THE SERENDIPITY GUIDE TO THE RAINFOREST – AGAMID LIZARDS
de Silva Wijeyeratne, G. (2003). The Serendipity Guide to the Rainforest – Agamid Lizards. Serendipity. November 2003. Page 8.
The Lizards of the Rainforest
Sri Lanka has 15 species of Agamid Lizards. In layman’s language, the Agamids are the type of lizards one sees in home gardens. These are relatively small reptiles, less than a foot long, from nose tip to the end of the tail. In contrast other four legged, lizard-like reptiles such as the Crocodiles and Water Monitors, are several feet long. Surprising though it may seem, the limbless snakes are more closey related to the garden lizards than the crocodiles which have a different evolutionary lineage.
Due to its long isolation from mainland Asia, 12 agamid lizards have evolved in Sri Lanka, which are endemic to the island. Some are spread out over a climatic zone such as the lowland wet zone as in the case of the Hump-nosed Lizard or the montane zone such as with the Black-lipped Lizard. Some species are confined to a small area such as Karu’s Lizard which is confined to the Eastern borders of Sinharaja and the Leaf-nosed Lizard which is found only in the Knuckles. The lizards shown below, are all endemic to Sri Lanka.
<Pix of Black-lipped Lizard>
The Black-lipped Lizard is the lizard you are likely to see on a walk to World’s End, in Horton Plains National Park. The lizard has also adapted to human presence, and the animal in the photograph is part of a small colony in the grounds of St Andrews Hotel in Nuwara Eliya. It is confined to the higher mountainous areas of Sri Lanka.
<Pix of Rhino-horn Lizard>
In the Descent of Man (1871), Charles Darwin carried illustrations of Rhino-horn Lizard. He speculated that the ‘horn’ found in the male, was a sexual signal of what biologists also now describe as a signal of ‘fitness’. Even today, with little behavioral studies having been performed, we are not sure as to the exact function of the lizard’s horn. This lizard is also found in the highlands of the island.
<Earless Lizard or Kangaroo Lizard>
The name Kangaroo Lizard gives an insight into this animal’s ability to leap a distance, several times it body length. Imagine a human leaping a distance of 50 feet. This animal can perform the equivalent in terms of its body length. It is relatively common in wooded and forested areas of the wet zone and in riverine areas in the dry zone. It is often encountered sunning itself on a rock beside the trail or on the bark of a tree.
<Pix of Hump-nosed Lizard>
The Hump-nosed Lizard is a spectacular animal, when it is displaying with its gular sac (throat pouch) extended. The display may be to ward off a rival male or to warn a human intruder to keep its distance. This lizard is confined to rainforests in the wet zone lowlands. It is quite often seen on small trees. The next time you are in Galle, look for it in the Kottawa Rainforest Arboretum.
<pix of Rough-horned Lizard>
The Rough-horned Lizard is also an animal of the lowland rainforests. It is very small, only a few inches long, and easily overlooked in the leaf litter. I was fortunate to have Hasantha Lokugamage (Basha) to spot this lizard for me, as it lay concealed on the forest floor.
The Serendipity Guide to the Rainforest is prepared by Gehan de Silva Wijeyeratne. For information on Educational Rainforest Tours contact Amila Salgado on email@example.com. Images are (c) Gehan de Silva Wijeyeratne, Fuji 100.