There’s “impressive”, then there’s “very impressive”, then there’s our Tree Agamas – Acanthocercus atricollis – here at Pamuzinda. They fall under the sub-order Iguania which includes Iguanas and Chameleons and are of the Family Agamidae These are very large Lizards up to about 15inches snout to tail-tip. There are upwards of a dozen species in Africa and I have photographed several others as far East as Iran. The ones to be found here on some of the specimen trees dotting the Lodge lawn area are semi arboreal and diurnal which makes them a photographers delight as they are not afraid to be on parade in full daylight, conveniently spread eagled on a low tree branch in reach of even the shortest of camera lenses.
If you spot a male and he is looking at you and bobbing his head up and down then beware because he is chatting you up as head bobbing is an integral part of courtship behaviour. They are insectivorous and their prey species comprise mainly Orthopterans (Grass Hoppers and Bush Crickets), flying insects, beetles and ants.
The males in particular have retained the features of their prehistoric ancestors and I can imagine no worse nightmare than being confronted by a Jurassic sized version of one of these.
The males have much larger heads than the females, developed, no doubt, in response to their aggressive and territorial nature when they frequently engage in what almost amounts to armed combat with competing males. They tend to live in small colonies with each dominant male surrounded by a number of submissive females, each of which can lay 10 or more eggs, and younger subordinate males.

Despite the gaudy blue headed and mixed yellow to orange body colours they adopt during the breeding season I was surprised to see the first male I tried to photograph virtually disappear as he climbed a tree. It does not seem to be well documented but they obviously possess the ability to change colour to blend with the background, much as does a Chameleon.
Whether this is a voluntary or automatic change and whether it is a response to some form of stress or threat I do not know but I would hate to think that my presence was seen as a threat. In fact a word of warning to all would be Lizard photographers is to the effect that many species of Lizard can shed their tails if they come under a threat such as you trying to get too close. There is the almost Old Wives Tale that if you pick a Lizard up by the tail it will come off in your hand and this is often true. What many do not realise, however, is that a Lizard will often voluntarily shed its tail even when just pursued or threatened. The tail end then wriggles madly for several minutes and the idea is that if you are a hungry predator you will take time out to eat the tail while the rest of the creature makes good it’s escape. It is also true that they can then regrow the shed tail but the new one never looks as handsome as the original and is always an obvious “add-on”.