Broughton, R.K.; Maziarz, M.; Hinsley, S.A. (2020). Marsh Tit (Poecile palustris) territory surveys in English woods during 2002-2020. NERC Environmental Information Data Centre. (Dataset). https://doi.org/10.5285/8d1b93d7-b8cf-4df1-9a5d-352dc16c5195
The dataset records the annual number of occupied Marsh Tit breeding territories in 74 individual woods and woodland patches in 14 English counties for variable periods between 2002 and 2020. Different woods were surveyed from between one spring period and for up to 17 annual springs. Territory counts were derived from a standard highly-repeatable survey methodology or from more intensive population studies that produced high quality results. Marsh Tits are a small (10 g) songbird that are specialists of mature deciduous and mixed woodlands and have undergone a substantial population decline in Britain over recent decades. Because of their large territories, Marsh Tits are difficult to monitor by passive surveys, and so these specific and more accurate methodologies were used. This data can be used to compare with other woods using the same or a comparable methodology, investigate population trends or population-habitat relationships, or to monitor population change in future repeat surveys of the same woods. The data is georeferenced and each of the 237 individual records provides the Great Britain Ordnance Survey (OSGB) National Grid x and y coordinates of the surveyed wood, and also the woodland area surveyed, name and location (county name) of the wood, year of survey, woodland type and survey method.
Surveys took place in early spring (February to April) just prior to nesting and represent the number of breeding territories in each wood. Woods were surveyed for between 1 and 17 consecutive years from 2002 to 2020. A playback survey method was the primary method used, see Broughton et al. (2018) for full details. Some woods were also surveyed with colour-ringing during detailed population projects, involving intensive marking and re-sighting/recapture, see Broughton et al. (2010) for this methodology.
Almost all surveys involved the entire woodland patch, but two large woods were only partially surveyed. These are indicated in the dataset. The territory counts for each wood are considered to be very reliable. The playback methodology was quality control tested (details in Broughton et al. 2018) and found to locate a mean 96% of birds present with a consistent estimate of territory numbers, although underestimates of approximately 10% may occur for larger woods (>70 ha).
Other useful information regarding this dataset:
Broughton, R.K., Hill, R.A., Bellamy, P.E., Hinsley, S.A. (2010) Dispersal, ranging and settling behaviour of Marsh Tits Poecile palustris in a fragmented landscape in lowland England. Bird Study 57, 458-472.
Broughton, R.K., Dadam, D., Maziarz, M., Bellamy, P.E., Hinsley, S.A. (2018) An efficient survey method for estimating populations of Marsh Tits Poecile palustris, a low density woodland passerine. Bird Study 65, 299-305.