Thrushes, like redwings, prefer rowan and other berries with small seeds
Image: Steve Round.
By September, the hedgerows are laden with berries, providing delicious pickings for people and birds alike. The intricate relationship between birds and berries has developed into a mutual dependence for survival.
Berries are an important food source for many birds during the winter, especially when the ground is too frozen to hunt worms or snails, and there are few insects about.
Some birds, like song and mistle thrushes, blackbirds, redwings and fieldfares, find most of their winter food from berries. Take care, though: some berries that are tasty treats for birds are poisonous to humans!
Some plants use berries as a clever way to entice birds and other animals to distribute their seeds. A plant that produces berries surrounds its seed in juicy, fleshy pith, rewarding the birds that eat them with vitamins and energy.
The dry pith of ivy berries contains nearly as many calories as Mars bars! In most cases, while the bird digests the pith and juice, the seeds travel undamaged through the bird's gut and may be dropped many miles from the parent plant. It's no coincidence that lots of young trees grow near a fence or post that a bird might perch on!
'It's no coincidence that lots of young trees grow near a fence or post that a bird might perch on!'
Some berry seeds, like those of juniper, will actually grow better after passing through a bird's gut, which removes natural chemicals that would otherwise prevent the seed from growing. Other berry seeds, like mistletoe, are sticky, and must cause birds some frustration when they stick to their bills! The birds wipe their bills on other trees, unwittingly sowing more mistletoe plants.
Most berries are either red or black. This makes the berries easier for birds to find them.
Evergreens, and plants that produce berries when their leaves are still green, generally produce red berries, which show up well against a green background. Blackberries are thought to show up better against leaves that have turned yellow or brown.
Birds feed in different ways. Redwings and starlings happily feed in flocks. Others, like the mistle thrush, may try to keep a valuable, berry-laden bush just for itself.
Thrushes and waxwings prefer berries with smaller seeds, like Rowan, as they are really only interested in the flesh, whereas other birds, like hawfinches, can make use of the seed itself, and so are attracted to berries with large seeds, such as hawthorn, blackthorn (which grows the sloes that go to make 'sloe gin'), cherries, and bullace (wild plum). The overall size of the berry is important, too, with larger berries like dog-rose hips generally proving too large for birds smaller than blackbirds or fieldfares.
The winter is a good time to consider planting fruit and berry-bearing trees or bushes in the garden. As well as the many native berry-bearing species (including rowan, holly, whitebeam, spindle, dog rose, guelder rose, elder, hawthorn, honeysuckle and ivy), attractive shrubs like cotoneaster, pyracantha and berberis are especially good for a wide range of birds.
Berry and fruit-bearing trees provide food for a range of insects and animals, too: hedgehogs, badgers, mice, squirrels and even foxes will all happily feed on them. All sorts of fruit are attractive to insects, and if you leave them where they fall in the late summer and autumn they will attract numerous butterflies to their syrupy goodness.
Fallen fruit can also provide birds with a cold-weather treat: pop some in the freezer, and save it for the winter bird table.
Thanks to David Saunders for the images.
The North Kent Marshes are a very special area and worth preserving at all cost.