The first real cold snap arrives quietly: a clear night, a hard frost, the birdbath solid by morning. For us it means digging out the thermals. For the blue tits, robins and goldfinches in the garden, it means a fight to stay alive until dawn. A small bird can burn most of a day's energy in a single freezing night, so what you do at the feeder this week genuinely matters.

Why a Cold Snap Changes Everything

Garden birds are well adapted to winter, but a sustained freeze is different. The ground hardens, so blackbirds and thrushes cannot pull worms; insects vanish; berries are stripped. Birds switch to whatever fat and seed they can find and feed frantically from first light to dusk. A blue tit weighs about as much as a £1 coin and can lose a tenth of its body weight overnight in severe frost. It will be at your feeder before you have drawn the curtains.

Consistency counts for more than quantity. A feeder full one day and empty the next is worse than useless, because birds waste precious energy flying to a site that has failed them. Once you start, keep going until the weather breaks.

Fuelling the Fire: High-Energy Food

Not all bird food is equal in a cold snap. Fat and oil content is what counts, so lean on the richest options you can offer.

• Sunflower hearts — no husk to discard, high in oil, and taken by almost everything from tits to greenfinches.
• Suet balls and cakes — choose the sort without a plastic net, or cut it off at once; legs and beaks get tangled.
• Peanuts — excellent in cold weather, but always from a mesh feeder so birds take small pieces, and never mouldy.
• Nyjer seed — the goldfinch favourite; a fine-ported feeder stops it spilling.
• Mealworms — dried or live; a magnet for robins and wrens, especially in the last hour of daylight.
• Kitchen scraps — mild grated cheese, soaked raisins, porridge oats, cooked rice and crumbled pastry are all welcome. Skip anything salty, spicy or mouldy.

Put out a little and often rather than one enormous heap. Damp food goes sour quickly, and several smaller portions across two or three feeders let more birds feed at once without squabbling.

Clean Feeders, Healthy Birds

Crowded feeders are a gift to disease. In cold weather birds congregate, and infections spread easily at a dirty table. Cleanliness is not fussiness — it is the kindest thing you can do for them.

• Wash feeders each week in warm soapy water, using a bottle brush for the awkward corners.
• Rinse well, disinfect with a bird-safe product or a diluted vinegar solution, and dry fully before refilling.
• Rotate feeders: clean one and leave it dry for a day while another goes out, which breaks the cycle.
• Clear spilled seed and husks from beneath the feeder, and shift the feeding station to fresh ground every few weeks.
• Wash your hands afterwards, and bin any food that smells sour or looks mouldy.

Fresh Water When the Ground is Frozen Hard

Birds need to drink and bathe in winter as much as in summer. When every puddle is iron-hard, a reliable source of unfrozen water can be as valuable as food — feathers must stay in good order to insulate properly.

• Use a shallow dish with a gentle slope and a few pebbles for grip; deep-sided bowls can be dangerous.
• Top up with fresh water each morning and again in the early afternoon. Warm water from the tap freezes more slowly.
• Never add antifreeze, glycerine or salt — all are toxic to birds.
• Melt ice with warm water rather than cracking it with force, and refill last thing at night so it is ready at first light.

A Corner of Shelter

Food is only half the story. On a raw, windy day, birds need somewhere to sit out of the weather and roost through the long night. A dense evergreen shrub, a thick hedge, an unpruned climber on a wall or a stack of logs in a quiet corner will all be used. A roost box fixed a few metres up, facing away from the prevailing wind, gives smaller birds somewhere tight to huddle. Resist the urge to tidy everything: seedheads left standing, leaf litter under shrubs and thickening ivy provide cover and insect food when there is little else about.

How to Watch Well

A cold snap brings the birds to you, and bare branches make them far easier to see. A few simple habits turn a casual glance into real observation.

• Watch at the two peak times: the first hour after sunrise and the last hour before dusk.
• Sit still, about five metres back from the feeders, and give it ten quiet minutes before the birds settle.
• Note who arrives first and who waits; the pecking order at a feeder tells you a great deal.
• Look out for cold-weather visitors — redwings, fieldfares, siskins, redpolls and the occasional brambling.
• Keep a simple notebook of species, numbers and weather. Patterns emerge quickly, and the record becomes a lovely thing in itself.

Position feeders either within a metre of a window or more than three metres away, to reduce the risk of collisions. And when the thaw finally comes, keep the food going for a few days longer. Birds that have relied on you will still be short of natural food, and the habit of watching will have become one of the quiet pleasures of the winter.