The lesser spotted woodpecker is the rarest – and smallest – of the UK’s three woodpecker species. It has also seen huge population declines over the past few decades. The reasons for their decline aren’t fully understood, but loss of open woodland habitat is likely to be an important factor.

They are difficult to monitor, as their small size and tendency to spend time high up in the woodland canopy make them a challenge to see. It is also thought that as they become less common, they are less likely to call and drum, making detection even more difficult. 

Because of this, confirming the woodpecker’s presence or absence on any given site is not always possible, and has relied on chance encounters.

In the past decade there have only been nine records of lesser spotted woodpeckers on BBOWT reserves. Moor Copse near Reading has had the most sightings, but all except one were before 2007, while the most recent record for Warburg Nature Reserve in South Oxfordshire was in 2013.   

The Woodpecker Network, an organisation dedicated to the study of UK woodpeckers, has developed a new technique to help: bioacoustic monitoring.

What did we do?

Using information from the Woodpecker Network, we placed acoustic monitors in four key BBOWT nature reserves where lesser spotted woodpeckers had been historically recorded, or where we had planned to manage trees affected by ash dieback. This took place during the breeding season, when they begin calling and drumming to attract mates - their drumming is similar to great spotted woodpeckers, but is longer and softer. 

These monitors recorded sounds from before sunrise and throughout the day, for at least five days. This allowed us to collect impressive amounts of data without making unreasonable requests of our fantastic volunteers!

The recordings were put through a system developed by the Woodpecker Network and the British Trust for Ornithology to detect the calls and drums of the woodpeckers. These were then manually checked by our ecology team – the automated system isn’t perfect and can occasionally mistake creaking trees for a woodpecker’s drumming.

What did we find?

Lesser spotted woodpeckers were heard in three of the four reserves: Bowdown Woods near Newbury, Finemere Wood near Aylesbury, and Parsonage Moor to the north-west of Abingdon.

The number of calls and drums varied among the reserves, with a total of 20 drums heard at Finemere Wood across all six days of recording, while only two drums were heard across two days at Parsonage Moor, out of a total eight days of recording there. However, as the drumming sounds from Parsonage Moor were quite distant, it is likely that they came from beyond the reserve boundaries.

This is the first time that lesser spotted woodpeckers have been heard from Parsonage Moor, demonstrating how important this new technique is to help us learn more about where this elusive and rare bird can be found.

The majority of all calls and drums were picked up before 7am, which is earlier than most of our volunteer bird surveys take place. Together with their rarity and elusive nature, enthusiastic birders would have a slim chance of actually spotting the woodpeckers, particularly outside of the breeding season!  

What's next?

Lesser spotted woodpeckers are often found in wet woodlands – though they are present in other woodland habitats - which are rich in insects and have plenty of dead wood for foraging and nesting. Knowing where populations are present helps us to measure the success of our woodland management work, including providing plenty of standing and fallen dead wood, and managing rides and woodland-edge habitats to encourage a diversity of insect life.

We will expand the surveys in 2027, starting earlier in the year and covering greater areas across more reserves. This will help us to piece together a full picture of where this elusive species is found, and how we can help it.

Much of the work we do to manage our reserves for wildlife is made possible thanks to the generosity of our members. 

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