Female bonobos form strong bonds with each other Anup Shah / Getty

When bonobos give birth, other females gather around to support and protect the mother. These “midwives” bely the notion that assistance during birth is unique to humans.

Until now there has only been one scientific account of a wild bonobo giving birth, published in 2014. On that occasion, other females stayed close to the mother.

Now Elisa Demuru of the University of Pisa in Italy and her colleagues have described three births among captive bonobos at primate parks in France and the Netherlands.

On each occasion, the …