ELEPHANTS TRACK FAMILY BY SMELLING URINE
12.13.07 - Leído 53 veces. Enviar esta notaThe animals use their strong memory and keen sense of smell to track family
WASHINGTON, U.S.; December 13, 2007.- An African elephant can recognize dozens of kin by the signature smell of urine, and uses its powerful nose to keep track of their whereabouts, according to a study published Wednesday.
A keen trunk coupled with a good memory is essential for the foraging pachyderms, which travel in ever-shifting groups ranging from a handful to several hundred individuals, the study says.
Drawing from developmental research on pre-verbal children, scientists from Britain and Kenya tested the ability of elephants in Kenya’s Amboseli National Park to distinguish kin from stranger.
The team, led by Richard Byrne of the University of Saint Andrews in Scotland, also devised experiments — called “expectancy-violation” paradigms — to see whether the animals knew where family members were at any given moment.
In March 2007, they placed individual samples of urine mixed with earth from females along the paths of 36 elephant family groups, and then measured the reactions.
Only female urine samples were used because the social structure of the African elephant — Loxodonta africana — is matrilineal.
The first female in a group showed very little interest if the urine sample was from an elephant outside its group, but stopped to reach with its trunk if the odor came from a familiar source.
African elephants are able to keep tabs on at least 17 females, and as many as 30 individuals, both male and female, at any given time, the study says.
The lead elephant displayed especially heightened interest if the pungent smell belonged to an elephant that was, at the moment the fresh urine sample was encountered, trailing behind with the family.
This expression of “surprise” at finding evidence that did not jibe with reality shows that the African elephant “can remember where some family members are in relation to itself,” the researchers conclude.
“The fact that individuals do not generally walk in the same order when travelling, suggests that keeping track of the location of other elephants could be cognitively demanding,” they commented.
Byrne and his colleagues conjecture that olfactory kin recognition is made possible by certain proteins found in urine, such as lipocalins and MHC markers.
The study appeared in Biology Letters, a publication of Britain’s defacto academy of science, the Royal Society.
(AFP)
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