Feeding Birds in Winter: What Changes

A small bird in a cold snap is running a very tight energy budget. A chickadee can lose around ten per cent of its body weight overnight and has to replace all of it the next day, in a few hours of daylight.

Winter feeding is therefore about fat, not variety.

What changes

Fat first.

• Suet — the single most valuable winter food. Woodpeckers, nuthatches, chickadees, wrens, creepers. Plain rendered suet or a commercial cake; avoid the ones packed with cheap filler seed.
• Black oil sunflower — high fat, thin shell, taken by nearly everything.
• Peanuts — whole in a mesh feeder for jays and woodpeckers, hearts for smaller birds.
• Nyjer — goldfinches, siskins and redpolls, which are often at their most numerous now.

Suet melts and goes rancid above about 20 °C, so it is a cold-weather food. In warm regions use no-melt cakes or take it in.

Feed in the afternoon as well as the morning. Birds go into the night having eaten as much as they can carry, and a topped-up feeder late in the day matters more than a full one at dawn.

Water matters more than food

Open water is scarcer than food in a hard winter and almost nobody provides it.

• A heated birdbath, or a simple immersion de-icer in an existing one.
• Shallow — no more than 5 cm — with a rough surface for grip.
• Never add antifreeze, salt or glycerine. All are toxic; salt also damages feather waterproofing.

A heated bath in January brings species that will never touch a feeder: thrushes, waxwings, bluebirds.

The birds change

The winter set is not the summer set, and this is where most confusion starts.

Arrivals:

• Dark-eyed juncos, feeding on the ground under feeders, flashing white outer tail feathers.
• White-throated and American tree sparrows.
• Redpolls, pine siskins and evening grosbeaks in irruption years, when the northern seed crop fails.

Departures: most flycatchers, warblers, swallows, orioles and hummingbirds.

Still here but unrecognisable: American goldfinches in drab olive-buff, and European starlings covered in white spots with dark bills.

Shelter

As valuable as food and almost never provided.

• Leave the brush pile. Prunings stacked in a corner is the best winter shelter in most gardens.
• Leave seed heads standing — coneflower, sunflower, teasel, ornamental grasses. Tidying the garden in autumn removes a winter food supply.
• Roost boxes, or nest boxes left up and cleaned out, which small birds use communally on cold nights.
• Evergreens, which is where everything goes in wind and snow.

Consistency, and the myth about it

Birds learn where reliable food is and factor it into their winter range, so keeping a feeder stocked through a cold snap genuinely matters.

But the common worry — that stopping will kill them — is not supported. Work on chickadees found feeders provided roughly a fifth of daily energy, and birds that lost access foraged normally. Going away for a fortnight is fine.

Keep it clean, especially now

Birds concentrate at feeders in winter, which is exactly the condition in which disease spreads.

• Clean every two to four weeks: hot soapy water, dilute bleach rinse, dry fully.
• Rake up the spill, which rots under snow and draws rodents.
• A bird sitting fluffed, unafraid, with crusted or swollen eyes means take everything down for two weeks and disinfect.

The last thing

Snow makes the ground feeders visible in a way nothing else does — juncos, sparrows and doves working under the feeder leave tracks and hollows, and a fresh fall is the easiest time of year to work out what is actually using the garden.