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Testudines · TestudinidaeEntry 8,852 of 21,572
Bolson tortoise, Gopherus flavomarginatus

Reptilia · Testudines

Gopherus flavomarginatusLegler, 1959

Bolson tortoise

Photograph by Mbtrap, CC BY-SA, via Wikimedia Commons

A ground-dwelling, nocturnal tortoise from the Nearctic region, reaching 46 cm across the shell.

Also called Mexican Gopher Tortoise.

Reptilia › Testudines › Testudinidae › Gopherus

Grows to
400mm
greatest recorded
Active
Nocturnal
Lives up to
15.8years
Lives
Terrestrial
Body length across Testudinidae

Longer than 69% of all tortoises anyone has measured.

69% of 45 species are smaller31% larger
99.8 mmthe whole family, smallest to largest1,200 mm

The bar is the rank itself: its length is the share of the family this animal exceeds. The chart below is the family’s real spread, on a logarithmic scale because body length here runs from 99.8 to 1,200 mm. The solid rule is this animal. Every bar is a count of real species, and nothing on this figure is estimated.

What is known

23 sourced facts, each taken from a named scientific dataset. How to read these.

Cited from a dataset unless a row is marked otherwise.

Standing in the world

Conservation status
Critically Endangered
Population trend
Decreasing

The animal itself

Colour on the back
Brown
Pattern on the back
Uniform
Pupil
Round
Venomous
No
Fangs
None
Longest recorded life
15.8years
Body temperature when active · measured in the wild
31°C88 °F

mean body temperature of active individuals in nature

Size

Length nose to tail · greatest recorded
400mm15.5 in

total length, tail included — Colston, Kulkarni, Jetz, and Pyron, 2020, BMC Evol. Biol., 20:81

Shell length, front to back · greatest recorded
460mm18 in

straight carapace length, measured in a line rather than over the curve

Body mass · greatestcomputed
10,956g24 lb

largely converted from length by allometry in the source

How it lives

Active
Nocturnal
Where it lives
Terrestrial
Habitat
Desert, Shrubland
Region
Nearctic
Highest it lives · above sea level
700m

Breeding

Reproduction
Oviparous
Average clutch
5.2eggs

Naming and history

Subspecies
No
Described by
Legler
Moved to another genus · since it was first described
No
Described in
1959

Keeping one

Bolson tortoise is assessed as Critically Endangered on the IUCN Red List. Species at risk in the wild are often covered by CITES and by national law, which decide what may be bought, sold, moved across a border or kept at all — and captive-bred and wild-caught animals are usually treated differently. Check the rules where you are before acquiring one. Nothing below is a judgement about keeping this species; it is what a published welfare standard says about space, and what the animal itself was measured doing.

12 ft 1 in × 6 ft(368 × 184 cm)

Minimum floor length × width, for one animal. Bigger is always better. The standard sets no height for turtles and tortoises.

The standard sizes this genus at 8 times carapace length, with the width half the resulting length.

For a third and fourth turtle the standard asks for at least 10% more floor area each, and 20% more from the fifth onwards.

Water depth is set against the animal's carapace width rather than its length, so no figure is given here. Dry-country tortoises need no water area, only occasional bathing; tortoises from wetter regions need a water dish.

Swiss law sets the same figure independently, which is why it is given with some confidence.

Gutachten über Mindestanforderungen an die Haltung von Reptilien (Sachverständigengruppe tierschutzgerechte Haltung von Terrarientieren), German Federal Ministry, 10 January 1997, section 5. The standard states these are recommendations rather than binding limits.

Swiss Tierschutzverordnung (TSchV), SR 455.1, Anhang 2, Tabelle 5 — legally binding minimum enclosure sizes, which give every land tortoise 8 × 4 body lengths for two animals.

From this animal’s own carapace length of 18 in (460 mm), at 8 times it — how this is worked out.

Active animals measured in the wild averaged 88 °F (31 °C).

Mean body temperature of active individuals measured in nature. A measurement of the animal, not a setting for a thermostat.

Feeding

765kJ per day

Worked out for an animal of 10,956 g, the heaviest recorded for Bolson tortoise — so it is the top of the range, not a figure for a particular animal. Weigh yours and the number will be lower.

An upper estimate, not a feeding target, and not veterinary advice. The equation covers only what an animal burns staying alive, so a growing, gravid or recovering animal needs more — and it was measured on wild animals, which move far more than one in an enclosure. Body condition and a vet who knows the species are what a feeding decision should rest on. Where this comes from.

What nobody knows

These are not gaps in our research. No scientific dataset records them for this species — and saying so is information you cannot get from a reference that simply leaves a field out.

  • — Still living
  • — Length snout to vent · greatest recorded
  • — Length snout to vent · adult female mean
  • — Length snout to vent · adult male mean
  • — Length snout to vent · adult mean
  • — Female length · mean, nose to tail
  • — Length nose to tail · adult male mean
  • — Length nose to tail · adult mean
  • — Largest female · snout to vent
  • — Largest male · snout to vent
  • — Largest female · shell length
  • — Largest male · shell length
  • — Hatchling length · snout to vent
  • — Hatchling length · nose to tail
  • — Largest juvenile · snout to vent
  • — Largest juvenile · shell length
  • — Egg length
  • — Egg width
  • — Body mass · a typical adult
  • — Body mass · adult female, mean
  • — Body mass at hatching
  • — Preferred body temperature · chosen in a laboratory gradient
  • — Diet
  • — Eats arthropods
  • — Eats vertebrates
  • — Eats plant matter
  • — How it hunts
  • — How the young develop
  • — Gestation or incubation
  • — Smallest clutch recorded
  • — Largest clutch recorded
  • — Mean clutch · smallest reported
  • — Mean clutch · largest reported
  • — Clutches in a year
  • — Clutches a year · fewest
  • — Clutches a year · most
  • — First breeds from · youngest recorded
  • — First breeds by · oldest recorded
  • — Hatchling length · smallest recorded
  • — Hatchling length · largest recorded
  • — Age at first breeding · female
  • — Mature from · youngest recorded
  • — Mature by · oldest recorded
  • — Size at maturity · smallest recorded
  • — Size at maturity · largest recorded
  • — Body temp in the wild · lowest mean recorded
  • — Body temp in the wild · highest mean recorded
  • — Limbs
  • — Sex decided by
  • — Status assessed · the year the Red List last looked
  • — Red List criteria
  • — Biome
  • — Active season · shortest recorded
  • — Active season · longest recorded
  • — Density · lowest recorded
  • — Density · highest recorded
  • — Home range · largest recorded
  • — Suborder
  • — Infraorder
  • — Type locality
  • — Active in
  • — Mainland or island
  • — Lowest it lives · above sea level
  • — Range size

Others in Testudinidae

Take this data

Everything on this page is available as data under CC BY 4.0 — use it freely, credit it, no permission needed.

This species as JSON · the whole dataset

Cite this page

The Reptile & Amphibian Encyclopedia (2026). Gopherus flavomarginatus. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/gopherus-flavomarginatus

@misc{gopherus_flavomarginatus_2026,
  title  = {Gopherus flavomarginatus},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/gopherus-flavomarginatus}
}

Sources

  1. Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
  2. Catalogue of Life (dataset 3LR), used under CC BY.
  3. Moura, M. R. et al. TetrapodTraits: a database of 33,281 tetrapod species. Used under CC BY 4.0. Observed values only; this encyclopedia does not publish its imputed predictions.