Males of this genus of lizards use their bright colours and head bobbing to proclaim their territory, taking residence on exposed perches (5). From these vantage points, the males typically use behavioural displays involving spasmodic push-up actions to attract females. A receptive female usually responds to a displaying male by nodding her head and, on his approach, arches her back to facilitate his grasp (5) (6).
Receptive female Agama lizards are characterised by pronounced, swollen abdomens as a result of egg production. During mating, the male holds the female’s body off the ground using one front foot and one hind leg, before inserting one of two penises into her cloaca for fertilisation. Although little specific information is available on the breeding behaviour of the spiny agama, clutch sizes in the genus tend to be relatively small (5). Once spiny agamas have dispersed from the site in which they were born, individuals tend to remain in their new home range for the remainder of their lives (7).
Male colouration determines social rank within the spiny agama’s small social groups. The bright head colour of breeding males is generally only acquired by dominant individuals. Subordinate males tend to occupy the outer regions of established territories, while dominant males are more frequently found at the centre. Dominant males use aggressive behaviour to defend their territory, but only direct aggression towards other males displaying bright colours (6).
The spiny agama is active during the daytime and feeds mainly on insects, such as ants. However, it also eats some vegetation and soft fruits of Capparis species (2) (5). Like other lizards of this genus, the spiny agama is largely a sit-and-wait predator, relying on its eyesight to locate and attack insect prey (8).
Internal temperature regulation is possible in lizards in the Agamidae family. By metabolically producing and distributing heat around the body, they are able to reach their optimum body temperature more quickly (7).