Rhinoceros iguana

The rhinoceros iguana (Cyclura cornuta) is a native of the Caribbean, and in particular the islands of Hispaniola (Haiti and the Dominican Republic) and Puerto Rico.

It is a large animal, measuring up 1.2 metres (4 feet) in length. It is characterized by several enlarged raised scales on the snout that look like horns. Males are larger than females, with larger horns and crests.

Rhinoceros iguanas walk ponderously with the head held up, but can run at speed when threatened. It will also bite and thrash its tail to defend itself. It is highly territorial.

Food consists of leaves and fruits.

Females will lay anything from two to twenty eggs in a burrow, which will be closely guarded.

Habitat destruction is a threat to the species, as are predations from non-native animals including dogs, rats, pigs and mongooses.

© John Welford

Seduction, lizard style

Female lizards in California have shown that, when it comes to choosing a mate, what matters most is the property he owns rather than any other attribute he might possess!

The lizards in question are side-blotched lizards (Uta stansburiana) that, being cold-blooded, depend on the heat of the sun. They live on rocky outcrops and the most prized site for basking is a boulder that stays illuminated for as much of the day as possible and has crevices underneath it that offer a hiding place should a predator turn up as well as a place where a female can lay her eggs.

The best boulders are subject to intense competition among male lizards, and soon become the property of the alphas in any lizard community. They then get to breed with the most females, which is all to the good in terms of species survival.

However, experiments have been done that show that being an alpha male is not in itself the reason why females will gravitate in his direction. When top-rated boulders are taken away from an alpha and given to a much punier male, the latter suddenly becomes a lot more popular with the ladies, probably much to his surprise.

It would appear that it is not only human females who can be seduced by the best rock in the window!

© John Welford

Water monitor lizard

The water monitor is one of the largest lizards that ventures into salt water. It inhabits low-lying coasts, rivers and estuaries in south-east Asia, Indonesia and The Philippines.

It grows up to 2.7 metres (9 feet) in length and weighs up to 35 kg (75 lbs). It has a long neck, strong legs and a flattened tail that it lashes from side to side in the water.

The water monitor is a predator with a wide-ranging diet, feeding on anything that it can overpower, either onshore or in the water. In common with other monitors, the water monitor will also feed on carrion.

Water monitors are sometimes seen near human habitations, where they scavenge on discarded food waste.

The water monitor lays eggs which the female places at the end of a burrow.

© John Welford

Thorny devil

I’m not sure that I would really want to have this little fellow on my hand, but apparently they are quite harmless – to humans anyway!

The thorny devil (Moloch horridus) is native to the deserts of the western half of Australia. It is a lizard that measures 6 to 7 inches (15 to 18 centimetres) in length, and its buff and tan colouring, with darker brown markings, is a good reason why it is rarely seen against the similarly coloured desert floor.

However, if you were to tread on one when not wearing adequate footwear you would soon know about it, thanks to the spines that cover its entire body. The largest spines are on the head and body, with smaller ones on the legs and feet. These spines are entirely defensive, because the thorny devil spends most of its feeding time in one spot, scooping up ants and similar small insects with its long tongue – up to 2,500 at a single meal. This would leave it vulnerable to attack from above if it did not have the protection of its spines.

The thorny devil moves slowly, rocking backwards and forwards as it walks.

Female thorny devils lay between three and ten eggs in underground burrows.

© John Welford