The willow's long, yellow flowers are a sure sign that spring has arrived. One swallow may not make a summer, but the return of summer migrants in April is a good indication that spring is under way. Country gardeners may hear a cuckoo or perhaps a nightingale, swallow or housemartin. The spotted flycatchers will come and nest in the climbers on the wall that their family has probably returned to every summer for a century or more.

A lot of wind-pollinated trees flower this month: oak with its golden tassels of male flowers, ash with its purple tufts of stamens, and pussy willow with its great rabbits' tails of custard-coloured pollen.

This is a good month to witness the cut and thrust of survival among garden wildlife, nowhere more so than in the pond. Its shallow margins are an arena for the struggle between predator and prey, but the natural balance keeps the whole community alive.

This year's batch of young foxes, badgers and squirrels all appear this month and, charming though they may be, a garden can have too much of a good thing. Whatever you do, avoid putting bonemeal on your lawn or in your borders unless you want fox cubs to join their parents in digging for buried bones. If you value your spring bulbs, feed the squirrels peanuts from a bird-proof feeder. One thing is certain: even if you could somehow rid yourself of the present crop of disruptive juvenile delinquents, in no time at all another family would move in and take their place.

Keep feeding the birds, but avoid whole peanuts unless they can only be pecked at through a fine wire mesh container and not taken away whole to young that could choke on them. Parent birds need all the sustenance they can get at this busy time of year and your feeding will mean that they can spare more juicy caterpillars for their young.

Swallows and housemartins return this month, but neither of them take readily to nest boxes. However, the spotted flycatcher is extremely reliable if you place a shallow nesting shelf on a sheltered, shady wall 90cm to 3m (3ft to 9ft) above the ground, where it will be well camouflaged by climbing plants later in the summer. Find time to watch this handsome little bird for a few minutes. It has a very predictable habit of fluttering out, snapping up a passing insect and then returning to its regular perch.

It is easy to see just how remarkably efficient birds like this can be. Some of their prey will be useful pollinators and predators, while some will be potential pests but the presence of a healthy population of insect-eating birds will simply help to maintain a natural balance.