Are you ready to count the birds this weekend? It’s the return of the RSPB Big Garden Birdwatch – the annual birdwatching event which gives the RSPB wildlife charity a valuable snapshot of how garden birds are doing in the UK.

You can help by signing up at www.rspb.org.uk/birdwatch, then counting the wild birds you see for just one hour, any time from Friday 24 to Sunday 26 January. You can count birds from your window at home, or perhaps put on a coat and settle down to count in your garden or a park.

The RSPB Big Garden Birdwatch is the largest, continuous, citizen science project in the UK, and the largest garden bird survey in the world. Last year more than 600,000 participants counted 9.7 million birds nationwide. The top species recorded nationally was the house sparrow, but the RSPB says its numbers were 60% down on the numbers recorded in the first Big Garden Birdwatch in 1979. The others in the top five were blue tit, common starling, woodpigeon and blackbird.

Don’t worry if you can’t tell a blackbird from a starling: when you sign up you can download a free Big Garden Birdwatch guide which includes a bird identification chart.

Only count birds that land, not those flying over. Record the highest number of each bird species you see at any one time, not the total you see in the hour. This ensures that the friendly robin which makes many visits during the hour is counted as one bird, not several!

If you’re really keen, you can do more than one birdwatch over the weekend, but each must be from a different location, as the RSPB can only accept one birdwatch per person per location. Each location should be documented when you report your results.

It’s important to send in your result even if you spot just one bird or none at all during the hour – that’s important information too.

You can get together with friends or family and count the birds you see together. However, you should only send in one set of results.

People have commented to me that winter seems the wrong time for the Birdwatch, as fewer of our feathered friends visit gardens at this time of year. In addition, the bird species we observe change from season to season.

The RSPB’s response is that winter is when garden birds need us most: if it’s cold, it’s likely more birds will come into gardens looking for shelter and food, which makes it easier to count them. And because Birdwatch takes place at the same time every year, it can look back over the years to see what has changed.

Beccy Speight, the RSPB’s chief executive, said: “Those who take part in the Birdwatch play an important role in helping the RSPB understand how UK birds are doing. With birds facing many challenges due to the nature and climate emergency, every count matters.

“Whatever you see – one blackbird, 20 sparrows or no birds at all – it all counts. It helps us build a vital overall picture of how our garden birds are faring from one year to the next. Our garden birds are counting on you!”

To take part, sign up at www.rspb.org.uk/birdwatch. Then you can download a bird identification chart, tips for your birdwatch and a voucher to spend at the RSPB shop.