|History of Stanpit Marsh|
Marsh Habitats through the Seasons
If you would like a printable version of a Map of Stanpit Marsh, showing the areas described, just Click on this Link.
Stanpit Marsh has a 7000 year history of human activity. In 1969 excavations on the eastern shore of Mother Siller's channel revealed artefacts left by Mesolithic coastal wanderers (3000 BC). As well as flint fragments, traces of Purbeck Limestone and stone from Portland were found (evidence of human movements across Dorset. At that time, the sea level was lower than today so there are likely to be more Neolithic remains now under water.
By the early Bronze Age, technology was more advanced as indicated by the 2000 year old artefacts found, including a well preserved cremation urn (now in the Red House Museum). After the Iron Age, material evidence of human activities is scarce. It is likely that, thereafter, people did not stay here for lengthy periods of time and consequently did not leave many artefacts. However, one may presume that hunting activities continued.
The Doomsday book entry for Stanpit village (1086) reveals that Stanpit was once known as 'Stanpeta' (meaning 2 estates with meadows).
More recently, in the late 18th Century, Stanpit Marsh was notorious for smugglers. Contraband was landed at Mudeford Quay, brought across the harbour and up the narrow channels that still criss - cross the marsh to this day. Mother Siller's channel used to stretch as far as the Ship in Distress, providing a quick and easy route through which goods could be landed and left in the care of Hannah Siller, the 'protecting angel' of smugglers. The climax of smuggling was the occasion of the locally famous battle of Mudeford on the 15th July 1784. Today the scout hut on Stanpit Recreation Ground is named 'Orestes' in memory of the customs 'lugger' sent to confront the smugglers.
100 years ago in the 19th century, agriculture dominated the marsh, as well as turf cutting for use as fuel, parts of the Marsh were kept relatively well drained. At one time Priory marsh was dry enough for Christchurch and Mudeford Cricket Club to play its first season there. A painting of this event now hangs at Lords cricket ground.
From the Victorian times up until the 1960s a great proportion of the marsh was regrettably lost. Both the golf course and recreation ground were formerly marsh. Today the marsh is very popular with dog walkers, fishermen, bird watchers, joggers and amateur naturalists.
Differences in vegetation across the Marsh are created by the change in water salinity from salt in the east to freshwater influence in the west. The outer eastern areas are composed of closely grazed dense turf, while to the west the freshwater marsh consists of a wider variety of flowering marshland plants. Grazing is an important feature of the Marsh, keeping grasses in check and enabling a stronger growth of flowering plants.
Grasses, together with aquatic vegetation, including algae left after receding flood tides, provide food for a variety of wildfowl. Gulls, herons and waders feed on amphibians, insects and worms, which might also be found in this habitat. Detritus, (decaying organic matter) deposited along the tide line, harbours additional food for gulls and waders, in the form of sandhoppers and other invertebrates.
At high tide, the grassy peninsulas of the Marsh provide vital, undisturbed roosting areas. All birds must conserve as much energy as possible and cormorants, whose feathers are not as waterproof as other birds, can often be seen here drying their wings.
The reedbeds on Stanpit Marsh are composed mainly of the Common reed [Phragmites australis]. Other plants may be present, particularly around the edges. Reeds are a familiar sight along Purewell Stream, at Great Spires, bordering the upper parts of Mother Siller’s Channel, and in the north east area of the Marsh.
Patches of open water and ditches often occur amongst the reedbeds. The flowering heads, leaves, stems and root systems as well as the water, mud and detritus surrounding them, provide a great variety of habitats for animals.
Salt-pans, Creeks and Streams
Salt-pans and creeks are a feature of the Marsh. Their brackish water levels vary extensively according to the state of the tide and the amount of rainfall.
Both water and mud provide a rich habitat for small fish and invertebrates such as worms, crustaceans, insects and molluscs. All these animals in turn, are a plentiful source of food for egrets, herons, ducks and waders.
Purewell Stream is fresh water where it enters the Marsh and supports a different range of small fish and invertebrate species from those found in brackish water. These animals, in their turn, attract a different variety of birds including Kingfishers. The stream also provides freshwater for the ponies and cattle which graze the Marsh.
Mud-flats and Harbour Waters
The mud-flats at low tide, especially the area known as Stanpit Bight, attract large numbers of feeding birds. Waders, ducks and gulls are supported by the rich supply of small invertebrates living in the mud.
The waders are beautifully adapted with their varying beak lengths to take advantage of all the feeding opportunities available at differing depths within the mud.
The harbour waters are rich with fish and crustaceans. Herons are often seen feeding on fish and crabs in the shallow waters, while cormorants and terns dive for fish in deeper waters. Aquatic vegetation provides food for swans and ducks.
Crouch Hill, the highest point on the Marsh, is a fairly open area scattered with gorse bushes. The dry, sandy, acid soil encourages the growth of short fescue grasses and small species of clovers, chickweeds, trefoils and Sheep’s Sorrel. It is well grazed by rabbits and ponies. Such areas are known as ‘acid grassland’ and are relatively rare.
Subject to erosion because of its sandy nature, the trampling of livestock and visitors, and rabbit burrowing, a fence was erected in 1982 on the top of the Hill, to create an exclusion zone. This allowed natural regeneration of the vegetation within the fenced zone and was an indication of the difference between grazing and non-grazing areas.
There has been some cutback of the gorse associated with a relocation of Natterjack toads to the Marsh [a Biological Action Plan Project] and the creation of artificial, temporary pools for spawn and tadpole development. The reduction of the gorse also aids acid grassland regeneration. See Natterjack Toad Update in REPTILE AND AMPHIBIAN gallery
The Scrub on higher sandy areas of the Marsh, consists of several habitats. It comprises small trees such as holly, hawthorn and rowan, and thick patches of bramble, Gorse and Honeysuckle. These are interspersed with open areas of acid grassland, pools and bog. Together with flowering plants, this diversity of vegetation and habitat attracts an abundance of wildlife.
In North Scrubs, the pools, some of them temporary, provide fresh water for drinking and bathing for the many woodland and hedgerow birds.
Grazing livestock and rabbits help keep the turf short and the scrub in check.
North, East and South Marshes
The flocks of Brent geese and Wigeon, a familiar sight in winter, leave the Marsh in April, heading for their breeding grounds in arctic regions. In mid spring, flowering Thrift casts a pink hue over the shortly grazed turf and Scurvy Grass flowers around the pools.
In April, the small number of grazing livestock increases with the arrival of additional animals. Foals are born on the Marsh in late spring.
Some of the pools within this area may be covered with the delicate white flowers of Water Crowfoot, indicating the influence of freshwater. The western reaches of the Marsh being mainly freshwater, can be quite colourful in spring with Celery-leaved Buttercup, Yellow Flag Iris and Marsh Marigold in flower.
Although not much is known about how many birds may breed successfully in this area, the Meadow Pipit can be seen in large numbers and their nests have been found here. The Skylark is not so frequently seen but may be heard singing as it hovers overhead.
In spring, reeds begin to grow and bright green shoots slowly replace the dead, yellow stems and leaves of winter.
Small animals such as the Wainscot moth and Gall midge emerge from their pupae after overwintering in the dying reed stems. Other invertebrates including insects and molluscs, awake from hibernation in the litter and detritus at the base of the reeds and become active, using the new growth of leaves and stems as a habitat in which to breed and feed. Damselflies, such as the Blue-tailed damselfly, may seek shelter in the reeds.
Birds, including Reed warblers, Sedge warblers, Reed buntings and Swans, nest in the reedbeds while other species, such as herons and Mallard ducks, seek cover here. This habitat is also frequented by the Water Rail, which may also nest here. Otter spraint [droppings] has been recorded on the Marsh close to the reeds, indicating that at least one of these shy and very welcome mammals visit this area.
Salt-pans, Creeks and Streams
As the water temperature rises, aquatic vegetation including algae begins to flourish.
Many invertebrate animals which have hibernated in the mud or bank vegetation of the creeks and pans over winter, begin to stir. Ragworms occupy higher levels in the mud and some become free swimming. Shore crabs move into shallower water; mud shrimps [Corophium] and common shrimps emerge. Young Grey mullet may make their way inshore and become trapped in pans and creeks.
In the freshwater of Purewell Stream the events are similar. Vegetation begins to grow and Sticklebacks, freshwater shrimps, Pond Slaters and Lesser Water Boatmen emerge, providing food for regular visitors such as Kingfishers and Mallard and their young.
Mud-flats and Harbour Waters
Small animals such as Ragworms, crustaceans and molluscs are moving to higher levels or emerging from the mud.
In spring, the variety and number of birds seen feeding on the mud-flats fluctuates. Summer migrants are arriving, some of which may stay for the season while others may just be passing through, and winter visitors are leaving. From the beginning of spring, some birds will be changing from their winter to summer plumage. The shrill call of the visiting terns now arriving is a welcome sound.
Very few waders breed on the Marsh, possibly due to trampling by livestock and predation by foxes and gulls. However, the resident Oyster Catcher has been recorded as nesting on Blackberry Point.
In spring, Grey Herons are nesting in the tall trees on Hengistbury Head. Cormorants do not breed locally, but do have nesting sites on the cliffs of Ballard Down at Swanage.
Grey Mullet and Flounders having spent the winter in the warmer waters of the sea, spawn there in the spring. Sea Bass also breed offshore in the spring.
In spring, the small flowering plants such as Least bird’s foot trefoil, Changing forget-me-not and Hop trefoil begin to flower. The gorse becomes a blaze of yellow and provides a potential nesting area for birds such as Linnets, Stonechats and Dartford Warblers. Other birds visiting the area are Meadow Pipits and the migrant Wheatear. Rabbits and their young graze the new growth of fescue grasses.
The Scrub in spring provides nesting sites for a variety of woodland and hedgerow birds such as Long-tailed tits, Blue tits, Great tits, Greenfinch, Whitethroat and Blackbirds. Crows regularly nest in the poplars behind North Scrubs, and woodpeckers can be heard drumming there, especially the Greater Spotted woodpecker.
The golden yellow Celandine and other early flowers provide nectar for butterflies awakening from hibernation or emerging from over-wintering pupae. The first broods of caterpillars can be seen in late spring.
Damselflies and dragonflies are now emerging from nymphs. Dragonflies can be seen on their territorial flight-paths hunting for insects.
Spiderlings may be seen in clusters around their egg sacs or nests, before they disperse into the undergrowth. Small mammals such as mice and shrews are breeding, and grass snakes are stirring from hibernation.
Frogs have been seen in the wetter areas.
Small shoots and saplings springing up now are grazed by livestock and rabbits.
North, East and South Marshes
Sea Lavender casts a pink hue over the Marsh in summer. Smaller flowers such as Sea Spurrey and Sea Milkwort are hidden within the turf. Large patches of Glasswort, a succulent and edible plant, are found in the wetter areas.
At high tide the outer reaches of the Marsh provide vital undisturbed roosting areas for the birds.
Young Grey Herons (from local breeding colonies, including the one on Hengistbury Head) can often be seen near reedbeds. Little Egrets, Redshank and Curlew are a common sight on the Marsh, and Kestrels might also be seen hovering.
Ponies congregate on outer grassy areas in hot weather to keep cool and free from biting insects. The groups include foals born on the Marsh in spring.
The Yellow Flag Iris is still flowering in June. Marsh Ragwort and Celery-leaved Buttercup also add a splash of yellow now. Water Dropwort and Brookweed are also in flower at this time of the year. Having disappeared for a number of years, the rare Marestail has again been recorded on the reserve in recent years.
Young Grey Herons and the Little Egret are also seen here. The melodious song of Skylarks may be heard in the sky over Central Marsh. Meadow Pipits can often be seen in small flocks, and visiting swallows and martins skim over the Marsh feeding on insects.
The Green-veined White butterfly frequents the damper areas of the Marsh. This species is often mistaken for the Small White but has darker vein markings on the underside of the wings.
The reeds and other plants in the reedbeds such as Fools Watercress and Hedge Bindweed continue to produce fresh growth of stems and leaves in summer. All provide food and cover for many different animals.
Insects such as beetles and midges metamorphose from aquatic larvae and pupae. Wainscot Moths and Gall Midges continue to emerge from old, broken reed stems. June heralds the arrival of Reed Aphids which spend the summer feeding on sap from the reed leaves. Ladybirds feed on the aphids. Other insects provide food for Reed Warblers and Sedge Warblers which might be nesting here. Snails climb the stems and leaves. Water Rails, Moorhens and their young enjoy the cover as they hunt for small invertebrates and plant food amongst the roots.
In late summer the one-sided reed flower-heads are formed, consisting of numerous purplish spikelets with silky hairs. The heads droop as the seeds ripen, providing food for Reed Buntings.
Otter spraint has been found close to the reeds – a welcome sign that otters visit the Marsh.
Salt-pans, Creeks and Streams
The green algae Enteromorpha, and Sea Lettuce, often colour the salt pans bright green in summer. Both provide a valuable source of food for Swans and Mallards in the creeks, and cover for small aquatic animals such as snails and shrimps.
Glassworts grow along the creeks – these are among the first (pioneer) plants to colonise the mud. Flowering Rush can be seen in some shallow water creeks. Wading birds such as Redshanks, Little Egrets and Curlews delve in the brackish water creeks and pans for the abundant Ragworms, Mud Shrimps, Sphaeroma, Larver Spire Snails and small fish.
In the fresh water of Purewell Stream, Water Starwort and Duckweed may be seen. Small invertebrates such as Pond Skaters, Water Boatmen and Freshwater Shrimps flourish, while many aquatic larvae and nymphs metamorphose into adult beetles, damselflies, dragonflies and caddis flies, providing food for birds such as Cetti’s Warblers and Whitethroats. Kingfishers dive for fish including the Three-spined Stickleback.
Mud-flats and Harbour Waters
The mud is home to a plentiful supply of food, accessible at low tide, for waders, gulls and wildfowl. Lugworm feed on decaying plant and animal matter in the mud. After swallowing the sand, the Lugworm extracts food particles and rejects the inedible sand, which is thrown up on the surface in the familiar worm-like casts. Tell-tale holes in the mud denote the presence of Ragworm which leave their burrows to scavenge or actively hunt their prey. Molluscs filter edible particles in the water through siphons. Crabs and shrimps bury themselves in the mud when the tide is out and emerge with the incoming tide to feed on seaweed and animal remains in the water.
Wading birds (such as Dunlin, Oyster Catcher and Lapwing), are joined by summer migrants such as the Common Sandpiper - all take advantage of this plentiful food supply.
The three main types of visiting terns seen now are the Little Tern, Common Tern and Sandwich Tern, and these can often be seen diving for food in the harbour.
The young of most common gulls and ducks should be seen now, especially the Shelduck.
Mute swans and their young can be seen in the harbour in summer. They are known to breed on Spellers Point where they can often be seen resting. In July the annual Swan Ringing takes place.
Cormorants and their young can be seen drying their wings on the grassy peninsulas in the harbour, and also on Blackberry Point. The young are brown with white underparts.
The most common fish to be found in these waters are Dab, Flounder, Grey Mullet, Pollack, Salmon smolt and Common Eels. Grey Mullet and Flounder fry enter the estuary and creeks in July and August where they feed and grow. Sea Bass fry also enter river estuaries in summer, venturing far up into brackish water.
The sandy soil tends to dry out in the summer sunshine and activities of ponies and visitors can cause erosion of the fragile turf. The grasses and small plants such as Subterranean Clover and Sheep’s Sorrel help to stabilise this area. Shelduck nest in old rabbit burrows, and have in past years raised young here.
Some of the summer flowering plants within the scrub are Meadow Rue, Fleabane and Marsh Mallow, a local rarity. (Unfortunately, some of these plants are grazed by livestock whilst in bloom.)
Large patches of flowering Fleabane, bramble and Honeysuckle attract bees and a variety of butterflies. Several species of butterfly lay their eggs on Stinging Nettles. The Small Tortoiseshell and Peacock lay their eggs in batches, therefore the caterpillars can easily be seen; whereas the Comma and Red Admiral lay eggs singly, making their caterpillars more difficult to find. The Painted Lady butterfly (a migrant) arrives in June and in some summers can be seen in vast numbers.
The bramble flowers provide a ready supply of nectar for butterflies, and the leaves are a food plant for the caterpillars of a variety of moths such as the Vapourer and Oak Eggar.
By mid-summer, many species of damselfly and dragonfly take advantage of the food and shelter that the scrub offers. The large hawker dragonflies can be seen on their territorial flight-paths hunting for insects. The smaller darters are camouflaged when resting on twigs and difficult to spot until disturbed. A dragonfly rarity, whose markings make it more noticeable, is the Scarce Chaser.
Some of the woodland and hedgerow birds seen here might still be feeding young. Not many summer migrants visit this area, but one which has been recorded is the Chiffchaff.
Numerous young of grasshoppers and crickets can now be seen in the undergrowth, and maturing spiders and their webs begin to appear in the shrubbery.
Frogs and froglets might be spotted in the wetter grassy areas, although the temporary pools may dry up in the summer.
North, East and South Marshes
In autumn, South Marsh, in particular, is a patchwork of colour as Glasswort in the damper areas begins to redden. Hidden in the turf of these marshes, a few plants of the Spurrey family continue to flower into September.
High spring tides often completely flood the Marsh, making it quite inaccessible. As these floods recede, worms and other invertebrates which have come to the surface provide a plentiful food supply for waders and gulls. The tide strand line of dead reeds and other vegetation also harbours insects and crustaceans such as Sandhoppers. After a flooding high tide, Sea Lettuce [Ulva] and Enteromorpha also litter the Marsh.
Having spent the summer months in their breeding grounds in Arctic Siberia, the migrant Brent Geese and Wigeon arrive in late September/October. They feed in large flocks on the outer marshlands.
Many Lapwing who have spent the summer rearing young in local fields, return to the Marsh. Coots can also often be seen in groups grazing the grassy peninsulas with other water birds. Herons and Little Egrets are a familiar sight feeding in the pools and creeks, as well as the resident Teal, Britain’s smallest duck. Young herons may be seen in close proximity to one another whilst learning feeding skills. Redshanks, and the semi-migrant Greenshank might also be seen. At high tide, these and other resident birds may be feeding on insects, and other invertebrates within the marsh turf.
The marshland peninsulas provide undisturbed roosting areas for the birds during high tide. These areas are vital during the latter months on the year, when energy must be conserved for the body to withstand the colder weather.
By late September most plants will have finished flowering. Sea Aster (of the same genus as garden Michaelmas Daisy) and Water Mint provide a vital source of nectar for late-flying butterflies. The Green-veined White (which favours damp areas) can still be seen in flight in September. This species overwinters in chrysalis form.
With the breeding season over, some birds become more sociable and once again form small flocks. Pipits can often be seen in this area, and the Starlings are a fascinating sight as they dive and circle over the Marsh in one huge swarming mass. This grouping not only provides ‘safety in numbers’, but is also beneficial when hunting for food. From autumn onwards, the migrant Brent Geese can sometimes be seen grazing Central Marsh. Herons and Little Egrets are also often seen feeding in the pools and creeks here.
As vegetation dies back, Central Marsh is more exposed, and high equinoctial spring tides can flood most of the area creating an unrecognisable landscape. Detritus, left after flooding tides, often collects quite thickly in front of North Scrubs, and is ideal cover for wintering insects and crustaceans – a potential food supply for scavenging Crows and Magpies.
In autumn the number of grazing livestock is reduced. The cattle, and some ponies and foals are removed from the Marsh.
During the autumn the large, branched purple panicles of the reeds droop to one side and become a mass of silky down, made up of long hairs attached to seeds which are dispersed by the wind. Slowly the reeds die back as the leaves break away and the stems become pale and brittle. Breakdown and decay of this material provides a protective and fertile feeding layer (litter layer) for worms, crustaceans and insects.
The reeds survive the winter with the help of oxygen which diffuses through the remaining hollow stems. These act as airways to the long, creeping root systems in the mud below. The hollow stems also provide a protective habitat for overwintering animals such as woodlice, earwigs, spiders and the larvae and pupae of Wainscot moths. Meanwhile the Plum reed aphids, which have been feeding on the reed leaves, produce winged forms which fly back to fruit trees for the winter. A few adult dragonflies and damselflies may be seen in early autumn but most die before the end of September.
The reeds continue to provide cover for a number of birds including Reed buntings, ducks, coots and herons. Reed warblers are preparing to depart and pre-migratory flocks of martins and swallows may use the reedbeds as a temporary roost prior to their long journeys.
Salt-pans, Creeks and Streams
Aquatic vegetation, including the algae, dies back in autumn. As decay proceeds, a rich layer of organic matter is produced, providing plenty of food for detritus feeders such as shrimps. Many aquatic animals become relatively inactive as the temperature falls. Some, such as dragonfly and damselfly nymphs spend the cold months on the bottom while others, including ragworms and Corophium, burrow deep in the mud. Some, including pond skaters, leave the water to lay eggs and survive the winter on land. Others, such as shore crabs and prawns, move into deeper water which is warmer than the Marsh creeks and pans.
Small fish shelter in water around the bases and roots of aquatic plants.
Birds such as herons, egrets, Curlews, Redshanks, Greenshanks and gulls may have to search and probe the mud more deeply for their prey. However, as this food source is relatively inactive there will be plenty to eat. Teal (Britain’s smallest duck) return to the Marsh at the end of the breeding season. They also feed in the pools, but are surface feeders.
The whole Marsh, including the pans and creeks, may become flooded at times, particularly during the autumn equinox.
Mud-flats and Harbour Waters
Although harbour waters get colder during autumn, and invertebrates burrow deeper into the mud, food for the wading birds is still plentiful.
By September the summer-visiting Terns have left our shores for warmer waters off the coast of Africa. As summer migrants leave our shores, winter visitors arrive, including Sanderling, Dunlin, Black-tailed Godwit, Turnstone, and Knot. Observation of the waders on the distant mud-flats is sometimes difficult. However, the birds may become more visible as they approach the shore in advance of the incoming tide. It is then that the birds take advantage of the marshland peninsulas to roost whilst waiting for the tide to go out again.
Gulls and waders change to their winter plumage at this time of the year – the larger Herring and Black-backed gulls having a speckled appearance to their head feathers. But more noticeable is the change in the Black-headed gulls, which lose the majority of their black head feathers, retaining just a few behind the eye. The tawny-coloured young gulls now form small groups, as they learn to fend for themselves. Oyster-catchers develop a white throat band in the winter.
Outside the breeding season, from autumn onwards, Swans tend to be more tolerant of each other and form small flocks in the harbour. Swans that may have nested further up-river, return to the estuary with their young. Cormorants are a familiar sight in the estuary. They can be seen roosting, and drying their wings, on the grassy peninsulas and distant Blackberry Point.
High equinoctial spring tides swell the harbour water towards late September and may flood the Marsh. The harbour provides ideal sheltered waters for young of many fish, which, in turn, provide food for Cormorants, herons and egrets.
In autumn, Salmon, which have been maturing out to sea, travel through the harbour and up-river to spawn. Sea Trout migrate into rivers in early autumn to spawn. The young may spend a year or more in the estuaries and creeks before migrating out to sea. Eels, having reached maturity up-river, pass through the estuary and out into open seas en-route to spawning grounds in the mid-Atlantic. Young Mullet and Flounders return to the sea in late autumn to find deeper, warmer waters for the winter.
Many of the small plants on Crouch Hill die back in autumn, but Sheep’s Sorrel still in flower, may cast a very red hue over the area. The eroded areas, enhanced by a combination of reduced rainfall over the summer and trampling by ponies and visitors, become more exposed and vulnerable.
The seat overlooking the harbour provides a good outlook point for viewing resident and autumn migrant birds while they are feeding. The seat was erected in memory of Dorothy Baker, a councillor whose hard work and interest in the Marsh resulted in its being designated a Nature Reserve.
Some adult spiders and their webs may still be seen on the gorse and moth caterpillars overwintering in their protective silken nests on the brambles. Rabbits are less active but continue to feed on the Hill. Stonechats, Greenfinches, Linnets and pipits are often seen, together with gathering summer migrants such as Yellow wagtails, Wheatears and swallows. At this time of year swarming Starlings may alight in this area.
Most plants will have finished flowering by the end of September, but Fleabane still in flower, provides nectar for butterflies preparing to hibernate as adults. All butterfly eggs will have hatched and will overwinter either as caterpillars or pupae.
Adult grasshoppers and most crickets cannot survive the winter. Their eggs, which are laid in the ground during the summer, will overwinter in this state.
A few spiders can actually survive the winter in the adult form, their bodies containing a variety of ‘antifreeze’ substances. But most orb-web spiders die. The next generation survives the winter in egg-sacs, either as eggs or spiderlings.
Decaying leaf matter and logs provide ideal cover for insects and other animals that overwinter in the adult form. Frogs, toads and snakes may take advantage of rabbit burrows in which to hibernate.
Many small trees and plants produce berries – Hawthorn, Rowan, Blackberry, Holly, Ivy and Honeysuckle. Together with rose hips, these provide food for the birds when insect life is unavailable. Hops (the favoured food plant of the caterpillars of the Comma butterfly), can be seen flowering amongst the brambles now.
Teasels, grasses and thistles provide seeds for seed-eating birds such as the Goldfinch and Greenfinch.
Heavy rainfalls in the autumn, perhaps combined with high tides, create very wet areas in North Scrubs.
North, East and South Marshes
During the winter months, these areas are vital for the birds. In order to conserve energy and maintain body warmth, birds must have areas where they can safely rest between low tides.
If insufficient food is available from the mud-flats, waders (including migrants such as Knot, Greenshank and Grey Plover), and other water birds, may search for food on the open marshland. In extremely cold weather, the need for finding food becomes greater than fears for safety, and sometimes birds can be seen feeding relatively close to the pathways. It is vital at such times that their disturbance is avoided.
Brent Geese are a regular sight on the Marsh in winter. Having arrived in autumn, they favour these outer marshlands for grazing, and feed together in one noisy flock, sometimes numbering 2-300 birds. The number of birds over-wintering on the Marsh is increased by flocks of Lapwing and Snipe coming over from Europe if the weather is particularly bad there.
Grey Herons and Little Egrets are a familiar sight feeding in the pools and creeks.
Ice or a heavy frost creates a glistening scene, and the rare occasion of snowfall transforms the landscape. If wildlife is not visible, a little detective work on footprints in the snow, or mud, may indicate which birds or animals have visited an area.
The migrant Brent Geese can sometimes be seen grazing here, and Grey Herons, Little Egrets and Teal are also often seen feeding in the pools and creeks. Because of its location, with visitors walking round on all sides, it is, however, not a suitable place for birds to roost.
In winter when the vegetation has died back, and the reeds have turned a rusty colour, Central Marsh is a bleak, exposed landscape, and is at times completely flooded by a combination of high tides and heavy rainfall.
The golden colour of the reedbeds adds a glow to the Marsh in winter. As the reeds die back they turn from greyish green to yellow, often breaking and disintegrating. A rich litter layer forms at ground level both in the water and in higher, drier areas. The reeds remain alive by storing feed reserves in underground stems or rhizomes and remain dormant until the spring protected by the surrounding silt.
Invertebrate animals such as Wainscot Moth and other insect pupae, woodlice, earwigs and fly larvae, overwinter within the dead, hollow reed stems above water level. The litter layer is also an excellent food source for detritus feeders.
Below water, the reed debris mixes with silt where it decomposes more rapidly. Once again it provides protection from the cold and a food supply for small animals such as Chironomid larvae (non-biting midge larvae), aquatic worms and other invertebrates.
The reedbeds also provide some birds and mammals with protection from the hazards of winter. Coots, moorhens and mallards seek shelter there, and also possibly Otters.
Salt-pans, Creeks and Streams
Long cold periods and freezing temperatures, plus excessive flooding are some of the winter hazards faced by plants and animals living in the above habitats. Aquatic vegetation tends to die back, surviving the winter in a dormant form underground. Dead material forms a rich layer of organic matter under water, providing animals with some protection from the cold. Detritus feeders enjoy this rich source of food. Surface water may freeze leaving a fluid layer underneath.
The body temperature of invertebrates and fish, changes with that of their surroundings, so these animals become less active in winter. Many have evolved successful methods of overcoming the problems of reduced mobility and freezing.
Flounders, shore crabs and prawns move seaward where the deeper water is warmer. Dragonfly and damselfly nymphs, mayfly larvae, Gammarus, shrimps and flatworms survive on the bottom amongst the mud and detritus. Burrowing invertebrates such as worms, some aquatic insect larvae, and certain crustaceans burrow more deeply where the temperature fluctuations are less than on the surface.
Chironomid larvae, [non biting midge], and Tubifex worms, surviving in the mud, turn bright red with the increasing levels of the respiratory pigment haemoglobin, which takes up any available oxygen. Water fleas also may produce blood pigments and many form resistant coats overwintering as dormant forms. Many invertebrates can survive freezing temperatures because the higher salt content of their bodies depresses their freezing point.
Mallards, herons, Little egrets, and some waders such as Redshanks and Godwits search for food in these habitats.
Mud-flats and Harbour Waters
During the winter, as the temperature of harbour water decreases, invertebrates burrow deeper into the mud. This potential food supply for the wading birds may become less accessible. It is during these times that the birds resort to other sources of food such as pools, creeks and open marshland.
The shorter days of winter, and harsher weather, make feeding difficult for the birds. Every opportunity to feed, when the mud-flats are exposed, is taken advantage of, even during the night. The smaller species are more vulnerable in these inhospitable conditions, as their surface area is far greater in relation to their volume, and so their body heat is lost far more quickly than that of larger species.
Winter visitors include waders such as Dunlin, Sanderling, Black-tailed Godwit, Turnstone and Knot.
Coots might be seen amongst the other water birds, diving in the harbour waters for aquatic vegetation. Cormorants are a regular sight within the harbour, and can be seen roosting, and drying their wings, on distant Blackberry Point and on the grassy peninsulas.
Fish are cold-blooded animals, and are unable to maintain a regular body temperature. During the winter this creates hardship for those fish living in the freshwater environment of streams and rivers. As the water temperature decreases, the fish tend to lie motionless near boulders or vegetation and hardly feed, or retreat to deep pools where the waters may be warmer.
Life for those living in the sea, however, is not so harsh. Because of its vastness, the open sea maintains its warmth and rarely becomes as cold as rivers or lakes. It also has a much lower freezing point than fresh water, due to the salt content.
However, as harbour waters are shallow, during severe cold weather fish such as Grey Mullet and Flounders may retreat into the warmer open seas. Sea Bass also move into deeper water for the winter. The severe winter of 1962-3 saw a very rare sight of a harbour freeze.
Crouch Hill rises about five metres above sea level and in winter is exposed to the cold, wind and driving rain. A few flowers remain on the Gorse while the low-lying plants in the turf die back, surviving underground or as seeds and fruits half-buried in the soil. The dead material contributes to the very thin layer of humus overlying the sandy soil, as do the rabbit and pony droppings. Fungi help in the decomposition processes. The soil profile becomes more clearly visible in winter if you look in the pony scrapes on the Hill.
The rabbit borrows are clearly visible. As always, Crouch Hill is a very good point from which to view the birds roosting and feeding on the mud-flats and in the harbour.
The Scrub areas, particularly North Scrubs, need management. In order to encourage new growth, and retain the acid grassland, bramble and gorse have to be controlled. Other invasive plants such as bracken are also removed to encourage vegetation that is supportive of wildlife. Conservation work is normally carried out during the dormant months of winter to cause as little disturbance as possible to the wildlife.
Life for the wildlife is harsh, and for animals not hibernating, many hours of the short days of winter are spent looking for food. Birds will be feeding on seeds, berries and any insects that might be found. Small birds, such as the Tit family, need to spend up to 9 hours a day searching for food. Some woodland birds, such as Long-tailed Tits, live in small family groups. The success of finding food is made easier with more pairs of eyes. Continuous calling to one-another keeps the group in touch. Some birds can lose over a quarter of their weight trying to keep warm.
Although for most of the winter the Scrub looks bare and lifeless, a snowfall or heavy frost creates a magical scene – frosty-edged leaves, glistening cobwebs and maybe a winter wonderland of snow-laden shrubs and trees. Then, in just a few short months, this dormant landscape will be transformed as new life emerges in spring.