Data checks

After uploading the data in the PECBMS Online tool, national coordinators are invited to check the data on species numbers, indices, time totals and trends for errors in calculation, weak and suspicious data. National indices and time totals – species by species – are also checked for their inter-annual consistency (comparison with previous trends and indices). All suspicious data and inexplicable inconsistencies should be explained, therefore the coordinators of national monitoring schemes are asked to add a comment explaining the situation. National coordinators also recommend to use/not to use the data of a specific species for further calculation. After all the controls, national coordinators validate the dataset and the PECBMS coordination unit is automatically informed about the data delivery.

The PECBMS coordinators check the national data again, mainly focusing on control for the consistency of indices and time totals with previous dataset. If necessary, all weaknesses and inconsistencies are consulted with national coordinators. After the control and consultation procedure is finished, the PECBMS coordinators finally approve the data delivery.

Additionally, documentation from previous data analysis is checked and used for decisions in some cases. Data with persistent serious data problems are excluded from the computation.

Suspicious data – national species data are subject to closer examination when:

  • Slope (Multiplicative) < 0.6
  • Slope (Multiplicative) > 1.5
  • Slope (Multiplicative) standard errors > 0.5
  • Percentage of scheme time totals of the species > 95% of the national population size of the species in the European Red List of Birds (BirdLife International 2021)
  • The ratio of national population size to scheme time totals > maximum of species population size in the European Red List of Birds (BirdLife International 2021)
  • Number of zero counts < 1
  • Number of missing counts < 1
  • Index value < 0.5
  • Index value > 1000
  • Scheme time totals < 1
  • Scheme time totals > 1000000
  • More than one year with index = 100 and SE = 0 present in the results
  • Indices and/or time totals are inconsistent with previous dataset.