The innocent-looking meerkats are known to work well in groups, but a new study of violent behavior has named these animals as the most murderous mammal known to science.
For the new study, José María Gómez and colleagues from the University of Granada in Spain came up with a list of 1,024 mammal species based on the number of deaths that were caused by members of the same species. They found that 19.4 percent of all meerkat deaths were the result of murder by their own kind.
Meerkats are catlike carnivorous mammals that live in groups called mobs. A meerkat mob often has about 20 members, but bigger families may have 50 or more.
Despite living in social groups and cooperatively hunt, meerkats have murderous capabilities. Their violence has already been documented by the scientific community. In a 2006 study, researchers from the University of Cambridge revealed that female meerkats resort to infanticide to maintain dominance or secure resources.
The researchers observed that with the strict hierarchical society of these animals, pregnant dominant females would kill litter born to subordinates. The subordinates also kill other pups born to other females to ensure better resources for their offspring.
"Despite dominants largely monopolizing reproduction, subordinates do attempt to interfere with the breeding attempts of others, in order to maximize their own meager share," said Andrew Young, co-author of the 2006 study, which was published in Biology Letters.
The new study conducted by Gómez and colleagues showed that despite their relatively small size, meerkats are more murderous than the larger brown bear whose murder rate is only 9.7 percent.
Other animals that made it to the most murderous mammal list include the Blue monkey, Red-fronted lemur, Mongoose lemur, Black lemur, New Zealand sea lion, Long-tailed marmot, Lion, Banded Mongoose, Grey wolf and Chacma baboon.
Gómez and colleagues said that they conducted the study with the aim of understanding the origins of human behavior. Between 500 and 3,000 years ago, rates of lethal violence among humans were between 15 and 30 percent.
"The psychological, sociological and evolutionary roots of conspecific violence in humans are still debated, despite attracting the attention of intellectuals for over two millennia," the researchers wrote in their study, which was published in the journal Nature on Sep. 28.
"Here we propose a conceptual approach towards understanding these roots based on the assumption that aggression in mammals, including humans, has a significant phylogenetic component.