Methods 2012

Compiled by Petr Voří¹ek, Arco Van Strien, Willy Van Strien, Jana ©korpilová, Ian Burfield and Richard D. Gregory

What is new in 2012 data update?

  1. In 2012, the indices and trends for 148 common European species has been produced. This includes 3 new species compared to the last year (Alectoris rufa, Luscinia svecica svecica, Tetrao tetrix).
  2. Number of countries contributing to the PECBMS remain the same as in 2011; altogether 25 European countries have provided data in 2012.
  3. New national schemes within the country have been included in Germany: data has been newly combined from two national surveys - Häufige Brutvögel alt covering period 1989-2010 and Häufige Brutvögel neu covering period 2004-2010.
  4. New national schemes within the country have been included in Norway: data has been newly combined from three national schemes - Norsk Hekkefugltaksering, HFT covering period 1996-2008, Terrestrisk overvåking, TOV-I covering period 1996-2008, and Terrestrisk overvåking - Ekstensiv, TOV-E covering period 2006-2010.
  5. Data from Cyprus comes from two monitoring schemes: Volunteer Common Birds Census and Western Cyprus Common Bird Census; in Western Cyprus Common Bird Census data has been provided over the longer time period this time so both schemes now cover period 2006-2010.
  6. Data from Slovakia has not been updated and so cover period 2005-2009.
  7. Computation procedure as well as data quality control has not undergone any change, it has been kept consistent with last year data update.
  8. In the indicators´ presentation, we newly present the trend of each species included in the indicators, and the numbers of species in each indicator which are moderately or steeply declining, moderately or strongly increasing, stable and uncertain.

The methods that PECBMS uses to produce species population trends and indices and wild bird indicators have been described in several scientific papers. The internationally accepted standards according to which national monitoring schemes, being the data source for PECBMS, are organized, are available in textbooks and scientific papers. Also, the PECBMS Best Practice Guide (Voří¹ek et al., 2008) contains many information on methods. But as a consequence, the information on methods is scattered. On this web page we bring together all this information to facilitate the understanding of data collection, and analysis procedures. The text in Methods proceeds step by step, from national bird monitoring schemes to European multispecies bird indicators, and ends with a chapter on quality control performed at each step.

The most important questions that have been asked about PECBMS methods and interpretation of results are answered on a separate page: Questions and Answers.

Information on the aims & structure of PECBMS, the results, the use, some history and future plans is given on the page What is PECBMS?

Production of European population trends and indices and indicators: an overview.


1. National species indices and trends

1.1 Counting birds
Box Field methods
Box Detectability
Box Selection of sample plots
1.2 Production of national indices and trends
Box Missing values I
Box Trend interpretation and classification

2. Supranational species indices and trends

2.1. Delivery of national data to PECBMS coordination unit
Box Data checks
Box Participating countries
2.2. Combining national data into supranational outputs
Box Missing values II
2.3. Types of supranational results that PECBMS produces

3. Multispecies indicators

Box Geometric means - an example
Box Species selection and classification

4. Quality control

4.1. On the national level
4.2. At delivery to PECBMS
4.3. For supranational indices and trends
4.4. For multispecies indicators

5. References and further reading


Copyright © - EBCC 2004-2017 - All rights reserved