Natural History of the Basingstoke Canal[Published 1972, 2nd ed. 1981]
Published by:- The Surrey and Hampshire Canal Society Ltd
Second Edition 1981
The Basingstoke Canal winds its way, from the now town of Basingstoke, through 37 miles of Hampshire and Surrey countryside to Byfleet, where it joins the Wey Navigation.
The western end, from Greywell to Basingstoke, was abandoned and progress- Ively filled In following a roof fall in Greywell Tunnel during 1934. The remaining 32 miles of the canal, although left to fall derelict in recent times, are now being restored.
The geology of the surrounding area is mostly greensand. This forms an acid, sandy soil where pines, bracken and heather predominate. The canal, by contrast, offers a more lush environment and a different range of fauna and flora. Some are relatively rare, but common or uncommon they are part of our environment. To observe how plants and animals are Interdependent, how they have adapted to particular conditions is a fascinating study. This booklet, however, is not for the specialist. It is for anyone who likes a walk by the canal and is interested in the things to be seen there. If it succeeds in adding at all to your enjoyment of the canal, It has achieved its main purpose.
Through the winter the canal lies silent and seemingly lifeless. For many wild creatures survival Is at stake. If snow ond Ice persist too long, lack of oxygen may threaten underwater animals with suffocation. Fortunately, winters In Southern England are rarely that severe and, by remaining inactive, many pond creatures keep their oxygen requirements to a minimum. So, under the surface, life continues, although it may not be obvious, like the dormant frog half buried in the mud in the canal bed.
Above the water lavel there is also less activity in winter. Squirrels are lively enough whenever the weather is not too cold, but many smaller animals are in hibernation. However, with trees end undergrowth bare, winter can be a good time for seeing birds. Watch out for the WREN, a very active little bird, rather mouse-like, as it forages fcr insects among fallen leaves and low thickets. Because of their size, these little birds are particularly susceptible to cold and often roost communally in winter, a dozen or more huddled together for warmth.
Another very agile bird is the TIT, most likely to be seen where there are stands of beech or oak trees. Different species often flock together in winter, so you may see a mixed group of, perhaps, BLUE TITS, MARSH TITS and GREAT TITS moving around together. Competition for food is minimised, for the various species have different feeding stations. Blue Tits, the smallest of this group, tend to feed high up in the trees, looking for small insects among the twigs and under the bark. Marsh Tits feed on lower branches, taking rather larger insects and seeds, whilst the largest of the three, the handsome Great Tit, Is often seen on the ground, searching for insects snd fallen nuts. The WILLOW TIT greatly resembles the Marsh Tit, but is less likely to be found In a mixed flock. Unlike the Marsh Tit, which has no particular liking for marshes, the Willow Tit really does frequent and nest in swampy thickets of willow and birch along the canal edge.
Winter is also a good time for looking at trees. Without their leaves, the structure of the branches is more easily seen, and the pattern and colouring of the bark, the papery white SILVER BIRCH, with its dark reddish twigs, is too well known for comment. Equally distinctive is the way the ridged bark of a SWEET CHESTNUT often twists in a spiral up the trunk. The 'Iambstail' catkins on the HAZEL are always a welcome sight - a reminder in January that spring is coming. Many other trees, birch and alder for example, have catkin type flowers, but the hazel is one of the earliest and showiest. The catkins themselves are the male pollen-bearing organs. The female flowers are less plentiful - little bunches of crimson threads only 1/8" across - and come out later, when the catkins are mature and ready to shed their pollen.
As the sun gains in strength and begins to warm the water, life in the canal stirs. Very Important, although not obvious, Is the increase in plankton - the minute plants and animals which are the basic foodstuff on which so many other creatures are dependent.
One of the first to emerge is the FROG. By mid-March frogs will be looking for a suitable place to spawn. Often this will involve travelling over a considerable distance to arrive at a spawning ground which, to human eyes, looks no different to the frog's winter quarters. Yet, year after year, they return to the same spot. In the past a stretch of the canal along by Chequers Bridge, Crookham, has proved very popular. By the end of March, or the beginning of April, the jelly-like clumps of eggs are laid.
The common TOAD usually spawns about two weeks later. The eggs are not laid in clumps, but in long strings, wound like bunting amongst the water weeds. Toads and newts have attracted a great deal of superstitious fears in the past, yet both are entirely harmless animals, even helpful in controlling slugs and similar pests. Toads are surprisingly intelligent and quite friendly animals. The NEWT, like the toad, lives on land for most of the year, but during April it returns to the water to breed. The female lays her eggs singly, usually on a leaf that can be folded round and stuck down to form a protective envelope. The male, for this brief season, develops a striking crest and handsome orange colouring on his belly.
The onset of the breeding season in the world of birds means not only fine plumage, but also fine voices. Males sing vigorously to proclaim their territory and win a mate. The most renowned songster, the nightingale, is a migrant and does not arrive here until late April. Rather shy, it has been described as a 'skulking bird' with a 'preference for damp places'. Although it sings during the day, the nightingale is best heard on a still Spring evening, when other birds have fallen silent. Do not be deceived, however, into thinking every evening song comes from the nightingale. Robins and Sedge Warblers, among others, sometimes produce their beautiful songs after dark. But for a really virtuoso performance you must be up early enough to catch the dawn chorus, when thrushes, warblers and blackbirds are all in full spate.
Spring flowers, to most people, mean primroses, wood violets and bluebells, all of which can be found along the canal. There are earlier flowers, but they are not so attractive. DOG'S MERCURY commonly flowers in February, but the flowers are very small,, greenish-white. By March COLTSFOOT can be found. It is a yellow, dandelion type of flower, abundant on waste ground and often described as a 'pernicious weed'. The large leaves do not appear until later. In times past they were made into cigars for asthmatic persons. Goldfinches apparently like the downy underside of these leaves for lining their nests.
As spring progresses, all manner of insects, most of whom have been dormant through the winter, make themselves felt. Many of the aquatic creatures in the canal are insect larvae, like the nymph - the larval stage of a dragonfly. After hibernating through the winter, it spends the early months of the spring patrolling the canal bottom, ready to shoot out its hinged jaws and snap up any smaller creatures within range. By mid-May, it Is ready to emerge and crawls up the stem of a plant, out of the water, for the final moult. After breaking free of the nymph skin, the adult dragonfly crawls higher up the stem, to rest and dry its delicate wings before flying off, leaving behind the empty larval case still clinging to the plant.
By late June the water has developed a temperature gradient. Even in 4 or 5 feet of water, if It is relatively still, the bottom may be several degrees cooler than the surface. Many fish prefer the cooler water and keep within the shade of the banks. When the water level fell seriously during the years of neglect the fish population reduced greatly. In places along the canal the water in summer was little more than a series of pools and marshy patches, where no aquatic life of any size could survive. At Deepcut the canal bed had been colonised by emergent plants. Yellow IRIS made a gay showing but their roots and stems trapped more debris and the bottom continued to silt up.
In many places, even where the water level Is adequate, the canal Is choked with weed. The weeds are a vital part of the canal's ecology, absorbing carbon dioxide from the water and replenishing the oxygen. Too much weed can prove a barrier to fish and so impoverish the life of the canal. Despite this, there are still plenty of fish In the water, particularly in some sections of the summit pound In Hampshire. CARP, one of the best known of coarse fish, is probably not a native species but was introduced long ago for food purposes. No monastery in medieval times would have been without its 'stewpond', well-stocked with carp to provide fresh fish for the monks. Watch out for the PIKE, not easy to see as its muddy colouring and habit of lying motionless In the water make it very inconspicuous. Although the pike lives mainly on fish, it will snap up any likely victim that comes too close, including young mallards and moorhens.
By mid-summer most birds are busy feeding their young and as the MOORHEN often raises three broods in a season it is not uncommon to see a family of fluffy chicks being shepherded through the reeds at the edge of the water. The moorhen is strictly vegetarian, feeding on various pondweeds. Other birds are attracted to the canal for its fishing, including the KINGFISHER, which is the most beautiful of all the British birds. In Victorian times bargees used to trap kingfishers which were flushed out as the boats passed under the bridges, for the brilliant feathers were used to trim ladies' hats. Now the bridges are used as a sheltered nesting site by the bird.
Another fashion which has fortunately disappeared is that for brooches made out of butterfly wings. Even our common butterflies are noticeably less common today than they were ten or twenty years ago and some of the uncommon species are facing possible extinction. Clearance of wasteland and widespread use of insecticides and weedkillers have destroyed the butterflies and their environment. In a heavily populated area, the Basingstoke canal helps provide a foothold for survival. More than most insects, butterflies depend on the sun. They are too fragile to contend with high winds, so a hot, still, summer's day is the ideal weather. Most butterflies feed mainly on nectar, although they will drink water and juice from fruits also. Purple and pink flowers seem to be preferred and one which seems particularly attractive is Hemp Agrimony, which is plentiful along Deepcut and elsewhere on the canal. Caterpillars are usually restricted to specific foadplants; peacocks, tortoiseshells and red admirals all share a liking for stinging nettles. Less well known is the WHITE ADMIRAL, found in patches of woodland. The striking contrast of the white bands on its dark wings provides surprisingly effective camouflage under the trees, where shafts of bright sunlight alternate with dark shadow.
During the heat of the day many animals remain inactive, so early morning or evening, as dusk approaches, are more rewarding times. One of the lagest British mammals is the BADGER - not often seen, because it is a cautious end definitely nocturnal animal. However, in summer, when the nights are very short, it sometimes emerges before dark to start its feeding. Badger setts often extend large distances underground and may remain in use for generations. A large community of badgers that live near the canal at Horsell are currently threatened with the development of a housing estate. Using fox terriers, volunteers have helped to excavate twenty or more animals and move them to new sites, undisturbed by building contractors.
By September the days are getting shorter and the evenings chillier, but it is the most colourful time of all for a casual walk along the towpath. The leaves on the sweet chestnuts, sycamores and beech turn to gold and bronze. Blue-black fruits on the wild plum and shining black privet berries tangle with a mass of crimson hips, scarlet woody nightshade and dark red hawthorn berries. Clouds of old man's beard, the wild clematis, envelope the bushes, whilst the most vivid colour of all is provided by the spindle tree with its mass of curiously shaped pink and orange fruits. Among the fallen leaves, there are plenty of fungi, Including many edible toadstools - but be sure to get expert identification before trying any of them.
All this fruit fulness is part of the build up for winter. Primarily the various berries, seeds and spores are a means of propagating the species which produce them, but they are important to the survival of other species too. Animals preparing to hibernate need to eat well and store up fat for the winter months. Even those that remain active, like the ROBIN, need an extra layer of fat to help them survive spells of bad weather. Many birds, and some butterflies, leave in the autumn to spend the winter in milder climates. It is not generally realised that the robin is a partial migrant. Some, mostly females, fly south in the autumn. The BLACKBIRD is another partial migrant; some of our winter population are temporary visitors from Scandinavia.
On the canal floating vegetation is less dense. The tiny duckweeds are annuals, dying each autumn after they have released their seeds into the water.
WATER SOLDIER, which completely covers the water near Ash Vale in summer, does not die, but the whole plant sinks below the surface in autumn. A freshwater SPONGE taken from the canal at this time will be covered in small brown globes. These are gemmules, a resting stage which will survive when the parent colony disintegrates during the winter.
Any tadpoles still present by September are most likely to be newts. Frogs and toads complete their metamorphosis in 2 - 3 months from hatching. Some newts also finish their transformation by August, but many cease developing and over-winter as tadpoles, to complete the process next spring. The adult newt, like the adult toad, will spend the winter in some sheltered cranny on the land, under a stone or a fallen log. As winter approaches activity declines and endurance is all that is required.
The vegetation that surrounds the canal, shows little sign of order but this apparently haphazard profusion is misleading. The canal is not a single environment; it provides a number of distinct habitats, or zones of life, which can be classified according to the characteristic plants which occupy them. Of course, these zones are not rigidly separate from each other and there are many plants which flourish in a wide variety of conditions.
Starting away from the water, on the outside of the towpath, there is most variety. For most of its length the canal Is passing through built-up areas and sandy heathland, although towards Basingstoke the soil overlies chalk. In places meadows and fields border the towpath. There are hedgerows and shrubs, patches of woodland, with many different sorts of trees. Here, furthest from the canal, its influence is least felt. Typical woodland flowers can be found, like bluebells, or meadow flowers like poppies.
Around the towpath, where the soil remalns moist but is not water-logged, are the MARSH PLANTS. These require plenty of moisture but cannot Iive in standing water; meadow sweet, many sedge grasses, or purple loosestrife are examples. Closer to the water, where soil never dries out, are the SWAMP PLANTS. These are found right at the water's edge, like marsh marigold, or perhaps even standing in the water where it is sufficiently shallow, as with the yellow flag and bulrushes.
As the water becomes deeper the EMERGENT PLANTS, with their roots in the soil, flowers above water, give way to either totally submerged or free-floating plants. Pondweeds are a group of SUBMERGED PLANTS, and the FLOATING PLANTS are typified by the duckweeds.
Even within the water there are different zones of life. The canal is relatively shallow, with no part so deep as to prevent light from penetrating and plants from growing on the bottom. Plants provide shelter for many smaller aquatic creatures, larvae, water bugs, snails and beetles. The mud and debris on the canal bed attract certain species like crayfish, which are scavengers. Some fish are bottom feeders but fish also require open water. The surface of the water is another area with its own inhabitants. Water skaters movr across the surface film and gnat larvae hang from its underside.
Because the canal is man-made its sides are very steep and it may be very difficult to distinguish one zone from another, indeed some may not be present. It will be obvious that the water level is the main controlling factor.
N.B. This is in no way intended as a complete account. The species described here have been chosen as characteristic of the canal, or because they illustrate a point of particular interest. No specific locations are given, for most of these plants can be found along different sections of the canal. A particularly varied and pleasant walk can be taken from Brookwood, starting at Plrbright Bridge, to Ash Vale. Most of the species mentioned can be found along this stretch.
Scot Pine (PINUS SYLVESTRIS) and Silver Birch (BETULA PENDULA) are typical of the dry sandy soil of this area, between Brookwood and Aldershot. What is striking along the canal is the great variety of trees, so that the pines, which cover acres of the surrounding countryside, are pushed into the background. Most of the common deciduous trees are to be found - Oak, Ash, Beech, Spanish Chestnut and, quite unrelated, Horse Chestnut.
Willows (SALIX) are plentiful along the damp margins of the canal. They are mostly small, fast growing trees. Osier banks used to be more common in the past, when the flexible shoots of some species were widely used in wicker-work. Many species have bright orange or red bark, which makes them colourful in winter. By Easter the catkins, "pussy palms", are fully out. An infusion of willow bark was an old remedy for fevers, doubtless effective, as the bark contains salicylic acid, the active ingredient of aspirin. There are nearly twenty British species, and a number can be seen along the canal. Crack Willow (S. FRAGILIS) is ao called because Its smooth twigs are fragile and easily broken at the joints. The ready occurrence of hybrids makes the group difficult to classify properly. Cricket bats are often made from a hybrid form of the Crack Willow and the White Willow (S.ALBA).
Guelder Rose (VIBURNUN OPULUS) is an attractive shrub, sometimes called Water Elder. As the name suggests, it thrives in damp places. The flowers are borne in a flat, white head. In autumn the leaves turn dark crimson and the berries, translucent, blood-red, give off a pungent smell of decay.
The Spindle tree (EUONYMUS EUROPAEUS) has very smooth, green, angular twigs, which were formerly used for skewers, or spindles. The flowers are insignificant but in autumn the deeply lobed, rose coloured fruits split to reveal bright orange seeds. Tennyson described the Spindle as:
"The fruit that in our autumn woodlands looks a flower".
Honeysuckle (LONICERA PERICLYMENUM). A climbing shrub, well known for the fragrance of its flowers. The leaves appear very early in February, and the flowers in July and again in the autumn. The twining stems do little harm to well established trees but are powerful enough to check and distort the growth of young saplings.
FLOWERING PLANTS illustrative of the different zones of vegetation around the canal:
Foxglove (DIGITALIS PURPUREA). 21 - 5' Biennial, fl. June - Sept. Large downy leaves. Flowers bell-shaped, purple (sometimes white). The English name Is a corruption of Folk's glove, i.e. Fairies' glove, while the Latin name Is a reminder that the foxglove yields a product which is poisonous in large doses, but medically useful as a heart stimulant in small doses.
Wood Sage (TEUCRIUM SCORODONIA). 1' Perennial, fl. June - Sept. Flowers small, yellowish green. The wrinkled, sage-like leaves are bitter to taste. The plant has been used as a substitute for hops.
Bluebell or Wild Hyacinth (ENDYMION NON-SCRIPTUS). 1' Perennial, fl. May. Too well known to need description, but it Is worth noting that in Scotland "bluebell" generally refers to the Harebell. Occasionally pink or white forms are found.
Broad-leaved Helleborine (EPIPACTIS HELLEBORINE). 1' - 2' Perennial, fl. August. One of several members of the Orchid family to be found along the canal. It has large ovate leaves and a tall flower spike, bearing up to a dozen, or more, typically orchid shaped flowers, with green sepals and purple lips. Fortunately It Is not a showy plant, although attractive close to, and so escapes being picked very often, and so destroyed.
Twayblade (L1STERA OVATA). 1' - 2' Perennial, fl. June - July. Another orchid. A large pair of leaves, rather similar in shape to those of the Board Halleborine, enclose a single, tall spike of small, yellowish green flowers. The flowers have a long, lobed lip. The Twayblade likes damp woods and shady pastures.
Marsh plants (liking damp, but not wet, conditions)
Meadow Sweet (FILIPENDULA ULMARIA). 2' - 4' Perennial, fl. June - Aug. A common plant of damp meadows. The handsome, creamy white flowers resemble Spirea, to which it is related. Sweetly scented.
Great Willow Herb (EPILOBIUM HIRSUTUM). 4' - 5' Perennial, fl. July - Aug. The largest of our Willow Herbs, it will spread extensively by means of underground suckers. Other members of the family found by the canal include E. ADENOCAULON, an introduction to this country, which is rapidly establishing itself.
Purple Loosestrife (LYTHRUM SALICARIA). 2' - 4' Perennial, fl. June - Aug. A very handsome plant, with tall spikes of richly coloured flowers. It can be found among sedges and rushes along the canal banks.
Yellow Loosestrife (LYSIMACHIA VULGAR1S). 2' - 4' Perennial, fl. July -Aug. Despite the English name this plant bears no relation to the preceding one. It Is common in damp places and was reputed to calm wild beasts and take away strife from yoked animals.
This group also includes a large number of sedges (CAREX) and rushes (JUNCUS, both families being well represented along the canal.
Swamp Plants (wet conditions, will tolerate standing water).
Flowing Rush (BUTOMUS UMBELLATUS). 3' Perennial, fl. July - Aug. "Rush" is a misnomer for this beautiful plant, which is the sole representative of its genus. The rose pink flowers, an inch across, are borne in a loose cluster at the top of the stem. The leaves are sword shaped, similar to iris. An uncommon plant.
Great Reedmace (TYPHA LATIFOLIA). 6' Perennial, fl. July - Aug. This plant "has usurped the name Bulrush from Scripus lacustris ever since Alma-Tadema painted it surrounding the infant Moses in his basket", (McCllntock & Fitter). The less common Lesser Reedmace can also be found along the canal. It is similar in appearance, but altogether smaller and more slender.
Arrowhead (SAGITTARIA SAGITTIFOLIA). 1' Perennial, fl. July - Sept. Easily identified by its striking, arrow shaped leaves. The flowers are carried in 3 - 5 whorls around the stem, white or pinkish, with a purple centre.
Yellow Flag (IRIS PSEUDACORUS). 2' - 5' Perennial, fl. May - Aug. The creeping rhizomes of this popular iris are successful in colonising shallow waters. The rhizome also yields a black dye and the seeds are said to produce an ersatz coffee, when roasted.
Bogbean (MENYANTHES TRIFOLIATA). 1' Perennial, fl. May - July. Sometimes called Buckbean, or Marsh Trefoil, the latter name referring to the large leaves which are divided into three segments. The flowers are very beautiful, pink in bud, opening to reveal five thick, white petals with inner surfaces covered in a lacy fringe, which gives the flower an almost furry appearance.
Aquatic plants with floating leaves.
Water Crowfoot (RANUNCULUS AQUATILIS). Perennial, fl. May - Sept. The name R. Aquatilis was used by Linnaeus to cover a group of very similar plants now divided into separate species and sub-species. Water Crowfoot belongs to the same family as the Buttercup. The flowers are very similar, only with white petals and yellow centre, and the surface leaves are also similar in shape, though smaller than the Buttercup. The underwater leaves, however, are quite different; they are very finely divided and quite lacking in rigidity. Hence they offer little resistance to the movement of the water and are less liable to damage.
White Water Lily (NYMPHAEA ALBA). Perennial, fl. June - Aug. The large floating leaves of the water lily provide shade and shelter for small fish and other aquatic creatures. The surface of the leaves is strongly water repellant. The flowers, described by one botanist as "perhaps the most magnificent of our native flowers", rise out of the water as they open, during the heat of the day. This helps to ensure the pollen is properly dispersed. In evening the flowers close and sink into the water again.
Yellow Water Lily (NUPHAR LUTEA). Perennial, fl. July - Aug. Much less striking than the White Water Lily. The flowers are smaller, somewhat globe shaped, held several inches above the water.
NYMPHOIDES PELTATA. Perennial, fl. July - Aug. No common English name, though sometimes listed as Water Villarsia. Nymphoides means 'having the form of a water lily' and it could well be taken for such. It has round floating leaves and a yellow flower, fringed at the base. An uncommon plant, mainly found in the South and East.
Duckweed (LEMNA). Annual. Small green plants, which float in masses on the water's surface. Like the Water Lily they provide shade and harbour many insects, which make them popular food for ducks and others. Usually they multiply by offsets, but occasionally flower. Varieties found by the canal include L. Polyrhiza, an unusual species with purplish leaves, and L. Triscula (Ivy-leaved Duckweed) which floats just below the surface of the water.
Frog-bit (HYDROCHARIS MORSUS-RANAE). Perennial, fl. July - Aug. Round, floating leaves and delicate, 3-petaIled, while flowers. The name "Hydrocharic" comes from the Greek words for "water" and "elegance".
Water Solider (STRATIOTES ALOIDES). Perennial, fl. June - Aug. Sword shaped, serrated leaves, rather aloe like, attractive white flower. Not a common plant, but one which sends out runners and spreads rapidly once established.
Canadian Pondweed (ELODEA CANADENSIS). Perennial, fl. May - Sept. A common aquarium plant. Introduced from North America, it has spread very rapidly and is very common. The stem is brittle and pieces broken off can grow as independent plants. It is a major food plant for water fowl and fish, but can easily become so dense as to crowd out other plants and the fish themselves. The flowers are insignificant, raised on a thin stem above the water.
Water Violot (HOTTONIA PALUSTRIS). Perennial, fl. May - June. The leaves are narrow fronds, typical of many submerged plants, but the flowers are arranged in whorls around a smooth stem, which rises several inches above the water level. They are pale lilac with a yellow eye. Uncommon.
To deal In any systematic way with the myriads of Insects that live on, in or around the canal is a task far beyond the scope of this pamphlet. More than three-quarters of all the species in the animal kingdom are insects and the majority of these would not draw the attention of anyone but an entomologist. The canal does harbour a number of interesting Hemipters and Coleopters, including Tapinotus Sellatus, but, since this pamphlet is not intended for the specialist, this section deals mainly with butterflies. A few other groups will be found in the section on aquatic animals.
These creatures are one of the most beautiful, and vulnerable, groups of our insect population and their numbers tend to fluctuate very noticeably, although there has been a marked decline overall, during the present century. Not only Is our climate very variable, but suitable environments - wasteland - are becoming scarce. Settled sunny spells are needed for a butterfly to feed, mate and lay its eggs. Some species live for only a week or two, so bad weather can have a severe effect. Most species are quite specific in regard to foodplahts for the caterpillars, with the result that cultivation of the land, forestry, or even building developments may destroy a very localised species.
Most moths are nocturnal, although there are a few day flying species. If you are unsure whether it is a moth or a butterfly that you have found, a quick check is to look at the antenna. If it has a blunt, clubbed tip, the insect is a butterfly, if it is feathery, it is a moth.
DRAGONFLIES & DAMSELFLIES
The brilliant colours and shimmering wings of these insects make them an attractive sight as they swoop and hover above the water. The sub-order of ZYGOPTERA (Damselflies) have slender bodies, two pairs of similar wings and a rather fluttering flight. The ANISOPTERA (Dragonflies) are generally stouter and stronger, with forewings and hindwings of slightly different shape. Both are carnivorous, hunting and capturing other insects on the wing. The large, compound eyes, that cover most of the head, give them a very wide sphere of vision. There are seventeen species of damselflies and twenty-six dragonflies. Several have been recorded along the canal, including AESHNA GRANDIS, one of the largest dragonflies with conspicuous yellow wings, and a much rarer species, ORTHETRUM CANCELLATUM.
Dragonflies are extremely swift and agile fliers. They can reach speeds of twenty miles per hour, fast enough to capture most other insects. Their speed and agility, the ability to turn quickly, to brake, hover and rise also, helps them escape from pursuing birds. When hunting,, the dragonfly flies in a fairly random manner, often over a considerable distance. The damselfly, however, always remains close to the water's edge. Territorial flights are much shorter and the insect spends a good deal of lime hovering in fixed positions along its 'beat'.
The life cycle has already been described. The eggs are laid in the water, some species just dropping them over the canal, others either partially or entirely enter the water to deposit the eggs. The first year of life is thus spent under water. Around May or June the nymph crawls up a reed or plant stem into the air and the adult emerges. Most dragonflies are short lived and the adult survives for a month or two only.
The clumps of woodland and undergrowth which fringe the canal attract a wide variety of birds. The many midges and insects to be found wherever there is water attract more birds, while the canal itself supports various waterfowl. Again it is possible to mention only a representative sample of the many species which may be seen.
Great Spotted Woodpecker
Little Grebe, or Dabchick
Great Crested Grebe
Although these notes have highlighted some of the water birds found on the canal, many woodland and hedgerow species can also be found here. Some, such as tits, have been mentioned elsewhere.
The number of mammal species is relatively small, compared with other forms of animal life. The canal is a good place to watch for animals which come to drink, especially in the early morning and at dusk.
A number of species which live In the water have already been mentioned in other sections. Apart from the fish, dragonfly nymphs and tadpoles (of newt, toad and frog) there are many Interesting creatures to be found. Because the water provides such a distinct environment, it seemed more convenient to group some examples of aquatic life together, regardless of other means of classification.
Creatures like the water flea end the tadpole are Important links In the food chain which supports other creatures, up to the biggest pike or heron.
The original source of energy is sunlight, but this can only be converted Into sugar by green plants. Much of the canal's energy, therefore, comes from the tiny, planktonlc plants In the water. This process of manufacturing living substances through photosynthesis is the primary stage in food production. The animals, like the water fleas, that feed on the plants are first -order consumers. Second-order consumers, e.g. bass, in turn feed on these, and are themselves eaten by third-order consumers such as the heron. Finally all these plants and animals must die and their remains are reduced by scavengers, e.g. crayfish, and broken down by decomposers, or bacteria. Thus the simple nutrients are released into the water and made available to the plants once more, to assist the process of photosynthesis, and the cycle Is complete.
Great Silver Beetle
Great Diving Beetle
Great Hamshorn Snail
The main body of this booklet has attempted to give an indication of the great variety of fauna and flora in and around the canal. It is no more than an Introduction, a brief sampling. There are very many more species that have not been mentioned than the few that have.
Since shortly after its inception in 1949, the Nature Conservancy has designated parts of the canal 'Sites of Special Scientific Interest'. This classification has been mainly based on the rich flora and the aquatic life. The environment the canal provides is quite distinct from the country through which it passes; as a result there are several species here which are not generally found in Surrey and Hampshire. But in general these species do depend on the canal's continued existence as a canal.
Restoration is essential. This is not to say it is without problems. For example, Water Soldier has smothered the water near Ash Vale. It must be cleared for navigation to be possible. But Water Soldier is an interesting plant which Is not found elsewhere in the area, so clearance must be undertaken carefuly, not to entirely wipe out the species from the canal. This should be quite possible; the plant multiplies easily by runners and there are ponds where it can flourish undisturbed.
Excessive growth of plants like the Water Soldier is one of the main problems of any neglected waterway. On the Whitewater, a trout stream which the canal crosses in an aqueduct, one of the regular tasks of the management is to see that the weed is cut. On a navigable waterway the constant passage of boats is sufficient to keep weed in check. At the same time the boats help to move and aerate the water. There is a slight danger of pollution, but this is slight, some of the purest reservoirs in this country have pleasure craft on their waters. The greatest pollutant is likely to be people throwing rubbish; to prevent this is the responsibility of each and everyone of us.
Restoration, then, is essential. It cannot be done entirely without disturbance, but it must be remembered that the canal is a man-made feature of the landscape. Neglect involves the more serious disturbance of the natural balance, to restore, in this case, is to maintain it. An ideal situation might be where the towpath was kept cleared, to permit easy walking and access for boats, while the further bank was left free of interference. In the days when the Basingstoke was a working canal, it was an even better site for natural history than it is today.
In conclusion, I would like to quote the opinion of Mr. J.E. Lousley, an acknowledged expert and one who has known the canal since the days when the bargees still used it -
"I am convinced that conservation of the canal is dependent on restoration of a through flow of water. Breaking it up into sections of stagnant water wil not maintain the plants and animals of interest to naturalists. Such sections are likely to become objectionable and useless for recreation also. It seems to me that all conservation and amenity bodies have a common interest in this and naturalists should support the restoration of use for navigation".
Things to do
Careful observation end accurate records are the starting point of any natural history studiss. A small notebook and pencil, a large scale map, perhaps even a simple camera will enable you to record what you saw, where, and when. If note Is also taken of weather conditions you may discover something new about, perhaps, migration or breeding habits of a particular animal.
If you are uncertain of the identification of a species, a rough sketch with some brief notes about size, colour, habit, specially noticeable features, etc. will be more reliable than an unaided memory when you come to look it up.
Keeping a diary of seasonal change along one particular section of the canal is an interesting project for those who live close enough to visit it regularly. Include notes of temperatures, etc.
Another fascinating study is the life cycle of a single species, such as a dragonfly. Part of the life cycle of many Insects can be watched in captivity - e.g. caterpillars. Tadpoles can also be reared in an aquarium. But be sure that such creatures have adequate space, the right foodstuffs, proper conditions to live in.
Tracing food chains through observations is another possibility.
Let us know ... of any interesting or unusual occurrences along the canal, plants, insects, birds, aquatic life forms. Your criticisms of this booklet - your suggestions? Write to: Mrs J E Manser, 10 Highfield Crescent, Southampton SO2 15F, or any committee member of The Surrey and Hampshire Canal Society.
If you are not already a member - Join the above society!
Don't pick all the flowers and then leave them to die along the towpath, or in a hot car. If it is anything rare or unusual, or If you are not certain what it is, better not to pick at all. Observe, record, leave for others to enjoy.
Don't disturb birds unnecessarily, specially during the breeding season. It is illegal to take eggs from the nest. With some species it Is even required that you get permits to photograph the birds.
Don't leave litter, or throw it Into the canal. In short, enjoy the open eir, the wildlife around you, without disturbing, destroying or disfiguring it.
Of all the many books, these are a few suggestions:-
Towpath Walks by the Basingstoke Canal, by David Gerry. A collection of rambles along canal towpath, public footpaths, bridleways and country lanes exploring some of the lovely countryside through which the cana! passes. There are short rambles and long ones, and circular ones for those who like rambling by car.
Boats from the Basingstoke's Past, by Tony Harmsworth. Along the canal can be seen the rotting hulks of the barges and narrow boats which once traded on the cut. The booklet identifies each boat, tells you where to see it, and all about the history of the vessel. It also contains notes on the old days of barge building at Ash Vale, records of craft which traded on the cnnal, and their cargoes.
Waterside Inns of the Basingstoke Canal, by Jon Talbot. Historical details of the Canal's public houses, together with an recount of the Servlces offered today.
A History of the Basingstoke Canal, by Glenys Crocker. The booklet traces the history of the canal, from the application for the original act, through to its current condition.
The Society was formed in 1966 to campaign for public ownership and restoration of the Basingstoke Canal which was at that time privately owned.
Both Hampshire and Surrey county councils acknowledged the wide amenity value of the 32-mile waterway, and with the active support of the Surrey and Hampshire Canal Society to restore the navigation, they agreed to purchase it.
By 1976, following protracted negotiations leading to compulsory purchase orders, the two county councils acquired their respective lengths of the canal. Today, with the aid of voluntary labour organised by the Society and Job Creation schemes, the canal Is being restored for use as a multi-purpose recreational amenity.
Apart from organising voluntary working parties, the Society has an active social programme throughout the year and publishes a regular Newsletter. If you would like to join the Society or find out more about It, please send a stamped addressed envelope to:
[the Membership Secretary]
Last updated April 2006