Reptilia · Squamata
Trioceros jacksoniiBoulenger, 1896
Jackson’s chameleon
Photograph by Movingsaletoday edited by Muhammad, Public domain, via Wikimedia Commons
A tree-dwelling, day-active, meat-eating chameleon from the Afrotropic region, reaching 167 mm snout to vent.
Once published as Chamaeleo jacksonii — those names reach this page.
Reptilia › Squamata › Chamaeleonidae › Trioceros
- Grows to
- 167mm
- greatest recorded
- Eats
- Carnivorous
- Active
- Diurnal
- Lives up to
- 9years
Longer than 89% of all chameleons 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 18.2 to 300 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
45 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
- 2013
- Population trend
- Stable
The animal itself
- Limbs
- Four legs
- Venomous
- No
- Fangs
- None
- Longest recorded life
- 9years
- Preferred body temperature · chosen in a laboratory gradientmeasured
- 32.1°C
- Body temperature when active · measured in the wild
- 30.4°C87 °F
- Body temp in the wild · mean, when active
- 29.2–30.4°C85–87 °F
Carey and Judge 2000: 1, Slavens and Slavens 1999: 8 years, 2 months; Hughes 1988: 4 years 7 months, Necas 1999: 9 or more, Rogner 1997: 9, Measey et al. 2014: 6.6 for females in the field, LeBerre 2009: over 8 in captivity, Lin and Nelson 1980: 6.6 in nature
mean body temperature of active individuals in nature
body temperature of active animals in nature
Size
- Length snout to vent · greatest recorded
- 167mm6.5 in
- Length snout to vent · adult female mean
- 107.3mm4.25 in
- Largest female · snout to vent
- 107.3mm4.25 in
- Hatchling length · snout to vent
- 28.5mm1 in
- Largest juvenile · snout to vent
- 28.5mm1 in
- Body mass · greatestcomputed
- 84.78g3 oz
- Body mass · a typical adult
- 32.57g1.1 oz
- Body mass at hatchingmeasured
- 0.58g0.02 oz
max 167 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
- Carnivorous
- How it hunts
- Mixed
- Active
- Diurnal
- Where it lives
- Arboreal
- Habitat
- Forest
- Biome
- Tropical & Subtropical Grasslands, Savannas & Shrublands
- Active season · months of the year
- 12months
- Region
- Afrotropic
- Mainland or island
- Mainland
- Elevation · above sea level
- 1300–3200m
- Range size
- 31,172km²
invertebrates, small vertebrates and some plant material (Necas 1999)
mixed in an invasive population (Measey et al. 2014)
e.g., Spawls et al. 2018
1500-3200 (Kenya Reptile Atlas (http://kenyareptileatlas.com/), 1600-over 3000 (Spawls et al. 2018), 1600-3000 (Hughes and Blackburn 2019), 1300-3000 (Malonza and Bwong 2023)
Breeding
- Reproduction
- Viviparous
- Gestation or incubation
- 190days
- Average clutch
- 16.95eggs
- Eggs or young per clutch
- 5–57eggs
- Mean clutch
- 12.2–21.7eggs
- Clutches in a year
- 1.5per year
- Clutches a year
- 1–2per year
- First breeds at
- 6–22months
7-21, mean 12.2 in Hawaii (Goldberg and Kraus 2011), 29 (Van Wilgen and Richardson 2012), 11-40 (Loveridge 1920), 15-30 (LeBerre 2009), depends on subspecies, maxima 12-50 (Stipala 2014), to 28 (Branch 2014), 7-30, doubt a record of 52 (Kenya Reptile Atlas (http://kenyareptileatlas.com/), 7-50 (Spawls et al. 2018), 7-28 (Hughes et al. 2018), 7-52 (Hughes and Blackburn 2019)
Naming and history
- Suborder
- Sauria
- Infraorder
- Acrodontia
- Subspecies
- Trioceros jacksonii jacksonii (BOULENGER 1896) Trioceros jacksonii merumontanus (RAND 1958) Trioceros jacksonii xantholophus (EASON, FERGUSON & HEBRARD 1988)
- Described by
- Boulenger
- Moved to another genus · since it was first described
- Yes
- Described in
- 1896
- Type locality
- Kenya
Keeping one
2 ft 2 in × 16.5 in × 2 ft 2 in(67 × 42 × 67 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 6.5 in (167 mm), at 4 × 2.5 × 4 times it, following the German federal welfare standard — how this is worked out.
In a laboratory thermal gradient this species settled at 90 °F (32.1 °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.
10kJ per day
Worked out for an animal of 85 g, the heaviest recorded for Jackson’s chameleon — 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.
Morphs
0 with peer-reviewed genetics behind them, 2 resting on breeder consensus. Most references present both with the same confidence.
- Hornsbreeder consensus
Three forward-pointing horns on adult males. Females carry one small horn or none.
Worth knowing. The horns this species is known for belong to adult males; they are a sex difference rather than a variety, so an animal without them is a female rather than a different form.
- Subspecies and localitybreeder consensus
Adult size, horn length and how yellow or green the animal is, following the population it descends from. The yellow-crested form is the largest and the one most often kept.
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
- — Body mass · adult female, mean
- — Eats arthropods
- — Eats vertebrates
- — Eats plant matter
- — How the young develop
- — 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
- — Density · lowest recorded
- — Density · highest recorded
- — Home range · largest recorded
- — Active in
Others in Chamaeleonidae
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). Trioceros jacksonii. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/trioceros-jacksonii
@misc{trioceros_jacksonii_2026,
title = {Trioceros jacksonii},
author = {{The Reptile & Amphibian Encyclopedia}},
year = {2026},
url = {https://www.allanglescreatures.com/species/trioceros-jacksonii}
}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.