Ray Toble, a Victoria University Master of Science student said that female hamadryas baboons from Wellington Zoo, New Zealand are changing their sex cycle so that they have a higher chance to mate with someone other than their leader male. There are currently two harems in the zoo exhibit; one with three females and the one with six females. Toble found that females from the smaller harem had a fertile phases that's on average three days longer than the females in the larger harem.
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Is this a behavior unique to Wellington Zoo population? Can this behavior be observed in other zoo populations and in the wild? I think more research and observation needs to be done on this topic but it is certainly fascinating to see that female hamadryas are calculated in their reproductive success. One thing I am not clear about, are there only two male hamadryas baboons at the Wellington Zoo or are these females increasing their chance to mate with male bachelors in the same exhibit.