Category — Gorillas
In the early years of wild gorilla research it was observed that they did not utilized bodies of water much and got most all of their moisture from the succulent vegetation they consumed. Most of this information came from research being conducted with mountain gorillas. (Gorilla beringei beringei). Of course a life in the rainforests meant they would frequently get very wet but never were they seen to submerge portions of their bodies into deeper water. This was very true of mountain gorillas as they lived on very hilly terrain where large pools could not form.
To the contrary, zoo gorillas have been known for many years to enjoy a dip in their habitat water features and even submerge their heads at times. One of the classic stories from the vast Cincinnati Zoo and Botanical Garden (CZBG) gorilla history recounts a time when an expecting female gorilla “Amani” climbed down into the shallow water moat in front of the gorilla exhibit out of sight. When she climbed back up she was carrying her newborn baby. This baby was named “Kubatiza” which means “baptism” in Swahili. There have been many enriching episodes involving zoo gorillas and water over the years but it wasn’t until the 90s that more in “depth” (pun intended) observations of wild western lowland gorillas (Gorilla gorilla gorilla)( the same species housed in zoos) revealed that gorillas actually do frequent pools of water.
The longest running research project show casing gorilla water usage is the Mbeli Bai Study in the Republic of Congo. Bais are naturally occurring marshy clearings in the rainforests. Gorillas come to these bais to wade out into the water to feed on the very mineral rich vegetation floating on the surface, primarily hydrocharis. They spend hours in at the Mbeli Bai selectively harvesting choice pieces and then carefully stripping it down to eat the tasty pith.
While congregating in the open clearings, gorillas use the time to work on their social game as well. Many times two family groups will mingle while the silverbacks representing each group posture and try to impress each other and the ladies of the other’s group. Sometimes lone bachelor males show up to spar with other silverbacks through audacious chest beat displays, augmented with dramatic water splashing. Occasionally, these swooning efforts pay off and a female might decide to migrate to a different silverback or at least consider the invite until their next meeting.
Additionally, the first recorded case of wild gorilla tool use was documented by the Mbeli Bai Study, when a female gorilla modified a stick and used it to measure the depth of the water prior to entering. Of course as with water play, zoo gorillas have been using sticks and other items as tools to manipulate food out of puzzle feeders for many years but to see this done in the wild with no human influence or prompting was a huge discovery.
Over the years researchers have identified over 300 different individual gorillas that frequent Mbeli Bai, along with forest elephants, yellow-backed duiker, sititunga antelope, buffalo, red river hog, colobus monkeys, crocodiles, otters, African fishing eagles and many other species. They are learning important behavioral and demographic information critical to conserving them and their very threatened Central African rainforest habitat. CZBG is proud to have supported and partnered with the Mblei Bai Study and related research efforts in North Congo for 15 years.
February 10, 2016 No Comments
It’s hard to believe, but Gladys the gorilla turns three years old today! Since arriving at the Cincinnati Zoo as a one-month-old orphan, we have had one fun and fulfilling adventure with her. However, Gladys has a lot of adventures still to come on her long road to adulthood.
As with people, gorillas take a long time to grow up. For females, it takes about 10 years to mature, and for males, it takes 13 to 15 years! During these years, they go through several stages, each one building on the previous stage. Until they are three years old, gorillas are referred to as babies and they are dependent on their mothers for nourishment. They will start sampling solid foods by around one to three months old, but will nurse from mom for three to four years. The amount they nurse will gradually flip-flop with solid consumption over those years.
Gorillas are born with very little natural instincts. Unlike a snake or spider that pretty much know everything they will need to survive the second they hatch, gorillas have many learned skills they must acquire over many years. Gorillas have over 13 different vocalizations and inflections, along with many facial expressions and body postures that form a complex language. They start learning this language from day one. They have rules of social etiquette to learn as well as survival skills about where to go or not go, what to eat and what to embrace or fear. Baby gorillas build their motor skills and strength during this stage as well, all setting the foundation for the next phase.
Between three and six years old, a gorilla has pretty much moved out of the “baby” phase and is considered a juvenile. They are no longer dependent on their mothers for milk and rely solely on solid foods. Although they still need their mothers and families for comfort and protection at times, three-year-old gorillas have more confidence to explore even further and spend long periods away from mom. They enjoy a new level of relatively carefree freedom while learning a few harder life lessons along the way. Their personalities begin to become more defined during this stage.
Between six and 10 years old, gorillas are referred to as sub-adults. They are still not fully grown physically. The carefree playfulness of being a juvenile is augmented by more adult-like interactions and experiences. Sub-adults learn to shape breeding postures though regular wrestling and playing bouts, although females do not reproduce in the wild until they are about 10 years old. By now, they have very distinctive personalities formed by previous experiences that will greatly influence their futures. There is a clear hierarchy within gorilla society. The pecking order is set based on many factors including the status of their mothers, intelligence, physical size and political savvy. During the sub-adult stage, young gorillas work very hard to establish their social status through both positive interaction and aggression as they define their individuality even more.
By 10 years old, gorillas are considered adults. Females may have migrated from their natal groups to improve their social life with a new family. They become new mothers and begin teaching young gorillas how to become adults. At 10 years old, males most likely have been driven from their natal group by their father as they have become too rambunctious and challenging to the cohesiveness of the family. Ten-year-old males are keenly interested in breeding, but are not quite mature or physically impressive enough to attract females so they go through an extra stage called “blackback”. During this stage, blackbacks may live as solitary males or find other blackbacks to hang out with in a bachelor group, kind of like a gorilla YMCA.
By the age of 15 years, blackbacks have grown into their full size and are now called silverbacks. All male gorillas become silverbacks. Silverbacks, of course, get a silver coloration on their backs and develop large musculature on their heads. This enhanced sagittal crest and large body size, combined with a silverback’s specific personality, can attract females. Once a gorilla has reached a full silverback stage, he can acquire females in his group and start his own family.
So as Gladys reaches the juvenile gorilla stage milestone, it’s fun to review where she has been and look forward to what is in store on her long road to becoming an adult. We’ll watch her personality take further shape through positive and challenging life experiences. The bottom line is three years old is a great age to be a gorilla, especially when you have two younger sisters to go on the adventure with!
January 29, 2016 4 Comments
Along with celebrating the 50th gorilla birth this year and announcing big plans to expand the popular Gorilla World habitat, the Cincinnati Zoo will be celebrating 15 years of wild gorilla conservation work with the Nouabale Ndoki Project (NNP) in 2016.
This project, located in the Republic of Congo, umbrellas several very important efforts that help critically endangered wild western lowland gorillas (Gorilla gorilla gorilla). The Zoo’s original funding for NNP went to the Mbeli Bai Study, the longest running field research study on this species of gorilla. Researchers gather valuable demographic information needed to define what gorillas require to survive as their threatened rainforest habitats continue to shrink. Keep up with the latest news from the Mbeli Bai study by visiting the new web site and blog, following their Facebook page, and reading the most recent newsletter.
Over the years, the Zoo increased its contributions to other gorilla-related projects in this area, including the “Mondika” gorilla tracking study site and an education outreach program for local communities called “Club Ebobo”. Ebobo is the word for gorilla in Lingala, the local language.
As we celebrate the expansion of our gorilla family and facility here at the Zoo, it is important we recognize and celebrate the fine work being done in the field to help conserve this flagship species.
December 14, 2015 1 Comment