In 2023 HOS was commissioned by Forestry England to survey breeding Dartford Warblers in the New Forest. The area surveyed was primarily the New Forest Special Protection Area (SPA), including land managed by Forestry England, National Trust, Hampshire County Council and Wellow Parish Council. Some small inland heathland areas elsewhere within the New Forest National Park were also surveyed.
213 one kilometre squares were surveyed over the period April-June 2023 using the national methodology. These included all squares known to have suitable breeding habitat and/or where Dartford Warblers had been recorded in the preceding six years.
Analysis of data indicated a total of 544 Dartford Warbler breeding territories within the New Forest SPA and a further 27 territories outside of the SPA. This is the highest ever recorded in the New Forest SPA; twice as many as in 2014 when 268 territories were found and four times as many as in the last survey in 2018, when only 135 were found following unusually cold weather during February and March 2018.
A report covering the New Forest area was provided to Forestry England and can be found here.
HOS volunteers also surveyed Dartford Warblers at other Hampshire sites so that we could assess the county-wide population.
A record total of 893 territories was recorded, far more than the 228 territories found in 2018. Data from the Thames Basin Heaths and Wealden Heaths where annual surveys take place suggest that the peak count across Hampshire may have been in 2022 – in which case a total county population of over 1,000 pairs would have been possible.
A county-wide analysis was published in Hampshire Bird Report 2023.