Page 130 - World of Animals - Book of Sharks & Ocean Predators

Sharks & Ocean Predators
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The courtship of a fearsome beast

Despite their fearsome reputation, saltwater crocodiles have a surprisingly gentle courtship
ritual and the females are nurturing mothers that guard their young fi ercely
Saltwater crocodiles mate during the wet season, with preferring to lay their eggs in nests constructed from
the males competing loudly for females. In a bid to vegetation, in sheltered locations away from the tidal
demonstrate their eligibility, they open their mouths, waters of estuaries. The eggs take between 65 and 114
expand their chests and emit infrasonic and audible days to hatch while the female defends the nest. She waits
sounds that shake the nearby water. This often escalates to in nearby water channels and is efficient at warding off

fighting, with violent tail-whipping and biting. would-be predators, but the biggest threat to the nest is

BELOW When

male and female Once a male has secured his territory, he’s free to flooding, with around 70 per cent of eggs drowning.

crocs court, attempt to mate with any female he can find. If the The nest not only provides protection from predators
they o en stay female is receptive to mating, she will raise her head to and prevents the eggs from drying out, it also plays a

near each other,
swimming side signal submission and the courtship ritual can begin. vital role in determining the gender of the hatchlings.
by side Male saltwater crocodiles are among the most aggressive The surrounding temperature often dictates the sex of a
animals on the planet, but when pursuing a female they newborn reptile, so instead of having the classical X and Y
employ gentler tactics. They have scent glands on chromosomes, whether or not a crocodile hatchling is male

their chins and rub their heads against the female’s or female is defined by how hot or cold the nest is. Eggs
snout to cover her in pheromones. Partners will only develop into male hatchlings if the temperature
also swim together, with the male dipping is very near to 31.6 degrees Celsius (88.9 degrees
below the female to blow bubbles on her Fahrenheit) – more than a degree or two above or below
and performing infrasonic water dances, this temperature will produce only females.

vibrating his flanks to create a low- The first few years of a saltwater crocodile’s life are

pitched sound in the water. incredibly dangerous and the hatchlings are vulnerable to
However, even if a male is attack by predators of many different varieties. The female

successful in courting a female, remains with her offspring for the first few months, as
another male may attack the pair they huddle together in crèches, calling to one another to
during mating and the fi ghting stay together. Within a year they begin to venture further
often continues in the water. away, but larger male crocodiles pose a signifi cant threat
During the wet season, and very few hatchlings make it to adulthood. Those
saltwater crocodiles move inland to that survive go on to become almost invulnerable to any
freshwater swamps and marshes, predator, other than humans.
“The fi rst few years
of a saltwater
crocodile’s life are

incredibly dangerous
and the hatchlings

Just like for many other are vulnerable to
creatures in the world, the
mating season is a tense
time for saltwater crocs attack by predators”

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