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Friday, April 22, 2016

Baby Yola confident as she learns gorilla ways

Posted by: Stephanie Payne-Jacobs, Zookeeper


Photo: Jeremy Dwyer-Lindgren/Woodland Park Zoo.

At 5 months old, Yola’s physical strength and self-confidence continues to develop in leaps and bounds, influencing the steps we take to ensure a smooth transition into her gorilla family. We’ve come a long way from the initial visits during Yola’s first months, which consisted of a mostly sleeping infant, to the current youngster in perpetual motion.

Photo: Jeremy Dwyer-Lindgren/Woodland Park Zoo.

Yola’s burgeoning confidence and expanding knowledge of complex gorilla social cues is evident in the way she interacts with her mother and responds to the activities within her group. She watches closely as the gorillas communicate vocally and physically throughout the day. Yola has observed rambunctious play sessions, common displays of dominance and subordination, nest building, foraging and occasional disputes peacefully settled.

Photo: Jeremy Dwyer-Lindgren/Woodland Park Zoo.

As Yola’s independence and confidence flourish, the visits between Yola and her mother Nadiri have become increasingly interactive. In the early months of the visits, before Yola was mobile, keepers would often have to assist Yola with the transition from human caretaker to gorilla mom, giving her a few pats of encouragement and comfort during this time. Now, however, she merely sits and watches expectantly for her mom to join her and the visit to begin. Both Nadiri and Yola anticipate their time together and enjoy one another’s company. Establishing this bond between them has been an important part of the process towards integrating Yola into her group.

Photo: Jeremy Dwyer-Lindgren/Woodland Park Zoo.

Yola and Nadiri’s comfortable bond with one another has allowed keepers to gradually reduce the amount of time that they are present for the visits, giving Yola a better sense of what it will be like to be a full-time member of her gorilla family. Instead of sitting close by throughout the visit, keepers now watch or listen from afar, tending to other needs of the unit. Yola now spends most of her time with Nadiri playing on various climbing structures. She is now adept at climbing and grasping, holding on with one hand or foot while simultaneously reaching for her mom or another nearby branch. Yola’s grip with her hands and feet is so incredibly strong that her human caretakers no longer need to hold her. She simply hangs on. This not only helps build and maintain her muscles, but also encourages her natural behavior, as clinging to her mother’s arm or back is how she would typically be traveling at this age.




In addition to climbing and grasping, Yola is now knuckle walking like a champ, and is able to follow her mom from place to place. Keepers have noticed that when Nadiri moves, even shifting her position by just a few feet, Yola will climb down to move closer to her mom before climbing back up off the ground. Occasionally, however, Nadiri will move around the corner into another room and out of Yola’s sight. Depending on Yola’s mood, she will continue climbing without much concern, or immediately begin whimpering for her return. Nadiri is very receptive to Yola’s vocalizations, and will return to reassure Yola with a content grunt (which is similar to a much louder cat’s purr). This immediately calms Yola down.

Before Yola could walk as quickly and steadily as she does now, we would often see Nadiri encourage Yola to travel throughout the rooms using this vocalization. When Nadiri would get too far ahead of Yola, causing her to vocalize, Nadiri would return within Yola’s sight and content grunt, as if to say, “You’re fine, I’m right here. Now come this way.” When Yola’s emotional needs have required more than a content grunt, Nadiri has comforted her further with a few hearty pats on the head, or gently covering Yola with a nearby burlap blanket. This is Nadiri’s preferred calming gesture towards her baby (and one that keepers have adopted for the sake of consistency and to best mimic Nadiri’s behavior). Surprisingly, this seems to work, as Yola will calm down and begin walking or climbing out from under the burlap blanket, contented and ready to get back to business.

Photo: Jeremy Dwyer-Lindgren/Woodland Park Zoo.

Lately, however, there has been little need for Nadiri to comfort an upset youngster. Since Yola is such a confident walker and climber, Nadiri is rarely too many steps ahead of her daughter, and the fact that Yola has some control over this seems to have brought on a new sense of self-assuredness that is apparent in her quiet determination to be near her mother. For her part, Nadiri has become increasingly playful with Yola, soliciting play with her through touch, picking her up and allowing Yola to climb on her. Nadiri was even observed balancing Yola on her feet as she lay on her back, much like the “airplane” game many of us have played with our own kids.

Yola’s range of vocalizations is also a good measure of age appropriate development. She is very expressive about things that upset her or make her feel unsure, and while the vocalizations associated with these feelings may sound similar to those who are less exposed to gorilla communication, there is a subtle difference in tone and delivery that expresses each emotion distinctly. We’ve even heard a warning grunt or two—much like the occasional disciplining grunt that she hears from her mother—when she has opposed strongly to something she dislikes. Most often, however, Yola exhibits a great affinity for giggling and open-mouth laughing, usually encouraged by some serious tickling and wrestling.

Photo: Jeremy Dwyer-Lindgren/Woodland Park Zoo.

Another developmental milestone occurred just last week, when Yola’s two upper molars erupted, bringing her current number of teeth to 10. Like any teething youngster, everything ends up in her mouth. As a result, Yola’s human caretakers have had to master the warning, or correcting, vocalization which is best described as a sharp, loud cough. She is much more receptive to this vocalization—proper gorilla-speak—over the human response of “OUCH!” 

Photo: Jeremy Dwyer-Lindgren/Woodland Park Zoo.

With her growing number of teeth, Yola’s chewing ability is finally catching up with her interest in solid foods. She is beginning to pick up and eat, rather than just mouth, the items that she sees her mother eat. So far, Yola has shown a preference for cucumber, romaine, celery, kale, carrots, spinach and any fruit she can quickly get a taste of before her mother reclaims it. Nadiri is very patient with her baby, but Yola seems to know instinctively that when Nadiri makes that correcting vocalization, she needs to give up that prized food item she’s taken from her mom. One of the first solid foods Yola tasted and consumed came from the most important gorilla food group of all: browse. Favored, edible foliage, or browse, is one of the main components to a gorilla diet, and Yola seemed to appreciate this fact from the start, with some of her favorites being willow, fern, forsythia flowers and bamboo. 

Photo: Jeremy Dwyer-Lindgren/Woodland Park Zoo.

We are all incredibly pleased with Nadiri’s patient and nurturing interest towards her baby. Yola’s strength and activity level increase daily, influencing the interactions between mother and daughter and strengthening their bond. In the next few weeks, based on the signs that Yola and Nadiri give us, we will be working on the steps involved towards physically introducing Yola to her other group mates, Leo and Akenji. The success of this integration will be the result of the invaluable gorilla skills Nadiri and the other gorillas have exposed Yola to over the last five months. We are all looking forward to watching these skills in action as she becomes a thriving member of her gorilla group. 

Editor’s Note: 

This Earth Day, Yola reminds us what’s at stake for critically endangered western lowland gorillas. In honor of how Yola brightens our world, let’s brighten the future for wild gorillas. 

Thanks to you, Woodland Park Zoo supports conservation efforts through the Mbeli Bai Study, building the scientific basis for conservation strategies. Learn more about the zoo’s wildlife work in Africa and beyond. 

8 comments:

  1. Why is Nadiri in a concrete and metal cell? It looks like a prison.

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    1. The video shows one of several private, indoor dens that Nadiri and Yola have access to away from the main outdoor exhibit area. Here they can safely bond and play together before Yola is physically and socially ready for the larger exhibit space. Meanwhile, Nadiri has the choice to access the full environment including outdoor areas.

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    2. Thank you so much for responding. That makes total sense! :)

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  2. Thank you, Stephanie, for an intimate, detailed, and fascinating glimpse into growing up gorilla in a captive and caring environment. <3

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  3. I am so glad things are going well. Congratulations to the gorilla crew.

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  4. It has been a pleasure to document the growth of many infants at this Zoo over the years. Congratulations to all of the hard working staff.

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  5. Thanks again to all if the Woodland Park Zoo Staff members for their tireless work in wildlife conservation.

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