as being a ‘killer’ of cows and horses is just beginning to bloom. More subtle and lower to the ground are the dandelion-like Cat’s-ear followed by succulent Biting Stonecrop, and even shorter in height the pea-like Bird’s-foot trefoil (often known as eggs and bacon) and Lady’s Bedstraw. The latter was formerly widely used to stuff bedding prior to the arrival of the modern day mattress. Its aroma described by some as smelling like honey (or dried hay!) was said to aid in a good night's sleep whilst the Scandinavians used it as a sedative for women during childbirth.


In contrast are the pinks and purples of rosebay willowherb. This large robust plant stands relatively tall and often grows in dense clumps. In the past it has grown most prolifically on ground that has been scorched bare by fire (hence its often used name ‘fireweed’) but thankfully we have escaped fire ravages of a major scale in recent years. In a good year it can create a distinctive pink swathe through the older dunes. All these plants provide a home for a bewildering array of insects ever in search of nectar. It really is the time to be out in the dunes in search of our native wildlife. 


Dark Green Fritillary, a large strikingly marked butterfly of the sand dunes

Look out specifically for the Dark Green Fritillary butterfly. This orange and black ‘sprite of the dunes’ moves fast from bloom to bloom,  unless you are fortunate enough to find one that has just emerged. Then its full range of colours can really be appreciated. With its orange and black chequered upperwings and its stealth like movements I often liken it to a tiger of the insect world! So if it is orange and black why is it called the Dark Green Fritillary? If you are lucky in gaining a close up view, look out for very fine dark hairs covering its thorax and also its beautiful green underwings with white spots. These spots when seen on the right day can shine with an iridescence that makes them resemble jewel-like pearls. These are best seen when the butterfly is low to the ground. I have occasionally seen the odd one actually laying its eggs in the sand on the small stems of violets that its caterpillars like to feed from.


Foxes and Cubs, sometimes referred to as 'the Devil's Paintbrush'.

One plant that offers a slightly different hue is the striking orange Foxes and Cubs or Orange Hawkweed. It too is a great source of nectar. This plant however is not a native, being introduced to the UK in the 17th century from Europe. It gains its main English name from the orange colour resembling a fox’s fur and the buds found in waiting underneath looking like its cubs. Yet another old name for it is the rather more sinister Devil’s Paintbrush.

Andy Bloomfield
Warden