Kent Ornithological Society surveys nightingales
Bird watchers are being asked to count the number of nightingales spotted in Kent as the migrating birds return to the UK from Africa and southern Europe.
The Kent Ornithological Society (KOS) said the species had disappeared from many parts of the UK and Kent was one of its last strongholds.
In the last census run by KOS in 1999, bird watchers spotted 1,212 singing nightingales in the county.
Nightingales arrive in April and sing until late May and early June.
They leave again from July to September.
A KOS spokesman said volunteers were needed to take part in a new survey that would start in April.
Each volunteer takes responsibility for an area of land and makes two morning visits when the nightingales are arriving, and then two night visits while the birds are singing, if any are found.
All singing males are then plotted on maps provided by the society.
He said KOS was also organising a series of events across Kent in May so people could hear nightingales sing.
He said: "Although Kent is a stronghold of nightingales in Britain, many people may have never heard their legendary song.
"The KOS is organising a series of events across the county in May to give people a chance to hear the melodic song of the nightingale before it is too late."
The events will be organised after the nightingales have established their territories for this year's breeding season, he added.
Figures from the RSPB said the UK was estimated to have 6,700 pairs breeding annually, with the highest densities to be found in Essex, Suffolk, Norfolk, Kent and Sussex.
When nightingales sing, they can be heard throughout the day as well as at night, the RSPB said.
The bird charity described their "famous song" as a fast succession of high, low and rich notes that few other species could match.
Source: BBC News