Cosy and warm

John Beech – Land Management Adviser

Hygge (pronounced hoo–gah) has been a major trend for this Christmas period. It’s a Danish ‘concept’ of living cosily e.g. wearing thick socks whilst drinking hot chocolate and watching Murder She Wrote – which can make us feel better about the icy and harsh season outside.

For a number of wild animal species, they have their own version of hygge except for them it’s a necessary survival mechanism. Hibernation is an extended period of deep sleep, or torpor*, which allows animals to survive the winter extremes. By reducing their metabolic rate and lowering body temperature this enables them to sit tight, conserve their energy and survive through the cold periods when food is scarce or has little energy value. *Animals in a state of torpor rather than sleep can venture out to try and find additional supplies during warmer winter spells.

In autumn as the temperature begins to fall and the nights draw in, many of the small mammals that live in our fields, woodlands and hedgerows forage for extra food to store over the winter and look for a suitable site (a hibernaculum) to hole up in for the coldest part of the year. Autumn months are often one of the better times of year to see small mammals in the North York Moors such as mice, voles, shrews and Hedgehogs (Erinaceus europaeus) out and about eating vast quantities of food to build up fat reserves which will carry them through to the spring.  Following this period of feasting they retreat to somewhere suitably warm and undisturbed and begin to enter into a period of hibernation, which can last for up to four months of the year depending on the harshness of the weather. Also in autumn bats relocate to hibernation roosts looking for a constant temperature and to avoid frosts and freezing e.g. caves, trees and built structures.

And it’s not just our small mammals that hibernate:  Queen bees dig in for the winter and also some species of moths and butterflies, like the Duke of Burgundy (Hamearis lucina) which hunker down in grassy tussocks. Many of our reptiles and amphibians also hibernate. Adders find warmer crevices under boulders or in dry stone walls. Newt species spend the winter in the muddy banks of ponds, under paving slabs, piles of wood or in a handy compost heap. Common Toads (Bufo bufo) sleep out the winter buried deep in damp places such as leaf piles or compost heaps, before emerging to travel back to their traditional breeding sites in early spring. The Common Frog (Rana temporaria) which needs to keep damp is able to partially freeze in its state of hibernation before thawing out in spring. Occasionally such species come out of hibernation during any short sunny spells in the winter to make the most of the weak sunshine, only to return to their hiding place when the temperature falls again.

Malkin Bower, Bilsdale - in winter - copyright NYMNPA.

So as you’re reading this, hopefully somewhere cosy and warm, spare a thought for our wildlife that’s out there sleeping through the winter, hidden away from view deep in their retreats, practising their own life saving hygge and waiting for the first signs of spring.

A to Z – starting, unsurprisingly, with A

We thought we’d try something new, new for us anyway. Now and again we’re going to post bits and pieces on conservation. the National Park and the North York Moors – under each letter of the alphabet. That’s the plan – we’ll see how far we get.



The North York Moors includes large areas of forest owned and/or managed by the Forestry Commission. These forests were planted at the beginning of the 20th century when in a time of uncertainty following World War One it was decided that the nation needed to create and maintain its own timber resource. This afforestation had a dramatic long term effect on the landscape of the North York Moors which continues today. Timber and other wood products from both public and private enterprises in the National Park remain economically important to the North York Moors.

Boltby Forest - Southwoods - NYMNPA

Boltby Forest - Southwoods - NYMNPA

This is using the word afforestation as it is understood nowadays – turning land into forest by planting trees. In medieval times afforestation meant designating land as forest and therefore placing it under forest law, separate from common law. A forest meant an area for hunting belonging to the Crown; so heathland and grassland as well as woodland, wherever deer and boar and other game animals would live.

ALCATHOE BAT Myotis alcathoe

This bat was first identified as being in the United Kingdom in 2010 – in Sussex and in the North York Moors. It could have been here for years it’s just that it’s difficult to distinguish from other bat species. The Alcathoe bat lives in woodland and swarms with other bats to mate before hibernation. One of the records in the North York Moors was from the autumn swarming at one of the Ryedale Windy Pits.

Alcathoe bat. From


Alum was one of England’s earliest chemical industries, operating in the North East Yorkshire region from c.1604 until 1871. Alum (aluminium sulphate) was important in textile production which was our main export in the 17th century, and was used as a compound with potassium (e.g. seaweed) and ammonia (e.g. urine – at first collected locally and later also shipped in from coastal towns) to make vegetable dyes colour-fast. With the exception of one Alum Works in Lancashire, North East Yorkshire produced the entire supply of English alum until the early years of the 19th century. The main Alum Works and Quarries were along the coast, which provided better exposures of the mineral together with the most practical means of transport to markets when travelling by sea was a much better prospect then setting off across country. Although softened by over a century of weathering and coastal erosion, the extracting and processing industry has left huge imprints on the North York Moors landscapes which can still be seen today for example at Ravenscar, Saltwick, and Kettleness.

Saltwick Nab Alum Works - NYMNPA Saltwick Nab Alum Works - NYMNPASaltwick Nab Alum Works - NYMNPA

Saltwick Nab Alum Works - NYMNPASaltwick Nab Alum Works - NYMNPASaltwick Nab Alum Works - NYMNPA

(WILD) ARUM (Arum maculatum)

Also known as Lords and Ladies, Cuckoo Pint etc.

Grows on hedge banks and on woodland edges in the leaf enriched soil. Common throughout Britain and Ireland.

Looks like something from science fiction and has a life cycle to suit.

Has large shiny green leaves sometimes with dark blotches, followed by a thin leaf like cowl growing up through the centre and partially opening to reveal a smelly purple-ish central spike (March/April). This smelly heat emitting spike attracts insects which then slip down into the plant and are temporarily trapped in the base where they pollinate the tiny hidden flowers (female) and collect pollen from the male flowers to carry elsewhere once released. The leaves and initial spike wither away and are replaced by another spike growing upwards topped with the female flowers as small berries which turn from green to red (July/August). Birds eat the berries – but they’re unpalatable and poisonous to humans, as is most of the plant.

Wild Arum. From Arum. From


The Esk is the principal Atlantic salmon river in Yorkshire. The whole of the River Esk catchment is within the North York Moor National Park.

The rod catch on the Esk in 1923 was 950 fish per year, this number has declined to about 170 fish in 2010. The National Park Authority’s Esk Pearl Mussel and Salmon Recovery Project has been running since 2007 and its aims include reversing the decline in the Atlantic salmon population in the river by improving water quality, improving in-river and riparian habitats and removing barriers to vital fish migration.

Atlantic salmon. From - picture by Thomas Kitchin & Victoria Hurst


i.e. the right attitude to work positively with people in the National Park to listen to what others have to say; to try and tackle concerns; and to take forward National Park purposes together.

The latest example of this attitude in action has been the Dales and Moors Farm Innovation Pilot Project where the North York Moors National Park worked with the Yorkshire Dales National Park and neighbouring Areas of Outstanding Beauty across the wider area and used skills funding through the local LEP to provide free business and environmental advice to guide local farmers into producing their own whole farm plans and tailored proposals for sustainable ways forward for their farms.


White-clawed crayfish - Helen Webster, NYMNPAAustropotamobius pallipes are native White-clawed crayfish. The upper tributaries of the
Yorkshire River Derwent in the National Park still support populations of this nationally declining species. What with needing clean aquatic habitats, competing with non-native aggressive signal crayfish, and suffering from deadly crayfish plague, the White-clawed crayfish are in a perilous situation. Just when you thought their luck couldn’t get any worse, one of these Yorkshire Derwent tributaries, the River Rye, tends to dry out in the summer at one particular location because of sink holes, leaving the local population of White-clawed crayfish and other aquatic creatures stranded.

So just like a year ago, last week we had to launch another rescue mission. Alex led a team of Emily, Simon (who has a licence to trap and/or remove crayfish), Helen the Planning Officer, Alex’s partner Toby, and a helpful man called Jim and his dog. They managed to collect and relocate upstream of the sink holes around 500 White-clawed crayfish (including females carrying hatchlings) as well as 20+ lamprey and 40+ small fish that were scooped up with them.

River Rye crayfish rescue 16 7 15 - Alex Cripps, NYMNPARiver Rye crayfish rescue 16 7 15 - Helen Webster, NYMNPA







River Rye crayfish rescue 16 7 15 - Helen Webster, NYMNPARiver Rye crayfish rescue 16 7 15 - Helen Webster, NYMNPA









River Rye crayfish rescue 16 7 15 - Alex Cripps, NYMNPA

River Rye crayfish rescue 16 7 15 - if you look closely you might make out the hatchlings on the abdomen - Alex Cripps, NYMNPAA couple of weeks before the Environment Agency (EA) had carried out a fish rescue at the same location. The EA rescued and re-located 265 Brown Trout, 65 Grayling, 5 Lamprey and 100s of minor fish species including minnows, stone loach and bullheads. They also rescued 50 White-clawed crayfish, some carrying eggs.

Down below

Entrance to Windypit - NYMNPAA Friday or so ago a couple of the younger and more flexible members of National Park staff (Emily and Jo) joined an expedition down a windypit in the south west corner of the North York Moors.

To find out what happened next, and to discover what a windypit actually is – have a look at this account by Nick from the Ryedale Natural History Society, who went too.

Looking back up out of windypit - NYMNPAInside the windypit entrance - NYMNPA








Emily (I think) inside the windypit - NYMNPAGoing further and further in... - NYMNPA 








Like Nick says, the windypits are incredibly important as unusual geological features (a number are designated as Sites of Special Scientific Interest), as intriguing archaeological sites, and as valuable habitat for swarming/roosting bats.

For additional information see the York Caving Club’s website.

Hunting out Ancient Trees – in the North York Moors

Alasdair Fagan – Conservation Graduate Trainee

Alex (my fellow Conservation Graduate Trainee) and I have been tasked with the discovery, measurement and recording of each of the veteran trees on the Hawnby estate on the western side of the National Park. This is an area noted for its high proportion of tree cover which is a characteristic of the landscape in this part of the North York Moors.

Old/Notable/Ancient/Veteran Trees

Ancient and veteran trees are of high importance biologically as they support a diversity of different plants, birds, fungi, bats and insects. The Natural England FEP Guidance – Ancient Trees defines veteran and/or ancient trees as ‘Trees that are or look old relative to others of the same species’. Characteristics include:

  • Very large girth for the species
  • Hollow or hollowing trunk
  • A large quantity of dead wood in the canopy

The veteranisation of a mature tree is the first indication of the tree’s truly old age and as a part of this inevitable ageing, provides visual signs that the tree has begun to approach the end of its life (hundreds of years in the case of some trees) and in the meantime provides valuable habitats through processes like the decaying of wood.

Different species of trees have differing lifespans and so some tree species will reach maturity and veteran status much quicker (Silver birch for example) than those with longer life expectancy (such as Oak). A difference in the length of time it takes trees to veteranise is inherently valuable to the biodiversity of the area’s ecology, providing habitats for those organisms that depend on a continuous cycle and creation of veteran characteristics to survive.

The Survey

Data recorded from the Ancient Tree Hunt suggests that there are over 102,200 Veteran and Ancient trees in Britain, giving it the highest proportion of Ancient tree cover in the whole of Europe. But there are still parts of the country that have yet to be fully surveyed for these important trees.

This particular survey that Alex and I are carrying out on Hawnby estate involves identifying the species of each veteran tree and recording the tree’s girth, condition, any biological interests associated with the tree, and any threats currently posed to the tree that we might be able to address in order to ensure that it is able to endure for as long as possible.

We’ve used aerial photographs, and Ordnance Survey modern and historical maps (including from over 150 years ago) to establish areas where we suspect there may still be important, notable and veteran trees that aren’t yet part of the Ancient/Veteran tree current record.

We use GPS to record the location of each of the trees we record. Being able to see where veteran trees are across the North York Moors and being able to compare associated data allows us to build up a picture of this asset and to target efforts to keep the trees going as long as possible and at the same time to plant and manage new generations of trees nearby.

The search for veteran trees has so far proved eventful with a valuable opportunity to experience the beauty of the North York Moors National Park during autumn. We’re now up against the seasons as autumn has turned into winter and so it inevitably becomes harder to identify tree species without leaves.

An Unexpected Encounter

We also had a number of encounters with wildlife and the seasonal timing of the survey ensured that we got the chance to see many weird and wonderful species of Fungi.

Something that Mark the Woodland Officer here at the National Park told me when I first began: ‘whenever you look at a veteran tree, always make sure you walk all the way around it first’. Good advice indeed as it is often very easy to assume a tree is in good health when judging it on its appearance from one side, but on further inspection the other side may reveal that the tree is entirely hollow and well into its decline phase. Because of this advice, during the survey Alex and I decided to investigate what appeared to be a dead/relic branch that was still partly attached to the trunk of a tree but had clearly been removed forcefully by a weather event some time ago. As I approached the tree and leaned round the back to peer into the hollowing stem, my gaze was met by the bright yellow and beady eyes of a Common buzzard who was probably perching in the hollow whilst on the lookout for its next meal. The few silent seconds of disbelief (probably on both accounts) were then abruptly brought to an end as the impressive Bird of Prey turned, spread its wings and silently glided away to an alternative (more private) tree nearby.

Heritage of the North York Moors

Our Linking Landscapes programme aims to connect fragmented woodland habitats and areas of high ecological value. Veteran trees (and their associated ecology) have an important role. Many of our most notable and veteran trees are visible today in fields and along dry stone walls and hedges as remnants/relics of historical field boundaries, they remain important features of complex habitat networks throughout the landscape and as part of the programme we’re planting new in-field and boundary trees to ensure that tree habitats remain even when the veteran tree itself has died.

But the biodiversity value of veteran trees within our landscape is something which we cannot replace in the short term. Many species associated with the habitats provided by these trees are specialists and depend on veteran trees for their survival, either directly (beetle larvae living within, and feeding on, the freshly decaying wood) or indirectly (birds and bats regularly utilise the hollows associated with veteran trees for nesting and roosting sites).

It is important that we plan ahead and attempt to provide the best opportunity for the development of future generations of old and veteran trees that we can.

If you come across an Ancient/Veteran Tree – please tell the Ancient Tree Hunt. If you come across an Ancient/Veteran Tree in the North York Moors National Park – please let us know as well.

Hedgerow possibilities: part 1

Kirsty Brown – Conservation Project Assistant

Hedgerows are an important feature of the English countryside, adding to the aesthetic value and character of the landscape around us. Data collected by the Countryside Survey 2007 indicated that there was just under 250,000 miles (402,000 km) of hedgerow in England (Countryside Survey data owned by NERC – Centre for Ecology & Hydrology). Field boundary hedges in and around the North York Moors can be of considerable wildlife value and are a living historic record of demarcation.

What’s in your hedge?

The number, variation and type of plant species in a hedgerow can point towards its age, and some hedges are remnants of ancient woodlands. Rare plants may thrive in and around the footings and ditches. Hedges support a wealth of wildlife as they provide food, shelter and nectar. Pollinators such as honey and bumble bees take full advantage of the early spring flowers of blackthorn and late-season ivy flowers. A plethora of invertebrates live within hedges, seeking out the nooks and crannies, leaves, fruit and soil. Voles, shrews and rabbits create their tunnels in a maze beneath the roots, using the thick hedge to hide from predators as they search for food. Larger mammals such as badgers and foxes also frequently live in and around hedgerows, making use of the food supply and shelter. Bats are known to use these linear features as food sources or as a commuting highway to get between the roost and feeding grounds, choosing the more sheltered side in strong winds. Birds of prey such as kestrels and owls may use the hedgerow trees as look-out posts and resting spots whilst they digest their prey. Many other species of bird use hedges throughout the year for shelter, nesting and roosting sites.

Mycorrhizal fungi are associated with hedgerows and boundary trees. Mycorrhizae are found between plant roots and the soil, helping plants gather the moisture and nutrients (such as phosphorus) that they need in exchange for carbohydrates and sugars in a mutualistic relationship. Root diseases also appear to be reduced in presence of mycorrhizae. The mycorrhizae and fungi effectively extend the root system, and it has been said that a single oak tree might have up to 19 km of mycelium associated with it! Cultivation and the application of fertilisers can supress and disrupt this beneficial underground network. For more information – the BBC recently produced an article on these connections, describing how plants can even communicate aphid attacks.

Hedges criss-cross the landscape and form important habitat connections for wildlife, allowing greater freedom of movement between different habitat ‘islands’. Our Connectivity programme looks to develop these habitat connections, and other organisations have similar projects such as the Wildlife Trusts’ Living Landscapes. These efforts stem from the Government’s Natural Environment White Paper.