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Family : CHELIDAE
Species : Chelodina mccordi
Maximum carapace length : 19.7 cm (MCZ 176730).
Chelodina mccordi,
or 'Roti Island Snake-necked Turtle', is one of the world's rarest freshwater turtles. This
relatively small species was first described by A.G. Rhodin in 1994,
after a study of historical specimens from the island of Roti (or 'Rote')
in eastern Indonesia.
Between 2003 and 2006, reports and sightings of the presence of
closely-related turtles on the larger, neighbouring island of Timor began to
draw the attention of researchers (Kuchling et al, 2007; McCord et al, 2007): specimens were
acquired, and then
formally described and named.
As of 2020,
Reptile Database recognise two subspecies of this rare turtle: i) Chelodina mccordi mccordi
which occurs
in 2 lakes
on Roti Island, Indonesia and ii) Chelodina mccordi
timorensis in Lake Ira Lalalo, Timor-Leste (formerly East Timor, which
was once part of Indonesia).
The climate of both Roti and Timor is classified as 'tropical savannah'.
Lakes and other waterbodies, such as rice paddies, which support this turtle
are typically seasonal, shrinking in area during dry periods.
For example, Google Earth images of Lake Ira Lalalo on Timor-Leste show that
this elongated waterbody shrinks
from 15 km in length during wet periods to less than 3 km long during dry
periods. The lake is surrounded by waterlogged grassland and swamps, with
significant human impact.
Chelodina mccordi has a grey-brown, flattened, rounded
carapace and an extremely long neck (which can be twisted to reach any part
of the turtle's body). Its head is elongated and somewhat flattened, and its
nostrils are small and dorsally located. There are rounded tubercles on the
neck, and the iris is white.
When withdrawing into their shells, snake-necked turtles must twist
their necks laterally (Fig. 3), however one side of the neck remains
vulnerable to predators.
Thus, rather than employing a defensive strategy, these turtles may twist
their neck backwards to bite potential attackers. Potential predators in
Lake Ira Lalalo may include the
Estuarine Crocodile Crocodylus porosus. There is a sizable
population of this crocodile in the lake (Kaiser et al, 2011).
Some species of Chelodina are fish-eaters, however the diet and
detailed ecology of Chelodina mccordi appears unstudied.
Shown here are images of an example from Lake Ira Lalalo photographed during the first herpetological survey of Timor-Leste in
2004-2009. The turtle was for offered for sale to surveyors by a local resident but,
rightly, was not purchased (Kaiser et al, 2011).
Chelodina mccordi is at risk from over-exploitation - locally it is
eaten and is used in cultural practices, and is also under pressure from the
international pet trade.
Within the combined region of Southeast Asia and New Guinea, Chelodina mccordi is the westernmost example of the genus.
Four other species of Chelodina occur in southern and western New Guinea, and
additional species occur in Australia.
Figs 1 and 2 : Example of Chelodina mccordi timorensis, from Lake Ira
Lalalo, Timor-Leste (elevation 300 metres).
Fig 3 : Front view, showing how the head and neck are twisted and
withdrawn sideways into the shell for protection.
Fig 4 : Typical human-impacted habitat at the margins of Lake Ira
Lalalo, comprising flooded grassland dotted with occasional trees.
All photos thanks to Hinrich Kaiser.
References :
Kaiser H, Carvalho VL, Ceballos J, Freed P, Heacox S, Lester B, Richards SJ, Trainor CR, Sanchez C, O’Shea M (2011) The herpetofauna of
Timor-Leste: a first report. ZooKeys 109: 19–86. doi:
10.3897/zookeys.109.1439
Kuchling G, Rhodin AGJ, Ibarrondo BR, Trainor CR (2007) A new subspecies
of the snakeneck turtle Chelodina mccordi from Timor-Leste (East
Timor) (Testudines: Chelidae). Chelonian Conservation Biology 6:
213–222.
McCord WP, Joseph-Ouni M, Hagen C. (2007) A new species of Chelodina
(Testudines: Chelidae) from eastern Timor Island (East Timor). Reptilia
(GB) 52: 53–57
Rhodin, AG. (1994). Chelid turtles of the Australasian Archipelago: II.
A new species of Chelodina from Roti Island, Indonesia. Breviora
(498): 1-31
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