Crocodiles, Turtles and Tortoises

A single gallery displays images of saltwater crocodiles from Order Crocodilia together with turtles and tortoises placed in Order Testudines that I photographed in their natural habits. See Taxonomy note at the end of this page.

Crocodiles, Turtles and Tortoises

Crocodile Notes

Saltwater Crocodiles are ‘Red List 2020’ assessed as ‘Least Concern’. Distribution is in the tropical regions from India to northern Australia. Habitat includes brackish and freshwater rivers, estuaries, swamps, lagoons and billabongs, they can tolerate high salinity seawater. They eat fish, birds and mammals, and grow to 8 m.

The first image is a female saltwater (estuarine) crocodile hauled out on a bank in Yellow Water region of the Kakadu National Park. Yellow Water is part of the South Alligator River floodplain about 80 km from the north coast.

The other two crocodile photos are juveniles hauled out at the Buloh Besar River. The youngest juvenile was resting on a large tree trunk in the river. I estimate from focus distance and image in frame to be around 0.5 m. There is a small population, possibly as many as ten individuals, which inhabit Sungei Buloh Wetland Reserve, Kranji Reservoir and other Singapore rivers.

Turtle Notes

I photographed three of the seven extant marine turtle species in coastal waters or on the beaches of tropical islands where females come ashore to nest. The ‘Red List 2020’ assessment of the hawksbill is ‘Critically Endangered’, green turtle is ‘Endangered’ and leatherback is ‘Vulnerable’.

Hawksbill Turtle is one of my favourite reptile species. In Seychelles, the females come ashore during daylight hours to lay their eggs. They occupy all tropical oceans where they feed on toxic sponges.

Green Turtle I photographed several individuals from a zodiac and on the beaches on five Galápagos Islands. Some of my most memorable sightings were females visiting the beach to nest, individuals swimming and pairs mating. The locations included Punta Cormorant on Floreana, Playa Dorada and Sullivan Bay near Bartolome, the lagoon at Elizabeth Bay on Isabela, and Punta Vicente Roca on Isabela.

Leatherback Sea Turtle They are the largest turtle species, around 130 cm to 180 cm and weigh from 300 kg to 600 kg. Their diet is soft-bodied animals almost exclusively jellyfish. They have a worldwide distribution. Females nest on sandy tropical beaches at night.

The final images are species of snapping turtle and a slider (terrapins):

(a) Saw-shelled Turtle is an Australian endemic. It has not been ‘Red List 2020’ assessed but the IUCN/SCC (Species Survival Commission) Tortoise and Freshwater Turtle Specialist Group (TFTSG) draft assessment is ‘Least Concern’.

(b) Red-eared Slider [Terrapin] is a North American species introduced to South East Asia that I photographed in Singapore. It is known locally as a red-eared terrapin and characterised a successful invasive species.

Tortoise Notes

There are eleven endemic species of Galápagos Giant Tortoise, about half are ‘Red List 2020’ assessed as ‘Critically Endangered’, the others are ‘Endangered’ or ‘Vulnerable’. There are two tortoise breeding centres that rear young turtles in captivity and then release into the wild at around 5 years of age. Visitors are only likely to see the three-wild dome-shelled species that I photographed.

‘Critically Endangered’ Santa Cruz Giant Tortoise at Rancho El Manzanillo in the western highlands. The ranch hosts the second largest population of the western species which is also the second-largest dome-shaped giant tortoise in the Galápagos.

‘Endangered’ San Cristóbal Giant Tortoise in the grounds at Galapaguera de Cerro Colorado Tortoise reserve and breeding grounds and education centre which is important to guarantee the long-term future of this species. The image is a young non-breeding individual roaming in the reserve.

‘Vulnerable’ Volcán Alcedo Giant Tortoise is one of five species found on Isabella island.

Crocodile, Turtle and Tortoise Taxonomy

The Reptiles Photo Album webpage describes the higher-level taxonomy for the featured families placed in order Testudines (Turtles, Terrapins, Tortoises) and order Crocodilia (Crocodiles).

(1) Crocodiles feature species from one family: Crocodylidae (Crocodiles).

(2) Turtles, Terrapins and Tortoises feature species from five families:
(a) Cheloniidae (Sea Turtles),
(b) Dermochelyidae (Leatherback Sea Turtle),
(c) Chelydridae (Snapping Turtles),
(d) Emydidae (Sliders),
(e) Testudinidae (Tortoises).