Bumper year for UK 'hummingbird' sightings
Data from the British Trust for Ornithology (BTO) Garden BirdWatch survey, carried out by volunteers across the UK, show a fourfold increase in the number of gardens recording Hummingbird Hawk-moth in 2022, making it a record summer for the charismatic moth.
Hummingbird Hawk-moths are most regularly seen in the UK in July and August. These large, colourful insects are often mistaken for hummingbirds because of the way they hover over flowers and use their long tongues to drink the nectar. In July 2022, 5.2% of Garden BirdWatch gardens recorded a visit from Hummingbird Hawk-moth, compared to just 1.3% in a typical year, while the proportion rose to 7.5% in south-east England. In Scotland, where the species is much rarer, it was reported from 1.2% of gardens, more than three times the summer average.
BTO Garden BirdWatch participants have been seeing large numbers of Hummingbird Hawk-moths this summer (Gary Vause).
Hummingbird Hawk-moths are particularly fond of pink and purple flowers like Buddleia, Red Valerian and Viper's Bugloss. Watching these plants on warm, sunny days is the best way to spot one yourself – look out for a chunky moth with orange wing patches and a black-and-white rear end to its body.
The influx probably has its origins in the current long spell of warm, southerly winds that carry the moths north from their Mediterranean strongholds. There is also a possibility that rising temperatures mean a growing number are able to overwinter in the UK: in suitable conditions, Hummingbird Hawk-moths will spend the colder months tucked away in thick vegetation, a tree hollow or even a garden shed.
While most Hummingbird Hawk-moths recorded in the UK are thought to be visitors from overseas, a number do breed here, laying their bluish-green eggs on plants such as Cleavers ('sticky willy') and bedstraws. A single female can produce as many as 200 eggs, which grow into stripy green caterpillars up to 6 cm long.
Rob Jaques, BTO Garden BirdWatch Supporter Development Officer, said: "The striking appearance and unusual behaviour of Hummingbird Hawk-moth means the species attracts lots of attention from gardeners and nature lovers alike. Thanks to the citizen scientists who record these and other species in their gardens, BTO Garden BirdWatch is able to track the fortunes of the wildlife on our doorstep and learn how our green spaces can best support biodiversity.
"As climate change has an ever-more obvious impact on the species we see around us, the data our amazing volunteers collect has never been more valuable than it is today."
BTO Garden BirdWatch is free to join and a brilliant way to make a difference for science and conservation. Find out more at www.bto.org/gbw.