Lizards, Skinks and Geckos
Lizards, Skinks and Geckos
Lizards, Skinks and Geckos Notes
All species are ‘Red List 2020’ assessed as ‘Least Concern’, except for the ‘Endangered’ Otago Skink. Most lay eggs (oviparous), as do most other reptiles. Apart from the nocturnal house gecko, the other featured species are diurnal. They vary in size and weight from small geckos measuring only a few centimetres to the large monitor lizards up to 2 m and weighing 20 kg.
Water Monitors are the second-largest semiaquatic lizard species which grow to around three metres in length. Their habitat includes forest, shrubland, wetlands, rural gardens, and urban areas. They are sometimes known as the Malayan Water Monitor found in South Asia and South-East Asia. They scavenge and hunt, eating anything smaller than themselves.
Clouded Monitors are medium-sized which can grow to around one and a half metres in length. They are native to South East Asia, Java and Sumatra. Habitat includes scrubland to rainforest often encountered while digging for food amongst leaf litter or high up in tree canopy.
Water monitor nostrils are at the tip of its snout while clouded monitors nostrils are midway between its eyes and the end of its nose.
Common Wall Lizard has a European distribution. It prefers open, sunny areas with little vegetation and often seen near old houses and old stone walls.
Skinks are lizards that belong to a large family with around 1500 species. They have smooth scaled skin, small legs, mostly diurnal and are generally carnivorous, feeding on insects. They vary in size; small skinks have a snout-to-vent length up to 7 cm, and medium-sized skinks over 8 cm, including the tail, length doubles, or triples.
Many-lined Sun Skink is medium-sized; its habitat is secondary forest often seen on the forest floor.
Greater Windward Skink photographed in a heavily degraded secondary forest on Trinidad. Data on this species is sparse.
Seychelles Skink is a medium-sized endemic found in various habitats such as urban gardens, forest, shrubland and plantations.
Eastern Shingleback Lizard is a short-tailed, slow-moving species of blue-tongued skink. The name shingleback refers to the only subspecies native to eastern Australia. This subspecies endemic occupies semi-arid areas of eastern and South Australia.
Bauxite Rainbow-skink an Australian endemic found in savanna, grassland and rocky areas of northern Australia.
Major Skink distribution includes coastal eastern Australia, Fraser Island and Papua New Guinea. Habitat includes rainforest, heathlands, woodlands and rocky outcrops.
Otago Skink distribution is in upland Otago and a small area near Wanaka. I photographed this re-introduced species at the Orokonui Ecosanctuary in Otago. The skinks are within an enclosure in the sanctuary, surrounded by a predator-proof fence projecting this rare skink and other endangered species. The New Zealand Department of Conservation lists this skink as ‘Nationally Critically Endangered’. They feed on a wide variety of insects and fruits.
Whiptail (Ameivas and Tegus) Lizards
Gold Tegu photographed in Trinidad, where it is locally known as a tiger lizard. It inhabits tropical forest and is native to middle and South America. A medium-sized lizard, males are larger than females; they feed on insects, invertebrates, mammals, reptiles, birds, fish and sometimes fruit.
Giant Ameiva often forages on the ground for food such as insects and fruit. Resident in South America, including Trinidad. Habitat includes savanna, grassland, and rainforest.
Nocturnal and Day Geckos
Common House Gecko is a nocturnal insectivore often seen in urban areas and houses at night, mainly near artificial lights. Its distribution is worldwide in tropical zones. Other habitats include forest, savanna, rocky regions, desert, and plantations.
Blue-tail Day Gecko is endemic to Mauritius, a widespread diurnal species found in warm, humid areas amongst trees and bushes.
Upland Forest Day Gecko is another diurnal Mauritian endemic mainly found in upland areas but confined to Black River Gorges National Park.
Water Monitor Photo Essay
Water Monitor Photo Essay Notes
On a visit to Sungei Buloh in 2016, I was fortunate to witness and photograph a couple of large males fighting in the pond near the Wetland Centre. I have selected five images from the wrestling match. When I started photographing them, one had drawn blood, so the fight was in full swing. One seemed unscathed and eventually pined the other down before chasing the bloodied one off into the mangrove swamp. My photographic encounter lasted about seven minutes, but the fight must have been much longer as I was late to the scene.
The next two sequences show a sizeable old adult scavenging for food; it found a dead fish in the undergrowth. And a youngish individual, catching and dispatching a large Asian Toad (Duttaphrynus melanostictus). The toad was bleeding from the neck profusely as it bites and batters it to death.
The remaining three images show a juvenile with a long-forked tongue and young individuals swimming and climbing trees.
Lizard Behaviour Notes
Clouded monitors are good tree climbers. The images show a youngster and an adult climbing and descending, respectively. The other three photos display an adult finding and eating a worm while foraging in leaf litter.
Images of whiptail behaviour include the giant ameiva lizard foraging for fallen fruits and the gold tegu showing its forked and foraging.
Eastern shingleback lizards, also known as a stumpy lizard, belong to the genus Tiliqua (Blue-tongued Skinks) part of the Scincidae (Skinks) family. The first image depicts an individual showing its flat blue-tongue that I photographed at Mount Monster Conservation Park in South Australia. I also came across a pair of shinglebacks in the park. Male and female shinglebacks pair for life but spend about ten months foraging alone. Once a year, the same pair will come together to mate. Shinglebacks are opportunistic omnivore feeders, and the final image shows individual foraging on Granite Island that came across a flower blossom and stopping to eat it.
Lizard, Skink and Gecko Taxonomy
The Reptiles Photo Album webpage describes the higher-level taxonomy for the featured families placed in suborders Autarchoglossa (Skinks, Monitors, Tegu and Wall Lizards) and Gekkota (Geckos), both part of the order Squamata (Lizards, Skinks, Snakes).
The Lizards and Skinks displayed images that include species from three of the thirteen Autarchoglossa families:
(a) Varanidae (Monitor Lizards),
(b) Lacertidae (Wall Lizards),
(c) Scincidae (Skinks),
(d) Teiidae (Whiptails).
Geckos featured photos from the Gekkonidae family, one of the seven families placed in suborder Gekkota.