All Angles Creatures
Squamata · PhrynosomatidaeEntry 18,678 of 21,572
Fence Lizard, Sceloporus undulatus

Reptilia · Squamata

Sceloporus undulatusBosc & Daudin, 1801

Fence Lizard

Photograph by Connor Long, CC BY-SA, via iNaturalist

A ground-dwelling, day-active, meat-eating lizard from the Nearctic region, reaching 77 mm snout to vent.

Also called Eastern Fence Lizard, Mescalero Dunes Fence Lizard, Mescalero Prairie Lizard.

Once published as Sceloporus edbelli, Sceloporus elongatus — those names reach this page.

ReptiliaSquamataPhrynosomatidaeSceloporus

Grows to
77mm
greatest recorded
Eats
Carnivorous
Active
Diurnal
Lives up to
4years
Body length across Phrynosomatidae

Longer than only 38% of all species in Phrynosomatidae anyone has measured.

38% of 168 species are smaller62% larger
47 mmthe whole family, smallest to largest175 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 47 to 175 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

49 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

Still living
Extant
Conservation status
Least Concern
Status assessed · the year the Red List last looked
2007
Population trend
Stable

The animal itself

Limbs
Four legs
Venomous
No
Fangs
None
Longest recorded life
4years

Degenhardt et al. 1996: 4, see Alcala 1966, p216 citing Crenshaw (3 years); Slavens and Slavens 1999: 1 and 11 months

Preferred body temperature · chosen in a laboratory gradientmeasured
30.4–34.1°C87–93 °F
Body temperature when active · measured in the wild
32.45°C90 °F

mean body temperature of active individuals in nature

Body temp in the wild · mean, when active
27.9–37°C82–99 °F

body temperature of active animals in nature

Size

Length snout to vent · greatest recorded
77mm3 in

max 77 mm SVL (Feldman et al. 2016)

Length snout to vent · adult female mean
64.5mm2.5 in
Largest female · snout to vent
64.5mm2.5 in

snout-vent length; the source column mixes this with straight carapace length

Hatchling length · snout to vent
25.65mm1 in

max 91 mm SVL (Feldman et al. 2016)

Largest juvenile · snout to vent
24.5mm1 in
Body mass · greatestcomputed
15.67g0.55 oz

computed from length by a family-level allometric equation, not weighed

Body mass · a typical adult
8.26g0.29 oz

AnAge rates this record "low"

Body mass · adult female, meanmeasured
7g0.25 oz
Body mass at hatchingmeasured
0.55g0.02 oz

How it lives

Diet
Carnivorous

invertebrates and small lizards (e.g., Stebbins and McGinnis 2018) / arthropods only, Gibbs et al. 2007, Zimmerer et al. 2016

How it hunts
Sit and wait

e.g., Gibbs et al. 2007, Shenbrot et al. 1991, Mesquita et al. 2016

Active
Diurnal
Where it lives
Terrestrial
Habitat
Forest, Grassland, Rocky, Shrubland
Biome
Deserts & Xeric Shrublands
Active season · months of the year
6–12months
Region
Nearctic
Mainland or island
Mainland
Elevation · above sea level
30–3048m

0-3048 (Stebbins and McGinnis 2018)

Range size
148,982km²
Density
1–112.5per hectare
Home range · largest recorded
826m2

Breeding

Reproduction
Oviparous

Dominguez-Guerrero et al. 2022

Sex decided by
Genes, XX/XY
Average clutch
8.5eggs
Eggs or young per clutch
3–17eggs

6-13 (Gibbs et al. 2007), means 5.55-11.8 (Mesquita et al. 2016), means 5-6 (Hibbitts and Hibbitts 2015), 8 (Shaw 1952, n=1), 6-8, mean 7.33 (Minton 2004, n=3), 3-15, mean 8.02 (Jimenez-Arcos et al. 2017), 4-17 (Stebbins and McGinnis 2018), Lopez-Alcaide et al. 2020 (mean 9.1 citing Angilletta et al., 2001), Angilletta et al. 2001 (means 9.1, 8.4), 3-16 (Zimmerer et al. 2016), Dominguez-Guerrero et al. 2022 (mean 7.4), 5-15 (Phillips et al. 2022)

Mean clutch
4.26–14eggs
Clutches in a year
3per year
Clutches a year
1–5per year
First breeds at
9.5–24months
Age at first breeding · female
1095days

Naming and history

Suborder
Sauria
Infraorder
Pleurodonta
Subspecies
No
Described by
Bosc & Daudin
Moved to another genus · since it was first described
Yes
Described in
1801
Type locality
Mexico

Keeping one

12 in × 12 in × 7.5 in(31 × 31 × 19 cm)

Minimum length × width × height, for one animal. Bigger is always better.

The standard sizes ground-dwelling species at 4 × 4 × 2.5 times snout-vent length.

Mindestanforderungen an die Haltung von Reptilien (Sachverständigengutachten), German Federal Ministry for Nutrition, Agriculture and Forestry, Animal Welfare Division, 10 January 1997. The standard states these floor areas are recommendations rather than binding limits.

From this animal’s own snout-vent length of 3 in (77 mm), at 4 × 4 × 2.5 times it, following the German federal welfare standard — how this is worked out.

In a laboratory thermal gradient this species settled at 87–93 °F (30.4–34.1 °C).

Preferred body temperature, recorded in a laboratory gradient where the animal could choose freely. A measurement of the animal, not a setting for a thermostat.

Feeding

A prey item should be no wider than the space between the animal's eyes.

Widely used across reptile husbandry references. The stated reason is that the gap approximates the width of the throat, so wider prey is associated with impaction. This is established practice, not a measurement.

2kJ per day

Worked out for an animal of 16 g, the heaviest recorded for Fence Lizard — 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.

  • Length snout to vent · adult male mean
  • Length snout to vent · adult mean
  • Length nose to tail · greatest recorded
  • Female length · mean, nose to tail
  • Length nose to tail · adult male mean
  • Length nose to tail · adult mean
  • Largest male · snout to vent
  • Largest female · shell length
  • Largest male · shell length
  • Hatchling length · nose to tail
  • Largest juvenile · shell length
  • Egg length
  • Egg width
  • Eats arthropods
  • Eats vertebrates
  • Eats plant matter
  • How the young develop
  • Gestation or incubation
  • Hatchling length · smallest recorded
  • Hatchling length · largest recorded
  • Mature from · youngest recorded
  • Mature by · oldest recorded
  • Size at maturity · smallest recorded
  • Size at maturity · largest recorded
  • Colour on the back
  • Pattern on the back
  • Pupil
  • Red List criteria
  • Active in

Others in Phrynosomatidae

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). Sceloporus undulatus. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/sceloporus-undulatus

@misc{sceloporus_undulatus_2026,
  title  = {Sceloporus undulatus},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/sceloporus-undulatus}
}

Sources

  1. Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
  2. AnAge, Human Ageing Genomic Resources (de Magalhães et al.), used under CC BY 3.0.
  3. Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
  4. Catalogue of Life (dataset 3LR), used under CC BY.