Local communities

Alasdair Fagan – Woodland Creation Officer

My job here at the National Park Authority means that I get the opportunity to be out and about in the North York Moors and get to places that most don’t get the opportunity to see. These hidden places are special for all sorts of reasons, in particular I get the chance to see some extraordinary woodlands – I admit I might be a little biased.

Recently we were out monitoring a woodland planting project near Castleton which meant we had to trek through a small existing woodland to get there. This was a combination of well-developed riparian (wet) flood plain woodland along river margins, wet marshy grassland filled with flowering plants and ancient woodland remnants creeping up the valley sides including oak, birch, hazel, alder and willow. Many of the woodland spring flowers were still in bloom and the woods were a lush green and bursting with insect and bird life.

Ancient Semi Natural Woodland site. Copyright Alasdair Fagan, NYMNPA.

As we approached the edge of this woodland I noticed something wriggling in the grass – it was a slow worm! Coming across this legless lizard species (Anguis fragilis) was a first time for me. Obviously I wouldn’t usually pick up/disturb wildlife but in this case I took the opportunity to move the slow worm to the cover of an old iron sheet as they are quite high up on the menu for many predatory species (birds, adders, badgers etc.).

Slow worm - copyright Alasdair Fagan, NYMNPA.

On the way back as we ducked, scrambled and tramped back through the same woodland I almost tripped over what can only be described as a large mound of leaf litter on the edge of a clearing. As I looked a little closer I noticed that the surface of the mound was moving – it was alive with wood ants! I was surprised to see them here as. I previously worked in Scotland and had always associated wood ants with more northern forest habitats. But they were definitely wood ants and they are surely an indicator that this particular woodland is in good ecological health.

Close up of a Northern hairy wood ant. Copyright Alasdair Fagan, NYMNPA.

Northern Hairy Wood ants (Formica lugubris) are a species of wood ant found in Scotland and in only two areas in England – the Peak District and the North York Moors. They are a fascinating species – I’m no expert yet but here are a few facts about our internationally important Northern Hairy Wood Ants:

  • The Northern Hairy Wood Ant currently has a near-threatened conservation status.
  • Northern Hairy Wood Ants ‘farm’ sap-sucking aphids (that favour oak and birch) for their honeydew. They gently stroke the backs of the aphids which then produce the sugar rich liquid in exchange for protection, and the ants use it to feed their young.
  • The ants take specific roles in the aphid farming process including; ‘shepherds’ who collect the honeydew, ‘transporters’ that move the honeydew to their nest, ‘guards’ that protect their aphids from competitors, and ‘scouts’ that search out new aphid colonies.
  • They employ a polydomous (many homes) nesting strategy whereby they have a number of nest mounds which operate as a single colony. The founding of additional nests allows for the expansion of the colony allowing it to grow and capitalise on new foraging and feeding opportunities spreading out through suitable habitat. If a smaller outlying nest is attacked or in danger then it will be abandoned and the inhabitants will return to the central nest.
  • Similar to other ants foraging workers leave pheromone trails, to good nectar sites or to groups of aphids, which direct other foragers to these valuable resources. The trails can persist for months.
  • The nest mounds of Northern Hairy Wood ants provide accomodating habitat for other invertebrates too. These include a variety of beetle species as well as the Shining guest ant (Formicoxenus nitidulus). This ant species lives within wood ant nesting colonies, accepting food from the host species and establishing its own discrete nests inside hollow twigs within the larger nest, raising its own brood. The Shining guest ant is a species of conservation interest, a priority species of the UK Biodiversity Action Plan and listed as ‘vulnerable’ on the IUCN red list.

Northern hairy wood ant nest - if you look carefully you can just make out the well camouflaged orange/black coloured ants. Copyright Alasdair Fagan, NYMNPA.

The intricacies of woodland ecology are often complex and astounding. My job means I work on woodland planting and creation and by the very nature of the timespan of trees I know that I’m likely never to see these new woodlands in their future glory. Therefore it’s very important to me to keep a perspective, looking at woodlands at a landscape and spatial scale and considering woodlands over their likely lifetime. Woodland visits like this one are what inspire me to want to create new woodlands and plant more trees, to establish the woodlands of the future.

If you might be interested in creating woodland in the North York Moors and would like more information about opportunities please contact me or call on 01439 772700.

Bees’ needs

Aside

Following on from Abi’s bee blog post a fortnight ago, it’s now Bees’ Needs Week 2018.

Top 5 Actions that people can take for bees and other pollinators – you don’t need to be a farmer or a major landowner:

  • Grow more plants
  • Let your garden go wild (even just a bit of it)
  • Leave your lawn to grow a bit more
  • Live and let live when it comes to pollinators and their homes
  • Avoid using pesticides

Wild bee on Field Scabious

Evaluating bees

Abi Duffy – Conservation Trainee

One of the sounds of summer is the recognisable buzzing of busy bees. Bees are a beautiful symbol of British summertime, but much more importantly are one of the best performing pollinators vital for pollinating plants and crops across the world.

Bee facts:

  • Of the 270 species of bee to have been recorded within Britain, 27 of these are bumble bee species and there’s only 1 honey bee species.
  • Wild bees pollinate two thirds of British crops whilst cultivated honey bees pollinate the remaining third.
  • The exact economic value of pollinators in the UK is uncertain due to small numbers of studies but is estimated at hundreds of millions of pounds (DEFRA).

I’ve been wanting to learn more about bees and how to identify different species, I was fortunate enough to travel to the Field Studies Council’s Malham Tarn Residential Centre at the start of June to take part in a Steven Falk Bee Workshop. Steven wrote the ‘Field Guide to the Bees of Great Britain and Ireland’ which we used throughout the workshop, making use of the guide’s dichotomous keys and illustrations and photographs of the different bee species.

It was a really interesting course – we focused on the habitats around Malham Tarn and the bees that can be found there. The habitats we visited included nationally important calcareous (limestone) grassland and fen/mire (wet grassland) habitats which are part of the Malham-Arnecliffe Site of Special Scientific Interest. We saw fabulous plants such as Bird’s Eye Primrose, Butterwort, Northern Marsh Orchid and Water Avens which was particularly popular amongst the bees.

We identified thirteen different species of bee using these habitats. These included the Tree Bumblebee (Bombus hypnorum), a Red-tailed Bumblebee queen (Bombus lapidarius), the Bilberry Bumblebee (Bombus monticola) and the Moss Carder Bee (Bombus muscorum). To ID accurately we learnt to catch the bee carefully with a net and then place it into a container to get a closer look at the head, thorax and abdomen to look for distinguishing features. After a few minutes the bee is released back where it was found.

Declines in bee populations are due to a dangerous combination of reasons which together add up to a growing crisis – reasons include climate changes, creeping urbanisation, agricultural practices including using pesticides, a decline in habitats including the loss of meadows – unfortunately 97% of wildflower meadows in Britain have been lost since 1937.

Bees need continuous legume-rich flower habitat to sustain populations. Lots of bee species live in large colonies and need enough flowers in their surrounding habitat to sustain up to 400 worker bees over a season so that a colony can successfully produce new males and queens. Remaining species rich grasslands like meadows have become isolated across the landscape as areas shrink and contract, such habitats need to be better linked by creating corridors and stepping stones for bees to move through and between and so be able to make best use of the nectar (and pollen) producing plants. Like many other species, bees benefit from ecological networks where semi natural habitats are biggerbetter and more joined up (Making Room for Nature, 2010, John Lawton)As well as the species rich grassland areas themselves there are other useful linear versions such as species rich road verges, arable farmland flower margins, and native species hedgerows which can all act as useful corridors for pollinators. Domestic gardens with bee friendly plants can act as useful refuelling stops/stepping stone habitats. 

The Pollinator Monitoring Scheme brings together experts and the public to monitor pollinator populations over time. Anyone can join in with the Flower-Insect Timed Count, which is reassuringly complex.

If you want to help build up a national picture of bee populations then The Great British Bee Count continues until the 30 June this year. There is an App to help you to ID and record the different bee species you see. Sightings will help the experts to understand how bees are faring and results feed back into the Pollinator Monitoring Scheme.

State of our Soils (and Wonderful Worms)

Sam Newton – Natural Heritage Trainee, Land of Iron

Charles Darwin was an undoubted genius, according to most people’s definition – so it should come as no surprise that he was interested in earthworms. He even wrote a book with the catchy title The Formation of Vegetable Mould, through the action of worms, with observations on their habitats.

Cartoon of Charles Darwin in Punch magazine (1881) - he studied worms for many years, even playing music to them!

Earthworms are fundamental. They are ecosystem engineers – a term associated with important ecological outputs, which can often be stalked by controversy because of the affects caused e.g. Eurasian Beaver (Castor fiber). However, everyone can get behind earthworms; they are the only species playing a significant role in pedoturbation and are a major player in pedogenesis.

What are pedoturbation and pedogenesis? Well, they’re words we should all know. They describe the process of mixing between soil horizons resulting in healthy homogenization, and the formation of soils through biogeochemical processes.

Organic rich woodland soil. Copyright Alasdair Fagan, NYMNPA.

Soil is the unconsolidated material on the top level of the earth in temperate climes. In the UK most plants grow in soil. Our soils are under pressure from erosion/loss, compaction and decline in organic matter. In the 2015 bestselling book, What Nature Does for Britain by Tony Juniper, estimated the annual cost from soil degradation is between £900 million and £1.4 billion, while studies suggest soils will be too degraded for production within around 100 harvests. The need for solutions is urgent.

These aren't sandbanks - this is the sediment (soil) runoff from the Thames, as seen from the International Space Station in 2014

Soil health targets are included in the Government’s new 25 Year Environment Plan. Further national measures are planned through legislation during 2018 to manage all soils sustainably, including devising a soil health index, and updating guidance on crop establishment and optimal tillage choice.

Earthworms are crucial for tackling these problems and maintaining the health of soils. Still little is known about earthworms, despite Darwin’s efforts. We know there are 29 species in the UK, split into four groups: composters living in organic rich vegetation, epigeics living amongst leaf litter, endogeics living in the soil, and anecics living in vertical burrows. They all eat (and so recycle) decaying material, help drainage and aeration, and are food for many other species (so crucial for biodiversity). The fact that all four groups and all the species have varying ecology enhances their benefits to the reducing of erosion, compaction and the loss of organic matter, therefore benefiting the entire ecosystem – including us.

It will be very important to increase our understanding of distributions and ecology of each earthworm species, to help us to properly conserve and encourage worms to be a vital partner in such a time of soil health concern.

What is known about worms...all earthworms are hermaphrodites - mating head-to-tail by covering themselves in mucus and exchanging sperm. From Science Learning Hub.

The Earthworm Society of Great Britain and Northern Ireland has information regarding the recording of earthworms, identifying different species, and further facts on their biology and ecology.

The British Society of Soil Science is supporting the advancement of soil science in the UK. The more we understand the resource the more we can do to conserve and enhance it.

Lunch time research

Joan Childs – Head of Volunteer Service

When I returned to live in North Yorkshire recently, I unearthed some old records of the rare hoverfly Parasyrphus nigritarsis from the Farndale area, and decided to look for this species along the River Rye, Helmsley – close to where I now worked, because it looked to be a similar habitat. This section of the riverbank is designated as a Site of Importance for Nature Conservation (local designation for important wildlife sites) from Helmsley Bridge down to West Ness.

Swathes of dock (Rumex spp.) by the River Rye, Helmsley. Copyright Joan Childs, NYMNPA.

The larvae of this hoverfly feed on the eggs and larvae of Chrysomelid beetles on alder, sallows i.e. willows, and dock (Rumex spp.). Back in May, I found some of the dock beetles by the River Rye, and started to turn the dock leaves over to look for their egg clusters on the underside. While I was doing this I noticed that a hoverfly was engaged in exactly the same search pattern as me, hovering around the leaves, and disappearing underneath them, one by one! This behaviour, and the broad, dark-orange stripes on the abdomen, suggested that I had found the hoverfly in question.

Adult P nigritarsis showing the black feet from which it gets its name. Copyright Joan Childs, NYMNPA.

Catching one of the three I saw confirmed that it was, and that it was a female. Several of the clusters of dark orange beetle eggs were overlaid by the paler yellow eggs of the hoverfly.

Dock beetle egg cluster overlaid by the pale yellow eggs of P nigritarsis. Copyright Joan Childs, NYMNPA.

In June, I returned to the site and found that larvae had emerged from the P nigritarsis eggs and were feeding on the beetle eggs and larvae. Over the next few weeks the larvae were observed feeding and growing, eventually becoming harder and harder to find as they dispersed following the beetle larvae and then going into diapause (suspended development) in leaf curls and in the leaf litter, where they will spend the winter before pupating and emerging as adults. The hoverfly larvae will face a number of potential dangers over the winter, including a rise in water levels depositing mud across the lower dock leaves, and possible negative effects from agricultural land management.

Growing P nigritarsis larva feeding on beetle eggs. Copyright Joan Childs, NYMNPA.

Having found a technique for locating the P nigritarsis, I checked many clusters of beetle eggs on dock in a number of other sites, but did not find any further hoverflies. This suggests that this is a genuinely scarce species, not just overlooked. Other sites where the beetle occurred on dock but the hoverfly was not present, showed extensive beetle feeding damage to the leaves – which did not exist at the site by the River Rye, showing that P nigritarsis can significantly affect the beetle population.

Letter from Scotland

Sam Jones – previous River Esk Project Student

I still recall the morning as, fresh-faced and hopeful, I sat in the back of a bus trundling along country roads towards the North York Moors. As we turned a corner and crested a ridge I was gifted my first view of the National Park and I could feel butterflies in my stomach, this would be my first real job in conservation. This was the start of my life serving the environment as I saw it then (and still do now I suppose). That was about four years ago, things have moved on quite a bit since then.

I worked for the National Park Authority on a year in industry placement back in my third year of University assisting with the Esk Pearl Mussel Salmon Recovery Project lead by Simon Hirst aimed at conserving the remaining Freshwater pearl mussel population in the River Esk. It was a wonderful and varied experience.

At the end of my time I spent a week wading through ocherous becks in the very upper reaches of the Murk Esk. I was rather cheekily using my last few weeks working at the National Park to collect data for my upcoming final year project. I collected samples of upland invertebrates from becks through moorland and coniferous woodland to test the effects of acidification on aquatic life, and to see how the impacts of acidic moorland and plantation woodlands compare. My project has now been published although you need journal access to see the whole thing. Simon has asked me for a basic summary of my findings and conclusions – so here goes…

I used aquatic invertebrates as indicators of environmental degradation. It’s well recognised that moorlands and uplands can have acidification issues, and the North York Moors may well be one of the most extreme areas for it in the UK with its nearby zones of industry. Acid issues have been recorded in local becks in the past, including severe fish kills. However my results were a little surprising. Originally I thought that plantation woodland, being the newer and least natural habitat (compared to moorland which is also man-made habitat), and having less ability to slow down and buffer the incoming water, would have a much more degraded community. However, my results showed significantly more acid sensitive species living in the woodlands than the moorland. This was despite the fact that previous studies had recorded lower pH values (i.e. more acidic) in plantations than in moorlands. I think that the reason for this is the woodlands provide a more diverse and richer freshwater environment for the invertebrates to live in. This is a good sign as it shows that the conifer plantation woodland, that so much of our countryside is dominated by, may not have such a bad effect on aquatic life as once assumed. The aquatic communities were also generally healthier than would have been expected given the severe acidification. I think this shows that the species of invertebrates living in the uplands of the North York Moors are well adapted for highly acid conditions and that, despite the seemingly poor chemical results, life in the upland becks is thriving.

What happened next? After I graduated from the University of York I went on to work for Natural England, the Environment Agency and now I’m part of an ecological consultancy. I’ve come full circle, and recently I was lucky enough to get accepted for a PhD up in Inverness studying Freshwater pearl mussels. Apparently they needed someone with more waders and bucket experience than lab experience, and I fitted the bill.

Scotland is one the great bastions of the Freshwater pearl mussels with populations of tens of thousands in numerous rivers and multiple populations with favourable age structures and reproductive ability (unlike in the Esk sadly). As such, my PhD is to study these populations and monitor them using traditional methods. However the focus of the investigation is to allow comparison of conventional survey methods with new eDNA techniques. Environmental DNA (eDNA) is a method of monitoring species or habitats using the DNA that is freely found in the environment. All organisms living in an environment discard DNA, whether through waste, dead cells, carcasses, etc. and this can be picked up in trace amounts in water, soil, and even air. With Freshwater pearl mussels the hope is that DNA markers and techniques can be designed to allow detection of small or isolated populations of pearl mussels in rivers simply from a scoop of river water downstream of these prospective populations. There is also potential that the techniques could be used to monitor the size, health and population structure of these populations and perhaps even help identify sub species or genetically distinct populations. Whether this is possible or not, the possibility of cheaper and easier monitoring of pearl mussels fundamentally helps with conservation efforts.

I’m hoping to be able to keep Simon and the Esk Project up to date with our findings and perhaps provide some new information and techniques that may help the Esk’s own struggling mussels over time.

Anyway, that’s my little summary of things. I hope you guys found this interesting.

Thanks for reading, and keep on supporting the National Park,

Sam

A to Z: a multiplicity of Ms

M

MAGNETITE

As mentioned previously, in the 1850s a seam of iron rich ironstone was discovered in Rosedale. Also known as lodestone, magnetite had long been a valued mineral because of the amount of iron ore it contains, so much so that it is often magnetic.

Rosedale - copyright Colin Dilcock, NYMNPA

The discovery in Rosedale led to the rapid development and expansion of the mining and calcining industry there and in the wider area. There were great expectations …

“Professor Phillips delighted and informed the company by his description of the ‘Ironstones of Cleveland’ … The Rosedale band at its richest points, yielded 50 per cent [ore] and in many places 42 per cent. The Rosedale stone was magnetic and contained phosphorous, it was not merely magnetic, but it had an inherent magnetic polarity … There must spring up over the Cleveland district, through the working of the iron ore, great towns, with a numerous and active population; and, as a result, the moorland would be brought under cultivation and this once dismal tract of 20 square miles would rejoice in all the material means that could promote human happiness and prosperity…”

From a meeting of the British Association for the Advancement of Science at Leeds, as reported in the Manchester Courier and Lancashire General Advertiser, 2 October 1858.

However the actual magnetite seam was soon exhausted leaving the industry exploiting poorer ironstone and slowly declining into the 20th century. The magnetite proved to be rather a flash in the pan.

This Exploited Land of Iron logos

MESOTROPHIC LAKES

There are very few natural lakes in the North York Moors due to geology and climate, which makes Lake Gormire on the south western edge of the National Park even more remarkable. In the last Ice Age a hollow was formed by a meltwater channel between the edge of the moving Vale of York ice sheet and the edge of the North York Moors gritstone escarpment. The channel damned up and the lake left behind divided into two bodies of water – Gormire and the much smaller, Buttermere.

These are mesotrophic lakes – containing a narrow range of nutrients in medium concentrations. This type of lake chemistry is rare and becoming rarer as lakes are effected by artificially increased levels of nitrogen and phosphorus and so become eutrophic. Lake Gormire is surrounded mainly by semi natural woodland and fed by springs and so largely circumvents the risks of artificial diffuse pollution and nutrient enrichment.

Because of their chemistry Mesotrophic lakes can support higher levels of diversity of macrophytes (algae), aquatic plants, invertebrates and fish. The fen (‘mire’, ‘mere’) plants around Gormire/Buttermere reflect the acid soil, so there is Marsh cinquefoil Potentilla palustris, Common skullcap Scutellaria galericulata and Tufted loosestrife Lysimachia thyrsiflora, as well as Bog bean Menyanthes trifoliata and Water horsetail Equisetum fluviatile. Gormire is particularly popular with noisy water birds, mating toads and freshwater leeches, all exaggerating the primeval sense inside this Ice Age hollow.

Lake Gormire from Cleveland Way, north of Sutton Bank - copyright Mike Kipling, NYMNPA

Lake Gormire and the area around it is a designated Site of Special Scientific Interest. The cliff slope woodland above Lake Gormire is the Garbutt Wood Nature Reserve managed by the Yorkshire Wildlife Trust.

MILKY WAY

The Milky Way is a galaxy of billions of stars and planets sometimes partly visible to the naked eye as a milky looking band of light in the night sky.

Milky Way and Perseid Meteor Shower Sutton Bank - copyright Russ Norman Photography.

We’re in the middle of the Dark Skies Festival 2017 here in the North York Moors National Park. The dark skies over National Parks make it easier to see the lights of the galaxies around us. This February is particularly good for viewing Orion and also a very bright Venus.

February 27 1920   The mysterious stars

…Later in the evening a half-moon shone in a filmy sky across which, from S.E. to N.W., ran a Noë-ship of thin white clouds. A soft mist hung in the far valleys, but the nearer moory slopes loomed clearer. In the pastures the furze bushes were startlingly like huge black beasts grazing on the rimmed herbage. No sounds broke the utter silence of the moonlit hills; the wind had almost died away, but as I stepped over the little rill from Thunderbush Farm [Commondale], I heard its faint, musical ripple.

The ever-mysterious stars flashed through the interspaces of the filmy clouds and circled silently above the dim earth. Sirius flashed due south whilst mighty Orion hung high above the moor edge, his glory somewhat dimmed by the moon. What would life have been without the stars?”

A Man of the Moors: Extracts of the Diaries and Letter of Frank Elgee.

MINI-BEASTS

We use the term mini-beasts for the tiny invertebrates that go without notice until they’re looked at under the microscope and a menagerie of marvel and dread is revealed.

Identifying and counting river invertebrates is a very useful way of assessing the health of a river at a particular spot. Certain species indicate good water quality and others, poor water quality; a change in species/numbers indicate a change in water quality e.g. a pollution incident. There is a national programme of riverfly monitoring led by the Riverfly Partnership. Results are recorded centrally and indications of a potential incidents are reported to the Environment Agency. The National Park run a number of local Riverfly Monitoring Workshops for volunteers – the next one is 1 March.

MOSCHATEL Adoxa Moschatellina

Moschatel is a perennial unobtrusive plant which likes the damp, shady conditions found along woodland edges and on shaded hedge banks. It flowers between March and May, producing five lime green flowers on top of a leafless stalk, four flowers face outwards and one flower faces upwards, forming a cubic which has led to the plant’s other common name – Townhall Clock. The plant grows along the ground through rhizomes with the flower stalks growing up through its leaves to only c. 15cm tall. It is a common plant but easy to miss – look out for it in early spring before it gets hidden by taller plants.

Moschatel at Sieve Dale. Copyright Ami Walker, NYMNPA.

MOTTE AND BAILEY

Historic England suggest there are over 600 motte castles or motte-and-bailey castles in England. These were early medieval fortifications built by the Normans and made up of a large mound of earth/rubble (the ‘motte’) with a defensive palisade and tower on top, and an embanked enclosure with other buildings (the ‘bailey’) adjoining.

A motte and bailey castle could act as a fort when required as well as providing the residence for the local landowner/representative of the King and a centre for feudal power. They were often built on high ground to take advantage of the extra height to dominate the landscape and overlook access routes.

Soon after the beginning of Norman rule in England came the ‘harrying of the north’ – a military campaign to overcome and overwhelm the population in the north of the country and hammer home the idea that the Normans were here to stay. The new motte and bailey castles were a highly visible tool for holding that ground and reinforcing that message.

By the 13th century castle design had moved beyond the basic motte and bailey. Although the timber structures have largely gone, the earthworks are often still traceable in the landscape, and rubble mottes and the remnants of stone towers remain. Many are scheduled. Examples in the North York Moors include Hood Hill, Easby motte, and Foss Castle.

MOTHS

Moths are often considered the poor cousins of butterflies in the Lepidoptera family. The most obvious difference between butterflies and moths are that the former are active during the day whereas moths are mostly (but not all) nocturnal, feeding on the nectar of night blooming/night scented plants. Another difference is that when resting, butterflies usually close their wings whereas moths leave theirs open and this makes it easier to examine their intricate patterning and refined colouring. But as with most ecological questions – what is the difference between butterflies and moths? – there is no obvious answer and always an exception. Moths can be just as colourful, just as beguiling and just as in peril, as butterflies. For more on moth conservation see here.

Shandy Hall, Coxwold has become a location for moth study and reporting over the last few years. The gardens there provide a semi-natural/cultivated habitat for many species – over 400 different species have been recorded in the gardens to date.

Previously on the North York Moors A to Z … A, B, C, D, E, F, G, H, I, J, K, L

Ageing Mussels

Simon Hirst – River Esk Project Officer

As mentioned previously, the River Esk in the North York Moors is the only river in Yorkshire with a Freshwater pearl mussel population Margaritifera margaritifera. The population is estimated to be comprised of approximately 1,000 individuals and is in drastic decline, so much so that it is on the verge of extinction. The decline is due to a number of linked causes such as water pollution, choking of the river bed by sediment build-up, deterioration in fish numbers and habitat degradation.

A dense bed of healthy adult mussels in Scotland. Copyright Sue Scott - SNH,

We’re working to improve the riparian habitat and so help secure the local population of Freshwater pearl mussel in the River Esk. We recently sent a sample of mussel shells from the Esk* over to the Swedish Natural History Museum in Stockholm, in order to determine the age of the mussels in the River Esk. The maximum age of Freshwater pearl mussels in the wild has been shown to vary considerably, from a low of 35 years in Spain (warmer, lower latitude rivers) to over 200 years in arctic areas (colder and high latitude rivers). Information from the ageing study would tell us how long we have left to save the Esk population from extinction and help identify the approximate time when the River Esk mussel population went into decline.

Dr Elena Dunca from the Swedish Natural History Museum sectioned (cut though) the shells supplied and then counted the growth lines on the mussel shell using a high powered microscope.

1

Growth lines visible on the freshwater pearl mussel shell.

Esk FWPM - Age and length graph - Swedish Natural History Museum

This age/length graph will allow us to age fairly accurately any mussels we find in the wild in the future just by measuring them.

A total of 10 shells were aged by Dr Dunca, and the graph below shows that the mussels sent to Sweden ranged in age from 45 to 88 years of age.  The mussels in the River Esk also showed normal growth rates.

Esk FWPM - Length frequency graph - Swedish Natural History Museum

Length frequency graph of mussels in the River Esk

The smallest live mussel we have found in the Esk up to now was 75mm (approximately 28 years of age). This means the last time the Esk mussels reproduced successfully in the wild was in the late 1980s. The largest mussel we have found in the Esk was 156mm (approximately 100 years of age), which means it was born around the time of the First World War. The vast majority of the mussels are around the 130mm-140mm size range (approximately 80 years of age). We now know for scientific certainty that the Esk has an ageing population in need of help!

The best hope for our mussels is for them to start to successfully reproduce again. We’re working with the Freshwater Biological Association (FBA) who are carrying out captive breeding work in the Lake District. We hope to re-introduce the captive bred young Esk mussels from the FBA Facility back into the Esk once the riparian habitat is restored enough to sustain them, and so ultimately stop this species from becoming extinct in the wild (of Yorkshire).

* Please note – No mussels were harmed in the making of this study! We used empty shells that were found on the banks of the Esk.

Thanks to our funders at Biffa Award, for their support to carry out this vital research work.

Biffa

Biffa Award is a multi-million pound fund that helps to build communities and transform lives through awarding grants to community and environmental projects across the UK, as part of the Landfill Communities Fund.

Benefiting bees

Roy McGhie – Conservation Project Assistant

Recently my colleague Ami and I went on an organised farm walk near Menethorpe to the south of the North York Moors. The event was led by the Campaign for the Farmed Environment and the theme was habitat management for pollinators. The walk was well attended by local land managers who wanted to know a bit more about the benefits that pollinators provide, and how they might most easily encourage them, in particular on otherwise unproductive areas of their land.

The main focus of our discussion was inevitably bees – our most efficacious pollinators.  We were given copies of an excellent booklet from the Centre of Ecology and Hydrology called ‘Habitat Creation and Management for Pollinators’.

We’ve mentioned bees a number of times before in this blog, but felt it was about time they had their own post because they are so important.

CFE Farm Walk - a pollinator meadow on the farm we visited full of red and white clover and meadow vetchling. Copyright NYMNPA.

In the UK whilst there is only one species of honey bee Apis mellifera (both wild and semi-domesticated), there are about half a dozen common bumble bees and over twenty common species of solitary bees like mining bees, mason bees and leaf cutter bees.

The bee flying season can begin as early as March and extend right the way into October, as long as there is food i.e. nectar and pollen available. Most species of bees can survive over winter if there is somewhere for them to hole up.

Bumble bees on a thistle - copyright NYMNPA.

The anatomy of different bee species varies greatly, and so to assist most species it’s best to have a wide range of flower species from which they can feed. As some of the mining bees have short tongues of only 4-5mm, they need open flowers such as cow parsley and daisies. The garden bumblebee Bombus hortorum on the other hand has a tongue that can extend to around 12mm, so it can feed from flowers with a long corolla (i.e. petals) like foxgloves and honeysuckle.

As well as fragrance, one of the other things that attracts bees to flowers is colour. So its worth considering maintaining colours throughout the season. For example, coltsfoot and hawk’s beard provide yellow colour from about February to June, and then cat’s ear How we see it (left) and how a bee might see it with UV shades visible (right) - Klaus Schmitt.and bristly oxtongue do the same from June to October. Similarly, a successional combination of white deadnettle, oxeye daisy and yarrow can ensure there are plenty of white flowers throughout the year. Interestingly, it is thought that bees can see in ultraviolet, which means how they perceive flowers will be very different from how we do.

Establishing and managing a wildflower meadow is one of the most effective ways of ensuring bees have a suitable habitat. In addition it is thought that on arable farms having a flower-rich margin on at least 1% of the land will provide significant benefit to pollinators, which in turn will improve crop production and quality. Hedgerows can be another useful way to help bees – cutting hedges on a two or even three year cycle will encourage more hawthorn and blackthorn flowers. When new hedges are planted, a greater species diversity (using hazel, field maple, crab apple, holly and willow where appropriate) will also mean that there is more food and nectar available for a longer period throughout the year.

Bees are fantastic creatures in their own right. They also provide a number of hugely important direct benefits for our countryside and environment. There are things we can do to encourage bee survival such as sowing appropriate wildflowers and creating habitat stepping stones, allowing what we might think of as typically weeds to flourish (in the right place), creating patches of bare ground in sunny dry spots which will allow solitary mining bees to nest, and leaving tall grass over winter which can provide places for bumblebees to hibernate and nest.

Bees are often in the news these days, mostly because they are in decline – they even need their own national strategy. If we can do our best to make the landscape more friendly, we can help give bees a better chance, and ensure they can continue to play a key role in pollinating our flowers, trees and crops.

Bee on red clover - copyright NYMNPA.

For a local initiative – see B-Lines Ryedale