Simple ways to make your garden irresistible to wildlife – an exclusive extract from Professor Chris Baines’ new book.
BEST-PRACTICE BIRD FEEDING
The commonest garden wildlife conservation gesture most people make is to put up a bird feeder. A bird table doesn’t need to be sophisticated. What matters is the way you use it. Once you begin putting out a supply of food, the birds from a wide area will quickly come to rely on you, and they can suffer if the free hand-outs suddenly stop appearing. The siting of the bird table is critical. In fact you should be thinking of a ‘feeding station’ rather than limiting yourself to a table alone.
Some garden birds are reluctant to feed high above the ground, and prefer to peck and scratch around at ground level. Hedge sparrows and wrens feed here, for example, and so some open ground around the base of the table is useful. If you concentrate your wildlife anywhere, the word will quickly get round to the local predators. You may have the odd sparrowhawk playing out its textbook sparrow-snatching role occasionally, but cats are the real menace, and you must take the problem seriously. Don’t put your bird table too close to potential moggie cover. Bushes and small trees are fine, so long as they are more than a leap away. Another possible hazard you introduce by bringing together a high concentration of birds is the risk of promoting infectious diseases. The steep decline in the number of greenfinches since the turn of the century seems to be one sad example of this problem. Keeping the feeders and the feeding area clean is therefore highly desirable. Hot soapy water and a scrubbing brush will do the trick if you clean up frequently. Tubular seed feeders will need a bottle brush for cleaning their interiors.
The choice of food you offer will affect the range of birds you see. You need to provide both hard and soft foods. House sparrows, tits and finches have tough beaks and are happy cracking sunflower seeds and corn, but insect-eaters with pointed bills are not likely to feed unless you provide something softer. I have had particular success with the cylindrical fat bars that incorporate dried insects. Robins are passionate about mature cheddar; goldfinches seem to find niger seed irresistible; blackbirds, fieldfares and redwings are at their most contented pecking away at soft over-ripe apples on the lawn. I pester my local fruit shop for bruised fruit from November onwards.
THE NEST BEST THING
Nest boxes are the second most popular technique for habitat boosting. In fact in most urban areas there would be few blue tits and great tits around if it wasn’t for the artificial nesting sites that we provide.
The simplest nest boxes to build are little more than a flat, open tray – just an artificial ledge for the bird to build on. A piece of wood 10–15cm square, with a 3cm upstand around the edge, is all you need. Fix this little tray about a metre above the ground on a wall or a fence where it will be camouflaged by the leaves of climbers, and you may attract nesting robins. Fix it a little higher and you may find that blackbirds or song thrushes will use it.
Most tray-nesting birds will also build in open-fronted boxes. These are little more than a basic tray with three sides and a roof, and they are generally sold under the name of robin boxes. They don’t need so much camouflage as the open tray, but they too are far better placed on a wall than a tree. A whole range of egg and chick thieves are able to climb or land in trees, and the open-fronted box is vulnerable.
The most familiar nest box is a closed box with a small hole in it. The size of the hole has a great influence on who moves in. A tiny hole just 3cm in diameter will leave bluetits with sole possession. Go up 5mm in size and great tits can manage to squeeze through, and the bluetits lose control. A 5cm hole opens up the market to sparrows and robins, and if you go any bigger, you are most likely to finish up housing starlings year after year.
If you have the problem of nest-robbing woodpeckers in your garden, the only effective defence is a box made of cement and sawdust, which is one reason why they are so widely used elsewhere in Europe.
Birds aren’t the only wild creatures you can persuade to move into artificial homes. A lot of insects lay their eggs in tiny, narrow holes. Wood wasps make their homes in log piles at the woodland edge, a few beetles are wood-boring by nature, and solitary bees are fascinating little creatures that will occupy other insects’ vacated holes. You can simulate this tiny niche by drilling lots of holes in logs. Some species will also oblige by occupying the holes created when you tie a bundle of drinking straws together and block up one end. Hang your little bundles under ledges and overhangs.
One useful way of concentrating a variety of mini-homes together in one spot is to build a dry-stone and earth bank. Stack stones randomly to form a double-sided wall, with a space in the centre. Keep incorporating layers of soil, and fill the middle in too. Make sure you leave lots of little holes through the stone facing which lead to bigger gaps in the centre.
If you pack one or two of the inner cavities with old nesting material from a mouse cage you will be providing irresistible conditions for queen bumblebees to occupy, and you can create bee nest sites elsewhere in the garden by burying clay plant pots in banks and shrub beds, so that just the hole in the bottom is visible. If more mouse bedding is stuffed inside these pots, you should have bees flying busily in and out of the drainage hole by midsummer.
There is another habitat booster that should find a place in everybody’s garden: the compost heap. We all produce mountains of waste greenery every year. Cabbage leaves, potato peel, weed seedlings, the excess waterweed from the pond all make wonderful compost if you allow time for them to rot down.
You need some sort of perforated container – either well-spaced timber planking, or well-staked netting, and the bottom of the heap should rest on the soil. You must make sure plenty of air is able to circulate around the heap, and you may need to protect it against heavy rain with a tarpaulin or a sheet of polythene.
Most of the actual organisms of decay are minute, but if you pull back the top layer of your heap you will see a whole host of different creepy-crawlies. Some of them, most notably the bright red little worms, are living directly on the dead plant material, breaking it down to a size that the smaller organisms can cope with. There will also be beetles, centipedes and other fast-moving wriggly creatures eating up the smaller organisms of decay.
With so much going on, it is not surprising to find that the compost heap becomes an important ‘fast food section’ of your wildlife garden. Some of the bigger creatures may spend almost the whole time there. You are likely to have a fat, contented toad or two living in the moist warmth of the heap, and your resident hedgehog may move into the compost corner too, at least for the summer.
The heat generated by the compost heap is an important feature of the habitat, providing ideal conditions for one or two of our more delicate wild animals to breed in. Slow worms in particular like to give birth to their tiny babies in the warmth of a compost heap, and grass snakes often lay their eggs there. Both of these creatures are perfectly harmless, and marvellous additions to your wildlife garden.
The grass snakes may get through a few of your frogs and toads, but the slow worm has a diet made up mainly of slugs and worms, and does nothing but good. If you build a compost heap, put in a pond, leave some of the lawn a little longer and stack the odd log pile around in your shrubbery, you will be providing the ideal habitat for slow worms and grass snakes, and your garden could become a safe sanctuary for two increasingly rare and handsome wild creatures.
This article is an edited extract from RHS Companion to Wildlife Gardening by Chris Baines, published by Frances Lincoln in hardback, RRP £25.