Kit Hill Country Park, which includes the hill and surrounding area, was donated by the Duke of Cornwall to the Cornish people to mark the birth of Prince William in 1985. The hill was formed in the same way as Bodmin Moor by magma pushing up beneath the existing sedimentary rocks to form a body of granite and mineral veins in the cracks formed as the granite cooled. The name "kit" comes from the Old English word for a bird of prey, and the Country Park still has a population of buzzards and sparrowhawks.
On a clear day there are views to the southeast (on your left) of the Tamar estuary and Plymouth including the suspension bridge.
The mining activity on Kit Hill has been mapped and is said to contain over 1000 shafts, pits and trenches in search of mineral ore. Minerals extracted included tin, copper, lead, silver and tungsten.
South Kit Hill Mine opened in 1856 and closed in 1874 and reached a maximum depth of over 100 metres. The chimney was for a steam engine which drove ore-crushing stamps for the adjacent dressing floors and pumped from the engine shaft via a flat rod system. Two rectangular embanked areas partly cut into the hillside were originally reservoirs providing a water supply for the processing floors which were connected by leats.
In the 15th and 16th Centuries, surface mining took place for tin and various pits on the surface remain from this.
Mine shafts were dug for several reasons as well as another way of getting people into the mine. One was to pump water up from the lower levels of the mine using a waterwheel or steam engine. Another was to haul ore and waste out of the mine (known as "winding") which was done with capstans and horses in the days before steam engines. The shafts associated with pumping or winding steam engines were often called "engine shafts". Mine shafts were also dug for ventilation and these are often marked as "air shaft" on maps.
Five hills in Cornwall are designated as Marilyn hills (coined to contrast with Munro - another geological term) which are local highest points, protruding above the surrounding land by at least 150 metres. They are: Brown Willy, Kit Hill, Watch Croft, Carnmenellis and Hensbarrow Beacon.
Kit Hill only just qualifies as a Marilyn hill, being 171 metres above the surrounding land. The summit is 1096 feet (334 metres) above sea level.
The tower on the summit of Kit Hill is the remains of a chimney stack for the steam engine used by the Kit Hill United (later known as Kit Hill Great Consols) mining complex. The steam engine, installed in the early 1850s, was used both to pump water from the mine and to drive winding apparatus to lift ore from the mine. Prior to the steam engine, a windmill erected in the 1830s stood at the top of the hill to provide power for the mine. The chimney stack is now festooned with transmitters and all-important lightning conductors, being the highest point for miles.
Until the end of the 19th Century it was traditional to celebrate St John's Eve on 23rd June in a bonfire festival known as Golowan from the Cornish word golow, meaning light. During the 20th Century, the tradition faded amid concerns over insurance claims from the fire torches and flaming tar barrels associated with the festivities. It has subsequently been revived by Old Cornwall societies, albeit in a slightly lower-risk form, involving midsummer bonfires from the 23-29th June.
As you descend from the summit, you pass a rock channel crossed at intervals by granite slabs. This was a flue which carried arsenic vapour, an impurity which was removed from the ore by roasting it in a furnace. Little remains of the calciner furnace at the far end apart from a little stone walling.
The largest of the shafts here is the North Engine Shaft (also known as "Old Crumbly") which was the principal shaft of the summit mine and is over 200 metres deep. The smaller shafts were used for ventilation and prospecting. Mining on Kit Hill ceased in 1884 due to the high cost of cutting through the hard granite bedrock.
In 1877 work began on a tunnel from Deerpark Wood in the area of Excelsior Mine towards the North Engine Shaft of Kit Hill mine. The intention was to create a deep adit that could be used to drain water from the mine and run a 2 mile tunnel all the way beneath Kit Hill. However, due to the tough bedrock, progress was slow and the work ceased after a year. In 1881, work recommenced when a new company took over the mine but by 1885 it was once again abandoned as being too costly. Tunnelling recommenced a third time in the 1930s but ceased by 1938 resulting in a tunnel that ran roughly half way to the North Engine Shaft.
In 1959, the tunnel was taken over for an altogether different purpose by the Atomic Energy Authority: detection of underground explosions as part of an effort to determine whether the Russians were secretly carrying out nuclear tests underground and how large the explosions were. In the Excelsior tunnel, small TNT charges were detonated to investigate an effect known as "decoupling" where a chamber of the right size can attenuate the pressure wave from an explosion that travels through the surrounding rocks.
The quarry at Kit Hill was for high quality granite. Large-scale quarrying began in the 1880s and the granite was used for sea defences in Plymouth, London and even Singapore! The stone was shaped and finished in the quarry before being shipped as completed pieces via the railway.
The lake now occupying the quarry pit is rich in wildlife including dragonflies and damselflies. The trees growing within the quarry provide perches for songbirds for which the surrounding stone cliff provides a nice acoustic.
Granite from the quarry was lowered on trucks down the incline to sidings which connected to the East Cornwall Mineral Railway. The incline worked on a balance system where a load of granite from the quarry descended as another load (e.g. coal for the steam engine) was raised.
Granite is pretty hard stuff. It ranks at 7 out of 10 on the Mohs hardness scale. It's harder than normal steel but not quite as hard as hardened steel (which is 7-8). Cutting on granite worktops is therefore not a good idea as knife blades become blunt quickly.
The Tamar Discovery Trail was created in the early 21st Century after Tamar Valley AONB was established. The 35 mile route - partly in Cornwall and partly in Devon - was originally indicated by waymarks with an apple symbol which is a reference to the area's horticultural heritage. It was known affectionately as the "apple trail" and some of these are still visible, inscribed into the wooden posts. More recently, waymark arrows with a bee (based on a new logo for Tamar Valley tourism) have been added to the route.
Although nearly all foxgloves are purple, a fairly rare white form does occur and an even more rare pink form sometimes occurs along with this.
The proximity to the Devon border is reflected in the place names being in the English rather than Cornish language. The River Tamar was a significant part of the trade network in mediaeval times so there would have been Saxon traders around in these parts speaking (Old) English in early mediaeval times and then after the Norman Conquest there were even closer links with Devon under a common ruling class.
There are a few different species of buttercup. One of most common is meadow buttercup (unsurprisingly found in meadows!) which is the tallest member of the family. Another common one is creeping buttercup which as the name suggests spreads through rhizomes so is more likely to be found in dense clumps in damp places. Its leaves are also more golden and glossy.
There are nearly 400 miles of public bridleway in Cornwall, marked with blue waymarks, which are also open to horses and cyclists, although there is no obligation to make them navigable by any means other than on foot.
Hazel and oak trees overhang the lane.
The (leather) "tanning" process got its name as it involved extracting the tannins from acorns or oak bark and soaking these into animal hides over 1-2 years to preserve them. From the brown oak juice containing the tannins, the colour "tan" was named and from this the expression "sun tan" arose.
Ferns produce 2 different types of leaf (although they often look quite similar). The normal leaves are used for photosynthesis of sugars just like in other plants. Ferns also produce a special kind of spore-bearing leaf which can often be identified from the dots on the underside. In hart's tongue ferns, these are really obvious.
The cluster of mines around Holmbush (Holmbush, Redmoor, Kelly Bray, West Holmbush, East Holmbush and South Kelly Bray) were thought to have been started in the early 1600s, working on a lode of lead ore, with a resurgence of activity in the late 1700s. During Victorian times, industrial-scale deep mining took place for copper ore in addition to the lead ore which also contained silver. The mines were worked from at least 1845 under various names, finally closing in 1893. During the early 20th Century (from 1919-21), the dumps of waste material were worked with newer technology to recover more of the minerals.
The lead ore found in Cornwall is a form of lead sulphide known as galena which often contains an appreciable amount of silver. This was first smelted to produce "argentiferous lead" and then the silver was separated by a process known as "cupellation". The molten alloy of the 2 metals was placed in an oxygen rich furnace which caused the lead, but not the silver, to oxidise. The lead oxide was then absorbed into a calcium-rich material such as the ash from bones or seashells, leaving the liquid metal silver on the surface of the "cake". The lead oxide could later be converted back into lead by smelting it with charcoal.
Kelly Bray was first recorded in around 1286 as Kellibregh as is Cornish for "dappled grove" as agriculture was the main industry until the 19th Century. In the 1820s this changed when the area was developed for mining, with a mining workforce of over 250 people recorded in 1843. Mining continued into the 20th Century with the last mine closing in 1946.
A swingletree is a bar of wood or metal used to balance the pull from an animal towing a cart as this alternates between the animal's shoulders. This is particularly important when the animal is wearing a breast-collar harness which can rub on its shoulders if the pull is uneven.
Blackbirds are one of the most common birds in the UK with a population of somewhere between 10 and 15 million. However, blackbirds were in steady decline from the 1970s through to the mid-1990s. The population has only relatively recently recovered.
Lesser celandines flower along the path in the spring.
Another name for celandine is pilewort as the tubers of the plant are said to resemble piles. Based on the "doctrine of signatures" (i.e. a plant that looks a bit like something must be a cure for it), the resemblance suggested to mediaeval herbalists that celandines could be used to cure haemorrhoids. This was done by applying an ointment containing crushed celandine leaves to the relevant area. Since celandine contains a poisonous compound, some attempts to ingest celandine in an effort to cure piles have not gone too well.
The huge trees growing along the wall are beech.
Beech trees can live up to 400 years but the normal range is 150-250 years. Beech trees respond well to pruning and the lifetime of the tree is extended when the tree is pollarded. This was once a common practice and involves cutting all the stems back to a height of about 6ft during the winter when the tree is dormant. The 6ft starting point kept the fresh new growth out of the range of grazing animals. When allowed to grow to full size, a beech tree can reach 80ft tall with a trunk diameter of around 3ft.
The Ramblers Association and National Farmers Union suggest some "dos and don'ts" for walkers which we've collated with some info from the local Countryside Access Team.
Do
Don't
Kit Hill lies on the western side of the Tamar Valley AONB. The fields mark the beginning of this.
The Tamar Valley Area of Outstanding Natural Beauty has a similar conservation status to a National Park. It encompasses an area of 75 square miles around the rivers Tamar, Tavy and Lynher, partly in Cornwall and partly in Devon. This also includes an area of Cornwall and West Devon mining landscape World Heritage Site, 41 county wildlife sites and over 1700 hectares of woodland. It was first suggested in 1963 that the Tamar valley area should be designated but this was only eventually granted in 1995.
There are four country parks in Cornwall, managed by Cornwall Council:
At least 18 burial mounds occur on the slopes of Kit Hill, including one beneath the chimney on the summit, and traces of early field systems can be seen on aerial photographs. Prehistoric people left their mark with a line of barrows along Hingston Down which include a Neolithic long barrow (approx. 3000 BC) on the lower eastern slope and round barrows from the Bronze Age (2000-1500 BC).
During the spring and summer you are likely to hear the distinctive call of the cuckoo as you walk around the hill.
Cuckoos are migratory birds that overwinter in Africa and are first seen, or more often heard, in Cornwall during the spring. The cuckoo is well-known for laying its eggs in the nests of other bird species. The adult cuckoo is a mimic of a sparrowhawk - a predator; this causes other birds to abandon their nests, allowing the female lay her eggs. Although cuckoo eggs are larger than those already in the nest, cuckoos produce eggs in several different colour schemes to match those of several species of bird. Since the cuckoo chick is a much larger than even the full-grown foster parents (which they seem not to notice, assuming their offspring is just a bit portly), it needs to monopolise the food supply. It therefore methodically evicts all other eggs and chicks from the nest.
Barrows are megalithic tombs constructed with stone supports and covered with a mound of earth. Archaeology has revealed that the ancient tribes of Cornwall practised burial of their dead. Important individuals, such as kings or tribal chiefs, were often buried in monumental tombs to indicate their significance. Valuable items such as weapons and jewellery were often buried along with the dead. However, many barrows have been subject to grave robbers over the ages, meaning much of this treasure has been lost.
Another bird often heard in Kit Hill Country Park is the buzzard and can usually be seen gliding overhead whilst calling.
Buzzards are not quiet birds! Their long, loud "pieeuuu" call can be often be the first thing to give away their presence and is one of the easiest bird calls to remember. It is thought that the original Latin word for buzzard was probably an onomatopoeia (i.e. an imitation of the bird's call) within the constraints of what was deemed an acceptable Latin word (suggesting "pieeuuu" would probably have resulted in being fed to the lions!).
The moorland surrounding Kit Hill is known as Hingston Down, made famous by the battle that took place there.
The Celtic stronghold of Dumnonia held off conquest by the Saxons until the early 8th Century, when Devon was conquered. The Celts in Cornwall managed to repel the Saxons for another century. Although they allied themselves with the Vikings, it is implied that they were defeated in 838 at Hengestdun ("Stallion Hill") in the Anglo-Saxon Chronicle. It has been suggested, based on the name, this might be Hingston Down although it is debated by historians whether a site on the Devon side of the Tamar is more likely. The Saxon victory has also been questioned given the very limited Saxon influence in Cornwall.
Tungsten (also known as Wolfram) is a rare metal which occurs as mineral compounds such as Wolframite (an oxide with iron and manganese). Tungsten is the hardest of all metals and has the highest melting point, imparting these properties when a steel alloy is made containing tungsten. This made it in great demand for arms in the World Wars. It still has many different modern-day uses including cutting tools, electronics, turbine blades and rocket nozzles.
Arsenic is a chemical element that is part-way between a metal and non-metal, known as a metalloid. In the natural environment it reacts with oxygen to form an oxide which readily dissolves in water to form arsenic acid. This is able to leech into groundwater and cause contamination. Deeper in the ground where sulphur is more available than oxygen, arsenic is found as sulphide compounds.
The name arsenic is ultimately from Arabic al-zarnīḵ where the "zar" element is a Persian word for "gold" (as an arsenic sulphide compound known as "orpiment" was used as a yellow pigment).
Arsenic disrupts the production of the ATP (energy carrying) molecules vital in the metabolism of multi-cell organisms (in plants as well as animals). Due to its toxicity, arsenic was used as an insecticide and rat poison, and by the ruling class to murder one another. As the toxicity extends to plants, highly contaminated ground often has limited or stunted vegetation.
Arsenic had a variety of chemical uses including metal alloys, clarifying glass and in pigments. In Victorian times, an arsenic-based pigment known as "Scheele's Green" (copper arsenate) was used to colour sweets green. Later, the same compound was used as an insecticide!
Arsenic pigments were also popular in Victorian wallpaper manufacture to create green and yellow print. Unfortunately in the Industrial Revolution smogs, these arsenic compounds reacted with the acidic coal fumes to form lethal arsine gas which is even more toxic than arsenic itself.
During Victorian times, having a sun tan was seen as common, as peasants working in the fields were out in the sunshine. In order to make their faces paler, women of the higher social classes rubbed arsenic into their faces and arms. They also mixed arsenic oxide with vinegar and chalk and ate this! The Victorian notion that women were "frail creatures" would certainly have been helped along by eating arsenic.
In America, during the 1870s, Colorado beetle was devastating cash crops including cotton, tobacco and staples such as potato. At the time, the most popular pesticides were arsenic compounds so this led to a sudden increase in demand for arsenic. Since this was soon after the collapse in copper prices, this delayed the closure of many mines and during this period, over half of the world’s supply of arsenic was produced from mines in Cornwall and Devon.
In order to be processed, ore-bearing rock mined from mineral veins needed to be crushed to a powder. In earlier times, millstones were used to grind down lumps of ore but later it was done using a process known as "stamping" where the ore was crushed by dropping heavy granite or metal weights to pound it against another hard surface (often a piece of granite known as a mortar stone - as in "pestle and mortar"). The crushing was automated first with waterwheels and later with steam engines. The process was far from quiet and could often be heard from a number of miles away.
The little yellow flowers with four petals all over the moor in July are tormentil (Potentilla erecta). Its common names include Bloodroot and Flesh and Blood because roots yield a red dye which is still used as an ingredient for artists' colours (tormentil red). The roots also have very a high tannin content and have even been used to tan leather. Extracts from the plant have been widely used in folk medicine and is it still used as a remedy for diarrhoea and as a lotion for skin sores.
Blackberries are closely related to raspberries and technically neither is a berry but an aggregate of many individual tiny fruits, each containing a tiny stone like a miniature cherry.
Blackberries are high in vitamin C, K and antioxidants. The seeds, despite being a bit crunchy, contain omega-3 and -6 fatty acids and further enhance blackberries' "superfood" status.
According to folklore, you should not pick blackberries after Michaelmas Day (now known as Old Michaelmas Day, roughly corresponding to 11th October) as this is when the devil claims them. The basis for this is thought to be the potentially toxic moulds which can develop on the blackberries in the cooler, wetter weather.
A project to analyse blackberries picked from busy urban roadsides vs quiet rural lanes found that there was a slightly elevated level of lead in the blackberries from busy roadsides which is thought to have accumulated in the soil when leaded fuel was in common use. Surprisingly, commercial blackberries from supermarkets also showed higher levels of lead than the wild blackberries from rural lanes.
An impressively purple blackberry, pear and ginger chutney can be made with blackberries stashed in the freezer. Simmer 500g blackberries, a few chilli flakes, 4 chopped pears and a finely-chopped 8cm piece of fresh ginger until the liquid reduces. Add 150ml distilled or white wine vinegar, and sugar to taste (amount will depend on tartness of the blackberries). Reduce a bit longer until the desired "gloopy" consistency is achieved and finally season with a little salt to taste to balance the sweetness.
To make blackberry wine, combine 2kg blackberries + 4 litres of boiling water in a plastic container with a lid. Once the water has cooled to lukewarm, mash blackberries and add red wine yeast and pectic enzyme (blackberries contain pectin so this is needed to stop the wine being cloudy). Cover for 4-5 days then strain through muslin.
Transfer the liquid to a demijohn and add 1kg of sugar. Top up with a little more water to make it up to a gallon. After fermentation, the wine should clear by itself; in the unlikely event that it doesn't, use some finings. Rack off from the sediment and bottle; it's worth allowing the wine a year or two to mature as it massively improves with age. As a variation, you can add 500g of elderberries and increase the sugar content for a more port-like wine which will need a couple of years longer for the elderberry tannins to mellow out.
Gorse is a legume, related to peas and like other members of the pea family it's able to get its nitrogen from the air. It's also tolerant to heavy metals in the soil and to salt. This makes it able to grow in Cornwall's harshest environments: moorland, coast and mine waste tips.
Like other members of the pea family, gorse produces its seeds in pods. The seeds are ejected with a popping sound when pods split open in hot weather. This can catapult the seeds up to five metres. The plants are able to live 30 years and survive sub-zero temperatures, the seeds can withstand fire and remain viable in the soil for 30 years.
Gorse seeds each contain a small body of ant food. The seeds also release a chemical which attracts ants from some distance away. The ants carry the seeds to their nests, eat the ant food and then discard the seeds, helping them to disperse.
The seeds of common gorse are the source of the chemical used to identify people with the rare "hh" blood group. The red blood cells in the vast majority of people (in blood groups A, B, AB and O) have a material called "H substance" on their surface. It turns out that the chemical extracted from gorse binds remarkably specifically to this and cells from the "hh" blood group (that have no H substance) are left alone.
Gorse is also known (particularly in the Westcountry) as furze from the Middle English word furs. This itself is from the Old English word fyres, closely related to the Old English word for fire.
Before the Industrial Revolution, gorse was valued as a fuel for bread ovens and kilns as it burns rapidly, very hot and with little ash. It was in such demand that there were quite strict rules about how much gorse could be cut on common land.
In more recent times, due to reliance on fossil fuels, this is now out of balance and gorse has increased in rural areas which have been abandoned agriculturally.
As gorse ages, it accumulates more dead material. The spiky, springy nature of the plant even when dead means air can circulate well through the dead material and when this dries out in the summer, it substantially increases the risk of fires. As gorse seeds have evolved to withstand fire, controlled burning can be used to used to keep the gorse at a young age where uncontrolled fires are less likely.
Gorse is present as two species along the Atlantic coast and size is the easiest way to tell them apart: Common Gorse bushes are up to 10ft tall whereas Western Gorse is more of a mat - less than 1ft tall. Common Gorse flowers in spring whereas Western Gorse flowers in late summer - early autumn.
In 2005 a man had to be rescued from a 10ft deep patch of coastal gorse by helicopter. Whilst mountain biking home along the coast from a bar, with the assistance of a not insignificant amount of alcohol, he managed to catapult himself into the bushes where he remained stuck for 2 days before being found by a passer-by. She asked if he needed help, to which he replied "can you ring the RAF?".
Between the two species, some gorse is almost always in flower, hence the old country phrases: "when gorse is out of blossom, kissing's out of fashion" (which is recorded from the mid-19th century) and "when the furze is in bloom, my love's in tune" (which dates from the mid-18th century). Common gorse flowers are bright yellow. Western gorse flowers are very slightly more orange - more like the colour of the "yolk" in a Cadbury's creme egg. Also like creme eggs, gorse flowers are edible but are significantly better for use in salads and to make a tea, beer or wine.
Common gorse flowers have a coconut-like scent but rather than fresh coconut, it is reminiscent of desiccated coconut or the popular brand of surf wax, Mr Zoggs. However, not everyone experiences the smell in the same way: for some people it's very strong and for others it quite weak. One complicating factor is that Western Gorse flowers don't have any scent, so you need to be sniffing a tall gorse plant to test yourself.
Flower scents are volatile organic compounds which drift though the air and has evolved as an advertisement to pollinating insects that nectar is available. Squeezing the flowers releases these compounds onto the surface where they can evaporate and therefore intensifies the smell. Similarly the warming effect of sunlight helps the compounds to evaporate faster and so the smell is more intense on sunny days.
Gorse flower wine can be made using 5 litres of gorse flowers stripped from the stems and simmering these in 5 litres of boiling water. Once the flowers are removed, 1.3kg of sugar should be dissolved in the hot water and allowed to cool to room temperature. Then add 500g of chopped raisins and juice and zest of 2 lemons and ferment with white wine yeast and yeast nutrient. Although flowers are present year-round, they are best picked in spring (April and May) when they are most profuse and fragrant.
Bilberries (known in Cornwall as 'erts) are closely related to blueberries. The fruits are much smaller but the flavour is more intense.
Like heather, bilberry is a member of the Ericaceae family and fungi in its roots help it extract nitrogen from acidic soils. Bilberries are therefore typically found on moorland where there is less competition from other plants.
Although Cornwall is home to the village of Bilberry (near Bugle), the name is not thought to be anything to do with the plant - more likely the "bury" relates to some form of ancient earthwork.
It is thought that rumours that the RAF used bilberries and carrots to improve night vision of bomber pilots were an elaborate decoy to conceal that Britain had radar which is what in reality made the pilots more effective.
Squirrels are rodents, closely related to chipmunks and slightly more distantly to dormice. The word "squirrel" originates from an ancient Greek word meaning "shadow-tailed", referring to the bushy tail of a squirrel. A family group of squirrels is known as a "drey" (also the word for a squirrel nest). A group of unrelated squirrels is known as a "scurry", though squirrels tend not to hang out in groups.
Grey squirrels were introduced to the UK from the USA in the late 19th Century and within decades they had replaced the native red squirrel in most parts of the country.
Compared to red squirrels, grey squirrels are able to eat a wider diet (including acorns), are larger so can survive colder winters, and are better able to survive in the fragmented habitats created by urbanisation. They are also thought to be carriers of a squirrel pox virus which they usually recover from but has been fatal to red squirrels, although red squirrels are now also developing some immunity.
To date, culling of grey squirrels has not reversed their domination of woodland habitat and alternative approaches such as planting food with contraceptives are being explored as a means to control the population. The theory is that infertile squirrels can compete for food against fertile squirrels, whereas culling can create a glut of food resulting in a higher number of squirrels surviving which replace those that were exterminated. Natural predators such as goshawks or pine martens also remove more grey squirrels than red squirrels. This is because red squirrels are more savvy having co-evolved with the predators so for example they recognise the scent of pine martens and actively avoid areas with this.
Squirrels assess each of their acorns before burying them. If an acorn is too light (which suggests it might have a hole), the squirrel will eat it immediately rather than risking it going mouldy.
In order to later find the nuts that they've buried, squirrels need to be organised. Some species of squirrel have been studied and found to structure their hoards by type of nut e.g. burying all their acorns under one tree and all their conkers under another. This is equivalent to us organising all the veg onto one shelf of the fridge to make it easier to remember where to look for them.
As well as forgetting where they buried some of them, squirrels may also lose a quarter of their buried food to birds, other rodents and fellow squirrels. Squirrels therefore use dummy tactics to confuse thieves by sometimes just pretending to bury a nut.
Squirrels eyes are positioned on the sides of their head which allows them to spot predators approaching from behind them. When a squirrel spots a predator, its runs away in a zigzag pattern. This confuses many of their predators but unfortunately it doesn't work well for cars.
Young squirrels suffer a high mortality rate in the wild and less than one in three make it to adulthood. The ones that do, live on average for about 6 years, although a lucky one can live to about 12 years old. In captivity, where there are neither predators, cars nor cold winters to contend with, they can reach 20 years old.
By using their tail as a parachute, squirrels are able to survive falls from high trees. This allows them to attempt risky jumps between treetops that don't always work out. They are one of the few mammals that can (but not always) survive an impact at their terminal velocity i.e. if a squirrel jumped out of an aeroplane, it may well survive.
In urban areas in cold countries such as Canada, a black form of the grey squirrel is more common which is able to withstand the cold better both by retaining more heat and also having a slower metabolism. In wilderness areas where predators are more common, the black squirrels don't seem to do so well, perhaps because they are less camouflaged against trees than the grey ones.
Several species of heather grow in Cornwall and are most easily recognised when they flower from July to September. The one with the most brightly coloured (purple) flowers is known as bell heather due to the bell-shaped flowers. This is the earliest one to start flowering - normally in June. Bell heather is usually interspersed with ling or common heather which has much smaller flowers which are usually paler and pinker and come out at the start of July. A third kind known as cross-leafed heath is less abundant but can be recognised by the pale pink bell-shaped flowers that grow only near the tips of the stems, resembling pink lollipops. A fourth species known as Cornish heath grows only on the Lizard and has more elaborate flowers which are mostly pale with a dark purple crown at the front.
Heathers and heaths are members of the Ericaceae family. The formal definition of a heather is a member of the Calluna genus within this family whereas heaths are members of the Erica genus. Bell heather is actually an Erica and therefore technically not a heather but a heath.
Heather plants have a symbiotic relationship with fungi which grows inside and between some of the plant root cells. Up to 80% of the root structure can be made up of fungi. The fungi are able to extract nutrients from poor, acidic soils that plants struggle with. In return, the plant is able to generate other nutrients (e.g. sugars by photosynthesis) that are useful to the fungi. A similar partnership between plants and fungi occurs in lichens.
Heather can grow in soils which have concentrations of metals normally considered toxic to other plants and they are also tolerant of salty (high sodium) environments on the coast. Their symbiosis with fungi restricts metal uptake through their roots.
Heather plants can live up to 40 years and over time they form woody stems. This provides them with a way of excreting heavy metals that they absorb by locking it up in the layers of dead wood (found by researchers as the areas in the plant with the highest concentrations). Their woody stems have also found many uses over the centuries including fuel, thatch and ropes. One other use has made it into the genus name for heather - kallune is Greek for "to brush".
The process of placing trig points on top of prominent hills and mountains began in 1935 to assist in the retriangulation of Great Britain - a project to improve the accuracy of maps which took three decades.
A plate (known as a "flush bracket" and marked with an ID code) on the side of each trig point marked a known measured height above sea level. The brass plate on the top with three arms and central depression (known as a "spider") was used to mount a theodolite which was used to measure the angles between neighbouring trig points very accurately. These angles allowed the construction of a system of triangles which covered the entire country and provided a measurement system accurate to around 20 metres.
Dragonflies were some of the first winged insects to evolve, around 300 million years ago in the "age of amphibians" before the dinosaurs. Fossils of early dragonflies have been found with wingspans of up to two feet across.
Dragonflies are named after the way they hunt, as both the larvae and adults are carnivorous predators. Mosquitoes form a large part of their diet both for adults and particularly for the larvae (nymphs). One dragonfly can eat tens of mosquitoes in a day and an average of over 100 per day has been recorded for the nymphs of some species. It is thought that this is an important factor in keeping the mosquito population under control. Dragonfly nymphs have a massive lower jaw to engulf their prey (a bit like an Angler Fish) and are also able to propel themselves by shooting a jet of water out of their anus.
Their two sets of wings beat out of phase, and the frequency, amplitude and the angles of each set of wings can be controlled. This allows dragonflies to hover in a completely stationary position for over a minute, perform extravagant aerobatic manoeuvres and even fly backwards.
Damselflies are predators similar to dragonflies but are easily distinguishable by the way their wings fold back parallel to the body when at rest whereas the dragonflies' wings are fixed at a right angle to the body. The Damselfly has a much smaller body than a dragonfly which means it has less stamina for flight. Nevertheless, it can hover, in a stationary position, long enough to pluck spiders from their webs.
Male damselflies have two sets of genitalia. At the start of mating a packet of sperm (spermatophore) is transferred outside of the male's body between the two and then passed on to the female who uses it to fertilise her eggs as she lays them. Female damselflies lay their eggs inside vegetation. For some species this is in water plants and the female can swim underwater for half an hour before returning to the surface to breathe. Males often guard the egg laying female to prevent a rival male from sneaking in and replacing the spermatophore with his own.
Damselfly eggs hatch not into damselflies but water-living nymphs which look a bit like a dull-coloured damselfly with a 3-forked tail instead of wings. The tail is actually a set of gills used to breath underwater. When the larva is fully developed, it climbs out of the water on a stem or rock. Its skin then splits open and a damselfly emerges with wings which need to be inflated and dry before it can fly.
Rosebay willowherb is a tall plant with a spike of pink flowers in late summer which can often be seen beside paths and tracks. Their long leaves have a distinctive thin, white vein along the centre.
The name "rosebay" dates from at least Tudor times and is thought to be based on loose resemblances of the leaves to bay leaves and the flowers to wild roses. The overall family are also known as "willowherbs" due to the resemblance of the leaves to willow leaves. The two names have since been brought together resulting in the slightly confusing duplicate description of the leaf shape.
Rosebay willowherb is known as fireweed in USA as it's found on burnt sites after forest fires. For similar reasons it was known as London's Ruin after the Great Fire. In the Second World War it was also known as bombweed due to its rapid colonisation of bomb craters.
It is a pioneer species which is good at colonising disturbed ground as its seeds travel long distances in the wind and remain viable in the soil for many years. It was considered a rare species in Britain in the 18th century but spread along the corridors cleared for railways in Victorian times.
Rowan is a small, deciduous tree that is native to Britain and is also known as "mountain ash" because it grows at high altitudes and the thin leaves superficially resemble ash leaves. However, rowan is actually a member of the rose family.
Another name for rowan is "(wild) service tree". This came about because the Old English name of the tree was syrfe and thus the "service" is in the sense of "serf".
Orange berries appear in July and, once ripe in late August-early September, can be used to make jams. The raw berries are too bitter to eat and contain a chemical that causes indigestion and can lead to kidney damage. Cooking the berries converts this chemical into a benign compound. Freezing reduces the bitterness so this can be done prior to cooking. In the days before freezers, waiting until the first frost before picking was used to achieve something similar.
Rowan is also sometimes called the "chequer tree", perhaps due to the spotted pattern of the fruit, and berries themselves are called "chequers". The berries were used to flavour beer and spirits which is thought to be the origin of the pubs with this name. However the Chequers Estate (country estate gifted to the nation in 1917 on the assumption that forthcoming Prime Ministers might not be from the landed gentry and therefore would be in need of one) is thought to be unrelated (instead based on "Exchequer").
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