Coordinators of national monitoring schemes deliver their national data to the PECBMS coordination unit annually. For information on data and contributing countries, see Box Participating countries.
The data delivered are the national yearly indices per species, the all-sites yearly Time totals (= the sum of birds counted across all sites per year), their standard errors, and the covariance between the yearly figures.
The outputs that national coordinators deliver to the PECBMS unit differ according to the program used for the calculation of national data. Specifically, if national coordinators use an old version of TRIM in Delphi or the software BirdSTATs, they deliver two files per species – so-called .out and .ocv files (see the paper by Pannekoek & Van Strien, 2001, or also see the website of Statistics Netherlands) – both produced by TRIM when calculating species indices at the national level.
If coordinators use TRIM in R modified for PECBMS called RTRIM-shell, they deliver three files – so-called _arg_output.csv, _indices_TT.csv and _ocv.csv tables– all produced by RTRIM-shell when calculating species indices at the national level.
Coordinators deliver all the files via an Online tool specifically created for PECBMS needs. The Online tool enables coordinators to check the data by using predefined criteria and to check the consistency with previous datasets. They can also add a comment to each species indicating any potential problems in the data. These comments are taken into account in further data analysis.
National data are checked for their quality using quantitative criteria (see Box Data checks).