Database on the global elevational distribution of all the bird species of the world

Hummingbird on branch
Metallura baroni is a range-restricted hummingbird species, only occurring in the highlands of southern Ecuador. Here, it is normally found between 1900- and 4000-meters elevation. Photo: Jesper Sonne

Citation

Rahbek, C., Fjeldså, J., Hosner, P., Sonne, J., Hansen, L.A., 2023. Global database on the elevational distribution of all the bird species of the world, Center for Macroecology, Evolution and Climate. Globe Institute, University of Copenhagen, Denmark.

About the database 

The database contains information on the minimum and maximum elevational range for the more than 10,000 birds' breeding distribution in units of meters above sea level. The species range limits follow the global taxonomies provided by the International Ornithological Congress IOC v.10.2 (Gill and Dorsker 2020).

The database is assembled from primary sources, such as museum specimens, expedition reports, research papers, atlas projects, unpublished locality lists, and georeferenced records from xeno-canto.org.

We also considered personal observations from colleagues with field expertise within specific groups and geographic regions. We then closed the few remaining gaps in the database using information from the Handbook of Birds of the World. The information is gathered using 600+ sources.

See the complete list of references here: Download references

A species' elevational range might differ between countries and biogeographical regions, and species may have unusual elevation distribution in a tiny part of its range. To obtain a single value for each species' minimum and maximum elevation, we aimed to obtain samples representative of the species' entire geographic range. We ignored occasional and vagrant observations of species occurring far outside the species' normal elevational range.

For a few species with limited elevational information, mostly derived from singleton geographic records, we added a 100 m buffer on their minimum and maximum elevational range. Moreover, to avoid over-filtering birds distributed close to sea level, we assumed that birds with a minimum or maximum elevation below 100 meters above sea level could occupy all elevations ≤ 100 m.

The database has been used to adjust the species' geographic distributions mapped at a spatial resolution of 1 x 1 geographical degrees (Rahbek et al. 2012). The adjustment consists of removing grid cells with elevations falling outside the species' elevational range limits (see examples in Sonne et al. 2022a, Sonne et al. 2022b), thereby reducing errors of commission commonly found in generalized species ranges.

By stacking the species' ranges on top of each other, we also estimate a region's altitudinal pattern of species richness. These richness estimations should be interpreted with caution and acknowledge that the range limits are generalized from the species' entire distribution and, thus, may not be accurate for a specific region or mountain slope. Therefore, using this database to map species richness across elevations is best suited for areas dominated by range-restricted species (e.g., Sonne et al. 2022a).

References 

Gill, F., and D. Dorsker. 2020. IOC World Bird Lost (v.10.2).

Rahbek, C., L. Hansen, and J. Fjeldså. 2012. One degree resolution database of the global distribution of birds. Natural History Museum of Denmark, University of Copenhagen, Denmark.

Sonne, J., B. Dalsgaard, M. K. Borregaard, J. Kennedy, J. Fjeldså, and C. Rahbek. 2022a. Biodiversity cradles and museums segregating within hotspots of endemism. Proceedings of the Royal Society B: Biological Sciences 289:20221102.

Sonne, J., P. K. Maruyama, A. M. Martín González, C. Rahbek, J. Bascompte, and B. Dalsgaard. 2022b. Extinction, coextinction and colonization dynamics in plant–hummingbird networks under climate change. Nature Ecology & Evolution 6:720-729.

Contact

Professor Carsten Rahbek