Источники
Ничего из этого мы не исследовали сами. Всё взято у учёных и фотографов, которые перечислены ниже, и мы благодарны каждому из них.
Taxonomy and occurrence data from GBIF (CC BY 4.0). Phylogeny from the Open Tree of Life. Identifiers and common names from Wikidata (CC0). Mammal traits from COMBINE — Soria et al. 2021, Ecology 102(6):e03344 (CC BY 4.0). Bird traits from AVONET — Tobias et al. 2022, Ecology Letters 25:581 (CC BY 4.0). Longevity data from AnAge, Human Ageing Genomic Resources — Tacutu et al. 2013, Nucleic Acids Research 41(D1):D1027 (CC BY 3.0). Reptile traits from ReptTraits — Oskyrko et al. 2024, Scientific Data 11:243 (CC BY 4.0). Amphibian traits from AmphiBIO — Oliveira et al. 2017, Scientific Data 4:170123 (CC BY 4.0). Fish traits from FishBase (CC BY-NC 4.0). Conservation status from the IUCN Red List of Threatened Species. Species descriptions adapted from Wikipedia (CC BY-SA 4.0).
If you reuse any of this data, please carry this block along with it.
Data sources
Every measurement on the site comes from one of these, and each animal’s page says which.
Textbook scaling rules
The Scaling lab and Scatter plot compare our own fitted lines with the classic size-scaling rules from the literature. Those come from:
- Kleiber (1932) — metabolic rate, the ¾ rule
- Lindstedt & Calder (1981) — biological time, the ¼ rule
- Jerison (1973) — brain size
- Damuth (1981) — population density
- Hirt et al. (2017) — top speed and the hump-shaped curve
Our lines are ordinary least-squares fits of log₁₀(trait) on log₁₀(body mass, kg), with 95% intervals from Student’s t distribution.
Licences with conditions
Three sources ask a little more than a name in the credits.
Species descriptions are adapted from Wikipedia under CC BY-SA 4.0. Share-alike means the licence travels with the text, so every profile names Wikipedia and links to the article it draws on. If you reuse a description from here, the same applies to you. The measurements come from the databases above, so none of them depend on Wikipedia.
Conservation categories come from the IUCN Red List, which asks to be acknowledged and does not allow commercial redistribution. Each category here is the one recorded on the species’ Wikidata entry, shown with a licence note. 1,402 of 1,698 animals on the site have one.
Every photo comes with its own licence, and each one shows its photographer, its licence and a link to the original. Of the 3,757 photos on the site, 2,067 are share-alike, so anything made from them has to carry the same licence. Photos whose licence forbids adaptation are not used.
This site is free and carries no advertising, which is what lets it use sources licensed for non-commercial use.
Licences last checked August 2026.