Meerkat bosses use subordinates as guinea pigs
Just as ancient emperors employed tasters to make sure their food was harmless, so meerkat 'queens' use more junior members of the group as guinea pigs.
They send out lower-ranking animals to check out busy roads, say Zurich-based scientists, giving an evolutionary advantage to the group as a whole.
The team observed several meerkat groups in the Kalahari Desert, forced often to cross a heavily-frequented road which runs through the reserve and effectively cuts their home range in half.
Field observations showed that in most cases it was the highest-ranked animal - the dominant female - who led her group to the road. Once they arrived, however, she yielded to a lower-ranked individual, who took up the role of 'guinea pig' to cross the road first.
Using this observational data, the team developed a relatively simple computer model to simulate for the first time the behaviour of a meerkat group, in which there are distinct social roles. It models a group of eight meerkats, one of which was assigned as leader.
In the simulations the eight 'meerkats' encounter a virtual barrier of variable size and risk.The model, says the team, clearly showed the reorganisation taking place at the front of the group - which the team interprets as indicating that the dominant female and the subordinate individuals have a markedly different appreciation of the danger.
"The dominant female's highly risk-averse behaviour appears selfish. However, it makes a lot of sense for the long-term survival of the group and the closely-related individuals in it," say the authors.
"Meerkats in fact minimise the threat to the whole group, even though it may imply for the 'test individual' to lose its life: the survival of all the group members may depend from that of the alpha individual."