Added 1 January 2012. Last updated 3 June 2022 with raising of several subspecies of A. atricollis to species level, removal of A. a. loveridgei, addition of A. margaretae and removal of A. zonurus, and update of Bibliiography.
15 or so species distributed across Africa, Middle East and Asia. Characterised by lack of occipital scale and, in the males, large heavy heads. Originally these lizards were considered part of the Stellio genus, but later assigned to Acanthocercus.
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QUICK INDEX |
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A. adramitanus, Anderson's Rock Agama |
A. annectans, Eritrean Rock Agama |
A. atricollis, Blue-Headed Tree Agama |
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A. cyanocephalus, Falk's Blue-Headed Tree Agama |
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A. cyanogaster, Black-Necked Tree Agama |
A. guentherpetersi, Peters' Ridgeback Agama |
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A. kiwuensis, Kivu Blue-Headed Tree Agama |
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A. phillipsi, Philips' Ridgeback |
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Species Name |
Common Name |
Distribution |
Size |
Notes |
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Acanthocercus |
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Anderson's Rock Agama |
Oman, Yemen, SW Saudi Arabia |
SVL 15cm, TL >40 cm |
Considered by some authorities (including the EMBL database) to be simply a variant of A. cyanogaster. |
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Eritrean Rock Agama |
N & E Ethiopia, Eritrea, N Somalia, NE Kenya |
Avg TL 25-32 cm, tail about 60% TL; max TL 34cm |
Lives among rocks on hill and rock outcroppings in dry rocky savanna and semi-desert. In N Ethiopia, lives in loose colonies, and SHDA note that large males may share the same refuge. Insectivorous. Kenyan range limited to extreme north-east. Scalation details: dorsal scalation keeled, in 70-85 rows at midbody. Other: head triangular, neck narrow; eye large; cluster of small spiky scales above and below ear opening; body slightly flattened; tail base broad. Coloration: sexually dichromatic; males dorsally pink with extensive black markings and pink tail base that becomes deep blue, larger males may have broad pale or bluish vertebral stripe tapering towards tail; stress may turn back yellow and black; females green-grey with black dorsal speckling, mature females having two rust-red patches on upper surface of tail base. Reproduction: no details available [SOURCE: SHDA]. |
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Blue-Headed Tree Agama |
S & E Africa |
Max TL 37cm (m), avg TL 22-30cm, hatchlings 8cm |
Widespread across much of sub-Saharan Africa. Found in moist savanna, woodland and forest clearings, but also in wooded suburbs. In the barer terrain of Ethiopia they can be encountered in more open habitat provided that there is opportunity to shelter in holes or beneath rocks [Largen & Spawls]. These agamids become accustomed to human contact, but their preference for ants might make them difficult captives, although SHDA record that a wide range of insects and other arthropods are also taken. In 2018 a number of subspecies (gregorii, kiwuensis, minuta, ugandaensis) of A. atricollis were raised to full species by Wagner et al who also declared A. a. loveridgei to be a synonym of A. gregorii. Scalation: dorsal scalation small and keeled, in 100-136 scale rows at midbody; males have irregular rows of big spiky scales along the spine; tail resembles fir cone, with caudal scales large and coarse, each tail segment having 3-4 rings of scales; two rows of 10-12 preanal pores. Other: stocky build; adult males have very large, triangular and broad head with swollen cheeks; eye fairly large, ear opening larger than eye, eardrum visible; body squat; tail broad at base, especially in males, tail tapers smoothly. Coloration; adult males when displaying have bright blue or turquoise head and throat, broad green or turquoise vertebral stripe, and green or yellow tail, becoming blue as it tapers; females have grey heads with green speckling and blue patches, and grey-brown or grey dorsum with black marbling. Reproduction: in S Africa, incubation is 3 months. [SOURCE: SHDA] |
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Zambia |
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Described in 2012: see Reptile Database entry for details. Found in two valleys. |
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Angola |
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Described in 2022: see Reptile Database entry for details. |
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Falk's Blue-Headed Tree Agama |
Angola, N Namibia, NW Zambia, SE Democratic Republic of Congo |
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Formerly variously considered as Stellio angolensis or as a synonym of A. atricollis. See Reptile Database entry for details. |
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Black-Necked Tree Agama |
Ethiopia, Eritrea, Somalia, Kenya, Yemen |
Max TL 35cm (m), avg TL 20-30cm,tail about 60%, hatchlings 8cm |
Believed by some authorities to be part of A. atricollis. Widespread across much of sub-Saharan Africa. Found in moist savanna, woodland and forest clearings, but also quite dry savanna. Also inhabits rocky outcrops. Scalation: dorsal scalation small and keeled, in 100-136 scale rows at midbody; males have irregular rows of big spiky scales along the spine; tail resembles fir cone, with caudal scales large and coarse; two rows of 10-12 preanal pores. Other: stocky build; adult males have very large, triangular and broad head with swollen cheeks; eye fairly large, ear opening larger than eye, eardrum visible; body squat; tail broad at base, especially in males, tail tapers smoothly. Coloration; adult males when displaying have greenish-white, bright blue or turquoise head and throat, broad green or turquoise vertebral stripe, and green or yellow tail, becoming blue as it tapers; females duller, more brown and grey, often with indistinct rusty flank blotches and vertebral stripe of blotches. Reproduction: in S Africa, incubation is 3 months. [SOURCE: SHDA] |
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Kenya, Tanzania |
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Coastal regions only. |
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Peters' Ridgeback Agama |
Ethiopia |
SVL 7½-10cm (m), 7-8cm (f) |
Described by Largen & Spawls in 2006. Similar in description to A. philipsi but larger. Largen & Spawls describe specimens as living among rocks and boulders in areas of dry Acacia scrub and in at least one area living in close association with A. annectans. Scalation details: a few enlarged, keeled and mucronate scales on the flanks, widely dispersed or in weak and isolated transverse rows; posterodorsal face of thigh with a few large, keeled and mucronate scales irregularly arranged and intermingled with numerous smaller ones; caudal scale rows 20-29. Coloration: no details available. Reproduction: no details available. [SOURCE: Largen & Spawls] |
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Kivu Blue-Headed Tree Agama |
Congo |
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Found around Lake Kivu. Formerly considered subspecies of A. atricollis but raised to species level by Wagner et al. |
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Namibia, S Angola |
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First described in 2021: see Reptile Database entry for details. |
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Ethiopia, Kenya |
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Formerly considered subspecies of A. atricollis but raised to species level by Wagner et al. |
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Philips' Ridgeback Agama |
Ethiopia, Eritrea, NW Somalia |
SVL 6-8½cm (m), 5½-7cm (f) |
Scalation details: enlarged, keeled and mucronate scales in series of distinct transverse rows at mid-flank; posterodorsal face of thigh with a few large, regularly arranged scutes and clearly separated from numerous smaller ones below; caudal scale rows 16-21. Coloration: no details available. Reproduction: no details available. [SOURCE: Largen & Spawls] |
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NW Somalia, adj. Ethiopia, Eritrea |
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Considered synonymous with A. philipsii by Largen & Spawls. |
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Uganda Blue-Headed Tree Agama |
Uganda, Tanzania |
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Formerly considered subspecies of A. atricollis but raised to species level by Wagner et al. |
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N Yemen, Saudi Arabia |
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"Die Hadramautagame Acanthocercus adramitanus (ANDERSON, 1896) - Systematik, Biologie und Vermehrung im Terrarium", Petr Necas and Mirko Barts, Sauria, Berlin 1995, 16(1):3-9. Gives details of biology and captive reproduction of the species.
“Lifting the blue-headed veil – integrative taxonomy of the Acanthocercus atricollis species complex (Squamata: Agamidae)”, Philipp Wagner, Eli Greenbaum, Aaron M Bauer, Chifundera Kusamba and Adam D Leaché, Journal of Natural History, Volume 52, Issue 13-16, 2018.