Tawny owls are making a comeback, wildlife experts hope after a baby was spotted in the Royal parks for the first time in more than a decade.

The last official survey carried out in 2005 estimated there were around 50,000 tawny owls across Britain but experts said evidence suggested numbers had fallen by 30 per cent.

Concern peaked last September when the British Trust for Ornithology (BTO) took the step of issuing an appeal for people to dedicate 20 minutes a week to listen out for the owl's “twit-twoo” call.

The unusual move came amid growing fears the hoot could be lost for good with light pollution and urbanisation credited as driving the demise.

However, the species is now said to be flourishing across London's Royal Parks.

On Tuesday, gardeners found a baby owl perched on a tractor in St James's Park, marking the first discovery of its kind in the grounds in 12 years.