Picture: blue tit. Click here for more autumn and winter bird photos. For more information and sound clips of the birds mentioned in this section, see the RSPB website.
The disappearance of foliage in November is a boon to birdwatchers in December. Suddenly birds can be seen as they feed busily on trees and bushes, racing against time to consume enough energy during the short daylight hours to keep them warm during the cold night ahead.
This is a significant struggle. Only a third of blackbirds and half of tits survive the winter, while just a quarter of robins reach their first birthday. This is despite the fact that in captivity (ie in ideal conditions, with adequate food and no predators) tits can live ten years, robins thirteen and blackbirds and starlings up to twenty.
Even so, birdsong gets a bit more prominent from mid December onwards as several species approach their mating seasons. How much song there is varies with the weather - mild temperatures or sunshine can increase it, though a very cold frost overnight may dampen it and on grey cold days you hear almost nothing. There is also more near human habitation than in fields and woods. With the exception of robins, most of it is probably due to first year males practising, rather than full blown singing to attract a mate.
Robins certainly are not practising. With both males and females aggressively territorial, both sexes sing throughout the autumn to ward off rivals. In order to mate in January they have to overcome their natural solitariness, however, and from mid December you hear the start of that process, with a pick-up in singing. As well as their somewhat formless warbling, they make a rapid clicking noise when agitated. Their fearlessness when confronted with humans and the fact that they choose obvious perches overlooking open ground (from which they pounce to feed) makes them one of the easiest birds to spot - and therefore a favourite theme of Christmas cards.
Great tits make a variety of sounds - including a double cheep followed by a churring sound, and a "see-choo-choo" call: all these are contact calls as they feed. In addition you occasionally hear a male bursting into its see-saw mating song, particularly in the second half of the month. Generally this is not sustained - you get a few minutes of it and then the bird stops. The less common coal tit also makes a see-saw noise, with the emphasis very much on the second syllable ("too-TWEE too-TWEE too-TWEE"). Both species are limbering up for January, when their mating season starts in earnest.
From mid December you can also hear blue tits singing their mating song, a rapidly repeated note which is an extension of the "zee-zee zit" call which they sometimes make while they feed. In addition they churr away to each other as they hop around the branches, their rattle having a slightly rising note at the end which distinguishes it from the great tit's.
Another song you may just hear from mid month is the rather random riff of the dunnock, which sounds a bit like a tune being played backwards: they also make a single 'tseep' as a call, though it is hard to distinguish this from a similar sound made by great tits.
Wrens may also very occasionally burst into voice - the key to identification here being a trill in the middle of a rapid run of notes. The trill is sometimes missing, however, indicating that the bird is still practising. Now and again you can hear the nuthatch making a "wit wit" or "de-dit de-dit" call. Very rarely, one gets carried away and makes a trilling noise or a "wee wee wee", both spring mating songs.
Another bird that is sometimes moved to sing is the song thrush, whose varied song, repeating each phrase three times, is not supposed to start till February. But sometimes in December you can hear them quietly rehearsing their phrases in a tree, or even breaking out into a more confident rendition.
Mistle thrushes may also very occasionally be heard singing in December, uttering clipped phrases a bit like a blackbird's but with much less variety or creativity. A characteristic of this bird is that it always sounds as if it is in the far distance even when it is quite close by. Sadly these days it is rather rare.
Blackbirds don't sing at this time of year, but they may indulge in prolonged bouts of tup-tup-tupping to mark their territories or to ward off predators - often, but not exclusively, at dusk.
In the second half of the month you may hear the drumming of a great spotted woodpecker: otherwise it can be occasionally be heard making a chik....chik.... noise as it feeds in trees. Very occasionally a green woodpecker breaks into its laughing "yaffle", or a somewhat flatter-toned version of it.
You may also hear wood pigeons or collared doves practising their riffs, or the throaty "woo" of a stock dove. In the woods at night there may be tawny owls hooting (the classic "hu-hu-hu-HOO" sound). Towards dusk in the same habitat you can hear the noisy clucking of pheasants as they settle down in communal roosts - something they do all year but which is more often noticed when nightfall is so early.
Otherwise, you sometimes see birds in flocks, feeding in the branches of trees or bushes. Particularly restless are long-tailed tits - balls of fluff with a long tail, which let out regular high-pitched squeaks (sadly only audible to those with young ears) and rasps as they hop through treetops in a frantic search for food. Goldfinches give themselves away by their excited chattering (for example when eating ash seeds) but despite this are astonishingly hard to spot, seemingly always high in trees.
Nothing like as common as they once were but still found now and then, flocks of sparrows cheep away, often from inside a bush and always near habitation, though one seems to hear them less frequently at this time of year than in the warmer months. Chaffinches are supposedly found in flocks too - apparently numbers of this bird are swollen in winter by migrants from continental Europe - but if they are around, they are very inconspicuous.
On bare arable fields you can see large flocks of rooks or jackdaws feeding, often mixed together in one flock. They also congregate by day on trees near farmland, and at dusk roost in a favoured stand of trees (for example, by Lewes station), greeting the dusk with a great deal of discordant cawing and flapping. Apparently this is not just squabbling for the best spot - research suggests they are also telling each other about feeding grounds.
Flocks of starlings - often migrants from Eastern Europe who swell our native population in winter, taking advantage of our milder winters - also feed on arable fields, as well as on any last remaining berries on hedgerows. Before roosting they form "murmurations" in the sky, wheeling in unison, possibly to confuse predators, or possibly just to reinforce social bonds. This used to be a common sight in cities, but is now mostly seen over wetland reserves (try RSPB Otmoor in Oxfordshire) or (rather more comfortably) on Brighton Pier, where as many as 25,000 gather in the twenty minutes or so before sunset.
Other birds that feed in flocks on farmland include wood pigeons (again, probably winter migrants from the continent) and gulls (lesser black-backed, common or black-headed).
If you see a flock of thrushes, they are fieldfares or redwings (the latter with a dash of red by the wing just as their name suggests). These come from Scandinavia to spend the winter in England, where they mostly feed inconspicuously in the fields. Sometimes they gather in large chattering groups in trees, however, and they may come into parks and gardens to feed on the berries of shrubs such as firethorn (pyracantha) or cotoneaster.
Also from Scandinavia are siskins, yellow finches that generally live among conifers but can be lured into alder or birch trees in winter. Do not confuse these with our native yellowhammers, who also live in flocks at this time of year - as indeed do corn buntings, though the latter are now extremely rare.
Insects
You may think that there are no insects around in December but you would be wrong. Look carefully and one can see small swarms of winter gnats on windless days. There are in fact ten different species of these in the UK, and the swarms are their mating dance, which they have evolved to do at this time of year to avoid predators. If you look at them under magnification (try focusing binoculars on them - not easy!) they are like miniature crane flies or mayflies.
If you turn over a rotting log in woodland you might also see woodlice or spiders. These are all inactive in winter, but not actually hibernating, a term which only applies to mammals. Instead what the insects are doing is known as "diapausing": they shut off their metabolism entirely, though if they are disturbed it instantly starts up again. If you leave them alone they will soon go back to their state of suspended animation.
The same is true of flies, which occasionally make an appearance on sunny days. Bumble bees and wasps overwinter in the shape of fertilised queens who make burrows or find a cosy nook to lie dormant in: all other members of the species die off in the autumn. If it is very mild, a queen bumble bee may emerge from her hole and take wing in December, thinking it is spring: she hopefully soon realises the error of her ways and goes back to bed.
Honeybees are different, living communally in their hives in winter on the honey they have hopefully built up in the summer; they may also be occasionally seen on the wing if there is a food source - for example on winter flowering cherry trees.
Peacock, small tortoiseshell, brimstone and comma butterflies also diapause as adults - Second World War pillboxes are apparently one favoured spot - and some red admirals, despite being migrants, seem to be learning the same trick. Very cold winter weather can actually benefit these species by killing off parasites, while in very mild weather you may be surprised to see one on the wing (red admirals are particularly prone to this).
Quite a few other butterfly and moth species spend the winter as dormant caterpillars - one of the things the great and blue tits are looking for as they feed. Insects also overwinter as eggs, larvae or pupae. Every species has to have some strategy to get through the cold months and populate the world anew in spring or summer.
More December pages:
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