18 SevenWorlds,OnePlanet BBC Wildlife December 2019
SEVEN WORLDS | ONE PLANET
2
1
population is known to migrate to
the Roper River in the Northern
Territory, where food literally drops
out of the sky.
During the dry season here,
animals struggle with the intense
heat – up to 46°C in the shade –
and a drought that can sometimes
last for six or seven months. At the
Roper River, however, underground
springs ensure there’s usually water,
and visiting to slake their thirst are
thousands of little red flying foxes.
When they reach the river, they
swoop down and soak the fur on
their chests, and then lap off the
water when they return to their roost
- that is, if they make it back.
Between a croc and a hard place
Waiting just below the surface
of the river are the freshwater
crocodiles. When a bat drops
down, the crocodile surges
out of the water, its jaws
snapping shut in the blink
of an eye. The bats,
however, are skilled flyers,
and the crocs are not that
good at catching them. So
why would the bats want
to risk death? And why
do the crocodiles bother?
Wildlife cameraman John Shier
was there watching them.
“The thing that hits you is the
angry heat, and it dawns on you
just how difficult it must be for
bats to handle it, and it starts to
make sense that they would want
to take such a risk to obtain
water,” says John.
“There are about 200,000
bats where we were
filming, so the odds of
any single bat being
taken by a croc aren’tthat great, probably no more than 10
in a morning. Then, you wonder why
so many freshwater crocs travel to
this small backwater and wait every
day for a chance to grab a meal.
The key, I think, is how well
adapted the crocs are to a sparse
and intermittent diet. Like many
animals in Australia, crocodiles
excel at expending as little energy as
possible, so if a croc can catch a bat
every few days, it’s worth the time
and effort to come here and hunt
every day for a month.”
31 Sharks amass
at a bait ball
o Australia’s
Western coast.
2 Wombats can
be found above
the snowline.
3 The cassowary’s
casque could
either act as a
thermal regulator
or help to amplify
the bird’s calls.