Lohse & Tygielski, 2012
Giant Anteater Introductions: Using Positive Reinforcement Training to Ease Introductions
Lohse, R. Zookeeper, Reid Park Zoo*
Tygielski, S., PhD, Zoo Area Supervisor, Reid Park Zoo*
*Reid Park Zoo, 1100 S Randolph Way, Tucson, AZ 85716, 520-631-5063
Giant anteater (Myrmecophaga tridactyla) introductions are challenging for a variety of reasons. Anteaters are solitary animals, often reactionary when threatened, have strong forearms and long claws capable of significant damage or death, and the breeding position is extremely vulnerable (and therefore may be uncomfortable) for the female. Despite these challenges, Reid Park Zoo has performed successful introductions utilizing howdy doors, target training, introduction at removable fences in exhibit areas, and positive reinforcement training for calm behaviors. Each step in the process, as well as the removable fence design for the exhibit space, is included in this paper. Two case studies are presented featuring two different pairs of animals at the Reid Park Zoo. The first case study discusses a pair of anteaters introduced in a traditional manner with minimal preparations at a howdy-door. This introduction was unsuccessful, but the same pair was later introduced successfully with the techniques outlined in this paper. The second case study is of two young and skittish animals that were successfully introduced with these methods despite many external interruptions caused by exhibit plumbing issues. Introductions that proceed at the animals’ pace are preferable because they seek to minimize the risk of injury and negative experiences for the animal. These types of introductions increase the chance of successful breeding and can also have a positive impact on animals’ overall confidence in relation to aversive stimuli. Unsuccessful introductions, on the other hand, can allow anteaters to practice aggression and rehearse bad behaviors that may affect future attempts at introduction and breeding.
Captive giant anteater introductions can be dangerous due to both physical and behavioral characteristics of the species. Physically, the animals have long claws and strong forearms for defending themselves. Behaviorally, the animals are solitary and often extremely reactionary if threatened or startled. Therefore, prior to introductions, it is ideal to have anteaters comfortable with their living areas (exhibit(s)/night houses) as well as their keepers/trainers. Reinforcing calm behaviors and a level of comfort around keepers will assist with the stress of an introduction. Minimizing or managing aggression appropriately can help speed introductions and potentially decrease risk of injury to either animal. Currently, the giant anteater population in captivity has 97 individuals with an SSP target population size of 150 (Population Management Center, 2011). The management plan estimates that 10 births a year are needed over the next 10 years to create a stable captive population. Considering that anteaters can be injured or killed during introductions, utilizing positive reinforcement for easing introductions is a productive and appropriate way to minimize stress and risk.
Step by Step Process
Preparations prior to giant anteater introductions include physical exhibit preparation, individual animal training, and clear communications with all staff in areas neighboring anteater exhibit for help and cooperation. The exhibit or introduction site should be modified as needed to prevent trap areas where one anteater could corner another. Also if the exhibit space does not have a shared fence line to work with the animals, a temporary fence constructed in the exhibit will be useful. Fence construction details follow later in the paper.
Individual anteater training includes confirming that each animal is comfortable in all the exhibit spaces and night house area. If the animal exhibits stress signs while in these areas, keepers can modify the environment to help calm the animal. For example, placing daily diet or food treats in the area of stress may encourage the animal to eat and be distracted or comfortable for a short period of time in the area. The keeper can then gradually build duration of time in that area of the exhibit until it becomes a positive place. Additionally, if the anteater is trained to hear a bridge and be fed by a keeper, the keeper can bridge calm behavior in the exhibit and toss insects or other reinforcers to the anteater. Positive reinforcement training can help build the animal’s confidence in different areas of the exhibit. Ideally anteaters should shift reliably to ease introductions. Again, positive reinforcement training can help minimize slow shifting and increase reliability. A calm and confident lone anteater should rarely demonstrate stress behaviors on exhibit like rearing, frantic pacing, blowing noises, or growling.
In most animal introductions, a howdy-door or howdy fence line can be constructed so that animals can experience each other through a safe barrier. If starting with a small howdy-door, make sure both anteaters are comfortable with standing at the door alone. Keepers can use treats or daily diet to encourage an anteater to spend time at door. Even better, if the anteater is conditioned to a bridge, keepers can select moments where the anteater is calm at the door to bridge and toss reinforcers to the animal. The anteater may not always eat the treats, but hearing the bridge will still signal that the anteater is exhibiting calm behavior. The presence of a new animal may override the desire to eat, but the training foundation can still help. The more time spent together at the howdy-door, the more likely animals will respond to bridges and reinforcers. The period at the howdy door may be several days to weeks depending on the two animals involved. When both animals are comfortable approaching the howdy-door and remaining calm, it is time to move to the next step.
If using a small howdy-door in the night house area or exhibit, it is ideal to then move to a larger howdy space. A temporary fence across an exhibit can be a great introduction aid and can be helpful if the anteaters successfully breed and separate space is needed for young anteaters to be housed with the female. The fence in this exhibit was 26’ long but of course would vary with each exhibit. A simple fence design used at Reid Park Zoo was made of galvanized metal fence posts (4’ 6” high not including the portion sunk into the ground) sunk into sleeves in the ground for the frame. Cattle paneling was then attached to the posts in approximately 4-foot sections. Roughly in the middle of the fence there is a 3’ wide gate that can swing and be locked open in either direction. The posts can be removed and sleeves covered with locking caps. The paneling is large enough that anteaters can reach faces through to smell each other and even feet through. The paneling is secure enough to keep animals separated but light weight enough that keepers can easily set up or take down fence once the sleeves are installed in concrete. No footer was used along the fence line; concrete was only poured at the sleeve location approximately every four feet.
The fence line can be used as an enlarged howdy-door. Keepers should first confirm that the anteaters are comfortable at the fence line alone by feeding them along it and having keepers train and reinforce along the fence line. Once both animals are comfortable coming to the fence line it can then be used as a howdy space. The advantage to having an entire fence line is that the animals can watch each other move more, smell and touch each other through the fence, but still be protected. Calm behaviors that should be reinforced include interest in watching other animal, spending time at fence together and smelling one another. Keepers can reinforce calm behaviors as much as possible and also feed diet and treats at the fence line to encourage interactions. Aggressive behaviors, including growling, claw raising, charging and rearing up on back legs, may occur initially as animals explore fence line together. These behaviors should not be reinforced. Stress-based behaviors include pacing, tense body postures, audible blowing air, and hiding from sightline of other animal. Over time and with reinforcement of positive behaviors, these stress-based behaviors should decrease. The fence line training will vary in length depending on the individual animals and how aggressively keepers incorporate accurate behavioral management techniques.
Another factor to consider when using a fence line approach is that each animal could become territorial about its current exhibit space. Switching exhibit spaces frequently can help both animals remain comfortable with the entire exhibit and decrease the likelihood that one animal will always chase the other out of its territory. Time should also be allowed prior to introduction sessions for each anteater to have access to both exhibit spaces through the gate, so that when introductions are taking place, they are comfortable moving between the yards.
Through all these steps outside variables should be kept to a minimum. Each animal is different and will have stress reactions to different stimuli. If possible consider and minimize these stressors during this training and introduction period. In some cases construction, leaf blowers, chainsaws, etc. may alarm anteaters and their reactions to these stimuli could have negative impacts on introduction training. It can be helpful to schedule training sessions when these agitating factors are at a minimum.
Once positive and calm behaviors are exhibited by both anteaters, introductions can move forward. The introduction area should have ample space and be free of areas where animals can get trapped (tight corners). Early sessions, in which the anteaters are testing each other and setting boundaries, should be short in duration and should ideally end on a positive note. Providing them ample time to grow comfortable at the fence line prior to the introduction reduces the chance of injuries and severe aggression. Sessions should continue daily, and keepers should increase the session time according to the anteaters’ response. This allows the animals to get into a routine of being together. Stop and start introductions with large breaks between can have a negative impact on the success of the introduction and can increase the chance of injuries and stress.
Case Study 1: Nico and Sophia
Nico was a 4-year-old male giant anteater at the time of initial introductions. Prior to coming to Reid Park Zoo he had only lived with his mother. Initially, keepers at Reid Park Zoo did not make training Nico a priority. He was not consistently rewarded for calm behaviors or shifting reliably. Nico tended to be a reactionary animal and did not settle into his exhibit calmly.
Sophia was a 12-year-old anteater who had previously been successfully introduced to 1 male and 1 unrelated female, and had given birth to four offspring. She was a confident animal who would initiate interactions and aggression but would also terminate it when Nico responded appropriately.
Initial introductions were unsuccessful, and both anteaters sustained injuries. Sessions were sporadic and spread over long periods of time, with different staff members participating for short periods. After a long period of separation with visual access through fence line, introduction plans were revisited with new staff designated to be the primary keepers throughout the introduction process. The plan included an evaluation of the behaviors presented by both anteaters at the fence as well as reinforcement of desired behaviors with food treats. Sessions were scheduled daily with the goal of increasing time together slowly and ending on a positive note.
The second introduction attempt included extensive planning and communication with staff involved. Behaviors of both anteaters and interactions were documented and assessed. Introductions began once anteaters were not exhibiting aggressive or stress based behaviors and were spending at least 50% of the day interacting at the fence line or watching one another. Their interactions were positive and included smelling each other, licking each other, and sharing food from the same bowl. Four months of intensive training at the fence led to a successful and injury free introduction. The timing may have been slower than desired, but that was in part based on the initial introduction and staffing limitations.
Case Study 2: Xander and Zoe
Xander is a male giant anteater, 4 years old at first introduction. He lived with his mother prior to introductions to Zoe. Xander can be a reactionary anteater with a lot of energy. When he was transferred to Reid Park Zoo he was not interested in typical reinforcers (avocado and honey) but did train for worms. Keepers spent many sessions every day teaching him to take rewards from them. An important goal of this training was to get the anteater comfortable with staff and his new surroundings.
Zoe is a female giant anteater and was 3 years old at first introduction. She lived with her mother prior to introductions to Xander. Zoe was very anxious upon her arrival at Reid Park Zoo. She was hesitant to come to keepers, easily agitated by loud noises, and anxiously paced the exhibit. Keepers worked with her for several months to increase her calm behaviors on exhibit and in the night house.
The first major challenge in their introduction was that Zoe exhibited extreme stress by pacing and making audible blowing noises whenever she had visual contact with Xander. At this point there was only a small howdy gate between the yards and Zoe would hide from visual contact with Xander and not participate in any interactions at the gate. The staff worked hard to make the area a positive place without Xander present, but Zoe still exhibited stress behaviors and new solutions were discussed.
At this point a removable fence was installed to increase the visual area for the anteaters. The goal was to design a fence that created flexibility in the exhibit space and was easy to install and take down. Permanent sleeves were put in the ground to put the fence posts in and the fence was attached to the posts. When the fence was not needed the posts and fence line were removed and caps over the sleeves were locked in place to prevent them from being filled in with dirt.
This solution allowed keepers to give Zoe time to become gradually desensitized to Xander’s presence. Each exhibit space had areas where she could hide from him, but by increasing the viewing area she could see him from areas in which she felt comfortable. As she exhibited calmer behaviors, and the frequency of stressed behaviors decreased, she was given more incentive with treats to get closer to the fence line. Food bowls were moved closer to the fence slowly for both anteaters. Behavioral observations showed a marked improvement in the reduction of Zoe’s stress based behavior, and as she became more comfortable she would spend time at the fence with Xander or show interest in what he was doing.
Each anteater was trained individually at the howdy-door and fence line prior to the beginning of introduction training. Trained behaviors such as “come” and “target” were used at the fence line to reinforce approaching the fence. The fence line was treated with favorite items, such as citrus, worms, avocado pieces and insects several times a day. Training sessions continued throughout this period and behavioral observations were documented. Throughout this time Zoe’s stress-based behaviors decreased and calmer behaviors were observed during interactions at the fence.
Initial introduction sessions were high energy with chasing, rearing, and growling, but no injuries. The first session was 5 minutes long and ended once the animals had separated themselves. Immediately animals were secured in night house, the gate in the fence line was closed and the fence was treated with reward items. Times were extended daily and sessions were going well when a construction issue occurred that required moving the anteaters out of their exhibit and night house holding. This move delayed introductions and keepers had to take a step back once it was completed to re-evaluate anteater behaviors at the fence line.
Fortunately, the animals readjusted quickly and sessions were continued, but another challenge came up when Zoe became possessive of her preferred area in one of the exhibits and began aggressively chasing Xander out of that area. After evaluating her behavior, introductions were stopped for five days. Zoe was not allowed access to her preferred area. Once introductions began again, the aggressive chasing ceased, and the session duration times could be increased daily. At first, anteaters were closely watched at all times by keeper staff. As time was increased, and they exhibited calm behaviors together, we incorporated Docent volunteers into the monitoring process.
One of the benefits of an introduction scheduled at the animal’s pace is the increase in its confidence. Zoe has had a dramatic decrease of pacing and stress-based behaviors. Aversive stimuli do not affect her as strongly as they once did, and she is more confident exploring all areas of the exhibit space.
Positive introductions paced for the comfort of the anteater are beneficial for the individual animals as well as for the long-term captive population of giant anteaters. Staff can aid in creating a successful introduction by implementing training programs to reinforce desired behaviors. There can be many external pressures applied to an introduction to complete it as quickly as possible, however some situations may require taking a step back. Taking the time to plan and assess the progress before, during and after introduction sessions can greatly improve the overall success of the pairing. Given that breeding in captivity is such an important part of the SSP for this species, successful introductions are can have a huge impact on the sustainability of the giant anteater population.
Population Management Center, 2011. Population Analysis & Breeding and Transfer Plan: Giant Anteater (Myrmecophaga tridactyla) AZA Species Survival Plan Yellow Program, Lincoln Park Zoo, Association of Zoos & Aquariums.