Environment A to Z of Canal Wildlife
A to Z of Canal Wildlife: M - O

Mallards, Moorhens & Maples*

Moorhen

Both Mallards and Moorhens (left) are very common along our waterways, even more so in the reeded margins of under maintained canals. But two more different inland water birds would be hard to find. The Mallard, Anas platyrhynchos, by far our most familiar duck, is a superb and fast flyer, taking to the air if disturbed, whilst the Moorhen Gallinula clioropus, a member of the family of crakes and rails is a poor flier and prefers to go into hiding when danger threatens. Both birds are so well known that they need no description. However as both are black Moorhens are sometimes confused with Coots. Coots are larger and plumper, and have conspicuous white bill and frontal shield whereas the Moorhens is bright red. Coots also prefer more open water so they are not common along canals

The male Mallard is a most handsome bird when in his full breeding plumage but after the season is over he resembles the dowdy female but can still be identified by his yellower bill. Also only the females quack, quack, quack loudly, the male makes a much quieter single, nasal note. The Mallard is a gregarious bird, sometimes forming large flocks, but once the monogamous pair bond has formed for the season then they become secretive. The courtship display ranges from bill dipping, (where the expression to duck originated), and tail wagging, to courtship flights of up to 10 minutes. The shallow nest, made with vegetation and twigs and lined with down, is built by the female, usually on the ground in thick undergrowth close to the water, but occasionally she uses a pollarded willow or hollow tree. On average between 9 to 13 grey-green, occasionally bluish 56 mm by 40 mm (2.25 by 1.6 inch) eggs are laid from March to May. Incubation is by the female and takes 27-28 days. The young leave the nest on their first dy and feed themselves. They are looked after by the female until they fledge and become independent at 50-60 days. The mallard is a widespread and successful bird mostly because of its opportunist feeding. It will eat a wide range of animal and plant food. As a dabbling duck, it thrives in the shallows of the canal side vegetation, where it can up end to take aquatic vegetation and animals. It can sieve the water for minute animals, even graze grass like geese. It also takes a wide range of animal food such as fish, eels, insects, molluscs, crustaceans, amphibians and small mammals and birds.

The Moorhen is not a moorland bird. It’s name is a form of mere-hen. Seldom seen in flocks it spends all its time on shallow water near dense undergrowth in which it can hide. It can sink when danger threatens leaving just its bill above water. When it does take to the air it patters off across the water flying low and dangling its legs. The Moorhen doesn’t have webbed feet like the mallard but partially webbed, very long toes, ~ aid its passage across floating vegetation. As it swims it jerks its head and pecks up food, including slugs, snails, worms, insects, seeds and vegetation, which float on the surface of the water or amongst bankside vegetation. Its nest is built near the water, often in a bush or low branches. It will aggressively defend the nest against all comers. The hen lays 5 to 11 eggs between March and July. They hatch after 21 days and the young leave the nest after 2-3 days.

Field Maple

Acer campestre is Britain’s only native species of Maple, the most common and well known member is the sycamore. It is quite common but few people will claim to have seen one. This is because it generally forms part of the hedgerow and is concealed amongst other common hedgerow bushes and trees such as ash, hawthorn, blackthorn, hazel and elderberry. On chalk soils and if it is spared from the flail or the hedgelayer’s billhook it will grow into a tall long lived tree. Sometimes known as the hedge maple, if allowed to grow as a hedgerow standard it will eventually form a domed crown of curved branches and straight shoots. The corky bark is ridged and burred. The leaves are the typical five lobed leaves of the maples but are somewhat smaller and emerge tinged pink in the spring. The small flowers are borne in clusters and are pollinated by insects. The paired fruits are winged, similar to the well known keys of the sycamore but are smaller, they fall to the ground spinning like miniature helicopters. As with all maples the foliage turns a spectacular colour in the autumn, however the colour differs between uncut bushes whose leaves turn dark red and purple, to hedging and trees that turn yellow, gold and russet..

NettlesSringingnettles

The dreaded stinging nettle Urtica dioica, cursed by walkers with bare legs and scrub bashers with bare hands, is so common along the canal bank and towpath hedge that it needs no description. Right from childhood we soon learn to recognise it and to avoid touching it at all costs. However the stinging nettle is quite an important weed. It was once regarded as valuable, the young tops can be used to make nettle beer, and can also be boiled and eaten as a vegetable which tastes like spinach. Dried leaves can also be used to make nettle tea. Before cotton was imported the stem fibres were spun and made into cloth. Cows find young nettles very tasty as they are immune to the stinging hairs. The stinging nettle, a perennial, can reach five feet in height and bears tiny green-white flowers from June onwards. The plant bears stinging hairs which are brittle and when touched easily break off after piercing the skin. This allows the poison liquid which is contained in the bulbous base to enter the wound and cause the irritation.

But the, unloved by humans, stinging nettle is the life-blood to certain butterflies. It’s the so called larval foodplant of several of our most beautiful native butterflies. To some, including the Small Tortoiseshell and Peacock, it is the only plant they lay their eggs on. To others, like the Comma and the beautiful Red Admiral it’s one of only two or three plants on which they lay their eggs. So keep an look out in early summer for masses of caterpillars merrily munching away on their favourite food, and remember without the nasty nettle there would be fewer butterflies and absolutely no Small Tortoiseshell or Peacock butterflies at all!

Of the three species of closely related newts (or salamanders) of the British Isles two are found in canals. They are the Smooth (or common) newt and the much rarer Great crested or Warty newt. They prefer the clearer, cleaner water of the undisturbed margins and side ponds of canals. Newts are most commonly only seen in water so they are often erroneously thought to live in the water but they actually spend most of their lives on dry land, although they do prefer damp places. They are amphibious spending their lives on land, entering the water in early spring to breed. This is when they are easily spotted and also when the difference between the sexes can be seen. The males are more brightly coloured than the females. The Smooth newt Triturus vulgaris grows to 100 mm long and has a spotted throat, the male has a wavy crest and is brown to olive brown and marked with spots. Its underside is yellow to rose with a middle of red with spots. The female is much drabber paler yellow brown and lacks a crest.

Newts

Newt

The Great crested newt Triturus cristatus can grow to 175 mm with some females even larger. They are olive brown and covered in black spots, the male has a high serrated crest and a bright orange and black belly. They are also covered in warty glands which secrete a sticky white poisonous fluid when the newt is threatened by would be predators such as snakes, birds and hedgehogs.

Newts have a complex courtship of dancing and tail wagging. The breeding procedure is unusual, as the male deposits a sperm packet in the water. This is then picked up by the female in her vent releasing the sperms into her body. Thus the fertilisation of the eggs is internal as opposed to the external fertilisation of toads and frogs. The female lays 200-300 eggs singly on water plants each enclosed in a protective coat of jelly. Just like frogs and toads the eggs hatch into a larval stage, similar to a tadpole, which has gills. In ten weeks lungs and legs have grown, the gills are lost and the young newt, an eft, leaves the water.

Although it may return to water to feed it will not return to breed until it reaches adulthood after two to three years. The adults also leave the water after the breading season to spend the rest of the year on land, living under stones and fallen timber and in dense vegetation. They emerge at night to feed, sometimes in the water, on slugs, snails, earthworms, insects and even small fish and tadpoles. They hibernate through the winter. Newts can regenerate limbs lost to predators.

Oak and Owls


The Oak is the most numerous and the most important tree in England. There are just two native species. The common or pedunculate oak has stalked acorns and short-stalked leaves whilst the sessile or durmast oak has stalkless acorns and long-stalked leaves. There are many hybrids between the two species and also several introduced species. However the Common Oak, Quercus robur, is the one you are most likely to encounter along the towpath hedgerow. The oak is a slow growing but long living and potentially large tree. Oak timber is particularly valued and has long been used in the construction of ships, furniture and barrels.
However as a wildlife habitat the oak is incomparable.

The oak suffers many diseases, is host to many parasites and, throughout its life span of around 250 years, can support possibly 2000 different organisms, far too many to mention here. They include about 65 mosses and liverworts, over 300 lichens, many types of fungus and innumerable insects, bugs and beetles, and over 200 different caterpillars of butterflies and moths. There are so many insects munching away at the leaves that the oak tree usually has to grow a second flush of leaves each year. The oak provides rich pickings for a great many animals, large and small, including mice, voles, shrews, squirrels, bats, deer, and birds, such as woodpeckers, tits, warblers, tree creepers and jays.

Even the leaf litter supports an amazing array of animals, insects, slugs and snails. The fallen leaves are broken down by huge numbers of micro-organisms and invertebrates to form a rich humus to enrich the soil. Fungi, armies of mites, springtails and woodlice attack dead wood and leaves, earthworms mix the products with the soil and fungi and bacteria finish the process. A gramme of soil may contain a 1,000,000,000 bacteria!

What better place for a top predator to be but in an oak? And that’s where the Tawny Owl can be found.tawny1_mo_200

Six species of owls breed in Britain. The most numerous is the 15-inch /375 mm long Tawny Owl, Strix aluco, or Brown owl. This owl, being nocturnal, is rarely seen but is quite often heard. It’s that owl that makes the familiar "t’wit t’woo". But actually, it’s two owls calling to each other, one calls "t’wit" and its mate replies "t’woo". Both sexes can make both hoots, but they are not made together. A favourite nesting site for the tawny owl is a hollow in a tree and a mature oak usually has a suitable one, and, as we have seen, it attracts plenty of visitors. The owl spends most of the day roosting, generally in woodland, flying only at dusk and dawn to search for its prey which includes mice, voles, shrews, birds, insects and worms. The owl perches on a branch and listens and looks for its prey foraging among the leaf litter or along the canal bank. It swoops down to catch it in powerful talons, returning to the perch to swallow it whole. The indigestible fur and bones are later regurgitated in pellets, sometimes many can be found beneath a daytime roosting site.

The Tawny Owl never makes its own nest and if it cannot find a suitable hollow tree it will occasionally nest in derelict buildings. Through the winter months it makes hooting calls around its chosen nesting site as part of its courting rites. They nest only once a year, as early as March, laying two to four almost spherical white smooth eggs. The female lays her eggs at intervals of two or three days, incubating them as soon as the first is laid. The eggs hatch 28-29 days later at the same intervals. The male does not sit, but brings food to the nest for the female and then the chicks. The parents are very caring, continuing to bring food to the young for several weeks after they leave the nest. So an ample food supply is a necessity and where better to find it but under the abundant oak and along the canal bank and hedgerow.