Birds make sounds for many reasons, not just to attract a mate. There are contact calls and alarm calls, begging squeaks and threating squawks. Some sounds seem to have obvious meanings, whilst others appear more like conversational chatter.

Contact calls are a common sound in winter, when many birds form flocks to find safety in numbers. As the name suggests, these sounds help birds stay in touch with the rest of the flock. They can be far-carrying cries, as birds call out to find each other over long distances, or softer sounds as flocks talk amongst themselves. Flying birds will often make contact calls as they search for other members of their species, or to help stay in formation if they’re flying as a flock.

Alarm calls are often harsh or explosive sounds, screamed out as a warning that danger is nearby. They warn other birds in the area that a threat has been spotted, but they also let potential predators know that the bird has seen them and is ready to run. For hunters that rely on the element of surprise, this may be enough to put them off.

These calls can be loud and panicked, but at the softer end of the scale there are anxiety calls. These are used when urgent action isn’t needed right now, but may be soon. Rather than shouting ‘our lives are in immediate danger’, they’re saying something more like ‘this is making me nervous’. The sounds are often short and repeated several times.

Birds can have different calls depending on the nature of the threat. They might have one alarm call for a ground predator, but a different sound for a bird of prey. If they’re feeling particularly bold, some birds even use a ‘mobbing call’ to try and drive off potential predators, particularly roosting owls. This agitated call encourages other birds to join them and try to irritate the owl into leaving the area.

Let’s explore some of the sounds you might hear in a woodland or wetland this winter…

Birdwatching in a winter woodland can be a boom or bust experience. Many of the common woodland birds form flocks, roving through the trees in fast-moving foraging parties. This means one moment an area can seem silent and bird-less, but ten minutes later it could be a hive of activity as the vocal flock passes through.

Long-tailed tits are responsible for a lot of the noise, calling to stay in contact with each other as they flit from tree to tree. Looking like feathered lollypops, these adorable birds call almost constantly. Perhaps they’re sharing tips on the best feeding spots, or just letting the others know there’s no sign of danger? Their selection of sounds includes a high-pitched ‘si si si’, a rippling ‘zerrr’ and a clicking ‘tuc’.

Blue and great tits often join these flocks or form flocks of their own, drawing in other species from nuthatches to woodpeckers and occasionally even overwintering warblers. You might hear the sharp call of a coal tit or, if you’re really lucky, the sneeze-like ‘pit-choo’ of a marsh tit. One very common companion of tit flocks is the goldcrest, whose soft ‘zhee zhee zhee’ is so high-pitched some people struggle to hear it.

Finches also form noisy flocks in winter. Redpolls and siskins sweep through the treetops, with a particular soft spot for stands of alder. Their calls often draw attention to them flying overhead or feeding amongst the canopy. Siskins have a variety of wheezing and rattling contact calls, as well as a sharp, whistling disyllabic ‘dee-u’ flight call. Redpolls have an almost metallic ‘chi chi chi’ flight call as well as a bouncy, rising ‘juih’.

One of the most common alarm calls in woodlands, parks and gardens belongs to the blackbird. They combine a slightly nervous disposition with a very loud voice. If they feel uneasy, they’ll express it with a series of deep ‘pok’ calls, which sound a little like a tiny dog barking. When they’re more alarmed, it becomes a sharp, repeated ‘chink chink’. Finally, in full scale panic they’ll give a rising rattle – often heard when you accidentally disturb one and it bursts out of the undergrowth.

Blackbirds aren’t the only thrushes you might hear. Each winter, we’re visited by huge flocks of redwings and fieldfares. They roam the country in search of berries, feasting wherever they find them – from hedgerows to woodlands, parks and even gardens. The flocks are noisy, with both species giving regular contact calls in flight and when they’re feeding. Fieldfares pair squeaks with a throaty chuckle, whilst redwings have a sharp ‘tseep’ flight call.

Wetlands are busy places in winter. Lakes and reservoirs fill with ducks, swans and geese as hundreds of thousands of birds head to the UK from northern and eastern Europe. They’re sociable creatures, feeding and even migrating in flocks. As a result, they’re generally very noisy!

Flocks of geese create a cacophony of sound, particularly as they take flight or gather to roost. They sleep, feed and fly together, so communication is essential. There are greylag geese with their familiar nasal honks and cackles, barnacle geese with a shrill bark, and brent geese with a deeper, gargling call. Some of the largest flocks, found around major estuaries, are of pink-footed geese. They have a squeaking ‘ink ink’ call that can be thunderous in huge numbers.

Our resident mute swans (poorly named, as they make a variety of sounds) are joined by visiting whooper and Bewick’s swans. Whooper swans are the commonest of the two, as well as the loudest. They travel in family groups and stay in contact with loud, bugling calls. The calls of a Bewick’s swan are a little softer and have a slight yapping quality.

Ducks add their own voices to the wetland soundtrack, a variety of quacks and whistles. Flocks of teal and wigeon are responsible for a lot of the noise. The calls of the males are high and excitable. Teals repeat a clear, sharp ‘peep’ that rises in pitch, whilst wigeons have a whistling ‘wee-oo’ that climbs excitably before falling as it trails off.

This is just a small sample of the winter soundtrack. There are hooting owls and wheezing bramblings; robins, dippers and other birds in full song; and so many other sounds to discover. Head to social media and let us know which you’ve heard with #12DaysWild