News Round-Up

Social status, not size, determines reproductive success for female mountain gorillas


Dominance rank among female mountain gorillas is not related to body size but does increase their reproductive output according to research publishing June 3, 2020 in the open-access journal PLOS ONE, led by Edward Wright from the Max Planck Institute for Evolutionary Anthropology, Germany, and colleagues.

Mountain gorillas are the largest living primate and display extreme size differences between the sexes, with males weighing around 200kg — twice as much as females. Body size is an important factor determining fighting ability in many animals and previous research has shown it influences dominance rank in male mountain gorillas.

To test whether this relationship exists in females, an international team of researchers measured the body size of 34 female mountain gorillas (Gorilla beringei beringei) monitored by the Dian Fossey Gorilla Fund International in Volcanoes National Park in Rwanda. They combined dominance rank data from behavioural observations, which have been conducted daily since 2000, with estimates of back breadth and body length for each adult female, calculated non-invasively using a frame mounted with lasers and a digital camera. MORE