A new study on the question “How many birds breed in Switzerland?” was published in Bird Study.
Nicolas Strebel, Hans Schmid, Marc Kéry, Thomas Sattler & Peter Knaus (2020): How many birds breed in Switzerland? An overview of the methods applied for estimating population sizes. Bird Study, DOI: 10.1080/00063657.2020.1732865
As part of the Swiss Breeding Bird Atlas 2013–2016, Swiss colleagues updated the national breeding population size estimates for all species. In this publication, they give an overview of the methods applied, illustrated with some examples. In the Appendix, they provide code and data that allows re-enacting most of the considered extrapolation methods 1:1.
In the report, Bestandsschaetzung der Brutvoegel in der Schweiz – Update 2013–2016 (in German), Nicolas Strebel and Peter Knaus summarise the methods applied for each species. We believe the report might be useful for others facing similar challenges.