The widest range of species is often found where two habitats meet - where woodland grades into grassland for example, where tall trees give way to shrubs and then wild flower meadow.
The varied heights of trees and shrubs, with its variety of feeding opportunities, make this a varied and particularly attractive habitat for many birds, like tits and warblers, and for butterflies like the speckled wood, which will breed in gardens.
It's easy to recreate something similar, with its constantly shifting mosaic of dappled sunlight and shade, simply by creating storied layers of vegetation in the garden.
Many birds like to nest in mature trees but even young trees are good places to mount nest boxes. If you plant native tree and shrub species that have a rich and diverse insect fauna, like birch, mountain ash (rowan) or hazel, blue tits and robins will visit them to collect caterpillars for nestlings.
Blossom trees like cherries, plums, pears and apples provide nectar and pollen for bees in spring and rotting fruit for autumn bird visitors and even for butterflies - peacock and red admiral butterflies love to drink the juice of over-ripe plums.In mature gardens old trees and even tree stumps are also a very valuable wildlife resource in their own right, sometimes attracting more exotic birds like great spotted woodpeckers and treecreepers that search for insects on dead branches and bark crevices
It's easy to recreate something similar, with its constantly shifting mosaic of dappled sunlight and shade, simply by creating storied layers of vegetation in the garden.
Many birds like to nest in mature trees but even young trees are good places to mount nest boxes. If you plant native tree and shrub species that have a rich and diverse insect fauna, like birch, mountain ash (rowan) or hazel, blue tits and robins will visit them to collect caterpillars for nestlings.
Blossom trees like cherries, plums, pears and apples provide nectar and pollen for bees in spring and rotting fruit for autumn bird visitors and even for butterflies - peacock and red admiral butterflies love to drink the juice of over-ripe plums.In mature gardens old trees and even tree stumps are also a very valuable wildlife resource in their own right, sometimes attracting more exotic birds like great spotted woodpeckers and treecreepers that search for insects on dead branches and bark crevices
Looper caterpillars
Looper caterpillars move forward by drawing their tail end forward, so that they throw their body into a loop, then gripping with their tail and stretching out their head-end. They are the larvae of moths known as geometrids, so-called because they seem to be measuring their movements with geometrical precision (which also accounts for their other name: inchworms.
Most trees and shrubs will have larvae of one of the many species of geometrids feeding on their foliage. They are a major component in the diet of blue tits and great tits during the breeding season; a pair of great tits need to find up to 700 per day to feed their brood by the time they are about to fledge.
Many geometrid larvae are amazingly well camouflaged, resembling dead twigs or matching the colour of leaves. When danger threatens they often 'freeze', remaining perfectly still and relying on their cryptic colouration to escape detection.
Spot the caterpillar (above): almost a perfect match!
Not all geometrids rely on camouflage. The larva of the magpie moth is brightly coloured. Birds that try to eat it find it distasteful and the warning colouration acts as reminder that they shouldn't make the same mistake twice.
White-lipped Snails
These striped snails will often climb into bushes either to graze on the algae that grows on the stems or to spend the driest months of the year in a state of dormancy called aestivation. Then they seal their shell opening with a layer of dried mucus and glue themselves to the stems.
White-lipped snails come in a variety of different shell colour banding patterns. Some, found most often on sand dunes, have no shell bands at all. The frequency of the different types varies from place to place and is thought be be related to camouflage (they are favourite food of thrushes), although exposure to sunshine may play a part to - snails with broad dark bands tend to heat up faster, plain pale shells are less likely to overheat.
Plant Galls
Wild roses in hedgerows often carry these mossy crimson growths, known as bedeguar or Robin's pincushion galls. They are caused by a tiny wasp that lays its eggs in leaf buds, inducing them to produce a mass of tissue where its grubs can grow and feed on special nutritive tissue that the plant produces.
This is the minute wasp that causes the growth, Diplolepis rosae. A large bedeguar gall will contain over thirty developing larvae but many never reach maturity because....
..... they are parasitised by this minute but deadly ichneumon wasp.
As the poet Jonathan Swift quipped:
"So nat'ralists observe, a flea
Hath smaller fleas that on him prey;
And these have smaller fleas to bite 'em
And so proceeds Ad infinitum."
More Galls
The strange growths on plants known as galls are induced by a variety of different organisms including fungi, flies and microscopic mites but the most elaborate are caused by gall wasps. The pink flying saucer-shaped galls and those that look like golden embroidered silk buttons on the oak leaf below are caused by two closely related species of gall wasp. The pink spherical gall is caused by a third species.
Some galls can be very destructive. This is the knopper gall, caused by a gall wasp that lays its eggs in very young acorns and causes them to develop into a gall that looks like green popcorn. Knopper gall wasps spend half of their life cycle on native oak trees and half on the introduced Turkey oak, which is cultivated in parks, botanic gardens and arboreta, so you tend to find knopper galls most frequently where the native and introduced oaks grow in close proximity.
This is the marble gall, accidentally introduced in the early 19th. century when the called, which are rich in tannin, were imported for the leather tanning industry. Here the wasp lays its eggs in a leaf bud, which develops into a woody sphere with the developing wasp inside. The exit hole, where the wasp has hatched, is clearly visible here. Blue tits learn to peck into these galls to eat the grubs in winter, when other food is hard to come by.
Several trees, such as sycamore, maple and alder (above) carry large numbers of small red pimple-like growths on their leaf surface in late summer.
These are pocket-like ingrowths caused by minute mites that feed and breed inside. Here you can see them emerging from the mouth of the pocket on the underside of the leaf, and .....
.... here you can see them highly magnified, under a microscope.
Native Trees for a Wildlife Garden
Native trees are a rich resource for insects, which use them as a food source, and for birds that feed on the insects. Large forest trees, like ash, oak or lime grow too large for all but the grandest gardens by there are several smaller natives that fit comfortably into a plot of any size and can even be grown in large containers.
Silver Birch
Attractive white bark, small leaves that turn lemon yellow in autumn and a graceful pendulous habit all year round make this a particular attractive species. It supports more species of insect than any other native tree apart from oak, so is a favourite feeding site for hungry blue tits and great tits in spring and summer. Over 80 species of moth caterpillar alone feed on its foliage.
In spring the tree produces these long, slender catkins from the tips of its twigs and.....
.................in autumn silver birch trees carry catkins of small seeds that are a good source of food for ....
..... siskins ......
...... and redpolls. Once the supply of birch seeds runs out they'll turn their attention to your bird table if you supply niger seed.
Rowan, also known as Mountain Ash
Rowan, also known as mountain ash, is an excellent native tree for wildlife gardens because it does not grow very large or cast too much shade and it also flowers when just a few years old. It's an all year-round wildlife resource.
Rowan blossom, which has a distinctive scent, appears in early summer and provides a rich nectar and pollen source for many insects, including wild bees.
Many hoverflies, like this Leucozona lucorum, live on a diet of pollen, so the dense masses of rowan flowers is a valuable resource for them.
Rowan produce heavy crops of berries which ripen in early autumn. Blackbirds are particularly fond of them.
The Value of Old Trees
As trees mature their smooth bark develops deep fissures that are home to spiders and a host of small insects that attract the attention of hungry nuthatches and tree creepers in winter.
Garden trees continue to be a wildlife habitat even after they are dead, so leave old tree stumps in the ground where they can slowly decay. Allowing ivy to grow over them can also enhance their wildlife value.
Many beetles lay their eggs in dead branches and tree stumps and the larvae slowly tunnel their way through the decaying wood. Its nutritional value is low but these specialist feeders are adapted to slow development, often feeding for two or three years before they pupate and then hatch as adults. This plump beetle larva would be a fine meal for a great spotted woodpecker.
Great spotted woodpeckers often visit bird tables in winter - and while they are in the garden they'll sometimes take the opportunity to explore old tree stumps for beetle larvae.
Perhaps the ultimate reward for a gardener who leaves old tree stumps to rot in the garden is discovering that the endangered stag beetle has chosen to lay its eggs in it. The larvae of these spectacular beetles take four years to develop, feeding on the rotting wood. The People' Trust for Endangered Species has useful advice for gardeners who want to help conserve stag beetles - scroll down to the bottom of the page to find links to their web site.
