With its oversized tail, pink markings and tiny spherical body the long-tailed tit is sometimes said to resemble a fluffy flying lollipop.
The birds migrate to Britain in October but have become elusive in recent years because of harsh winters which have left them struggling to find food.
But the mild conditions before Christmas led to a surge in populations, and new figures show the tit is now one of the top ten most common birds in UK gardens.
Results from the annual RSPB Big Garden Bird watch reveal that numbers have risen by 44 per cent since last year making them now as common as robins and chaffinches.
The miniature birds, which weigh less than £1 coin, can be spotted by their pinkish breast markings, pink rings around their eyes and undulating flight pattern.
They are also one of the most sociable birds, so seeing one means there are many more nearby and they are often hear calling to each other with a ‘si-si-si-si-si’ chirp and will even help feed each other’s young if their own chicks die.
Small insect-eating birds like the long-tailed tit are particularly susceptible to snowy and frosty conditions which make their food hard to come by, so warmer winters improve their survival rates.
Dr Daniel Hayhow, RSPB Conservation Scientist, said: “The weather can have varied effects on different groups of birds in terms of behavior and habitats used.
“The increase in long-tailed tit sightings, along with other smaller garden birds, just goes to show that in the absence of very cold weather these species can survive the winter months in much great numbers.
“The warmer temperatures have made it easier to find food, like insects, which in previous colder winters would have been harder to come by because of frosts and snow.”
England and Wales saw the warmest ever winter this year with an average temperature of 44.6F (7C), beating a previous high of 44.2F 6.8C in 1868-69.
Other birds that have benefited from the clement weather include the gold crest, Britain’s smallest bird, and the coal tit which can be spotted by its distinctive black and white head.
Sightings of goldfinches and greenfinches also rose by more than 20 per cent since last year
The house sparrow remains the most common bird found in gardens, followed by the starling and blue tit.
However despite this boost in numbers for smaller birds, many of the larger species are struggling. Sightings of well-known species such as black birds and song thrushes have experienced another drop.
This decline continues a trend that has seen the number of both species visiting gardens decline by 38 and 89 per cent respectively since the first Bird watch in 1979.
Sightings of collared doves, jackdaws, magpies, pigeons, crows and wrens were all down from the previous year.
Ben Andrew, RSPB Wildlife Advisor, added: “A lot of our favorite garden birds are struggling and are in desperate need of our help.
“Gardens or outdoor spaces are an invaluable resource for many species – they can provide a safe habitat and enough food and water to survive – which are likely to have a significant effect on their populations.”