Roman Catholic doctrine doesn鈥檛 have much to say about monkey morality, but there could be trouble if it did. Olive baboons in Nigeria sometimes consume natural contraceptives that may make the females less attractive to the males and almost certainly lower their chances of becoming pregnant.
That鈥檚 the conclusion of James Higham of Roehampton University, UK, and colleagues, who found high levels of phyto-progestogens in the faeces of female baboons in at certain times of year.
Like the synthetic progestogens used in the pill, phyto-progestogens have a hormonal contraceptive effect similar to progesterone. Higham鈥檚 team found that levels of these progestogens surged in females during the plum season. From August to October, the baboons in the study area feed extensively on the progestogen-rich black plum Vitex doniana. In a group of 13 females, the more progestogen excreted, the less the females鈥� rumps developed pink sexual swelling 鈥� which is what attracts male attention (Hormones and Behaviour, ).
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Primatologist Patricia Whitten of Emory University in Atlanta, Georgia, thinks that it might benefit the baboons, which are able to breed year round, not to conceive in the plum season, as this is the rainiest time of year, when disease is most likely.
