Karen Holmes and Marilyn McCormick, Omaha’s Henry Doorly Zoo
This presentation describes the involvement of docents in raising two baby gorillas with a comparison of differences in approaches.
The mother of the two infant gorillas discussed in this paper is a western lowland female gorilla born in 1995. This gorilla, the first gorilla produced by in-vitro fertilization, was born prematurely and was hand reared. Although reared with other infant gorillas initially at Cincinnati and later at Omaha, this female was not in a traditional social group of a dominant male, multiple females experienced in rearing offspring and infant or juvenile animals. This is significant in that the female did not have the opportunity to observe, interact and learn maternal behavior in a social group which seems to be the way that female gorillas acquire at least a portion of their maternal skills. Consequently when the first offspring was born to this female she had limited maternal interest or skills and, after providing the female with sufficient opportunity to care for the newborn, the decision was made to hand rear that offspring. It is interesting to note that the female did pay significantly more attention initially to the second offspring that was born but the infant still had to be hand raised.
The first offspring was born to this female in 2003 and the second in 2005. The Henry Doorly Zoo substantially altered their great ape hand rearing protocol during this time to enhance socialization of the animals.
Historically successful, traditional nursery techniques were utilized in rearing the 2003 offspring to about 2 years of age when it was introduced to the group. This included rearing the animal in the nursery with no direct contact with other gorillas initially and very limited contact until the time of introduction. Introduction of this first offspring to a social group of gorillas was successful but did involve a transitional period of limited behavioral stress for the animal as it acclimated to relatively unfamiliar surroundings and cage mates. When the 2005 gorilla was born the most significant modification to the traditional protocol was to raise the infant in the gorilla building rather than the nursery in order to expose the infant to other gorillas from day one, to identify and introduce a surrogate female to provide maternal and protective care for the young gorilla in the social group and most significantly to introduce the infant into the social group at the earliest possible time, about 6 months of age. Additional modifications were made in rearing procedures, all intended to maximize the improved socialization of this animal in the gorilla group and provide a smooth transition for the animal.
The modifications to the protocol were developed by the Henry Doorly Zoo management, nursery and great ape animal care staff in consultation with the Columbus Zoo, which has had a successful program of early introduction and socialization of multiple hand raised gorillas. Visits were made by the Omaha staff to Columbus Zoo and by Columbus Zoo staff to Omaha as this program was developed. The Columbus Zoo staff was also consulted for additional advice at different stages in the course of hand rearing the second infant.
The birth of Baina, the 2005 gorilla, presented an opportunity for a unique cooperative effort between the great ape animal care crew, the hospital nursery crew, and volunteer docent caregivers to provide 24-hour care. Sarah Dankof, Hospital Supervisor, and Dan Houser, Ape, Pachyderm, Sea Lion Supervisor worked together to set up nursery accommodations in the Gorilla Complex with two specific aims. The most important objective was to provide constant exposure of the infant to the gorilla group whether they were on display during the day or in holding at night.
Secondarily, we wanted the infant available for public viewing as well. In our facility two separate areas were arranged, one adjacent to the gorilla public display and one in the gorilla night holding area in the lower level of the building. A courier schedule was established to supply daily formula, vegetables, fruits and supplies from the zoo hospital/nursery facility. The security staff was also involved as they arranged for the night personnel to meet all-night volunteers at the zoo gate at midnight, escort cars to the gorilla complex, and unlock the gorilla facility.
Bambio/Baina Care Comparisons
With less than three years between the birth of Bambio and Baina, our methods of care changed significantly. Both animals had 24 hour a day care. However a significant difference was that the first animal did not have 24 hour contact with the care giver. The second animal was held constantly, even while sleeping in order to simulate normal maternal care by female gorillas.
Bambio was cared for like a human baby. She was swaddled in a blanket and placed in an infant seat when we put her down. She was cradled in our arms while being bottle fed Enfamil with Iron. At about five months she was fed from an infant feeding spoon; rice cereal followed in a few weeks by strained vegetables and later, strained fruit.
Bambio’s caregivers were the nursery crew and twelve volunteer docents. Every aspect of care was recorded on daily log sheets. Each morning the page for the preceding day was discussed between the morning caregiver and the hospital crew. Any changes in the routine were discussed with each caregiver as she came in on her shift.
One difference in the care of the two gorilla babies was the location and design of the care facility. Bambio was in a fairly sterile hospital nursery. During her stay in the nursery, she saw humans, her orangutan roommate, and the other animals that came into the nursery area for short stays, but she saw no gorillas. For enrichment, Bambio and her playmate, Amoi, played on a blanket with baby toys. Amoi was an orangutan that was three months older than Bambio and who had been in the nursery since her birth. The caregivers also played with the two of them. At night, Bambio and Amoi were put to bed in the zoo nursery, each in her own port-a-crib with a net covering over the top. They were tucked in with blankets and stuffed animals for warmth and comfort. They didn’t like being put to bed alone and usually screamed for a while before settling down and going to sleep.
At the end of her almost two year nursery stay, Bambio was taken daily to the gorilla complex for introduction sessions with the female gorillas. Eventually she was placed in the holding cages and was subsequently introduced directly to the adult female gorillas in the group. This was a somewhat stressful situation as the young gorilla adjusted to the arrangement.
Baina was cared for with techniques closer to a mother gorilla caring for her own offspring than a human caring for a human baby. Baina was also bottle-fed Enfamil with Iron, but without being cradled. At four months the animal care staff began to train her to take the bottle through mesh attached to one end of her jungle gym so that when the infant was introduced to the surrogate female during a time when she still needed to get milk but couldn’t be accessed directly, she would be familiar with taking her bottle through the enclosure mesh. When she achieved this step, she was taken to the mesh area of a door to her enclosure where she was fed her bottle through the mesh by a keeper on the other side. After a short period of being carried to the door mesh, she was placed a foot away from the door and encouraged to go to it by herself. The distance she was placed from the door was increased bit by bit until she would go to it from any place within the enclosure. Baina hung onto the mesh, and drank the formula without assistance. No baby food was given, but chunks of celery, carrots, and broccoli were introduced at just less than three months of age.
The infant gorilla had the option to hang on to a caregiver at all times but independent behavior was encouraged. Baina played by herself with boxes on the straw strewn floor of her enclosure and with the vegetable chunks and biscuits that were also placed on the floor. The purpose of the food was to train her to forage as the other gorillas do. Baina spent the nights sharing a recliner or a cot with a caregiver in an enclosure in the gorilla bedroom area in order to reinforce the sense of security the animal had, again as it would experience with a gorilla mother. Her area adjoined the enclosure where her grandmother, Rosie; mother, Timu; and sister, Bambio slept. A silverback male slept across the hall and ten other males slept in surrounding enclosures Although noises such as 2 a.m. food bowl throwing by a few of the young males occurred nightly, few problems interfered with Baina’s sleep.
Baina had a more diverse group of caregivers composed of the nursery crew, the ape crew, and eight volunteer docents. Every aspect of her care was recorded and discussed with the hospital crew member who came in the morning with prepared bottles and other supplies for the new day. Any changes in the routine were written on a message board, so all caregivers were aware of them. The caregiver with Baina wore a shirt that Baina was encouraged to cling onto just as a baby gorilla would cling onto its mother’s fur. During the day, time was spent in a small enclosure that adjoined the large indoor exhibit in the gorilla complex. Baina could see, smell, hear, and observe the other gorillas. Significantly, the other gorillas could see, smell, hear, and observe her.
The hospital nursery where we cared for Bambio was like a little apartment. We had a living room on public display from 8a.m. to 8p.m. furnished with a recliner and a rocker. When the curtains to the observation window were closed at night, we had a cot, a table complete with reading lamp, a television and VCR. The kitchen was furnished with microwave, refrigerator, and coffee pot. We even had our own restroom, and thermostatically controlled heat in the winter and air-conditioning in the summer! In the gorilla complex where we cared for Baina, the small enclosure upstairs smelled like gorillas and was furnished with only a recliner and an insulated cooler for bottles of water. We also had a fan upstairs but no air conditioning. We were relieved at noon by a keeper, so we could go to lunch and use the restroom downstairs. At 4p.m., we went off display and were escorted down to the basement which, while clean, had even more of a gorilla smell. There we had an enclosure with a recliner, a table with reading lamp and a cot. We had access to the kitchen area and the restrooms, although to reach them we had to pass by the silverback across the hall. He was very interested in Baina and came to the bars each time we came out of our doorway! At 8 p.m., it was lights out, and being the only human in the building was a bit intimidating. Noises of the gorillas awake and asleep, were constant, and the footsteps of the security guards as they walked the catwalks several times during the night could be startling.
But we’d do it again in a heartbeat!
Initial introductions were conducted by bringing Baina to the enclosure mesh near other gorillas. Selected keepers could sit with Baina on their lap and wait for Rosie, Timu, or Bambio to interact with her which they all did at different times. All females behaved gently and appropriately towards Baina with occasional nose and finger touching. Rosie was the most frequent to interact.
Reinforcement with Rosie
At the mesh, Rosie was very interested in the baby from the beginning. Any positive interactions that Rosie engaged in were rewarded. Positive reactions from Rosie included sharing treats with Baina, not displaying aggression if Baina reached for treats, and allowing Baina to chew or bite her fingers or pull her fur. To ensure that Rosie would not interfere with Baina’s feedings, Rosie was trained by keepers to ignore a baby bottle when the nipple was placed through the mesh. Rosie’s interest and sense of possession grew daily, and she was very attentive to anything happening to her baby. Time was also spent allowing the male gorillas to visually inspect and smell the baby if they were interested. Many of the males seemed intrigued.
To prepare for full-contact introduction, Dan Houser covered the unit with straw. Video cameras were placed to record the first encounters. Dan carried Baina into the enclosure and placed her on the floor in the middle of the unit. When he walked out and the door closed, Baina realized she was alone and she started screaming. Rosie was allowed entry, and she immediately scooped up Baina, stopping the screaming. Dr. Simmons commented, “Who gave Rosie the book? She certainly read it all.” The look Rosie gave the observing staff said it all; it left no question as to who would care for Baina.
Rosie has been Baina’s protector and surrogate mother from day one. At first, Rosie made sure that Baina was always with her, and she was very cautious regarding the other females’ proximity to her baby. She shared food with Baina while making sure that the others allowed Baina to eat her own share. In the beginning, Rosie would bring Baina to the mesh for her bottle, even waking her if she was sleeping. Each night, Rosie made a nest of old clothing, straw, or cardboard for a place in which she and Baina could sleep together. Gradually, she let the other females get close to Baina, but Rosie always kept a watchful eye on the situation. When the silverback, Mo, was introduced into the group, Rosie made it clear even to him that she was in charge. A slight movement from Rosie is all it took for the others to realize that she believed they had over-stepped the boundaries, and they backed away from the baby. At present, both Timu and Bambio often carry Baina on their backs and play with her. Bambio is her primary playmate as they are so close in age. Baina exhibits much more confidence and independence at two plus years than Bambio does even at almost four years old. Both Baina and Bambio are lately seen interacting with Mo, the silverback, and sitting together in the crook of his arm and napping next to him.
We have since raised a male orangutan infant in the main nursery using a similar program with the addition of the caregiver wearing a fake fur vest for him to cling onto. After attempts to encourage two adult females to accept him as a surrogate baby failed, it was decided to “peer” raise him with two younger females. One, his full sister, Amoi, was 4 years old at the time and the other, Sepalok, was 6 years old. At seven months, he was placed permanently with the two young females and eventually also with an adult female and her infant and all are doing well.
We are grateful for the incredible faith in the docents shown by the zoo staff.
Thanks to Dr. Lee Simmons, HDZ Director; to Sarah Dankof, Hospital Supervisor; and to Dan Houser, APS Supervisor for entrusting the care of these precious infants to us. Thanks also to the staff of the Columbus Zoo for sharing their experiences and advise throughout this experience.
Special thanks to Rosie. Because of her, successful surrogating was possible. Rosie rules!