Gorillas in professional zoological facilities are ambassadors for their threatened species. The groups managed scientifically in human care are mostly harem groups consisting of one silver back, his wives, and their offspring. It is important to have one male in a typical functional group, but zoological facilities often face the problem of too many males in a group because there is a 50/50 chance that a gorillas offspring will be male vs female. Due to this high ratio of male offspring, zoological facilities have considered bachelor groups as a solution, which is sported by natural social group formation observed in the wild. Dr. Marianne Nitsch from the Institute of Human Biology and Anthropology, Freie University Berlin, Germany has monitored such groups in zoological settings and found that all-male groups use similar mechanisms to coexist in captivity to those observed among wild gorillas. She is a proponent of bachelor pad groups and believes that it is advantageous for zoological to have then when faced with a higher population of males in human care.
Gorilla gorilla Noel (*1986, 165 kg) at Loro Parque | © Philipp J. Kroiß
When the president of Loro Parque, Wolfgang Kiessling decided to house western lowland gorillas, he pioneered the care of a bachelor group in a nature-like facility to support a breeding program in maintaining males, who have no place in a harem group. Loro Parque has since become a sanctuary for young gorillas waiting for breeding programs and older gorillas without the possibility of participating in a breeding program.
One of the most important gorilla facilities in the world
Loro Parque solves a huge problem for The European Endangered Species Programme (EEP) and other organizations around the world by facilitating an natural alternative by assimilation into their bachelor pad. Young males come to Tenerife and grow adult in the group and learn from the silver backs while they wait for a harem or if they are experienced but too old for a new one.
León’s (* 1989) is a success story and portrays how a bachelor group and its management works. He came to Loro Parque as a young gorilla, but was too old to stay with his family group and too young being the silver back for a new one. He integrated very well into the bachelor group and lived there for a few years before being sent to Brazil from the EEP to found a new gorilla group. Shortly after his arrival he became father of his first offspring and is now a great silver back for a wonderful new family of gorillas.
Loro Parque is also home to old gorillas that have little hope of being accepted into a new harem. It is also a retirement home for gorillas like Schorsch who is 44 and has turned blind requiring specialized care as he is not able to live on nature-like habitats like the most installations in professional zoological facilities. He is still interested in his environment and is very healthy despite of his handicap. “We interact a lot with him and he has a full enrichment program – some more than the others, because he’s alone”, explained Ignacio Ezquerro Sastre, a great ape expert and responsible terrestrial mammals at Loro Parque. In nature he would be either killed of starving or dying during a fight with a counterpart. As a senior in human care, he has a great second chance at life and is greatly cared for by passionate people.
Managing the bachelors
While manage such a group in comparison to a harem group can be challenging, it is worth it. In the morning at Loro Parque, the gorillas come out from their individual bedrooms complete with nutritional needs and personalized enrichment, they are greeted with the warm morning sun of Tenerife and their enclosure that has various types of terrain and even a waterfall. It is interesting to see the hierarchy of the group. What they eat, where they eat, and what they claim as their space is an indicator of where they are positioned in the hierarchy. Even if two Gorillas would not get along one day, they have enough space to avoid each other. In the evening the Gorillas come back in their individual bedrooms that are full of new enrichments to keep them busy until they fall asleep.
A concept for the future
Bachelor groups are important for a long-term breeding programs and should exist in more zoological facilities. Additionally, it is an important genetic reservoir and a shelter for old males. After Loro Parques pioneer work, zoos have started to make similar decisions and incorporate bachelor groups as a part of their western lowland gorilla management practices. The success of the bachelor program at Loro Parque will likely encourage more zoos to incorporate bachelor groups and educate visitors on the biology, social structure, and conservation of these amazing animals.