Put out the bird food - and start counting
Sightings, which people then send to the RSPB, help it monitor population trends for Britain’s birds.
To take part, people need to watch the birds in their garden or park for one hour at some point between Saturday and Monday.
A free pack can be downloaded at rspb.org.uk/birdwatch.
Daniel Hayhow, RSPB conservation scientist, said: “With over half a million people now regularly taking part, coupled with over 30 years worth of data, Big Garden Birdwatch allows us to monitor trends and helps us understand how birds are faring.
“With results from so many gardens, we are able to create a snapshot of the birds visiting at this time of year across the UK.”