NBMP annual report 2023: Worrying signs of change

Latest NBMP report on UK’s bat species shows nature can recover, given the right opportunity. But there are worrying signs of change which we need more data to understand.

To collect this data, we need more people to do a bat survey in their local areas.

The National Bat Monitoring Programme (NBMP) is an annual series of bat surveys undertaken by thousands of dedicated volunteers, which allow us to monitor changes in British bat populations.

Run by us in partnership with JNCC, NBMP has been running since 1997. The data we collect are used by the Government and conservation organisations to monitor the health of our environment, inform policy and improve the conservation of bats.

The latest NBMP report finds that out of the population trends for 11 of the UK's 17 breeding bat species, none have declined and five show encouraging signs of initial recovery from historical declines (prior to the 25 years since monitoring began).

However, for the first time NBMP data have been used to examine population trends over a shorter period of five years. And these trends are worrying, as they show that two iconic species may have started to decline. Over this shorter time scale, data from summer roosts show the brown long-eared bat has declined by 11.2% at the GB scale, while the lesser horseshoe bat has declined by 12.3% in England in contrast to a continued increase in Wales.

Short term 5-year trends for Natterer’s bat and common and soprano pipistrelle suggest that the increasing long-term trends have levelled off and are considered stable in the short term. The same pattern is exhibited by Natterer’s bat and common pipistrelle in England, Natterer’s bat in Wales and soprano pipistrelle in Scotland.

If you want to read the full NBMP report 2023, it can be downloaded on our website.

Kit Stoner (CEO of the Bat Conservation Trust): “I’d like to thank all the volunteers who have contributed data towards the National Bat Monitoring Programme report that was published today. Their efforts means that we can produce long-term trends for the 11 bat species we are able to monitor, and some of these species are showing early signs of recovery following historic declines. It is an encouraging sign that legal protection and conservation action are beginning to help their recovery. However, the short-trends over the last five years for some species are of concern and shows that we must remain vigilant.”

Firstly, the long-term results of the NBMP report are welcome news. But they must put in the context of huge historical declines in bats, the scale of which we are only now beginning to understand thanks to the use of genetic analysis. A paper published by the University of Exeter and BCT in 2023 showed that one species which remains endangered, the barbastelle, has declined by 99% over several hundred years.

Notably, in the UK we do not have many conservation stories with signs of recovery of species. As the State of Nature report 2023 recognised, some UK bat species are an exception to the decline of many wildlife species because they have benefitted from legal protection and conservation action. It is vital that current protections for bat species in the UK are maintained.

Secondly, we need to understand the worrying five year trends. And to do this we need more data.

We urgently need to understand what may be driving the short-term population changes. To do this the NBMP needs more people surveying their local bat species and joining our community of volunteer citizen scientists.

As such, we have designed a range of surveys, so that people with varied access to survey sites, technology or time can take part and collect valuable data. To find out more: Explore NBMP Surveys.