June 29, 2009

Size Of Lion Prides Correlated To Quality of Life, Territory

Lions in Africa and Asia form prides in similar fashion to street gangs in order to protect their territory from other encroaching cats, according to new research.

Researchers told BBC News that larger gangs have higher survival rates, which could help future conservation efforts.

Researchers have observed lions forming prides, which consist of one or more males and several females and cubs. However, experts have previously been unable to explain why prides were formed.

They assumed lions formed prides in order to form a large hunting gang, but researchers said there is no evidence to show that an effort to hunt in packs actually increases their hunting skills.

Another concept for lion prides is that they are formed in order to protect their territory from other gangs of their own kind.

Ecologists Anna Mosser and Craig Packer of the University of Minnesota in St Paul developed the first study to look at the behavior of 46 lion prides in the Serengeti National Park.

Presented in the journal Animal Behavior, the 38-year study showed where the prides roamed as well as their composition and how they interacted, researchers told BBC News.

But more importantly, it showed that the prides had an impact on the mortality and reproduction rates of female lions, researchers said.

Larger pride sizes were directly related to higher reproduction rates as well as a lower likelihood of being killed.

Additionally, prides with more females had a greater success rate in terms of land control.

"The most important way to think about this is that lion prides are like street gangs," Packer told BBC News.

"They compete for turf. The bigger the gang, the more successful it is at controlling the best areas. The main difference from humans is that these are gangs of female lions."

"The advantage of large group size for group-territorial animals has been suspected for a long time, but had never been proven with data," said Mosser. "With this paper, we were able to do just that because of the many groups studied over a long period."

What's more, researchers noted that male lions play a larger role in protection against other prides.

"Males turn out to be playing a greater role than we realized," said Packer. "Males attack females from neighboring prides, likely altering the balance of power in favor of 'their' females."

"It also confirms a pattern that is probably applicable for many species, including group-territorial ants, birds, and chimpanzees," Mosser told the BBC.


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