You don't have to go far to join in this weekend's RSPB Big Garden Birdwatch, in fact you can make yourself a cup of tea and take a comfy seat near the window and still take part. SIMON PARKIN looks at how to get involved.

Has there ever been a better excuse to stay in your armchair and stare out the window, than to say you're just counting the birds in your garden? And has there ever been a better way of involving children — whether that be your own, your grandchildren or your nieces and nephews — in the wildlife that surrounds us all and that we all too often take for granted?

The RSPB's annual Big Garden Birdwatch survey takes place this weekend and the charity is hoping that more of you than ever before will take part.

Last year, almost 500,000 people joined in the popular survey that provides a vital snapshot of the UK's winter garden bird population.

The annual count, which helps the RSPB monitor which bird species' populations are increasing or decreasing, started in the late 1970s, when the RSPB asked their junior membership to count the birds in their garden over the same weekend.

The 'one-off ' idea was so successful that it has been a regular event since 1979. Since then the bird-watching public have clocked up more than three million Big Garden Birdwatch hours watching and enjoying the birds in their gardens. They have also spotted six million birds, helping reveal the winners and losers in the garden bird world.

Carolyn Jarvis, Big Garden Birdwatch co-ordinator, says: 'Taking part not only helps the RSPB track the ups and down of garden birds, but it gives participants the perfect excuse to sit down with a cup of tea and enjoy the wildlife that they share their outside space with.

'You'll be a part of the biggest garden bird event in the world and you won't even have to leave the warmth of your armchair!'

Recent harsh winters have seen some garden bird populations drop, only to make a comeback after a good breeding season the following year.

Last year, some of the UK's smallest garden birds bounced back, and the wildlife charity wants to know whether they have managed to maintain their numbers.

The Big Garden Birdwatch is one of the first indicators to show how UK birds have fared during the previous breeding season and winter. With over half a million people taking part each year and over thirty years worth of data the results give an early indication of garden bird trends.

Carolyn Jarvis added: 'The RSPB keeps a watchful eye out for new and emerging trends from Big Garden Birdwatch results, which helped confirm that there was an alarming decline in birds like the house sparrow, starling and song thrush.

'It's important that we keep a close eye on how our birds are faring, like the house sparrow for example. With so many people stepping up and taking part in Big Garden Birdwatch, if a pattern emerges, we take it seriously. Half a million people can't be wrong and that's why the survey is so important.'

Taking part couldn't be easier. All you have to do is spend an hour watching and recording the maximum number of different bird species visiting your garden or local park at any one time.

You really don't need to be an expert to take part. Whether you're young or old, an expert or a beginner, it doesn't really matter. So don't worry if you can't tell your blue tits from your coal tits, as the RSPB has put together a guide to help you identify some of the UK's most popular garden birds. And youre findings are helping to build up a picture of what's happen to our natives species.

? For more information or to download a printable bird spotting sheet visit: www.rspb.org.uk/birdwatch

BINOCULARS OUT — GET INVOLVED

To take part all you need to do is watch your garden or local park for an hour on either Saturday or Sunday. Record the highest number of each species seen in your garden — not flying over — at any one time.

The best time to complete your survey is early morning as that's when birds are most active. It's also a good idea to put out a selection of foods, such as peanuts, seeds, fats and kitchen scraps, as you'll attract a greater variety of birds.

Once you've completed your survey, you can submit your results online. Some birds will return to your garden many times in the hour, so seeing the same blue tit come back 10 times does not make 10 blue tits.

Fill in the results on the counting sheet (which can be downloaded). The RSPB will collate and publish the results in March.

15 BIRD TO WATCH OUT FOR

1 House sparrow — The noisy and gregarious house sparrow is one of our most familiar birds. It feeds on seeds, grains and scraps on the ground and on bird tables. It is sedentary and rarely moves more than 2km from its birthplace. Despite being widely distributed throughout Britain (it was the most commonly spotted bird during the 2011 Big Garden Birdwatch) the population remains a red listed species.

2 Starling — The starling is a familiar bird throughout Britain. It is famed for its ability to mimic the calls of other birds and the mechanical noises in its varied repertoire of song. Smaller than blackbirds, with a short tail, pointed head and triangular wings, a starling looks black at a distance but when seen closer it has a sheen of purples and greens. Although still common in gardens, being seen in over half of all gardens during the 2011 Birdwatch, it remains another red listed species.

3 Chaffinch — The chaffinch is one of the UK's most common breeding birds, and is arguably the most colourful of the UK's finches. Its patterned plumage helps it to blend in when feeding on the ground and it becomes most obvious when it flies, revealing a flash of white on the wings and white outer tail feathers. It does not feed openly on bird feeders - it prefers to hop about under the bird table or under the hedge. It will usually be heard before being seen, with its loud song and varied calls.

4 Blue tit — Its colourful mix of blue, yellow, white and green make the agile blue tit one of the most attractive resident garden birds. Almost any garden with a peanut feeder will attract it; it will also feed on seeds, and scraps from bird tables and the ground. In winter it forms flocks with great tits, long-tailed tits and other woodland species as they search for food. A garden with four or five at a bird table at any one time, may be feeding 20 or more birds.

5 Woodpigeon — The UK's largest and commonest pigeon, it is largely grey with a white neck patch and white wing patches, clearly visible in flight. Although shy in the countryside it can be tame and approachable in towns and cities and was seen in 68% of Big Garden Birdwatch gardens in 2011. Feeds on grain, seeds, scraps, berries, buds and is quite partial to crops like cabbages, sprouts and peas.

6 Great tit — Bigger than the blue tit, the great tit is green and yellow with a striking glossy black head, white cheeks and a distinctive two-syllable song. It is a woodland bird that has readily adapted to man-made habitats to become a familiar garden visitor. It feeds on seeds and scraps on the ground, from nut feeders and bird tables where it can be quite aggressive, fighting off smaller tits. The great tit was seen in 61% of gardens surveyed during the 2011 Birdwatch.

7 Robin — With its bright, orange-red breast, brown back and dumpy shape, the robin is a familiar garden bird and was officially adopted as Britain's National Bird in 1960. It is the only garden bird to sing throughout the winter. Despite its cute appearance, the robin is aggressively territorial and is quick to drive away intruders.

8 Goldfinch — A small, dainty, highly coloured finch with a bright red face and yellow wing patch. Goldfinches often feed in small flocks, and its twittering call and black and yellow wings draw attention to it. It is a seed-eater that feeds on the ground, on seed heads of garden plants (although this is mainly male goldfinches as they have a slightly longer beak than females) and on seed-filled birdfeeders.

9 Blackbird — The males live up to their name but, confusingly, females are brown, often with spots and streaks on their breasts. The bright orange-yellow beak and eye-ring make adult male blackbirds one of the most striking garden birds. The blackbird has a long tail and often hops along the ground with its tail up. Its mellow song is a favourite, often described as the finest song of all British thrushes.

10 Dunnock — A small, easily overlooked bird, the dunnock creeps around under bushes in a mouse-like way. It is a brown and grey bird with a slender beak, which it uses to catch its insect and spider food. Sedentary, they rarely move more than a kilometre from their birthplace. When two rival males come together they become animated with lots of wing-flicking and loud calling.

11 Long-tailed tit — The longtailed tit is easily recognisable with its distinctive black, white and pink colouring, a tail that is bigger than its body, and undulating flight. Gregarious and noisy residents, long-tailed tits are most usually noticed in small, excitable flocks of about 20 birds. It feeds on insects, but is increasingly visiting garden bird tables and nut feeders in winter.

12 Collared dove — Distinctive with its buffy-pink plumage, black neck collar and long, white tail with a black base, the collared dove is usually seen singly or in pairs, although flocks may form where food is plentiful. It feeds on the ground but readily perches on roofs and wires. It feeds on seeds and scraps, from and around the bird table. After rapidly spreading across Europe in the early half of the 20th century, the collared dove is now one of our most common birds.

13 Coal tit — Whilst not as colourful as some of its relatives, the coal tit has a distinctive grey back, black cap and white patch at the back of its neck. It has a smaller, more slender bill than the blue or great tit allowing it to feed more successfully in conifers. A regular visitor to peanut feeders.

14 Greenfinch — Its twittering and wheezing song, and flash of yellow and green as it flies, make this finch a truly colourful character. Nesting in a garden conifer, or feasting on black sunflower seeds on the ground, bird tables and feeders, it is a popular garden visitor. Although quite sociable, it may squabble among other birds at the bird table.

15 Magpie — Magpies seem to be jacks of all trades – scavengers, predators and pest-destroyers, it's challenging, almost arrogant attitude has won it few friends. With its noisy chattering, blackand- white plumage and long tail, there is nothing else quite like the magpie in the UK. When seen close up its black plumage takes on an altogether more colourful hue with a purplish-blue iridescent sheen to the wing feathers, and a green gloss to the tail.