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

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

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 17^th 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

A touch of the Mediterranean

The Avocet – a bird often cited as a symbol of conservation success

This year has so far produced mixed fortunes for the reserve’s breeding birds. April proved cold whilst dry conditions prevailed through the spring, making the marshes less productive for our Lapwing population. The same however could not be said for the Avocet. This iconic bird has long been a sign of good conservation management. With many of the grazing marshes drying out quickly and areas of soft mud (so beloved of wetland birds) turning concrete hard we were extremely thankful for work that was carried out last autumn. The RSPB spoil spreader restored some of the in-field creek features that are a remnant of the days when the freshwater grazing marshes were salt marshes.  By removing the vegetation, the resulting muddy edges prove attractive for terrestrial invertebrates essential for birds to feed on. One particular area at Holkham proved an absolute magnet for birds. Black-headed Gulls were first to colonize and ended up at just over 200 pairs whilst Avocets quickly followed. By mid-June we counted 17 nests in one small area that had benefited from the attention it received. Ultimately, 76 pairs of Avocet were found nesting on the grazing marshes and we  had a count of 288 birds on one single day, a record for the reserve. At this busy time of year the marshes can be a cacophony of avian noises. Gulls shriek, Lapwings wail, Avocets ‘Kluut’ (their distinctive call and coincidentally their Dutch name too!) and Redshanks yelp. Sometimes the gulls take eggs or young Avocets but by and large they are sociable neighbours. There is also safety in numbers. Just watch when a marauding harrier or Herring Gull flies over head – the noise level increases as seemingly every bird gets up to drive the potential predator away. Lone nesting birds are much more at risk than those that favour larger congregations.

Holkham’s marshes where work had been carried out the previous autumn alive with Avocets, Shelducks and Black-headed Gulls.

A less productive area that dried out quickly in a rather parched April.

Avocet chick at about a week old.

The Avocet’s fortunes have not always been so rosy of course. Once plentiful along the marshes of the east coast of England it was persecuted to such an extent that in Norfolk it became extinct in the 1800s. Not only were its eggs collected to make puddings and pancakes but the birds themselves were shot, sometimes as a means of expelling spare ammunition after a day of shooting other quarry. As the birds became scarcer they became more desirable for collectors of eggs and stuffed birds, popular activities of the Victorian ‘naturalist’. Things changed very slowly and from the 1940s onwards birds began to nest again, initially at the offshore shingle spits at Halvergate Island and at Minsmere in Suffolk. Numbers slowly increased and by 1977 it was nesting again in Norfolk. At Holkham, the Avocet started breeding in 1989 thanks undoubtedly to the wetter grazing marshes that are managed with birds in mind.

Another very similar species to the Avocet, yet even more exotic is the Black-winged Stilt. Very much a bird of warmer climes it made the headlines nationally this year with multiple and unprecedented breeding attempts, including three pairs in Norfolk alone. We welcomed our first ever Black-winged Stilts to Holkham in May. However, the three pairs only stayed for a few hours. With global warming and ever growing numbers appearing in the country this could well be the next species to start to nest regularly. With our marshes suitable for Avocets (the same habitat of stilts) we await the future with great interest. Along with Spoonbills and Little Egrets the scene is becoming increasingly more akin to that of the Mediterranean. What will be next?

Holkham’s first ever Black-winged Stilts – sadly they only stayed a few hours.

Andy Bloomfield

Reserve Warden

BioBlitz at Holkham

Holkham’s internationally important wet grazing marshes

Biodiversity is a word we constantly hear in conservation circles these days. In a nutshell it describes the amount and variety of life found within a given area. Holkham is lucky. It has huge swathes of differing habitats within the boundaries of the NNR and therefore a huge amount of biodiversity. This is perhaps more obvious to the casual visitor than they might think. Even on a brief walk from the car park at Lady Anne’s Drive, along the boardwalk to the beach the visitor will pass through grazing marsh, pine woodland, sand dune, saltmarsh and foreshore. Just pause and look around and that biodiversity, that variety of life can soon be appreciated.

This all became even more apparent to me very recently. I was walking alongside one of the grazing marsh dykes carrying out our breeding bird monitoring. The dyke did not look particularly special, reed fringed with the shallower banks peppered with contrasting blooms of Water Parsnip and Water Forget-me-not providing a welcome splash of colour. It looked like any other dyke that can be found along the North Norfolk Coast. But was it? Whilst looking out for broods of Shoveler, Mallard and Coot I started to notice all manner of insects and invertebrates clinging onto or flitting in and around the reeds. Particularly obvious were a number of brightly coloured beetles of the family Donacia or ‘reed beetles’. They shine with iridescent golds and greens. Many were coupled up mating on the stems whilst others were flitting about singly in search of a mate. Up to 15 species are found in the UK and most require microscopic scrutiny to enable definite identification but for the un-initiated just watch them and revel in the glory of their jewel-like metallic colours. They are always found near water as the larvae live an aquatic life.

Donacia clavipes, a species of reed beetle new to the reserve.

Not far away was another vibrant metallic blue/green insect – the Blue Shieldbug which lives on beetles. Another shining black beetle turned out to be a very rare species, Plateumaris braccata. It is a localised wetland inhabitant of southern England and was a new species for the reserve. Not bad considering the reserve already has over 832 species of beetle on its list! Spiders abounded too. Most obvious were the Tetregnatha or ‘stretch’ spiders. They are very long bodied spiders with exceptionally long jaws. They too exhibit a metallic sheen but this time more silver than gold. Their webs are frail and simple, sometimes horizontal to the water’s surface with the actual spider sitting in wait nearby in a characteristic pose, with legs and body stretched out up the stems of vegetation. It would be patiently waiting for any moth or fly that would hopefully cruise into its web. A tiny but delicately marked almost white moth was not far away, the Small China-mark, another wetland species; its larvae live underwater and feed on duckweed.

The Blue Shieldbug, a devourer of beetles.

Another seldom seen inhabitant of the reserve was an insect and quite a spectacular one - a sand loving beetle called Cleonus piger. At close on 20mm with its large ‘nose’ (or rostrum to give it its technical term) it has quite a comical look, with some likening it to a miniature ant-eater! It has been seen on the beach/dune edge where its distinctive tracks in the sand give its presence away.

Almost an Anteater? - A very distinctive beetle Cleonus piger found on Holkham Beach for the first time.

This was just a snapshot of the variety of life found within one small fragment of grazing marsh, but illustrates perfectly just what can be seen if the time is taken to look. The commonplace can be very exciting when viewed for the first time and there are often creatures that are not commonplace, just there awaiting discovery.  So, if all this grabs your attention why not take part in the Norfolk Coast BioBlitz weekend on 22^nd and 23^rd  July? This event is open to everyone from novices to experts and aims to find and identify as many species as possible from Holme to Salthouse over a 24 hour period.  For more information check the events page at www.holkham.co.uk

Andy Bloomfield

Warden

March - Recent Sightings

March started with a real bang! While working on the front of the dunes a Long-eared Owl flew from the edge of the Pinewoods. The good luck continued with sightings of Pallid Harrier over the reserve and the Holkham area.

The reserve in all its glory

With the heavy rain, the wildfowl gravitated up the scrapes with 10,756 Wigeon enjoying the shallows along with 349 Teal, 208 Mallard, 270 Shoveler and 297 Gadwall. The Tufted Duck and Goldeneye preferred the ditches. Only 600 Pinkfeet were counted the majority already migrating north to their nesting grounds in Iceland and Greenland.

Waders such as Dunlin, Lapwing, Snipe, Curlew, Redshank, Golden Plover and the first Avocets have been coming and going. While there have been no sightings of Bitterns I heard their first growls along with plenty of squealing Water Rails.

Herons have been seen returning back to the Heronry

Birds of prey have been magnificent. 13 Marsh Harriers gathered on the reserve as well as Buzzard, Peregrine, Kestrel and Red Kites. The Norton Barn Owl is still a regular sight in the early mornings.

A Marsh Harrier checking out a possible nesting site.

Smaller birds have included Water Pipit, White Wagtail, Reed Bunting were seen as well as my first Treecreeper on the edge of the Pinewoods.

Our first invertebrates have been seen on the reserve with a surprise Buff-tailed and Early Bumble Bee flying past and a Small Tortoiseshell and Comma making an appearance.

There have also been a few fresh Peacock Butterfly about.

To top things off 3 Cranes were seen flying over the reserve on two consecutive weekends. 

PS While writing this a little Field Vole made an appearance, creeping through the open door and hiding behind my wellies! 

Why Birds?

Without the commotion of summer and with the promise of the survey season around the corner spring is one of my favourite seasons. Waders such as Lapwing and Redshank are migrating back to Holkham to nest; Spoonbills have been spotted; Pink-Feet have departed for Greenland and the warden team are preparing for the breeding bird survey season to start. But why do we and most other reserves concentrate so much time on monitoring birds? Why not mammals or insects?

Our early morning geese counts are nationally important.

To tell the truth, we don’t. At Holkham, we monitor a range of species such as Natterjack Toad,  Water Vole,  moths and a range of plants. We even have one of the longest running butterfly transects in the country.

However, birds are the relatively easy to monitor. Birds are conspicuous, meaning they are easy to identify and count. Mammals, on the other hand, are elusive and some groups of insects are difficult to identify without specialist knowledge and equipment.  Birds are also a great indicator species that respond to the health of the entire habitat and respond to changes in predictable ways.

Holkham is an important site for breeding waders. 

The link between bird species and their habitats make them key for identifying habitat quality. Waders at Holkham feed on important mud-dwelling invertebrates which depend on a delicate balance of mud, water and nutrients. Should the numbers of birds change it could indicate a shift in the habitat. The biodiversity of bird species can also indicate successful wider conservation efforts. A study of bird and butterfly species showed that the two were correlated which suggested that the number of bird species would also indicate the diversity of butterflies in small patches of habitat¹. Another study showed the spices richness of birds correlated with six other taxonomic groups².This shows that monitoring bird diversity can give a clear indication of overall biodiversity.

During the summer we map the calls of song birds in the pine woods.

Birds are incredibly useful as indicators for conservation as well as a familiar, fascinating and colourful creature.

1. Blair, R.B., Birds and butterflies along an urban gradient: surrogate taxa for assessing biodiversity? Ecological applications, 1999. 9(1): p. 164-170.
2. Kati, V., et al., Testing the value of six taxonomic groups as biodiversity indicators at a local scale. Conservation biology, 2004. 18(3): p. 667-675.