The Lesser Spotted Woodpecker is on the UK Birds of Conservation Concern Red List, having suffered declines in both numbers and range over many decades. It is therefore a high priority for conservation action, but its elusive nature makes it very difficult to detect and study. Without better information on Lesser Spotted Woodpecker ecology, it is hard to design and implement effective conservation measures to check and reverse its declines.

This study used passive acoustic monitoring to plug these knowledge gaps. Acoustic devices were deployed in Lesser Spotted Woodpecker habitat in southern England in the springs of 2024 and 2025. BTO acoustic experts developed a bespoke sound classifier to work within the BTO Acoustic Pipeline, enabling the automatic detection of drumming and calling of this species in more than 1,000 hours of recordings. In some cases, these devices successfully detected Lesser Spotted Woodpeckers at new sites, or in places where they had not been otherwise recorded for many years. This technique also readily detected the species at known sites, despite operating during periods of poor weather.

It is unlikely that these results suggest any improvement to the conservation status of Lesser Spotted Woodpeckers in Britain, but the population is probably larger and more widespread than previously thought. The paper concludes with recommendations for how to deploy acoustic monitoring as part of wider plan to understand the status of this enigmatic species. With a national survey under consideration and the upcoming Bird Atlas 2027–31 on the horizon, these insights are very timely.

Having declined massively in numbers and range in Britain over the last few decades, the Lesser Spotted Woodpecker Dryobates minor is a priority species for conservation action. However, its low numbers and infrequent drumming and calling mean it is an elusive species, making it a challenge to see, let alone monitor. In this paper we describe our trials of a novel approach to detecting the species – passive acoustic monitoring. This has proved highly successful in detecting Lesser Spotted Woodpeckers in trials at known sites in the New Forest, Hampshire. Subsequently, we have used the technique to successfully detect the species at many new sites across Hampshire, Sussex, Somerset and Kent, changing our perceptions of its numbers and distribution. For the first time, we have the makings of a practical method of monitoring Lesser Spotted Woodpecker numbers and distribution in Britain.