We may talk about a battle of the sexes when it comes to our species, but in the rest of the primate world, it really is a battle. We have the luxury of cultural hand-wringing about the shirt a Rosetta mission engineer wore in a YouTube video , but when it comes to chimpanzees, a shirt is the least of female problems. Previous research from the Kanyawara chimpanzee community in Kibale National Park, Uganda, has supported this "sexual coercion" hypothesis because the anthropologists found that males who directed aggression at certain females mated more often with those females than did other males. And the females prefer their males rough.

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By Colin Barras. Humans, meanwhile, show a variety of mating behaviours but often form monogamous couples. Michael Jensen-Seaman and Scott Hergenrother at Duquesne University in Pennsylvania think that it is the chimps — not humans — that have experimented with new sexual behaviours since our lineages diverged. But did male chimps inherit their mating plugs from the last common ancestor they shared with us or did they evolve it later? They found that the enzyme is four times as abundant in human semen as it is in chimp semen. The change is related to the way the ACPP gene is turned on and off. For clues about whether the human-chimp ancestor had similar levels of the enzyme to humans or chimps, the team turned to gorillas. The gorilla lineage separated from the human-chimp ancestor a few million years earlier, so offers a perspective on mating habits in the human-chimp ancestor. The analysis showed gorillas regulate ACPP in the same way as humans, suggesting that the human-chimp ancestor did as well.
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Vicious chimpanzee attacks are on the rise in western Uganda and one mother has shared her account of a chimp ripping off her toddler's arm and tearing out his kidneys. Ntegeka Semata, a mother-of-four in western Uganda, said that a murderous chimp kidnapped and savaged her two-year-old son while she worked on one of her farm fields in The ape came into the field, grabbed the two-year-old boy, and stole him away into the dense jungle. Pictured: File image of a chimpanzee. Chimpanzees in western Uganda have begun raiding local villages and farms for food, and they have reportedly kidnapped and killed at least six children in the country in recent years. At least six children have been killed by chimp attacks in recent years and countless others have been snatched and dragged into the forest. Researchers say that shrinking forest habitats are forcing the apes, which are famed for their intelligence, aggression and brutality, to come into contact with humans because their food sources are becoming scarce. While chimps are generally wary of adult humans, some suggest they're drawn by curiosity to smaller children. That curiosity can become dangerous because chimps are about one and a half times stronger than similarly proportioned humans, and they also have less precise control over their muscles, so they can sometimes act out far more forcefully than they intend to.
In a fashion similar to human girls, some young chimpanzees seem to play with sticks as if they were dolls. The findings, reported in the Dec. Though these patterns' origins will surely be argued, they add to the constellation of behaviors shared by humans with our closest living relative. Wrangham's group has studied chimpanzees in Uganda's Kibale National Park since the late s, following in the methodological steps of his mentor, Jane Goodall, whose exhaustive, patient fieldwork first revealed that chimpanzees use tools and are more like humans than once thought. The Current Biology paper is based on observations made between and , and represents hundreds of thousands of hours spent trailing individual chimpanzees from dawn to dusk, recording their use of sticks. Kibale's chimps used sticks to probe holes containing water and honey. They used sticks to hit and threaten each other. They played with them. And, finally, they carried sticks — holding them under their arms or in their laps, for hours at a time, even while walking and climbing and feeding and resting. Carried sticks were shaped differently than sticks used as weapons or probes, and "unlike other types of stick use, carried sticks were regularly taken into day-nests