Territorial conflicts can turn violent in humans and chimpanzees, two extremely territorial species. An international team of researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has studied the effects of territoriality on female reproductive success in wild Western chimpanzees and found that high neighbor pressure at times when females typically reproduce can lead to reproductive delays with longer intervals between births. Having many males in a group, however, is of advantage and speeds up reproduction.