We look at eight strategies birds employ to get them through the colder months.
If you walk around a woodland in 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. Spot a Blue Tit and among the throng you may also see Great Tits, Long-tailed Tits, tiny Goldcrests and more. Flocking together in winter improves the chances of locating food and there’s also safety in numbers. When birds feed, they can be more vulnerable to predators, and to keep their energy levels up against the cold, birds have to spend a lot of time feeding.
Huddling together during the cold of the night helps conserve body heat, and by roosting together birds also improve their chance of survival from predators. Starlings are famous for their winter murmurations, when hundreds and thousands can gather before dusk, wheeling and turning in the darkening sky before heading for a sheltered spot such as an empty building, leafless tree, under a seaside pier or a bed of swaying, yellow reeds. Rooks and Jackdaws also form large roosts during winter. Meanwhile in our towns and cities you could find flocks of Pied Wagtails roosting in trees, taking advantage of the warmer urban landscape.
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. 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.
Some birds prepare for the colder months by squirreling away supplies. Jays are a colourful member of the crow family, with jewel-like blue flashes on their wings. They also have an enormous taste for acorns. As autumn falls and the acorns ripen, Jays flock to our parks and gardens in search of acorns to hide away and eat at a later date. Just one bird can gather around 5,000 acorns hiding them up to several kilometres from where they found them. With so many acorns and so many hiding places, not all acorns are consumed and some will grow into oak trees, food for the Jays of the future.
Birds can also migrate in search of food and many species flock to the UK for winter. Fieldfares and Redwings are members of the thrush family that fly in from Scandinavia, Russia and other colder climes to feast on the berries growing wild in our hedgerows. The numbers of these birdvisiting each year fluctuates with the berry harvest in their home countries: the poorer the harvest, the more we’ll see in the UK.
Our estuaries, mudflats, marshes and other wetlands are also a magnet for migrating birds, as many species of ducks, geese and other water birds fly in from colder countries north and east of the UK. These muddy habitats provide rich picking for waders such as Curlews, godwits, Oystercatchers, Knots, Dunlins, Grey Plovers and Redshanks who feast on the worms, shellfish and other marine creatures. Meanwhile the wetland plants provide plenty of food for ducks, geese and swans to feed on.
Birds also move around within the UK – both those that live here year-round and those that have migrated for the winter. Water birds may be forced to leave iced-over lakes and rivers and you could see Kingfishers and Grey Herons appear at the coast to fish in salty, ice-free water until their favoured streams and rivers thaw.
Similarly, if the ground becomes too hard for birds like thrushes and Lapwings to probe for food, and natural food like berries, acorns and seeds are buried by snow, you could see flocks of birds flying to milder areas. This movement of 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’.
Think of a Robin on a cold winter’s day and many of us imagine a plump little ball with two stick legs! The reason for their round appearance is not an over-indulgence on fat balls at Christmas. Instead, Robins, like many other birds, fluff up their feathers when it’s cold. Doing so increases the amount of air held against their bodies which in turn helps prevent heat loss. Birds also grow more downy feathers in the colder months, and these soft feathers found closest to the skin also help keep birds warm in winter.
During a particularly cold spell, 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 more unusual visitors such as Blackcaps and Bramblings. 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.
You can help birds by putting out food in a hanging feeder and providing fresh water. Drinking and bathing is a vital part of the daily routine of birds, so a fresh water supply is particularly important in colder weather when usual water sources could be frozen. Crucially, be sure to keep your feeders and bird baths clean by washing them at least once a week to help the birds stay healthy. Take a look at our guide to How and When to Feed Birds in Your Garden for more advice, including the best foods to attract different birds, and how to help birds stay healthy.
