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International Polar Bear Husbandry ConferenceFebruary 4-7, 2004 Saturday, February 7EnrichmentThe ideal zoo environment would have a full-time enrichment coordinator, a real budget, a unifying institutional philosophy, and enrichment as a top priority. The reality is that we face three major obstacles: time, money, and red tape. How do we meet our enrichment goals regardless? Time: Lack of time is a major obstacle to implementing new enrichment ideas. Keepers who want to do something new must research the idea, solicit approval, collect/order materials, assemble the device, observe/record results, manage behavior, and clean/store the device. How can you complete these steps without having to do them all yourself? Here are some suggestions:
Money: The more money you have, the more enrichment devices you can provide to your bears. But since money is in short supply, how can you do more with less?
Red Tape: Getting your enrichment ideas implemented involves an often-lengthy approval process, tight budgets, dealing with public messaging/aesthetic concerns, and keeping documentation on results. Here are some tips to streamline the process:
Case study. Polar bears in the wild have an extremely diverse, variable environment to which they must constantly adapt. How can we replicate that quality in our exhibits? A variable exhibit environment leads to healthier, less-stressed polar bears. SeaWorld San Diego’s “Wild Arctic” exhibit opened in 1997. The facility has 1.2 bears (8 years of age), and creates a variable environment through three factors: training, environmental enrichment devices, and food variability. SeaWorld creates variability in training by emphasizing husbandry, by shifting the bears 8 to 10 times per day, and by offering cognitive enrichment that enables the bears’ problem-solving abilities. For environmental enrichment, keepers provide an array of toys, biological enrichment (kelp, trout, bamboo), and frozen enrichment. They create food variability by offering different types of foods and offering it at variable times and locations. All three factors are of equal importance, and decision-making is decentralized. It’s critical to make training, enrichment devices, and food variability truly variable--schedules, no matter how complex, are still schedules the bears will figure out (and that decreases variability). SeaWorld uses training as an enrichment strategy, not enrichment as a training strategy. Environmental enrichment provides myriad benefits, but can also involve risks. How can we incorporate risk assessment into our environmental-enrichment proposals? Risk assessment is the identification of a threat (harm, loss, or damage) to mission-critical activities (for example, enrichment) by a risk factor. Before we introduce a new environmental-enrichment device or idea, we must analyze the risks and balance potential threats. Who should be involved in risk assessment? Moore recommends a team comprised of the curator, veterinarian, keepers, nutritionist, and behavioral manager. The first step is to analyze the risk:
Next, balance the risk by utilizing enrichment strategies that maximize benefits and decrease risk. Risk-prone strategies may offer more benefits, so Moore recommends a cost/benefit analysis where you look at the risk potential (what are the harmful events that may occur) versus the predictability of a potential event (how sure can we be that this will/will not occur). The best situation is to have low risk potential with high predictability of occurrence. When you have high risk potential with low predictability, you are facing a potentially dangerous situation. After doing a cost/benefit analysis, you may still decide to offer a potentially risky enrichment--but with appropriate countermeasures in place to prevent harm, loss, or damage. Veterinary IssuesPart I of this presentation focuses on physical exams, anesthesia, and potential disease risks. Part II discusses skin and haircoat abnormalities. Physical Exams, Anesthesia, and Potential Disease Risks Many factors influence how a veterinarian delivers anesthesia to a polar bear. Important factors to consider are wild-caught versus captive, old versus young, fat versus thin, healthy versus ill, duration of procedure, depth of anesthesia required, type of drug used, outside temperature, season, and familiarity with drug. Delivery method may be oral or via blow dart, rifle dart, or hand injection. Polar bears are adaptable and hardy, with minimal medical problems. The most-common diseases reported in captive polar bears are parasitic diseases. Skin diseases and haircoat problems are also common. Dental disease can be the most problematic if not treated soon enough. Briggs recommends routine fecal exams and deworming. Case study. Waldron presented the logistics involved in doing an umbilical hernia operation on one of the Zoo’s polar bears. The umbilical hernia began as a small lump on the bear’s underside that, over time, became extremely noticeable--even to the casual observer. Waldron described the anesthesia, transport, physical exam, surgical, and educational procedures involved in this case. The surgery was successful and the bear recovered completely. This operation became an entire Zoo effort, involving the curator, keepers, veterinary staff, facilities, and education. Multiple factors affect skin and haircoat health. Stress plays multiple roles, and water quality is also likely to be a large component. This is Part II of Briggs’ presentation. Part I discusses physical exams, anesthesia, and potential disease risks. Finally, Briggs presented a summary of veterinary issues. Skin and Haircoat Abnormalities Environment: When a bear has skin or haircoat problems, look at the bear’s environment first. These environmental issues are important to examine:
Nutrition: Nutritional factors to consider are whether the bear’s diet contains appropriate amounts of fat and fatty acids, Vitamin A, and Vitamin E. Bacterial infection: Bacterial infection is not common, but it does occur. Look for multiple epidermal bacteria, “rain scald,” and secondary invaders from environmentally induced epidermal breakdown. Stress: Stress is difficult to quantify, but directly affects immune function--which can in turn lead to skin and haircoat problems. Stress directly affects metabolic rate and multiple hormone (steroid) pathways as well. There seems to be a correlation between decreased stress and improved haircoat, but the impact of stress on skin and haircoat needs further study. Fungal infection: Causes of fungal infection include moist conditions and soil-born fungi. The polar bear’s hair structure can be prone to fungal infection, and an immuno-suppressed animal is particularly susceptible. Scheels offers his services to zoos and receives approximately 20 significant cases per year. He also trains other dentists and veterinarians in providing dental care to captive animals, and trains keepers on symptoms to look for that may indicate early dental problems. Many of the cases on which Scheels consults are life threatening, because polar bears and other animals will hide discomfort. Because animals do not tend to show pain until the situation is critical, it’s important to look for early symptoms. Symptoms of dental problems can include loss of weight, drooling, slight behavior change, and body language (in the case of chronic pain). Open-mouth training is very valuable, and enables keepers to check for soft-tissue problems or discoloration. Dental problems common in polar bears include:
Diet is the best way to prevent many of these problems. Scheels also stressed the importance of having no chains or metal bars in enclosures--bears often chew on them and cause dental trauma. The polar bear’s mandibular canine is the primary tooth to save. Scheels would not consider doing a root canal for a minor tooth. He might consider doing a crown on a young bear to prevent a tooth from splitting. Pathology, diagnosis, and treatment are the same for all mammalian teeth. A dentist can prepare for animal work by studying skulls. Briggs summed up the Veterinary Issues portion of the conference by focusing on the importance of behavioral enrichment/training and encouraging more studies of stress in polar bears. Veterinary Issues, Summary
Physiological StudiesCase study. Fractures seem to occur more often in polar bears than in other ursids. Many fractures occur in cubs, and involve the radius and ulna. What is the most effective treatment option for these fractures? Could a Vitamin-D deficiency be a contributing factor? Fractures in polar bears are not uncommon. Trauma--falling into moats, slipping on ice, slipping and falling between rocks--is the typical cause of a fracture. Cubs experience fractures more often, likely due to their immature bones and youthful play. The radius and ulna are the bones most often involved--and that may be due to the fact that a greater percentage of total body weight is borne by a polar bear’s forelimbs. Surveying the treatment options and reviewing the results of 18 fractures in 11 animals, Lin suggested that internal fixation, rather than a cast, was the preferred treatment modality. This study also considered whether vitamin and mineral deficiency (specifically, Vitamin D, calcium, and phosphorus) played a role in fractures. In captivity, Vitamin-D deficient sows may have Vitamin-D deficient milk. In addition, polar bears experience minimal synthesis of Vitamin D through the skin--so they are dependent on diet to meet requirements. Decreased Vitamin D plus lack of exercise can lead to decreased bone density/strength and can predispose a bear to fractures. In two out of the three zoos surveyed, polar bears had low levels of serum 25-OH Vitamin D. Lin suggests that Vitamin D supplementation may be warranted. Ackerman did a telephone survey of 39 North American facilities with polar bears, to determine whether there is a correlation between diet and coat concerns. The survey data included 48 male bears and 62 female bears. Polar bears in the surveyed zoos are being fed a diet that includes meat, fish, dry food (Mazuri Polar Bear Chow), and produce. They are also given Vitamin A, lard, and fish oil. Many of the zoos see seasonal fluctuations in appetite--lower appetite in Fall and Winter, and increased appetite in Spring and Summer. Only 9.6 bears ate consistent levels year-round. Keepers were asked about coat concerns in their bears, and were given a response choice of None, Yes, or Thin Coat. Results were:
Coat concerns occurred more frequently in females than in males. Exhibit DesignJones was a keeper at the Philadelphia Zoo in the 1940s, and surveyed the history of polar bears in captivity. The first polar bear in captivity was recorded in 1,000 A.D. One was kept in the Tower of London in 1185. The first captive polar bears came from Norway and Greenland, after being captured by Norwegian whalers. The longevity record for a captive polar bear is 42 years (in Detroit). Zoo designer Carl Hagenbeck (d. 1913) promoted a “zoo without bars,” with moated exhibits where animals were displayed in a more natural habitat. Modern zoos have continued to build on that philosophy. The first zoo to successfully breed polar bears was the Milwaukee Zoo, where 1.3 bears were born in 1912. In 1919, of 29 cubs born, only 8 did not survive. Possible factors in the Zoo’s success included a large exhibit size (30 feet long by 18 feet wide) and free access to dens. Bears were bred to partial 1/3 generation. The Detroit Zoological Park has 2.4 polar bears. Poulsen described the Arctic Ring enclosure, currently the world’s largest polar bear exhibit. The entire exhibit comprises 4.2 acres, with 2 acres set aside for the polar bears. The polar bear area has both tundra and pack-ice environments, and includes a saltwater pool (in the pack-ice area), shallow freshwater pool (in the tundra area), den area, natural substrate for digging day beds, and moats to separate the tundra and pack-ice enclosures from each other. In addition, the exhibit includes a 70-foot-long underwater viewing tunnel so visitors can watch polar bears (and seals, in an adjacent exhibit) dive and swim. The Baltimore Zoo opened its “Polar Bear Watch” exhibit in October 2003. Bartos introduced the exhibit to conference participants and described the design process and how they helped their bears adjust to the new environment. The Zoo’s original polar bear exhibit was built in the 1940s, and consisted of a rocky land area and a large pool. The den area was restrictive and made keeper access difficult. The Zoo incorporated keeper input when designing the new exhibit. Designers also made last-minute changes to meet the new Manitoba recommendations. During the early construction phases, designers did routine walk-throughs with keepers--this enabled keepers to point out errors early, and gave them a sense of ownership. The new exhibit incorporates one of the tundra buggies used to view polar bears in Churchill. The public can go inside, sit, and view the bears in comfort. (The original windows were replaced to provide more safety.) The landscape was designed to mimic the tundra environment of Churchill and includes two pools. Both above- and below-water viewing are possible. Folia panels and changeable display cases offer interpretive information to the public. Construction of the holding building was completed first, giving the keepers a chance to move the bears and help them adjust to the new environment before they were put on exhibit. Due to construction delays, the bears had only 10 days in the holding facility before the exhibit opened. Keepers organized their training activities around helping the bears to adjust. The result? The bears’ stereotypical behaviors are virtually gone in the new exhibit, and visitor reactions have been extremely positive. When designing its new polar bear exhibit, Sea World Australia (not affiliated with the American company, SeaWorld) went to Manitoba for advice. It used and exceeded the Manitoba standards. Sea World Australia has 2.2 polar bears. The Sea World polar bear exhibit is L-shaped, with more than 14,000 square feet. The back area is almost as large as the front. The main exhibit has a saltwater pool as well as freshwater, ozone-treated pools. Underwater viewing is available for the public. Several exhibit features help manage Australia’s tropical heat and humidity. Keepers can create rain in three different areas of the exhibit, and seven large wind-tunnel fans (capable of creating wind from 1 to 25 knots) lift humidity out of an area. All dens have air conditioning, and because bears always have free access to the dens (except during cleaning), they have a choice of climate conditions. In an effort to minimize skin and haircoat problems due to dampness and humidity, back dens are filled with straw and fatigue mats (to allow air to circulate and keep bears off the concrete). Dig pits are self-draining and allow keepers to easily change substrate material when needed. Behavior TrainingKeepers/trainers and veterinarians have common goals, but do not always have a strong collaborative relationship. When both parties stay in regular communication with each other and demonstrate trust and respect, polar bears benefit from minimally invasive veterinary care and increased mental stimulation. When trainers/keepers were surveyed, 47% reported that they have formal training programs for their polar bears. 83% consider training to be an essential part of husbandry--but only 14% have direct vet involvement in their training efforts. However, 96% thought a collaborative relationship with the veterinarian would improve animal care and welfare. Open communication is a key factor in the vet-trainer relationship. Vets need to fully describe the procedure itself, associated sounds that may occur during the procedure, and potential pain levels. Then, the keeper can decide which behaviors to train, the time and duration of training, level of risk, and so on, in an effort to facilitate the procedure and the bear’s full recovery. If necessary, the keeper should be able to negotiate with the vet--for example, to delay the procedure if more training is required and it is medically possible to do so. Throughout this process, it’s important that both keeper and veterinarian set realistic goals. According to Briggs, virtually all procedures require some husbandry training. Basic husbandry behaviors that should be in a bear’s repertoire are the “paw present” and “open mouth.” Ideally, veterinarians and trainers should work together from the beginning of training--possibly by setting up a monthly session or using a vet tech if the veterinarian is unavailable. This desensitizes the animal and can reduce stress levels. We used to think polar bears could not and should not be trained. We now know that training helps to avoid undesirable outcomes and to encourage desirable outcomes. You can’t make a polar do anything he doesn’t want to do, so we need to create a positive attitude in the bear toward learning. Here are some tips on how to do that:
A polar bear’s behavior choices are directly related to the consequences that follow (for example, removal of positive reinforcement). We’re always training: polar bears respond to everything we do, so we often train inadvertently. If the frequency of an undesirable behavior is increasing, somehow it is being reinforced. As unwanted behavior arises, figure out the cause and do new training to address it. In designing training, you always need to consider the individual history of each bear. Once an animal learns a behavior it is difficult to unlearn it. Therefore, plan ahead so the animal’s first experience is a positive one. Every polar bear presents a different training challenge. Christie’s presentation on “Training 102” described some of the training approaches you can use for common situations. Regardless of the situation, these basic training approaches may prove useful:
For example, if you want to deliver pole injections to a bear, you might design a training plan that includes these techniques:
Advanced training approaches:
Case study. A challenging holding facility with minimal training areas required creative use of the existing space. The Lincoln Park Zoo in Chicago had minimal space for trainers to work with their polar bears. A barred exhibit door gave the only access to bears--and although this worked fine for general inspections, there was room for only one bear. This made it difficult to reinforce the second bear. Trainers found that by creatively using the existing space, they could create new training opportunities that also provided more diversity for the bears. For example, one day while cleaning the glass wall perimeter, Weitz observed that the scaffolding on which she stood was very interesting to the bears. She realized she could train the bears from there. The underwater viewing window became another training location--with the added benefit that visitors could be educated on how and why they trained the bears. In the off-exhibit area, the solid access door was changed to a mesh door to provide yet another training area. Trainers were able to teach “open mouth” and “paw present” behaviors, for example, at the mesh door. They also used a laser pointer while at the mesh door to teach the bears to get into position for hand injections, ear wipes, and so on. In summary, although the Zoo did not have the optimal design for training, trainers were able to use the existing space with slight modifications to increase the training areas and provide more diversity. |
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