EPOW - Ecology Picture of the Week

Impala Fight

Impala (Aepyceros melampus)
Lake Nakuru, Kenya 

Explanation:  On one misty dawn, here in eastern Africa, these two male impala met for a showdown.  

During the rut (breeding season), adult males defend their harems of females, and are particularly territorial in the presence of oestrous females (females ready to breed).  

The males become intensely intolerant of other males and defend their lot with particular dominance and threat displays, such as head-tossing, a low-horn threat posture, air-cushion fights (going through the motions of fighting without contact), and finally, direct contact fighting.  

The males cannot defend their harems forever, however, as they constantly have to monitor the presence of other males, keep their harem in check, copulate with females, and defend against invading males.  They soon become exhausted -- being able to defend the harem for only 3-13 days -- and give up their harem to more fit males who take over.