Credits & licences

All media on this site come from Wikimedia Commons and carry a free licence. The tables below give the author, the licence and a link to the source page for each file. Many recordings were originally made by volunteers of xeno-canto, the open archive of bird sounds.

Photographs

Recordings

Arrangement and sequence

The arrangement and sequence of orders, families, genera and species follow AviList, the unified global checklist of the birds maintained jointly by the major checklists. Above the level of the order stand clades: those follow the family-level genome tree of the B10K project and carry names from the PhyloCode.

• AviList v2025b
• Stiller et al. 2024, Nature 629, 851–860 (B10K)

Texts

The texts on this site were written for this guide. Factual data on measurements, distribution and status draw on standard field guides and the IUCN Red List.

Habitat photographs

Classification: EUNIS Habitat Classification (European Environment Agency), the A–J version. The English names are those of EUNIS; the Dutch and Spanish names were translated for this guide.

Typeface

The running text is set in IBM Plex Sans, the headings in Cormorant Garamond and the small labels in IBM Plex Mono — the typefaces of vorstman.com. Only the title of each page is set in Antonio, a narrow, tall grotesque in the spirit of the classic field guide covers. All four are under the SIL Open Font License 1.1 and are served from this site itself, so no request goes to an outside server.