The latest National Bat Monitoring Programme (NBMP) annual report is now available, providing population trends for 11 of Great Britain's 17 breeding bat species up to the year 2024. The latest results highlights both progress and emerging concerns for UK bat species, underlining the importance of continued protection and monitoring.
Run by Bat Conservation Trust in partnership with JNCC, the NBMP has been gathering data since 1997. The data collected are used by the government and conservation organisations to monitor the health of our environment, inform policy and improve the conservation of bats. While there are long-term signs of recovery for several species following large historic declines, short-term trends suggest new pressures may be emerging.
Long-term monitoring shows that five bat species in Great Britain – Greater Horseshoe Bat, Lesser Horseshoe Bat, Natterer’s Bat, Common Pipistrelle and Soprano Pipistrelle - have increased since 1999. The remaining six species have remained stable. Bat populations had initially been in decline since the early 20th century or earlier as a result of factors including agricultural intensification, habitat loss and persecution. But since the 1990s, some populations have increased, coinciding with conservation measures and protective legislation.
However, recent short-term trends suggest fewer increases and some emerging declines, particularly in specific regions. The data are collected by a mixture of roost counts during the summer at the breeding colony, hibernation surveys during the winter, field surveys and waterway surveys (for the water-loving Daubenton’s Bat).
Roosts counts across Great Britain show that Brown Long-eared Bat has declined significantly over the last five years with a particularly significant decline seen in Wales. At the country level, regional differences are emerging. Out of 25 combinations of species and survey types, only hibernation surveys of Greater and Lesser Horseshoe Bats in Wales show significant increases in both the long- and short-term. Ten trends are stable across both timeframes.
In contrast, 12 cases show a slowing or reversal in trend when comparing short-term with long-term results. In most of these, a previously increasing population now appears stable, but three cases show a significant decline in the short term.
While these short-term changes may reflect natural population fluctuations, the fact that these less positive results are widespread across species could indicate emerging pressures on bat populations. This highlights the need for continued monitoring and research to guide conservation efforts for these slow-reproducing and ecologically important species. As indicator species, bats help reflect the broader health of our ecosystems — meaning changes in their populations can signal wider environmental shifts.
The National Bat Monitoring Programme is just one of JNCC’s 11 schemes that monitor species throughout the UK. These monitoring schemes provide the evidence base that underpins effective conservation action. They are critical to helping us understand how nature is faring and whether policies impacting conservation are being successful. These insights on the impact of policies on species, combined with other monitoring data, will also enable us to project the likely impact of conservation polices and their effectiveness.
We are hugely grateful to the volunteers whose efforts make this work possible. If you want to support the future of bat conservation, you can take part in NBMP surveys – there's a survey for everyone.
You can download the full 2024 NBMP report from the Bat Conservation Trust website.
The annual report is underpinned by the Official Statistics which have also been published today on the JNCC website.