FEATURE HERE’S LOOKING AT POOJOSEPH DOUGLAS MANDLA WHITE, MIN HUI LIU, NATURE PRODUCTION/NATUREPL.COMPlants have evolved all kinds of creative ways to
disperse their seeds. Perhaps the most remarkable of
all, though, is a grass in South Africa’s Cape Province
calledCeratocaryum argenteum, whose shiny, pellet-
like seeds (top) mimic the droppings of antelopes
(bottom). Within hours, industrious dung beetles
scuttle over to roll the ‘droppings’ away, burying them
in the earth (dung beetles bury poo to use as a source
of food themselves, or for their larvae to eat). What’s
more, in order to bamboozle the phenomenal sensory
equipment of these beetles, the grass seeds also exude
a chemical cocktail that smells like antelope faeces.
In 2015, researchers at the University of Cape Town
discovered that the dung beetles eventually rumble the
ruse and don’t bother laying eggs in the seeds. But by
then the seeds are safely buried – the ploy works just
long enough to succeed.
Caterpillars are fast-growing munching machines. Their flesh
contains more protein than chicken, so it’s no surprise they’re
on the menu of so many insectivorous animals. The Asian
swallowtail, orPapilio xuthus, is one of several butterflies
whose caterpillars fight back by copying the shape, colour and
smell of bird droppings. But the masquerade is limited to young
caterpillars that don’t move around much, such as the one in this
photo. Eventually, the larvae are too large and mobile to pass
themselves off as poo, so during their final moult they acquire
green camouflage and, as an extra deterrent, a pair of scary fake
‘eyes’. “The Asian swallowtail displays amazing plasticity,”
says entomologist and BBC presenter Dr Ross Piper. “When it
needs to, its caterpillar swaps tactics and deploys a different
defensive strategy.” A Japanese study tested models of another
species of poo-mimicking caterpillar, and found that they fooled
birds only when curled up to resemble coiled droppings; replica
caterpillars with straight bodies were toast. It’s not clear if the
swallowtail caterpillars also have to strike uncaterpillar-like
poses in order to survive.�
DUNG DEAL
�SPECIES OR FAECES?