Romance, deceit, turf wars and struggles for survival – the invisible world of animal scent is full of drama
Words Victoria Williams
Getting familiar
Recognising scent is often the easiest way to work out who’s who
Many animals, from insects to mammals, rely on smell for identifying family and foes. Individuals have unique scent blends, and sensitive chemical receptors can pick up on the subtle differences. Deer have glands on the insides of their hind legs that secrete a fatty substance. This oily secretion sticks to the long, stiff hair growing around the glands until the deer decides to rub-urinate.
Rub-urination involves crouching slightly, bringing the hind legs close together and urinating – the urine flows over the tarsal glands and transports the secretion to the ground. Both sexes use this method of communication to leave information about themselves, especially during the rut. Others coming across the smell can tell whether the deer is an individual they know, a good potential mate or a rival best avoided.
Chemical defence
Few predators can stand the stink from these creatures
Predators targeting an opossum soon wish they hadn’t. The feisty marsupial will growl, hiss, drool and urinate to deter attackers. The aggressive behaviour lets an assailant know that it won’t be easy prey, and the dribbling makes it look like it might be diseased. If this doesn’t work, the frightened opossum faints and falls to the ground, looking like it’s dead and baffling predators that have instincts to chase after moving prey.
Really committing to the role, it then lets its tongue hang out, foams at the mouth and produces green mucous from its anal glands that stinks of decay and convinces a would-be predator that this is meat best avoided. ‘Playing possum’ can last for several hours, with the little actor waking up once the danger has passed.
THE OPOSSUM IS PARALYSED WHILE PLAYING DEAD, SO IT WON’T FLINCH EVEN IF A PREDATOR HAS A STRONG ENOUGH STOMACH TO APPROACH.
Disgusting deterrents
Turkey vultures
Turkey vultures don’t rely on glands for their scent defence. Since their diet consists of carrion – the flesh of dead animals – regurgitating their last meal produces a noxious smell horrible enough to put off any animal threatening them or their chicks.
Skunks
Should a predator ignore its warning stripes, a skunk can spray a foul concoction of sulphurous chemicals from its anal scent glands. Muscles near the glands shoot the liquid as far as three metres (9.8 feet), causing irritation and even temporary blindness to the attacker.
Stink bugs
Stink bugs are deserving of their nickname; members of this insect family release a pungent smell from pores on their thorax when they’re startled or in trouble. Some species smell like coriander, while others are descri
