‘Hatchlings usually emerge under cover of
darkness, and immediately head for the water.’
of 30 o C producing equal numbers of both sexes,
whereas higher temperatures will result in a
predominance of females, and lower temperatures
produce more males. The hatchlings emerge after
about 80 days, usually under cover of darkness,
and immediately head for the water, which they
recognise by reflections of light from the surface.
Adult Loggerhead Turtles occasionally fall victim to
large sharks an d Killer Whales, but their sheer size
makes predation events rare (although nesting
females are in a far more perilous predicament once
exposed on land). Adults have a reputation for
being somewhat snappy, and will often engage both
conspecifics and
other turtle
species with their
formidable jaws,
which are
routinely used to
crush hard-
shelled prey such as conchs. They will present the
full face of their shell to potential predators as a
shield and then use superior manoeuvrability to
seize opportunities to counterattack with their fear-
some bite.
The few that survive this maelstrom will orientate
themselves perpendicularly to the waves and
continue to swim for many hours until they are far
offshore. Juveniles will often utilise the protection
afforded by mats of floating Sargassum algae,
which they share with many other organisms. They
will drift in this pelagic environment until about 45cm
in size, whereupon they migrate to coastal waters.
The combination of a prolonged generation time,
coupled with low natural recruitment and total
reliance upon scattered nesting beaches renders
the Loggerhead Turtle especially vulnerable to any
additional threat. As a measure of the fragile
ecology of the
species, as little
as one in 2,000
female Logger-
head Turtles will
eventually return
to nest at the
beach of their birth. Loggerheads have been
accorded endangered status by the IUCN, and
international trade is prohibited under CITES. In
Australia, the species is protected by both
Commonwealth and State legislation. But despite
the difficulty in forming reliable population estimates
of such a cosmopolitan and migratory species,
available data from nesting sites continues to indi-
cate persistent and marked declines. This is easily
attributed to a suite of factors with a single common
causal agent: mankind. Incredibly, turtles and their
eggs are still consumed by humans in many parts of
the world where effective protection is lacking.
‘As little as one in 2,000 female
Loggerheads will eventually return
to the beach of their birth.’
Turtle eggs and newly-emerged hatchlings,
however, represent a convenient delicacy for a
veritable army of predators, including birds, reptiles,
mammals and invertebrates such as crustaceans,
insects and worms. Hatchlings that are not picked
off in their dash to the water must then run the
gauntlet of a horde of waiting fish, eels and crabs.