[ExI] ants again

[rex]

spike <spike66 at att.net> [2014-06-21 22:09]:
>
>   That whole ant war business is a hell of an interesting phenomenon if you
>   think about it.  Humans wage war, chimps have what Ann Druyan has
>   described as more of a rumble or gang fight, seldom resulting in serious
>   injury but definitely groups working in teams.

What? Chimps engage in wars and frequently systematically kill "enemies."

http://www.sciencedirect.com/science/article/pii/S0960982210004598

Lethal intergroup aggression leads to territorial expansion in wild chimpanzees

John C. Mitani, David P. Watts, Sylvia J. Amsler

Summary

Chimpanzees make lethal coalitionary attacks on members of other
groups [1]. This behavior generates considerable attention because it
resembles lethal intergroup raiding in humans [2]. Similarities are
nevertheless difficult to evaluate because the function of lethal
intergroup aggression by chimpanzees remains unclear. One prominent
hypothesis suggests that chimpanzees attack neighbors to expand their
territories and to gain access to more food [2]. Two cases apparently
support this hypothesis, but neither furnishes definitive
evidence. Chimpanzees in the Kasekela community at Gombe National Park
took over the territory of the neighboring Kahama community after a
series of lethal attacks [3]. Understanding these events is
complicated because the Kahama community had recently formed by
fissioning from the Kasekela group and members of both communities had
been provisioned with food. In a second example from the Mahale
Mountains, the M group chimpanzees acquired part of the territory of
the adjacent K group after all of the adult males in the latter
disappeared [4]. Although fatal attacks were suspected from
observations of intergroup aggression, they were not witnessed, and as
a consequence, this case also fails to furnish conclusive
evidence. Here we present data collected over 10 years from an
unusually large chimpanzee community at Ngogo, Kibale National Park,
Uganda. During this time, we observed the Ngogo chimpanzees kill or
fatally wound 18 individuals from other groups; we inferred three
additional cases of lethal intergroup aggression based on
circumstantial evidence (see Supplemental Information). Most victims
were caught in the same region and likely belonged to the same
neighboring group. A causal link between lethal intergroup aggression
and territorial expansion can be made now that the Ngogo chimpanzees
use the area once occupied by some of their victims.

-rex
-- 
Q:  Why do mountain climbers rope themselves together?
A:  To prevent the sensible ones from going home.