Over the years, bird observation activity has fortunately increased. Nevertheless, even in Switzerland there are still many square kilometers that ornithologists rarely or never visit. With “Terra incognita,” we would like to encourage you to occasionally observe birds off the beaten track, away from the well-known ornithological hotspots.

Complete observation lists are of particular value: they provide data not only on rare species but also allow for a reliable assessment of the abundance and distribution of all species—even those that are less frequently reported. The more complete lists are submitted, the more precisely trends can be identified and conservation measures targeted. We therefore warmly invite you to venture into less-explored areas on your next outing and submit a complete observation list from there. Every list counts—and who knows, you might discover something completely unexpected!

Number of complete observation lists per km² (2012–2026) (Status as of February 4th, 2026)

Figure 1 | This zoomable map shows where complete observation lists have been recorded from 2012 to 2026. Dark blue squares mark areas from which hardly any complete lists have been submitted so far.

Observation activity: Number of visits per km² in the past 5 year. (Status as of January 29, 2026)

Figure 2 | This zoomable map illustrates the number of visits per square kilometer in the past five years (2021–2026). Dark blue squares mark areas with little or no observation activity.