Reptilia · Squamata
Acanthocercus atricollisSmith, 1849
Blue-throated Agama
Photograph by Sunčana Bradley, CC BY, via iNaturalist
A tree-dwelling, day-active, omnivorous lizard from the Afrotropic region, reaching 171 mm snout to vent.
Also called Black-necked (Ridgeback) agama, Blue-headed tree agama, Southern Tree Agama.
Once published as Agama atricollis, Laudakia atricollis — those names reach this page.
Reptilia › Squamata › Agamidae › Acanthocercus
- Grows to
- 171mm
- greatest recorded
- Eats
- Omnivorous
- Active
- Diurnal
- Lives up to
- 10.9years
Longer than 92% of all agamids anyone has measured.
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 32 to 418 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
43 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
- 2019
- Population trend
- Stable
The animal itself
- Limbs
- Four legs
- Venomous
- No
- Fangs
- None
- Longest recorded life
- 10.9years
- Body temperature when active · measured in the wild
- 39.85°C104 °F
- Body temp in the wild · mean, when active
- 39.4–40.3°C103–105 °F
De Magalhaes & Costa 2009, Slavens and Slavens 1999, over 6 in TAU zoo (Hughes 1988); TAU museum records: 10 years and 11 months
mean body temperature of active individuals in nature
body temperature of active animals in nature
Size
- Length snout to vent · greatest recorded
- 171mm6.75 in
- Length snout to vent · adult female mean
- 113.9mm4.5 in
- Largest female · snout to vent
- 113.9mm4.5 in
- Hatchling length · snout to vent
- 34mm1.25 in
- Largest juvenile · snout to vent
- 34mm1.25 in
- Body mass · greatestcomputed
- 176.8g6.2 oz
- Body mass · a typical adult
- 81.5g2.9 oz
- Body mass · adult female, meanmeasured
- 31.96g1.1 oz
- Body mass at hatchingmeasured
- 1.1g0.04 oz
max 171 mm SVL (Feldman et al. 2016)
snout-vent length; the source column mixes this with straight carapace length
computed from length by a family-level allometric equation, not weighed
AnAge rates this record "acceptable"
How it lives
- Diet
- Omnivorous
- How it hunts
- Sit and wait
- Active
- Diurnal
- Where it lives
- Arboreal
- Habitat
- Savanna
- Biome
- Tropical & Subtropical Grasslands, Savannas & Shrublands
- Region
- Afrotropic
- Mainland or island
- Mainland
- Highest it lives · above sea level
- 3000m
- Range size
- 6,072,000km²
Arthropods (beatles, flying insects "and even small vertebrates", Branch 2005, see also Haagner et al. 2000), mostly ants and termites ( Pienaar 1966), insects (Wagner et al. 2018), arthropods, mostly ants, hymenopterans and beetles, plants in 25% of stomachs
(e.g., Butler 2005), mixed (van Huyssteen 2023)
e.g., Spawls et al. 2018, van Huyssteen 2023, Pietersen et al. 2021; but "has also been mentioned as exhibiting some nocturnal activity", Wagner et al. 2018, Pietersen et al. 2021
(e.g., Spawls et al. 2018, Tan et al. 2020, Pietersen et al. 2021, see also Wagner et al. 2018, van Huyssteen 2023), also somewhat Saxicolous and Terrestrial
0-2000 (Kenya Reptile Atlas (http://kenyareptileatlas.com/), 0-2400 (Spawls et al. 2018)
Breeding
- Reproduction
- Oviparous
- Average clutch
- 11.36eggs
- Eggs or young per clutch
- 1–17eggs
- Mean clutch
- 11.4eggs
- Clutches in a year
- 1per year
- Clutches a year
- 1per year
- First breeds at
- 18months
10 (Loveridge 1920), 8-15 (Zoffer 1996), 4-15 (Kenya Reptile Atlas (http://kenyareptileatlas.com/, Spawls et al. 2018), 5-14 (Schleicher 2015), 4-14 (Branch 2016), 4-16 (Pietersen et al. 2021)
Naming and history
- Suborder
- Sauria
- Infraorder
- Acrodontia
- Subspecies
- No
- Described by
- Smith
- Moved to another genus · since it was first described
- Yes
- Described in
- 1849
- Type locality
- South Africa
Keeping one
2 ft 3 in × 17 in × 2 ft 3 in(68 × 43 × 68 cm)
Minimum length × width × height, for one animal. Bigger is always better.
The standard sizes climbing species at 4 × 2.5 × 4 times snout-vent length.
Lives in vegetation, so height and climbing structure matter more than floor space.
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 6.75 in (171 mm), at 4 × 2.5 × 4 times it, following the German federal welfare standard — how this is worked out.
Active animals measured in the wild averaged 104 °F (39.8 °C).
Mean body temperature of active individuals measured in nature. 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.
20kJ per day
Worked out for an animal of 177 g, the heaviest recorded for Blue-throated Agama — 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
- — Preferred body temperature · chosen in a laboratory gradient
- — Eats arthropods
- — Eats vertebrates
- — Eats plant matter
- — How the young develop
- — Gestation or incubation
- — 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
- — Colour on the back
- — Pattern on the back
- — Pupil
- — Sex decided by
- — Red List criteria
- — Active season · shortest recorded
- — Active season · longest recorded
- — Density · lowest recorded
- — Density · highest recorded
- — Home range · largest recorded
- — Active in
- — Lowest it lives · above sea level
Others in Agamidae
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). Acanthocercus atricollis. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/acanthocercus-atricollis
@misc{acanthocercus_atricollis_2026,
title = {Acanthocercus atricollis},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/acanthocercus-atricollis}
}Sources
- Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
- Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
- Catalogue of Life (dataset 3LR), used under CC BY.
- AnAge, Human Ageing Genomic Resources (de Magalhães et al.), used under CC BY 3.0.