There was bad news for the cuckoo in a recent survey by Avon Wildlife Trust asking staff, supporters and West Country wildlife personalities to explain what convinces them that spring has begun.

Most agreed "a little bird" tells them, but none echoed Shakespeare, William Wordsworth or letter-writers to The Times in crediting the cuckoo as the signal.

Their favourite feathered herald of spring is the chiffchaff followed by great tits and skylarks.

"It's ironic," says Pat Ellingham, who carried out the survey for the Bristol-based conservation charity.

"The cuckoo is notorious for pushing other birds out of the way, but it seems it's getting pushed out itself now. From our results, the cheeky, cheery song that gives chiffchaffs their name is the sign of spring that many West Country wildlife-lovers wait for."

The poll was held after recent debate about the official start of springtime. Pat explains: "For centuries, the accepted date has been the vernal equinox of March 20/21, but the Met Office prefers March 1, while others pick the weekend when the clocks go forward. So we thought we'd ask people with first-hand knowledge of seasonal change to let us know what they go by."

Among the people questioned for the poll were Helen Gilks who runs Bristol's international acclaimed Nature Picture Library, broadcaster and book editor Rosamund Kidman Cox, Tim Martin, editor of the BBC's longest-running series Natural World, Tim McGrath of the Wildfowl & Wetlands Trust at Slimbridge, and Harriet Nimmo, chief executive of the Wildscreen Trust, the charity behind the Wildscreen film festival and the online "Noah's ark" ARKive.

Here's the trust poll top five with hints on where to find them:

Small, olive green warbler that can be heard calling "chiff chaff" in most local lowlands, including parks and fields. Tim Martin of the BBC Natural History Unit sums up their appeal: "I know spring is finally here when I walk through the Long Ashton golf course behind my house and hear the first chiffchaffs singing out their repetitive call from among the elder and willow bushes. Once you know their call you can't miss them – they seem to sing and sing all day long. I'm glad they're so loud and proud. Like spring itself, their song is an irrepressible force."

Britain's largest tit is easy to recognise with its bright green, yellow, black and white colouring. It's a woodland bird but also visits parks and gardens. Pat Ellingham says: "A sure sign of spring is when its 'teacher, teacher' pleadings come through my office windows from Brandon Hill in central Bristol."

Skylark song is also popular above farm fields, including those near Easton-in-Gordano and Failand.

As winter ends, woodland clearings and waysides fill up with yellow, mauve and white wildflowers. Sarah van der Meer, Avon Wildlife Trust's volunteering officer, says: "My proof of spring comes from our reserve at Burledge Hill overlooking Chew Valley Lake and the Mendips. Our volunteers have greatly improved the public footpath, giving the chance to pass primroses, early violets and lesser celandines as you make your way through the site – a beautiful place to see spring awaken."

Several Avon Wildlife Trust members say spring starts when frogspawn wriggles, to the excitement of children. One said: "My 10-year-old and his friends will sit and watch it for ages. They're absolutely fascinated to see new life begins."

Most garden ponds will have wriggling spawn by now, or visit the big ponds at Avon Wildlife Trust's Willsbridge Mill reserve between Bath and Bristol or at Folly Farm, Bishop Sutton.

Sniffing the air is the best way to locate the spiky white flowers of wild garlic. It gives off a strong garlicky-onion scent. The plant is edible and, so long as only a few are picked and roots aren't disturbed, adds bushcraft flavour to a picnic. Avon Wildlife Trust's Angela Davies says: "I know that spring is finally here when I visit the Priors Wood reserve near Portbury and pick up the wild garlic smell."

For directions to nature reserves mentioned here plus details of Avon Wildlife Trust walks, talks and events, visit www.avonwildlifetrust.org.uk or call 0117 917 7270. For information about the sites and activities of neighbouring wildlife trusts, visit www.swwt.org.uk