Gorilla Size Study (1 of 2) (IMAGE) Wildlife Conservation Society Caption This is an adult male gorilla -- also known as a "silverback" (far right) -- with a family group in Nouabalé-Ndoki National Park in the Republic of Congo. Conservationists from WCS and the Max Planck Institute for Evolutionary Anthropology recently discovered that larger male gorillas are more successful than smaller ones at attracting mates and raising young. Credit Thomas Breuer/WCS Usage Restrictions One-time usage only. Must use with the following credit: Thomas Breuer/WCS. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.