Project partners

British Trust for Ornithology logo
RSPB logo

Project partners

British Trust for Ornithology logo
RSPB logo

Woodcock survey results

Woodcock Survey 2023 summary results

Survey coverage and preliminary results produced by project partners GWCT:

This survey represents the third large-scale survey of breeding Woodcock (2003, 2013, 2023) and has been the biggest and most comprehensive yet. In total, 1343 1-km squares have been surveyed across Britain and Northern Ireland in 2023, including:

  • 1230 randomly selected 1-km squares. Only random squares are used to estimate population size as this avoids biasing the sample towards more favourable areas. In 2013, our population estimate was based on 829 randomly selected squares.

  • 139 randomly selected Scottish squares, a stronghold for Woodcock but typically difficult to cover owing to the remoteness of some sites.

  • 37 Northern Irish squares, the first time enough Northern Irish squares have been covered to produce a population estimate for the country.

  • 394 squares where Woodcock were detected. Of these, 96.4% received the required minimum of three visits.

Tab 1. Survey participation and Woodcock count summary comparison with 2013 national survey

Estimating population size

A ‘maximum count’ i.e. the highest count of the 3 visits, to estimate the number of males present at each site. This is done using a purpose-designed calibration equation. (Roughly, 3-5 registrations = 2 males, 6-8 reg = 3 males, 9-12 = 4 males, 17-21 reg = 6 males etc.)

Each survey site belongs to one of 48 ‘strata’. The strata are based on 12 custom regions (below) and 4 subcategories based on wooded area (4 x 12 = 48). For each stratum, we work out the proportion of surveyed squares that were occupied by Woodcock and, for those that were occupied, the average number of males.

These statistics can be used to produce an estimate of the number of male Woodcock occupying each stratum (i.e. by ‘scaling up’ based on the % occupied, the average number of males, and the total number of squares in each stratum).

Once a population estimate for each stratum is calculated, these are summed to create regional and national estimates. We can understand population change by comparing these with the results of the 2003 and 2013 surveys which followed a similar methodology.

Tab 2. 2023 survey coverage based on the 12 Woodcock survey regions. The regions are based on the distribution of surveyors and woodland, to try to encourage representative and even cover.

Fig 2.  Proportion of Woodcock squares occupied by region in 2023 (n = 1230 random squares).

Full results, including national and regional population estimates will be published in due course (est. spring 2024) and will be made available via the Woodcock Survey webpage.

Annual roding counts: 2003-2022

Thanks to a growing group of dedicated volunteers, we now have good data on the number of roding Woodcock for up to 200 sites across 24 counties since 2003.

The initial results (PDF, 390.23 KB), up to 2013, showed that counts were relatively stable until 2008. The number of roding males then declined steadily until 2015. In 2016 there was a substantial increase, giving the highest counts since 2008 – but numbers then reduced in 2017, stabilised, and declined again in 2020. In 2021 and again in 2022, numbers increased slightly, but the overall trend is for declne. 

Read the results for 2022 (PDF, 648.95 KB)

Woodcock annual trend 2003 - 2022

It is possible that weather has an influence on annual fluctuations in Woodcock numbers.

  • Heavy rain and low temperatures in April and early May might result in higher chick mortality.
  • In winter, low temperatures and lying snow will reduce food accessibility and could increase Woodcock mortality.

Given the general declining trend, which may involve factors in addition to weather, it is essential that we continue to count at least 100 sites per year in order to monitor future change more closely. 

2013 Survey Results and Publications

Over 800 randomly selected sites were surveyed in 2013, which has resulted in two papers being published using the data collected. 

Changes in population size and distribution

The first paper examines the change in population size and distribution in 2013.

Breeding abundance, habitat and landscape

The second paper examines the influence of habitat and landscape upon breeding abundance.

 Migration tracking results

GWCT have undertaken a fascinating Woodcock tracking project which has revealed some incredible journeys.  A total of 59 individuals were tagged at sites throughout Britain since the 2011/12 winter and their migration tracks show the routes taken to reach their distant breeding sites.  Breeding locations include Scandinavia and western Russia but one had travelled deep into central Russia.  You can view maps of varied return journies for each years of the tracking work.



Related content