Why fat matters most in a cold snap

When the temperature drops below freezing, a blue tit can lose a tenth of its body weight overnight. Small birds must keep their core temperature around 40°C, and shivering through a long January night burns an enormous amount of energy. A single sunflower heart or suet ball is not a treat; it is fuel for survival. Fat contains roughly twice the energy of carbohydrates or protein by weight, which is why high-fat foods such as suet and sunflower hearts are the backbone of a winter feeding station. Put simply, the colder the weather, the more valuable every calorie becomes. Robins, tits, finches, sparrows, and even winter visitors like redwings and fieldfares will all benefit from a reliable, high-energy supply.

Suet: the winter powerhouse

Suet is rendered animal fat, often mixed with seeds, insects, or dried fruit. It is the richest energy source you can offer, and it stays soft enough for birds to eat even on frosty mornings. Choose plain suet balls or cakes, or those enriched with insects and berry pieces for thrushes and robins. Hang them in a wire feeder, or smear suet into the crevices of a log or pine cone for a natural look. Great spotted woodpeckers, nuthatches, and all the tit species will queue up for it.

• Offer suet balls in a dedicated feeder, preferably with a roof to keep rain off.
• Place suet cakes in a hanging cage or on a mesh tray, not loose on a flat table where they can become soggy.
• For ground-feeding birds such as blackbirds and dunnocks, use suet sprinkles or a suet log placed low down.
• In very cold spells, put out extra suet in the afternoon so birds can top up before roosting.

Seeds that earn their place on the menu

Sunflower hearts are the single best all-round seed for a British garden. They are hulled, so there is no mess, and almost every bird from a goldfinch to a great spotted woodpecker will take them. Black sunflower seeds are cheaper but leave husks behind; hearts are worth the extra cost because every gram is edible. Nyjer seed is a favourite of goldfinches and siskins — use a fine feeder to stop it spilling. Peanuts, unsalted and fresh, suit tits, nuthatches, and woodpeckers, but never offer them mouldy or from a salted packet. A good quality mixed seed can work, but check the label: cheap mixes are often padded with wheat and barley that most garden birds cannot digest.

• Sunflower hearts: the everyday staple — offer in a hanging feeder or on a tray.
• Nyjer: for goldfinches and siskins, in a specialist feeder.
• Peanuts: unsalted, human-grade, and from a reputable supplier.
• Millet and canary seed: good for house sparrows and dunnocks, scattered on a ground tray.
• Mealworms: dried or live, superb for robins, wrens, and pied wagtails.

What to leave off the bird table

Bread is the classic mistake. It fills a bird’s crop without delivering much energy, and mouldy bread can cause serious illness. Salted snacks — crisps, salted nuts, bacon rind — are dangerous because birds cannot process excess salt. Cooking fat from a roasting tin is another no: it is soft, salty, and may carry bacteria. Avoid anything mouldy, and never put out milk or desiccated coconut, which can swell in the gut. If you want to offer kitchen scraps, stick to mild grated cheese, chopped apple, or cooked potato in small amounts.

• Bread: low nutrition and a risk if mouldy.
• Salted snacks: can be toxic to small birds.
• Roasting fats: salty, soft, and a hygiene risk.
• Mouldy food: bin it — never add it to a feeder.

Feeding hygiene in freezing weather

Cold weather does not stop disease. In fact, when birds crowd around a feeder, infections such as trichomonosis can spread quickly. Clean your feeders every couple of weeks with hot soapy water, rinse thoroughly, and let them dry before refilling. Move feeders around the garden to stop droppings building up in one spot. If you see a bird looking fluffed up, lethargic, or with a dirty face, take down the feeders for a fortnight and clean them thoroughly. A clean feeding station is a healthy one.

• Wash feeders with hot soapy water and a bottle brush.
• Rinse well — birds should not taste soap.
• Allow to dry completely before refilling.
• Rotate feeder positions to rest the ground beneath.
• Remove stale or wet food daily in winter.

Don’t forget unfrozen water

Birds need to drink and bathe even in freezing weather, but natural water is often locked under ice. Put out a shallow dish of fresh water, and check it each morning. If it freezes, pour on a little warm water — never use salt or antifreeze. A small ball floating in the dish can help keep a patch ice-free. A reliable supply of clean water will keep your garden visitors healthy and may even encourage them to stay close to your feeders.