Monitoring Selected Species

Special surveys are required to collect data on colony breeders, birds that inhabit particular locations, or secretive species. The costs are often high, so many species can only be monitored on an irregular basis.


We monitor population trends and distribution in Switzerland of colony-nesting species, rare species, or species originally held in captivity.


Using species-specific criteria, the breeding populations (and sometime breeding success) of selected species are recorded in a database or in tables. The data are based on chance observations reported to our Information Service (rare breeding birds), group-specific forms (cormorant, gulls and terns, swifts, sand martin, jackdaw, rook), regional area reports and specific inquiries.


Breeding population numbers are used to calculate population trend indices, which in turn are incorporated into the Swiss Bird Index SBI. A synthesis documenting the breeding activities of the past year appears annually in the “Ornithologischer Beobachter”.

The standardised collection of breeding population numbers means we can rapidly produce overviews detailing the occurrence of rare breeding species in space and time. Population trends of endangered species that are dependent on support measures (i.e. the common tern) provide information on the efficacy of these measures. Finally, the dispersal of newly observed breeding species is documented.

Project management

Claudia Müller