How this is put together

What the markers mean

Measured

Somebody weighed the animal, or recorded the figure directly from it.

Computed

Worked out from a different measurement. A body mass calculated from a length is not a weight, and this is the commonest of the three — most animals have never been weighed.

Cited

Taken as published by a named dataset, which took it from the literature.

Where enclosure sizes come from

Every enclosure figure is computed from the animal’s own recorded length using Mindestanforderungen an die Haltung von Reptilien, the expert report to the German Federal Ministry’s animal welfare division, 1997. It sizes ground-dwelling lizards at 4 × 4 × 2.5 times snout-vent length, climbing species at 4 × 2.5 × 4, and snakes as a fraction of total length. The standard states these are recommendations rather than binding limits, and it is worth repeating that they are a floor rather than a target.

Where the feeding figure comes from, and what it does not cover

Nagy, K.A. (2005), Field metabolic rate and body size, measured daily energy expenditure across 55 reptile species. Body mass alone explains 94.5% of the variation, which is why an energy figure can be given at all.

It covers only what an animal burns staying alive. Nagy states that food for growth and breeding is not included, so a growing animal needs more than the figure shown. And the animals measured were wild. One in an enclosure moves far less, so the figure is an upper estimate rather than a target.

Turning energy into a number of insects needs two things nobody publishes: the energy in a gram of each feeder, and what one of them weighs. Both are being measured. Until they exist the pages say so rather than estimating.

The sources

Catalogue of Life CC BY

The list of species itself, and the names — including the old ones, so a name nobody uses any more still reaches the right page.

SquamBase (Meiri 2024) CC0

Traits for 11,744 lizards and snakes: size, diet, activity, reproduction, and preferred body temperature.

ReptTraits (Oskyrko et al. 2024) CC BY 4.0

All 12,060 reptiles including turtles and crocodilians, which SquamBase leaves out.

AmphiBIO (Oliveira et al. 2017) CC BY 4.0

6,776 amphibians. Thinner than the reptile data, and the pages say so.

OMIA, University of Sydney cite on use

Morph genetics with the papers behind them — the gene, and the studies that found it.

GBIF Backbone Taxonomy CC BY 4.0

Common names for 8,756 species that Catalogue of Life has none for.

What we do not publish

• Species with too little recorded. 3,698 of them. They keep their addresses and say plainly that there is not enough yet, but they are not listed and not submitted to search engines. A stub presented as an entry is a promise we cannot keep.
• Anything a model wrote. The opening line on each page is assembled from stored facts; a clause we do not hold is simply absent.
• Care advice we cannot source. Where nobody has recorded a preferred temperature, the page says nothing rather than repeating a figure from another care sheet that got it from a third.