The cuckoo has long heralded the start of spring. But is this still so? This year Springwatch investigates...
Missed something? Keep up to date with the cuckoo's story here.
Nothing heralds the arrival of spring more than the familiar and loud call of the cuckoo – 'cuc-coo, cuc-coo' – on its return from a winter in Africa. This event is laden with folklore from cuckoo days and fairs to the number of calls supposed to predict the number years before you marry, have children or die!
Most will have heard them but less will have seen this bird the size of a pigeon with long wings and tail. Surprisingly they are often mistaken for a kestrel or sparrowhawk due to the grey upperparts and barring below.
The cuckoo is also famous for laying its eggs in the nests of other birds. Once hatched, the chick throws out the other eggs and is then fed all the food brought back by the unsuspecting surrogate parents. The most common victims of the cuckoo are reedbed and farmland birds, notably the reed warbler, dunnock and meadow pipit.
By respectfully observing these iconic birds in their natural habitats.
How about joining your local RSPB group to find out more about, and help with the conservation of the cuckoo. You can also help the BTO record bird migration and distribution throughout the UK with BirdTrack.

A last look at our cuckoo chick - what a monster!
The enhanced version of the site requires the Flash 8 plugin (or higher) to be installed and JavaScript to be enabled on your browser. To find out how to install a Flash plugin, go to the WebWise Flash install guide.
Just why are cuckoo chicks so massive? It seems that the host parents just can't stop feeding them.

Another look into the reed warbler nest reveals just how big that cuckoo is.
The enhanced version of the site requires the Flash 8 plugin (or higher) to be installed and JavaScript to be enabled on your browser. To find out how to install a Flash plugin, go to the WebWise Flash install guide.
With a tip off from the BTO at Thetford, we were shown a reed warbler's nest into which a cuckoo had laid its egg. Watch this fascinating video to find out what happens.
Pensthorpe Nature Reserve & Gardens
Host of Springwatch 2009.
Your cuckoo pictures
Slideshow of your amazing cuckoo pictures in the Springwatch Flickr group.