The warmest and sunniest spring on record this year has boosted the breeding of some of Britain's best-loved songbirds, data has shown.
A dry and warm spring has offered a glimmer of hope for critically endangered wild birds, scientists said. During the 2025 breeding season, May to August, breeding success was above average for 14 species, including the warbler, warbler, warbler, sooty, blue tit, great tit and robin.
During 2025, volunteer banders from the British Trust for Ornithology monitored 29 species of songbirds at specific sites as part of a project known as the Sustained Effort Site Scheme.
Participants trap the birds in the same location throughout the summer, allowing scientists to see how the numbers of adults and newly fledged chicks change over time and whether they survive better or worse than in previous decades.
Compared to the very wet spring of 2024, the 2025 breeding season saw above average success.
Dr Ellie Leach, banding program manager, said: “Thanks to the fantastic efforts of BTO banders, we know that the breeding success of 14 species in 2025 was above average, largely due to mild weather. This is welcome news.”
Leach said the contrast between the sunny, dry spring of 2025 and the constant rainfall of 2024 couldn't be starker. “[It] shows how important weather can be; This is especially true for young birds, which are less well isolated and less experienced at foraging in challenging environments.”
Migratory birds, including warblers, warblers, black caps, warblers and warblers, had above average breeding success. Nine species of native birds – coal tit, blue tit, great tit, Cetti's warbler, long-tailed tit, robin, hare, finch and goldfinch – saw a statistically significant increase in the number of breeders compared to the five-year average.
report says: “It is likely that all species benefited from mild and dry spring/summer weather, and continued good weather in the summer of 2025 increased the likelihood of second broods, leading to higher productivity.”
Despite higher average breeding success for 14 species, adult numbers of some of the world's best-loved songbirds are down this year, blamed on last year's poor breeding season.
Willow warbler and garden warbler numbers recorded in 2025 were the lowest on record.
Leach said the effects of climate change could make things worse for wild birds, with some species that are regularly monitored experiencing long-term declines in numbers.
British wild bird numbers continue to decline seriously. Most recent Red List of Protected BirdsThe list of threatened species includes beloved British birds such as the lark, starling, woodcock, house swallow, house sparrow and swift.
The majority of threatened species are farm birds, according to the RSPB, which says intensive farming methods, including the use of pesticides and fertilizers, are a major factor in the bird's decline.
