Eagle-eyed volunteers in the South West are needed to help count one of the UK's most elusive birds.
The Game and Wildlife Conservation Trust (GWCT) and the British Trust for Ornithology (BTO) are looking for 1,000 people across the UK to help them track the woodcock.
Because of the woodcock's secretive nature, there has long been uncertainty about its status.
In 2002, the woodcock was amber listed amid fears that the species had suffered a 74% decline in breeding numbers.
To determine whether the birds were under threat, the GWCT and BTO carried out the first ever national count of woodcock in 2003, which revealed that there were around 78,000 male woodcock in Britain.
Dr Andrew Hoodless, an ecologist with the GWCT, said: "Our first national survey posed some interesting questions about abundance. In our repeat survey this year we need to identify why Wales and South West England support so few breeding woodcock and why areas such as Kent and Hertfordshire appear to hold rather low densities of woodcock despite having relatively large areas of woodland."
This year's Big National Woodcock Count takes place in May and June. Some 1,500 woodland survey sites will be monitored across England, Scotland and Wales with additional sites to be included for Ireland.
The camouflaged birds, with their long slender bills, can be difficult to spot during the day. The technique for counting woodcock involves standing in a wood at dusk and counting the males as they fly past, making their distinctive roding or display calls in search of females.
Dr Hoodless said: "Woodcock have very specific habitat requirements in the breeding season and the survey will enable us to investigate how changes in woodland habitat and general land use over the past ten years have affected their numbers."
To take part in the Big National Woodcock Count, visit www.bto.org/woodcock-survey.