The journey

Each arc joins the country where a bird was ringed with the Strait, where it was recovered. These are not hand-drawn routes: they are 3,940 recoveries of 134 species, and they all converge here.

3,940
ring recoveries: 134
species: 41
countries of origin

White Stork · Photograph: xulescu_g, CC BY-SA, via iNaturalist

The Strait connects with 41 countries

This is read by place rather than by species: where the funnel pulls from. 3,940 birds ringed in 41 countries were recovered here, and they belong to 134 species. Choose a country to see which species link it to the Strait.

Species ringed in Guinea

White Stork1

A country counts here when one of its ringed birds turned up in the area. The figures say where birds come from, not how many pass through: they also reflect where most ringing is done. There is no monthly breakdown because the origins come from the text of the guide entries, which gives country and number but no date; crossing that with the passage calendar to suggest a «in September it connects with» would be making it up.

Editorial series of ring recoveries; it is neither a random sample nor a measure of abundance: it reflects where most ringing takes place. The GBIF ringing dataset does not allow ringing and recovery to be paired, which is why it is not used here. Movebank GPS tracks (CC0) will be added in the next phase.

36 GPS-tagged storks that crossed the Strait

From the study “LifeTrack White Stork SW Germany (2013-2023)”: 92 storks tagged in south-west Germany, of which 36 passed through the Strait. One position per day. Choose one to follow it.

Positions in the Strait, month by month: when they actually cross. Outside this window the same birds are in Europe or the Sahel.

Speed

Movebank Data Repository, DOI 10.5441/001/1.ck04mn78_2, CC0 1.0. Drawn from 13,392,932 GPS positions read and reduced to one per day.

Everything that crosses has its hour

The Strait is not a place of constant passage but a calendar. Each group has its window, and in September the ones marked below coincide.

Representative species: European Honey Buzzard — peak passagepassage windowtodayPhoto: European Honey Buzzard, Alidz31, CC BY · Black Kite, Valentina Eggler, CC0 · Barn Swallow, Donald Davesne, CC BY · Northern Gannet, Brooke J., CC BY

Representative species: Black Kite — peak passagepassage windowtodayPhoto: European Honey Buzzard, Alidz31, CC BY · Black Kite, Valentina Eggler, CC0 · Barn Swallow, Donald Davesne, CC BY · Northern Gannet, Brooke J., CC BY

Bibliographic source, pending comparison with Fundación Migres

See the routes