Look up: one of nature's most dramatic air shows will happen this month. "Starling flocks are really spectacular," says Peter Brash, an ecologist with the National Trust. "They look like wisps of smoke, changing shape. You'll see them mainly around reed beds. The numbers of starlings have declined in Britain but the big flocks you see at this time of year are probably coming from as far away as Russia or Siberia." The best time of day to see group displays is in the late afternoon when they come home to roost: as they are vulnerable to predators at this time, they return together. A likely site is at Frensham Littlepond in Surrey, and the West Sedgemoor RSPB reserve can have flocks of up to 3 million starlings.
By February herons need to be sitting on their eggs, so now is the time for a spring clean. "You may see one flying with a big stick in its mouth, or standing up in trees," says Brash. You might also see them in stubble fields, looking for voles (they also eat eels, fish – and other birds). "Herons have very traditional nesting areas and there are even records of the same heronry being used from the 1940s," says Brash. See them at Morden Hall Park in London, at Stackpole in Pembrokeshire, and on the Dee Estuary.
No, really. If the temperature hits 11C, look out for the red admiral. "It has a reputation for being our standard ubiquitous butterfly, but it's actually migrant," says Matthew Oates, an entomologist and conservationist for the National Trust. "With climate change they are hibernating successfully in increasing numbers. Ten years ago it would have been rare to have the red admiral as your first butterfly of the year; now it's odds-on favourite. You need 11C-plus sunshine and a calm, sheltered spot. You'll see them around buildings because that's where they hibernate." Also look out for the bright yellow brimstone butterfly, best spotted in woodlands anywhere in England and Wales.
The British Isles are home to the common seal (Phoca vitulina) and the grey seal (Halichoerus grypus). Low tide is the best time to see them. "Greys will haul themselves on to rocky coastline, while common seals are on sand bars or sand flats," says Brash. The best places to see them are Blakeney on the north Norfolk coast, Boscastle in Cornwall, Strangford Lough in Co Down and the Branscombe Estate in Devon (check before travelling, as there is reduced boat service in winter).
This wader breeds in the high Arctic but winters on the mudflats of the British Isles. Knots are best seen in spring at high tide; when the mudflats are covered, they look for farmland or an island in order to roost. Look around Morecambe Bay or the Dee Estuary in North Wales – but keep dogs on leads."Dogs can run out across a mudflat and chase the birds, and some of these birds need to feed constantly when the tide is low," says Brash. "Disturbance could make the difference between survival and death."
Horseshoe bats (the Rhinolophidae family) are a protected species well worth observing. "In the winter they're in caves and they're in torpor," says Brash. "But every few days they'll fly around a bit... On warmer nights, if the temperature reaches 10C or 12C, they'll come out and have a feed and water, and then go back into the cave. You need a bat detector to hear them – it slows down the sound so the human ear can hear it. They do a strange call, a bit like a bubbling sound." Greater horseshoes are the size of pears, lesser horseshoes the size of plums. Like other types of bat, the horseshoe has suffered from the overmanagement of hedges and trees. "Hedges were their motorways. That's how they navigated. Hedges used to be 25ft tall, but now they're shorter so they can't use them to feed from. They also feed on dung beetles, and because we don't winter cattle outdoors as much as we used to, and use nasty worming chemicals on cows, that's had a big effect on dung beetle populations." You're most likely to see horseshoe bats in Southern England and in Wales.
Forget Ricky Hatton: try agricultural fields in the early morning. "I often see hares, close to dawn, boxing in the fields near our office in Slough," says Brash. "The females stand up on their back legs and give the males a left hook. It's part of the mating ritual." See the big fight in open countryside, grasslands and stubble fields. Spot brown hares at Wicken Fen in Cambridgeshire and at Hardwick Hall in Derbyshire; in the Peak District and Snowdonia you might glimpse the rarer mountain hare.
The red squirrel (Sciurus vulgaris) is currently out feeding. "I'm afraid they are being pushed out by grey squirrels," Brash says. "The greys compete with them for food – they are slightly larger. But another factor is squirrel pox, which kills reds and is carried by the greys but doesn't affect them." Greys prefer broad-leaved woodlands, so reds are best spotted among conifers and on islands, where greys haven't yet reached. Try Formby Dunes near Liverpool, Mt Stewart in Co Down, and in Scotland, Northumberland, Anglesea, the Isle of Wight and the Lake District.
Trees and flowers
Warmer winters may also bring trees and flowers into bud earlier. Snowdrops are the keenest, and are prevalent throughout the UK, particularly in North Wales. But start looking too for the first catkins of 2008 dangling from hazel trees. Also blooming early are hedgerow and woodland flowers. Dog's Mercury (Mercurialis perennis) is a green perennial with erect stems bearing simple, serrate leaves: "It should be poking out of the ground about now, usually in hedges or ancient woodland," says Brash. And from February, look out for wild primroses in the woodlands and hedgerows of the South-west; try Watersmeet in Devon.