Whooper swan, adult, in snowy field

What do birds do in winter?

Winter is a great time to watch birds flocking together, sometimes in spectacular numbers. Their survival skills are tested to the when food becomes hard to find.

Safety in numbers

If you walk around a woodland in the winter you may be forgiven for wondering where all the birds have gone. In fact, there are likely to be plenty of birds about, but instead of being evenly spread throughout the area, several species group together in a loose, mixed feeding flock. Flocking together in winter improves the chances of locating food and huddling together during the critical night-time period helps conserve body heat. 

By sticking together, they improve their chance of survival, because together they are far more likely to spot a predator, like a sparrowhawk, before it's too late.

You may be lucky, and suddenly find yourself surrounded by blue, great and coal tits, goldcrests and chaffinches, twittering and feeding hungrily in one small area. Treecreepers, long-tailed tits and wrens also regularly do this. More than 50 wrens were once counted bedding down in a nestbox during cold weather - a snug fit indeed.

Three great tit eating Suet coated raisin pellets, from premium nut feeder

Night time challenges

Avoiding becoming someone else's dinner becomes even more challenging at night. Visit the countryside or city centre on a winter's evening and you are likely to come across a massive flock of starlings, wheeling and turning in the darkening sky, heading for a sheltered spot —an empty building, leafless tree, or a bed of swaying, yellow reeds.

It’s fascinating to watch these huge gyrating bubbles of birds, spinning in the sky, like fish shoaling together to dazzle their predators. When the birds decide it is safe to, they shoot down in a dark tornado of whirring wings.

Other species can be seen moving to their night-time roosts—you may have noticed the steady evening migrations of gulls, commuting from their daytime feast on a rubbish tip to a reservoir or lagoon, where they will spend the night on the water, alongside ducks and geese.

Rooks and jackdaws gather in their hundreds in farmland woods. Pied wagtails sometimes roost in their thousands in the warmth of power station cooling towers.

Starlings Sturnus vulgaris, gathering above reed bed at Ham Wall RSPB reserve

Timing is everything

For an individual bird, getting the timing right can determine whether you live or die. If you leave your feeding ground too early, you may struggle to find enough food, but if you leave it too late and miss the flock, you risk being picked off alone by a bird of prey.

It is the failing light that triggers many birds to head to their night roosts. In poor weather, starlings may be seen heading off to bed far earlier than normal. The opposite can also be true, and on bright, moonlit nights, geese may still be seen feeding, out on the frost-silvered fields.

Timing is also important if you want to see some of the UK's most breathtaking wildlife spectacles. Wintering waders, and other coastal species that feed on the exposed mud at low tide, use high tide roosts when the sea covers their feeding grounds.

Sometimes, these favoured areas of higher shingle or mud can draw in tens of thousands of birds while they wait for the tide to fall. 

 Knot Calidris canutus at a high tide wader roost at Freiston Shore RSPB reserve

Food, glorious food

The greatest test for wild birds in winter is to find food and ensure they eat enough of it to build - and maintain - adequate fat supplies to store on the body and ‘burn’ for energy.

This becomes even more difficult in hard weather when snow and ice hide once easily available natural food. Water birds may be forced to leave iced-over lakes and rivers; the ground becomes too hard for birds like thrushes and lapwings to probe and natural food like berries, acorns and seeds is buried. 

The ability to fly

Flying is the survival 'trump card' for birds and can lead to sudden - and dramatic - changes in the birdlife of an area. A sudden reduction in numbers may be the only clue that your local birds have moved on temporarily, but if you keep your eyes peeled, the emigration of other birds can be very visible during, and after, cold snaps. 

Lapwings and golden plovers arranged in neat ‘v’ formation, and flocks of ‘chuckling’ fieldfares flying to the milder south and south-west in search of ice free pasture are classic signs of ‘hard weather movement’. Kingfishers and grey herons appear at the coast to fish in salty, ice-free water until their favoured streams and rivers thaw.

The flip side of birds leaving one area is that they suddenly appear in those that are less affected by the weather or where food is still readily available. Examples might be ducks such as pochards, goosanders and goldeneyes arriving at your local reservoir or an increase in the number of chaffinches and greenfinches coming to your garden feeders.

Feeding behaviour

Hard winter weather may mean a change in behaviour rather than a change of location. Birds have to feed at an accelerated rate, but must also take adequate time out to rest and conserve energy. It is a fine balancing act and one they cannot afford to get wrong.

The smallest birds, like blue tits and goldcrests, have to effectively feed throughout the hours of daylight in winter and consume a vast quantity of food - as much as 30% of their body weight - to make sure they build the necessary fat reserves to get them through the long, cold nights.

Hoarders such as jays turn to the 'larders' they prepared in autumn when food was plentiful and dig deep in the snow to find the stores of acorn they stashed.

Your garden can save lives

During cold snaps, you will almost certainly notice more birds coming into your garden to seek sanctuary from the harsher environment in the countryside – particularly if you provide food on a regular basis. The variety of species may increase too and you may be lucky enough to attract unusual visitors such as blackcaps and bramblings.

Finding a regular source of high-energy food such as a garden feeding station is the equivalent of winning the lottery for wild birds and a well-stocked garden is a real lifesaver.

Birds will become dependent on the food you supply, so it is important to make sure your feeders are kept topped up to prevent them from having a wasted visit. Providing a fresh, ice-free supply of water is another cold weather essential - drinking and bathing is a vital part of the daily routine of birds.

You may well witness a flurry of bird activity first thing in the morning – as they replenish energy lost overnight - and last thing in the afternoon - to prepare for the long night ahead.

Where to go to see flocking birds

RSPB nature reserves are great places to watch winter flocks. Here are just a few that you could visit this winter:

For woodland walks, try:

To see flocking starlings, visit:

Watch thousands of gulls flying to their evening roosts at:

See congregations of rooks and jackdaws at:

To get a glimpse of pied wagtails, visit:

To see spectacular numbers of wintering wading birds, go to:

Pied flycatcher Ficedula hypoleuca, sitting in the branches of a tree, male, Co. Durham

How you can help
 

Great spotted woodpecker Dendrocopus major, juvenile bird on Premium peanut feeder in garden

What food can you leave out for birds and how can you keep your feeding station hygienic and pest-free? Here you'll find the answers to all your bird feeding questions.