The river Dour is just 7.5km long from its source to the sea, but is one of the UK's most important rivers for Brown Trout. Once the river was full of pollution from Dover's industries and few fish or other river creatures could survive. Today the river is a wildlife haven that passes right through the heart of the upstream villages and the town.
This bright yellow perennial plant grows up to 1.5 meters tall. The errect flat leaves grown up to 90mm long. The flowers are bright yellow, appearing from june until August then forming a dry fruit capsule 4-7 cm long in the late summer that contains numerous pale brown seeds.
Flag Iris grows best in very wet conditions and spreads quickly by both rhizome and water-dispersed seed. The rhizomes can survive prolonged dry conditions.
This small white heron with a black beak and legs and yellow feet eats fish. Originaly only a winter visitor, the birds now also breed in the UK so you can see them all year round, but numbers increase as winter visitors arrive.
This tall bird with distinctive grey and black feathering can be seen all year round near most open water. In addition to fish, herons eat amphibians, rodents and the young of other waterfowl. They may be spotted with outstrtched neck or hunched at rest.
Also known as kingcup, marsh marigold has large yellow buttercup-like flowers and large rounded, serated leaves with hollow stems. Found in wet and marshy places it is found all alonf the Dour.
All-black feathers, white face plates and their larger size distinguish coots from the smaller red-faced moorhens. Lobes on their toes act like webs to helpthem to swim. Coots eat plants, insect larvae and snails.
Spot bright blue and orange kingfishers as they hunt for fish, sometimes hovering above the water, but usually darting down from a riverbank perch to snatch fish or aquatic insects from the river.
Kingfishers nest in tunnels excavated into the river bank by both male and female. Breeding starts aound April and two or three clutches of six to seven eggs are laid. The eggs are almost round at 20mm size and are smooth white. After incubation of around 20 days, both parents feed the young which are ready to fly afer 27 days.
Lampreys are not true fish - they are primitive jawless invertebrates with a toothed funnel-like mouth, no scales and skeleton of cartilage not bones. They have no gill covers with seven gill holes down each side of the body. Although they are widely knownas paracites which feed on the blood and flesh of other fish, not all lampreys are paracitic. Lampreys lay eggs in gravel and juveniles develop in burrows.
Distingished from coots by their red and yellow beaks, white under-tail feathers and flank stripes, and smaller size, moorhens have long green legs, a brown-black back and blue-balck belly. They are nervous birds, seen all along the Dour. They eat seeds, fruit, water plants, grasses, snails, insects, worms and small fish. They nest on rafts of twigs, laying brown speckled eggs and may hatch more than one brood of chicks per year.
European eels are migratory fish. They are spawned at sea (believed to be in the Sargasso Sea 4,000 miles from the UK). The flat larvae are carries by ocean currents to Europe and by the time they swim upstream into the river on the Spring tide they have transformed into transparen "glass eels" or newly pigmented "elvers".
Eels mature in the river for up to 20 years, eating bottom-living creatures such as fish, larvae and nymphs. Eels can survive out of water for some time and may cross damp land in search of water. Mature eels return to the sea in the the dark in autumn. Their bodies change considerably ready for their new enviromnment. Large migrations can be observed onwet, stormy nights, particularly when the half moon is waning. Once at sea they no longer eat and must survive on their body fat for their long journey to the spawning grounds where they mate and die.
Eels are eaten by herons, other fish and humans.
Damselfies have a nymph and adult stage and both stages are carniverous - they eat other insects. DAmselflies are smaller than dragonflies and do not fly as strongly. They can also be distinguished by the fact that damselflies' wings are held along the body when at rest and that their front and back wings are of similar shape. Their eyes are seperated, wheras the eyes of the dragonfly usuallly touch and their wing shape differs between the front and back pair.
Adult damselfies eat small insects, including mosquitos and flies. They mature and gain their full colours, and may be on the wing for only a few weeks of their lifecycle. They have excellent eyesight with which to locate their prey and use their legs to grap and encircle their victims.
You may see male and female damselflies joined together in a heart shape while they mate, and they may fly joined together for some time after mating.The female lays her eggs in the water, on twigs or stalks of aquatic plants, depending on the species.
Damsel fly juvenile
Damselfly eggs hatch into larvae which live on the river bottom. They have external gills which look like three fronded tails and have a hinged jaw with two hooks, called the mask, which can be thrust forward to impale prey which is then drawn back into the mouth. The larvae are ferocious hunters and will hunt and eat anything that is smaller than themselves. They metamorphasise several times while they live under water, shedding their skins to allow growth and the development of more adult features. When they are ready for their final metamorphasis into an adult they climb up plant stalks and shed their nymph skin, called an exuvia, then rest and stretch their wings before their first flight.
Cased caddis fly
Cased caddis fly larvae can be found all along the Dour. The larvae make silk and use it to make a protective sleeve which is coated with sand, small stones and twigs from the river bed. Their front part protrude from the casing so that they can drag it behind them as they look for food. Cased caddis fly larvae eat vegitation. Once they are ready to mature caddis flies adhere their case to a rock, seal off the ends of the case with silk and pupate inside. The adult bites its way out, swims to the surface and sheds it skin then flies away. Adult caddid fly are moth-like but have hairy rather than scaly wings. They are nocturnal and eat only nectar or nothing at all, living for just a few weeks to mate.
These small crustaceans (around 20mm) are usually to be found wriggling on their sides with their bodies in a 'c' shape. Cillates (non paracitic creatures) adhere to their bodies. In strong currents they may take shelter under rocks and weeds. They feed on decaying matter. The males are larger than the females and can be seen carrying them before mating. The males also carry the eggs after mating. Water temperature decides the sex of the offsping with higher temperatures producing females. Freshwater shrimp are an important source of food for fish.
Mayfies are an ancient species dating back to the days of the dinosaurs!The adults are very short lived, flying in swarms above the water to mate, lay eggs then die withing just a few hours and reaely more than 24 hours. Most of the life of a mayfly is spent as a nymph (or naiad) underwater, where the it feeds on vegeation and algae, moulting it skin 20 or thirty times as it develops. The nymph phase may last up to two years depending on the species.
Mayfies are unique in that they have two winged phases of development. The nymph undergoes its last moult and emerges from the water as a "subimago" - a sexually imature winged stage. The mayfly rests on the bank before finally moulting to its adult form. The adult mayfly does not feed. Eggs are laid on the surface of the water and sink to the bottom. Mayfies may emerge in groups. All stages of the lifecycle provide important food for fish and other river life.
On the surface of the water, water crowfoot produces small white buttercup-like flowers with yellow centres in May and June. Surface leaves are similar to those of the buttercup and support the flowers on floating mats, but below thewater the leaves are finely divided into thread-like structures. Water crowfoot is an important habitat for snails, larvae and nymphs.
Stone Loach juvenile
The small slender stone loach feeds on the river bed of fast flowing clean rivers like the Dour. It hides under sands and gravel and often feeds at night, using the six whisker-like barbels around its mouth to feel for prey. Stone loaches eat mayfly nymphs, freshwater shrimp and other small invertebrates. The body is 8-12cm long with mottled brown and olive apaarently scaleless skin and a more grey belly. When threatened Stone loaches stay vey still relying on their camoflage to protect them. Femaoles can lay up to 10,000 eggs between April and August in sand, gravel and plants on the river bottom.
Mallards are a large dabbing duck. Juveniles males and femailes are hard to tell apart but by 14 months of age the males have distinctive dark green heads and a yellow beak, plus a curly tail feather that the females do not have. Mallards are sociable birds but they only pair up from mating from October or November until the eggs are laid from March to late May. Unpaired males group together to target single female ducks or mate with females who have lost their eggs. Males gather together in groups waiting for their feathers to moult in June after the breeding season. Mallards can live for up to 20 years and are omnivores feeding on insecta, snails, worms, and plant matter including roots and tubors. For most of the yeaqr the greater part of their diet is plant matter. Mallards seen on the Dour may be UK resident or migrating birds.
This perennial water plant is found at the edges of the water and mid stream in water up to 15cm depth. Water plantain can be shaded out by other species, so likes to grow in areas where the water levels change or ground may be disturbed. Elongated heart-shaped leave form around the base with small pale lialac hermaphroite flowers (with both male and female organs) forming or erect stalks up to 1m tall and flowering from Jun to August. The flowers open from mid-day to evening and are loinated by flies. The seeds ripen between July and September.
The female mallard is tan coloured with darker flecks and has an orange bill. In the breedign seeason the female seeks out a secluded place to nest, away from ground predators, and lays a clutch of 8-13 eggs. The eggs need to be incubated by the mother for 28 days and are able to leave her after 60 days. The ducklings can swim as soon as they hatch but stay with the mother for protection and food, and to learn about their environment. One they can fly they also learn their traditional migration routes from her. Her brood may remain with her until the mating seacon in the autumn.
Brown trout, female
You will need to look carefully to see brown trout as they are well disguised by their mottled camouflage of light brown body with silvery sides and black spots to look like the river bottom. Trout like to hide in weed, under bank overhangs and below bridges and are active at night and during the day. Females can lay 2000 eggs per kilogram of body weight. Although they can grow up to 20kg, in small rivers such as the Dour 1kg mature wight is more common. Brown trout eat invertebtrates, larvae, other fish, mice, frogs and birds as well as insects near the surface of the water.They can live for up to 20 years. Trout breed between November and March, scraping nests for their eggs, called redds, in the gravel. Eggs hatch at six to eight weeks. Trout will not breed inmuddy areas, and if the river bed is disturbed silt covering the eggs will suffocate them, so no work is carried out in the water during the breeding season.
Brown trout, male
The male trout is identifiable by his hooked, protruding lower jaw. After hatching both sexes of fish can be seen with a yolk sack still attached, which is gradually absorbed into the body as the fry quickly develop into juvenile "fingerlings". Brown trout first spawn at 3 years of age. A high proportion of males die after spawning.
Bullheads are also known as "Miller's Thumbs" because of the size and shape of their large flattened head. They have a large mouth and large dorsal fins. Bulheads can grow up to 18cm long are brown and mottled, to allow them to blend in with the river bed, with a paler belly. They feed from the river bed at dusk, eating aquatic insects, larvae, crustacians such as fresh water shrimp and the eggs of other fish.
At breedign time the females become plumper and the males change colour to become black with a white-tipped dorsal fin. Spawning happens between February and June. Eggs are layed in clumps undeneath rocks or in a pit and are guarded by the male, which fans them to ensure they have enough oxygen.
Brooklime grows along the river edge and has thick rounded fleshy leaves which van be upright or creeping, and juicy stems. Brooklime flowers from May to September producing spikes of bright blue flowers. The leaves of this perennial are visible all year round.
Found in wetlands all over Britain, Purple loostrife produces many spikes of purple flowers from one rootstock. The long leaves grow in opposed pairs up the stems and flowers appear in June and August whn their nectar is an important foodsource for butterflies and moths.
Water mint is the most common of Britain's mints. It has oposed pairs of oval hairy,toothed leaves growing on a square section stem which may also be hairy. The leaves are edible and can be used medicinally.
Water mint flowers from July to October producing whorls of tiny pink-lilac flowers where the leaves join the stem and a larger terminal whorl at the top of the stem.