People are being invited to devote an hour of their time this weekend to help conservationists get a snapshot of how our wildlife is faring.

The RSPB's Big Garden Birdwatch is described by the charity as the world's largest garden wildlife survey.

Under the project, people are asked to watch the birds in their garden or local park for one hour at some point on Saturday, Sunday or Monday.

Only the birds that land can be counted, not those flying overhead.

People are then invited to report the highest number of each bird species they see at any one time - not the total seen in the hour - to the charity.

Participants can also log some of the other wildlife they have seen throughout the year, such as foxes, hedgehogs or red squirrels.

RSPB Scotland director Anne McCall said: "With thousands of participants across Scotland, it's clear that people are truly passionate about their garden wildlife.

"It's a huge achievement to reach 40 years of the survey, and it reflects what an enjoyable and accessible experience it is."

Over the last four decades, hundreds of thousands of people have volunteered their time, providing over eight million hours of monitoring garden birds, RSPB Scotland said.

Across 40 years, the survey has shown increases across the UK in collared dove and wood pigeon numbers and declines in house sparrows and starlings.

Keith Morton, RSPB Scotland senior species policy officer, said: "Your garden can be hugely important for wildlife, especially in winter when it offers a vital source of food, water and shelter to birds.

"Big Garden Birdwatch is an opportunity to capture information on the wildlife visitors to your garden in an enjoyable, easy and inclusive way.

"We are now in our 40th year of the survey which means the results not only allow us to understand how birds are doing now, but it also shows us long-term changes."

The results of the survey, which runs from January 26 to 28, can be submitted online at rspb.org.uk/birdwatch