Advice from the Royal Society for the Protection of Birds (RSPB) about feeding wild birds.
Spring and summer
Only feed selected foods at this time of year. Good hygiene is vital, or feeding may do more harm than good.
During the summer months, birds require high protein foods, especially while they are moulting.
Black sunflower seeds, pinhead oatmeal, soaked sultanas, raisins and currants, mild grated cheese, mealworms, waxworms, mixes for insectivorous birds, good seed mixtures without loose peanuts, RSPB food bars and summer seed mixture are all good foods to provide. Soft apples and pears cut in half, bananas and grapes are also good. Some people use soaked dog or cat food and tinned pet foods, but these may attract magpies, crows and cats.
Avoid using peanuts, fat and bread at this time, since these can be harmful if adult birds feed them to their nestlings. If you feel you must put out peanuts, only do so in suitable mesh feeders that will not allow sizeable pieces of peanuts to be removed and provide a choking risk.
Home-made fatballs can go soft and rancid in warm summer weather, and should be avoided. Commercially produced fat bars are suitable for summer feeding but discard any remains after three weeks.
Temporary food shortage can occur at almost any time of the year, and if this happens during the breeding season, extra food on your bird table can make a big difference to the survival of young.
Birds time their breeding period to exploit the availability of natural foods: earthworms in the case of blackbirds and song thrushes, and caterpillars in the case of tits and chaffinches. It is now known that if the weather turns cold or wet during spring or summer, severe shortage of insect food can occur, and if the weather is exceptionally dry, earthworms will be unavailable to the ground feeders because of the hard soil.
Natural food shortages
If food shortages occur when birds have young in the nest they may be tempted by easy food put on birdtables to make up the shortfall in natural food, initially to feed themselves, but if the situation gets bad enough, they will also take the food to the nest.
If the food offered on your bird table isn’t suitable for the young chicks, it can do more harm than good, and can even be lethal to the chicks as they can choke on the food. It can be difficult for a human to gauge when food shortage in the wild occurs, and hence it is best not to put out food that is likely to create problems during the breeding season.
Therefore, never put out loose peanuts, dry hard foods, large chunks of bread, or fats during the spring or summer months.
Read more here
Read the BBC Guide to helping wild birds n your garden here