The Excellence of the Elephant’s Nose
An elephant’s nose is not only long, but it works really well too. Researchers have found that an African elephant has no less than five times more olfactory receptor genes than a human. This means that elephants probably have a superior sense of smell.
A good sense of smell is an important asset in the animal kingdom. It helps animals to find food and a mate and avoid predators. The ability to distinguish between a wide range of smells depends on the number and type of olfactory receptor genes an animal has.
Japanese scientists studied the genes of 13 mammalian species to learn more about how well different mammals can smell. They were specifically looking for olfactory receptor genes. The researchers identified more than ten thousand "olfactory genes" among the thirteen species studied. Each mammal had an almost unique repertoire: only three genes were found that occur in all the species.
2000 olfactory genes
The researchers found the largest number of olfactory genes in African elephants. They had an impressive 2,000 functional genes! This is more than twice as many as dogs, which are known to have a superb sense of smell, and five times as many as humans. The exact purpose of all 2,000 olfactory genes is not known, but this research already suggests that the elephant’s nose is not only very long; it also works really well.
Sniffing out hunters and bigger meals
Researchers in Kenya also noticed the elephants' remarkable sense of smell. They discovered that the animals could smell the difference between Masai herdsmen, who sometimes hunt them, and Kamba farmers, who leave them alone. The animals displayed much more fear in response to the smell of Masai clothing.
A test at an elephant sanctuary in Thailand also showed that Asian elephants can estimate the quantity of food that is present just by smelling it. The researchers gave the elephants two sealed, opaque buckets, each containing a differently sized portion of their favourite snack: sunflower seeds. The elephants could not see how many seeds were in each bucket, but they were able to smell the contents through the small holes in the lid. On most occasions the animals chose the bucket with the largest quantity of seeds. A similar study carried out with dogs and their favourite snack showed that the dogs couldn’t do it.
Enticing them away
Scientists are hoping to use these "scent studies” to improve relationships between humans and elephants. In Africa and Asia, fields used for agriculture are at risk from roaming herds of elephants, which makes peaceful coexistence difficult. Distributing enticing smells in different places could make it possible to entice the animals away from the fields – in other words, to lead them by the nose.