Training Birds for Husbandry and Medical Behavior to Reduce or Eliminate Stress
By Barbara Heidenreich
First presented at the Association of Avian Veterinarians Conference 2004
The history of animal training has evolved tremendously over the past century. What once was considered revolutionary is now expected practice with a variety of animal species in captive situations. Of incredible significance has been the training of animals for basic husbandry needs and medical behaviors. Via the use of operant conditioning with an emphasis on positive reinforcement, animals have been trained to cooperate and/or accept a variety of previously potentially stressful circumstances. Much of the ground breaking work in this field was generated from the marine mammal training community. This has since grown to include primates, elephants, rhinoceros, various hoof stock, bears, large cats and more. However, it is evident that this may be just the beginning of even more training accomplishments to come. There has been a heavy focus on training large mammal species for husbandry and medical behaviors. This is certainly understandable, as previous methods of trying to treat medical conditions or gain cooperation with a large mammal through force, restraint, anesthesia, etc, had the potential to be dangerous and detrimental. As we learn more about the application of operant conditioning with a focus on positive reinforcement and see people and animals benefit from the results, it is a natural progression to see this methodology permeate into other taxa.
Avian species, possibly due to their relatively small size, are still often captured and restrained for husbandry and medical procedures. It is considered standard practice in many cases. It is reasonable to assume that there will always be procedures that will require physical restraint to best serve the health and welfare of the bird. However, as has been demonstrated with large mammals, there is great potential to reduce and/or eliminate the need for the use of restraint to accomplish a variety of husbandry and medical goals. In addition, if restraint is necessary, animals can be conditioned to reduce the potential stress that may accompany restraint procedures. Many bird species respond exceptionally well to positive reinforcement. With an incredible capacity to learn, birds are excellent candidates for husbandry and medical behavior training.
The Value of Training Birds for Husbandry and Medical Behaviors
Training birds using positive reinforcement has been shown to be extremely successful in bird shows. Many people have seen free flighted birds willingly return to a handler/trainer on stage. Usually birds in show situations have also been trained to present a variety of behaviors that facilitate handling and program presentation. These behaviors include stepping up, sitting on a scale, going into travel containers and more. Training these behaviors may involve more hands on contact than is required to meet a specific collection’s training goals. However, examining the training practices of free flight presentations can provide some important insights.
Because a free flighted bird has the option to fly away if the experience is negative, it forces the trainer to learn to be extremely sensitive to bird behavior. A successful trainer will do his or her best to avoid any circumstance that might cause a bird to display fear, nervous or aggressive behavior. In addition, a successful trainer will also provide positive reinforcement as the consequence of the performance of desired behavior. By avoiding aversives and providing positive consequences, birds are more likely to present desired behavior. In addition, these practices can result in a situation in which a bird does not show behavioral (and most likely physiological) signs of stress. This can easily be applied to other training goals and circumstances.
Evidence of reduced stress in husbandry and medical procedures has been demonstrated many times with other animal species. Denver Zoological Gardens measured blood parameters of bongo (Tragelaphus eurycerus) after sedation via a dart or pole syringe. They also measured blood parameters on bongo (T eurycerus) conditioned with positive reinforcement for loading into a crate and a variety of other husbandry and veterinary procedures. Values for these blood parameters, commonly associated with stress, appeared to be lower in crate conditioned animals (Phillips, Grandin, Graffam, Irlbeck and Cambre 1995) By training an animal to cooperate in its own health care, life becomes less stressful for the animal and trainer. (Ramirez, 1999) Some other examples of procedures trained with positive reinforcement include tigers sitting calmly for blood draws, lions allowing their teeth to be brushed, primates presenting their arms for tuberculosis testing, killer whales urinating on cue. Anesthetizing or restraining these animals for procedures seems impractical now. However, this is not yet the case for many birds.
It is not uncommon for birds to be chased in the aviary until exhaustion allows them to be captured. Birds have also been hosed until too wet to fly to facilitate capture. Nets and towels are typical conditioned negative reinforcers to birds that have come to learn these items mean chase and/or restraint. While these methods may be relatively quick and easy for people to use, the effect to the bird may be more detrimental than helpful. Most birds fall into the category of “prey” in the wild. Capture and restraint in the wild usually is a precursor to death. Fight or flight responses most likely are exhibited by birds facing chase, capture and restraint. This can result in elevated corticosterone levels, increased heart rate, rapid breathing, elevated blood pressure and more physiological responses associated in the alarm reaction stage of stress. Some birds, if exposed often enough to capture and restraint, can learn to acquiesce and/or tolerate this practice. However, this occurs after a series of exposures to the stressful process or prolonged exposure to this type of stress. There is considerable research that shows the long term detrimental effects of repeated exposure to uncontrollable aversive events with both animals and people. (Mazur 2002) In one unfortunate incident, an African grey parrot (Psittacus erithacus) was so stressed by procedures utilized for nail and wing trims, the owner requested the bird to be anesthetized. The veterinarian chose not to do so, and as a result the bird expired during the procedure. (Wissman 2003)
Training with positive reinforcement can allow birds to learn to voluntarily participate in husbandry and medical behaviors and potentially avoid the stress associated with capture and restraint. Stress can exasperate an existing medical condition, cause nest or egg abandonment and/or become associated with the individual causing the stress. (Many animals learn to associate veterinarians with negative experiences and show stress responses or aggressive behavior at the sight of the veterinarian) In addition, birds trained with positive reinforcement are more likely to perform the required behaviors more often to earn the reinforcement. This allows more opportunities to monitor birds’ health. Collecting weights, visual and/or tactile exams and other preventative procedures can be much easier to perform. Preventative medicine with birds can be highly effective due to birds’ innate tendency to mask symptoms. Symptoms such as large weight fluctuations can be easily noted and signal caretakers to observe an animal for questionable health. Another interesting phenomenon that can occur from using positive reinforcement training is that sick animals will often still perform behaviors when cued. If a behavior in the past has been positively reinforced, that history of reinforcement may be powerful enough that even though an animal is symptomatic, it will still perform the requested behaviors. Again this can prevent the need to stress an already compromised animal to obtain medical information. Furthermore, as the following examples demonstrate, medical and husbandry behaviors with birds can be trained. Choosing to implement such advances in avian care and management can dramatically effect the quality of care provided to birds and progress aviculture into the future.
Examples of Husbandry Behavior Training
For the purposes of this paper, husbandry behaviors are described as behaviors that facilitate the day to day operation of a facility that manages birds on exhibit and/or in aviaries. These behaviors include, but are not limited to training birds with the use of positive reinforcement to do the following:
Stationing: To stand or sit for a period of time in a designated location.
Targeting: To touch a body part or direct a body part to a specific item (such as a hand, stick, overturned tub, etc.) This can sometimes be similar to stationing. For example if a turkey is trained to target its feet or stand on a rock, it may also be said to be stationing on the rock.
Shifting: To move from one location to another designated location. Typically the subject is prevented from returning to the original location by a physical barrier (such as a door)
A to B: To move from point A to point B.
Crating: To enter into a crate or travel container, allow door to be shut and container to be moved without the bird(s) showing signs of distress.
Recall: To return to a designated area when signaled.
While these behaviors can be useful for a number of different circumstances, they are especially helpful for managing birds that are not handled, display aggressive behaviors, live in large aviaries, and/or live in flock situations. The following examples illustrate the practical application of these husbandry behaviors.
At Disney’s Animal Kingdom Lodge, marabou storks (Leptoptilos crumeniferus) share a large exhibit with a variety of animals. Prior to training, feeding the storks by hand resulted in a keeper being surrounded and harassed by hungry large birds. To address this, the birds were trained to station on overturned rubber tubs. This training resulted in the birds waiting on their stations to be fed and reduced harassment of the keeper.
Also on exhibit at Disney’s Animal Kingdom Lodge are African crowned cranes (Balearica pavonina). The cranes on exhibit were required to shift between the exhibit and nighttime holding enclosures daily. During the shifting process, an imprinted male crane would display aggressive behavior towards the keeper. To reduce the aggression, the bird was trained to station on a series of overturned tubs on its way in or out of its nighttime holding. This gave the bird a place to focus its attention for positive reinforcement, as opposed to presenting aggressive behavior towards the keeper.
At Dallas World Aquarium, two jabiru storks (Jabiru mycteria) would consistently display aggressive behaviors towards keepers that attempted to enter the enclosure. In addition, one stork would drive the other stork away from the food. To remedy this situation, both storks were trained to station on separate wooden discs. This successfully eliminated aggression towards keepers and aggression related to competition for food. It also ensured each bird was receiving adequate food and allowed keepers to better monitor food intake in general for each bird.
At the Houston Zoo, aggressive rhinoceros hornbills (Buceros rhinoceros) were trained to sit or station on a particular perch while the keeper entered the exhibit. Teaching the birds they would be positively reinforced periodically for remaining on the indicated perch reduced aggressive behavior displayed by the birds and allowed the keeper to attend to the exhibit.
Another method to address aggressive behavior is to train an animal to shift from one area to another. This allows an animal caretaker to enter an enclosure without having to interact with an aggressive animal. At Disney’s Discovery Island a small shift cage was built and attached to the larger aviary to address hornbill aggression. The hornbill was then trained to go into the shift cage for its diet and closed in the area.
Training smaller birds in large aviaries for husbandry behaviors may seem to be too great a challenge. However facilities such as Moody Gardens have accomplished this. The Rainforest Pyramid exhibit at Moody Gardens is 10 stories. Sun bittern (Eurypyga helias) and fairy bluebird (Irena puella) have been trained to perform a recall when cued and voluntarily load into crates for transport and periodic weight measurements.
Bell bird (Procnias alba), spangled cotinga (Cotinga amabilis), troupial (Icterus icterus) and green aracari (Pteroglossus viridis) at Dallas World Aquarium also voluntarily load into a small wire cage used to transport birds to different enclosures. This training was completed in anticipation of moving the birds to a new exhibit. Knowing this move was to occur allowed staff the time to incorporate short training sessions daily, well in advance of the actual relocation.
SAIC Biosolutions produces mobile exhibits of 400 birds. These birds include finches (Taeniopygia guttata), cockatiels (Nymphicus hollandicus), budgerigars (Melopsttacus undulates), and rosellas (genus Platycerus). At the Hogle Zoo SAIC Biosolutions exhibit, all 400 birds have been trained to come off exhibit and enter crates. All 400 birds voluntarily load into crates twice a year for veterinary examinations and as needed for travel.
Examples of Medical Behavior Training
For the purposes of this paper, medical behaviors are described as behaviors that involve procedures that monitor or attend to the physical condition or health of the birds. These behaviors include, but are not limited to training birds with positive reinforcement to voluntarily participate in the following:
Sit or stand on a scale
Allow nail filing or trim
Allow trimming of flight feathers
Allow wrapping in a towel
Present foot for exam
Allow general tactile exam
Allow keel and breast muscle to be palpated
Allow preen gland exam
Allow touch with swab
Allow touch with gauze pad of alcohol
Accept medication in liquid delivered with syringe
Allow bandage change
Accept eye drops
Provide fecal on cue
Allow stethoscope exam
Allow body temperature reading
Allow cloacal swab
Allow ultrasound exam
Allow blood draw
Training medical behaviors can be more involved than training husbandry behaviors. In addition many of the examples presented in this paper involve birds that are comfortable with handling. However, some medical behaviors can be accomplished without the need to handle the birds. Creative thought and training most likely will provide impressive progress in the training of medical behaviors in protected contact situations in the future. A few examples of training of medical behaviors without hands on contact will be presented here. The following examples illustrate the practical application of medical behaviors with or without physical contact.
Obtaining a weight on a bird can be a very simple behavior to train. Parrots can be easily trained to step from a hand or perch onto a scale. However, birds not usually handled can also be easily trained to stand on a scale. At Disney’s Animal Kingdom Lodge, the simple behavior of stationing on a tub for cranes and storks was easily modified to standing on a scale. This was done by simply placing a flat scale on top of the tub. This same concept was used to train the jabiru storks (J mycteria) at Dallas World Aquarium to stand on a scale.
Birds on exhibit, held in enclosures, or in aviaries can also learn to stand on a scale. An Andean condor (Vultus gryphus) at the Oregon zoo often preferred to perch by the door to its enclosure. To obtain a weight on this bird, a scale was permanently and securely placed in the enclosure by the door. The condor simply continued to perch in its favorite location. However, this time the perch location had been modified to include the scale. This is also a very effective method for small birds such as finches. Favorite foods or food bowls can be placed to encourage perching on the scale to easily obtain weights on a daily basis.
At Dallas World Aquarium weights are easily obtained on cock of the rock (Rupicola rupicola), bell bird (P alba), spangled cotinga (C amabilis), troupial (I icterus) and green aracari (P viridis) by simply using Velcro to attach a bowl of favorite food items to a scale. The birds land on the bowl and the weight is recorded while the bird eats. This session is usually done just prior to placing the regular diet in the aviary to ensure the birds have an interest in the food items offered.
Training a bird to target to an object can also facilitate obtaining a weight. A bird that learns to follow a specific object, such as a hand, can be lured over a scale. John Ball Zoo used this method to teach a chicken to stand on a simulated scale.
Targeting was utilized to train a sick macaw to inhale medications at Parrots and People, a parrot sanctuary and adoption facility. Sheba, a blue and gold macaw (Ara ararauna), was showing signs of respitory distress. After a trip to Texas A & M University Veterinary Teaching Hospital, the bird was sent home with a prescription for Albutoral, which was to be administered when breathing difficulties were observed. It was recommended to administer the medication by attaching a nebulizer to the spout of container, such as a milk jug, with the bottom cut out. The birds head was to be put into the open bottom end of the container to administer the treatment. The bird, however had never been handled, or separated from it’s mate. Rather than capture and restrain Sheba and potentially further exasperate the problem, the decision was made to train the bird to voluntarily accept the treatment. This was achieved by training the bird to target the end of a stick with its beak. The stick was then inserted through a hole in a container. The stick was gradually pulled into the container to train the bird to put its head farther into the container. Other factors were gradually added to the training sessions. These factors included the nebulizer and a latex covering over the large opening of the container. The latex covering had a slit cut out to allow the bird to insert its head into the container, yet prevent the medication from escaping. Within one week, this bird had learned to voluntarily participate in the treatment. The bird remained in its enclosure during the treatment and handling was not required. In addition, it is possible this behavior can be modified as a way for birds to be trained to voluntarily accept inhaled anesthesia.
Training behaviors that require touching a birds body or introducing unusual objects can be achieved via a process known as conditioning. Positive reinforcement, usually in the form of food, is presented in association with the new circumstance or object. Introducing these new circumstances or objects is done in a manner that does not promote behaviors that indicate fear, nervousness or aggression in the animal. Training birds to accept nail trimming and flight feather clipping are familiar examples of this type of training. However this process can be applied to many medical behavior training goals.
Several parrots at Parrots and People, have been trained to accept various medical behaviors via conditioning. These behaviors include the following: allow nail filing, allow wrapping in a towel, allow foot visual and tactile exam, allow general tactile exam, allow keel and breast muscle to be palpated, allow preen gland exam, allow stethoscope exam. One of the parrots, a Panama Amazon (Ochrocephala panamensis), was trained to allow nail filing, keel palpitation and foot examination while the bird remained in an enclosure. This was to demonstrate how to achieve these behaviors with a parrot that is not comfortable with handling. The bird was trained to target its beak to an object in order to obtain a body position that facilitated the procedures, and then conditioned to accept the medical procedures.
Some other examples of utilizing conditioning to train medical behaviors include the following: Moody Gardens trained parrots to accept being touched with a swab and a gauze pad to facilitate application of medications. Staff also trained parrots to accept liquid oral medications through a syringe. SeaWorld of San Diego used conditioning to treat a chronic bumble foot problem on an African fish eagle (Haliaetus vocifer). Training the bird to accept the application of topical medication and bandage changes allowed the staff to avoid the difficult and stressful task of capturing and restraining the eagle on a daily basis. This bird was also conditioned to accept an intramuscular injection without restraint. Staff at the Taronga Zoo in Australia conditioned an Andean condor (V gryphus) to accept eye drops without the use of restraint. Staff at the Utica Zoo conditioned a hyacinth macaw (Anodorhynchus hyacinthinus) to accept cloacal insertion of a thermometer to monitor this bird’s health. This became especially important when the bird did become ill. Although the bird was symptomatic, a solid positive reinforcement history with this behavior allowed keeper staff to obtain a temperature from this bird without incident.
Dolphin Discovery in Mexico has taken the training of husbandry and medical behaviors to new levels. In addition to the behaviors mentioned above, their collection of ten macaws will voluntarily participate in blood draws and are also being conditioned to accept radiographs and ultrasound examinations. Most of the staff at Dolphin Discovery learned animal training skills by working with marine mammals. By applying the same training skills and structured training program to their bird collection, they achieved unheard of goals in the bird training community. By exploring options outside the constraints of traditional bird care practices, incredible progress can be made in the care and management of avian species.
Developing a Training Program
The previous examples demonstrate training birds for husbandry and medical behaviors can be accomplished. It may be surprising to learn that achieving some of these training goals can be relatively easy.
It is often stated that facilities find it difficult to invest time in training. However, facilities are training all the time. Although it may not be a structured training program, any time a bird is aware and reacts to a caretaker’s action, training is occurring. For example: a frightened bird that flys to the back of an enclosure because a caretaker has picked up a broom, may have learned to associate aversive stimuli with that caretaker. In addition every time the same food bowl is placed in an enclosure, a bird may learn to associate positive reinforcement with that bowl. This can be a highly powerful training tool. An important step towards developing a training program at a facility is to teach staff to be aware of their actions and how it effects bird behavior.
To facilitate efficient use of time, facilities can also keep training sessions short. Sessions can be 5-10 minutes. They can occur whenever birds are being fed. They can also occur several times throughout the day, or just a few times a week. Usually more training sessions in a given time allows training goals to be achieved faster. However, training goals can still be achieved with infrequent sessions over a longer period of time. Sessions can also be relatively passive depending on the desired behavior. For example training birds to go into a crate may be as simple as placing food bowls closer and closer to the crate over a period of days. Facilities with young birds can begin exposing those birds to unfamiliar objects they may encounter later in life. Often young birds are more accepting of new things. Associating items, such as crates, stethoscopes, nail clippers, scissors, etc. with feeding times can help desensitize birds to these objects. Staff can easily turn a feeding session into a training session.
Although training can be easily introduced into a daily routine, the time invested to develop a structured training program has tremendous benefits. Eventually husbandry and medical procedures can be performed quickly, efficiently, and calmly and save time in the long run. Instead of viewing training as an additional luxury to include in daily operations, consider viewing training as essential to the successful operation of a facility. Zoological facilities are beginning to realize not only the benefits to day to day facility operations, but more importantly the benefit to animal health and welfare. Behavior Husbandry programs in zoos are emerging as a requirement for the American Zoo and Aquarium Association (AZA) accreditation. Rather than squeezing in time to train, many zoos are moving towards ensuring staff have time to train and structured training programs are in place.
Any facility or person caring for birds can benefit from training husbandry and medical behaviors. To truly experience these benefits, consider implementing a structured training program. A training program may involve educating staff about behavior modification theory, developing training goals and strategies, implementing training sessions, record keeping, and follow up on progress. While describing the details of developing a structured training program is beyond the scope of this paper, there are resources available to facilitate program development. These include private consultants, organizations such as AZA, The International Association of Avian Trainers and Educators (IAATE), Animal Behavior Management Alliance (ABMA), workshops, literature, websites, listservs, peers, colleagues and more. Please see the resources section of this paper for more specific contact information on these resources.
In the past, the words “bird training” conjured up images of birds on bicycles and roller skates. Today, training is an essential tool we can utilize to provide for the health and welfare of the avian species we steward. It is my hope that the examples presented in this paper will provide inspiration and motivation for bird caretakers to explore ways to reduce stress in husbandry and medical procedures in their avian collections by developing structured training programs. Training has the power to do much more than entertain us. It can facilitate efficient daily operations and improve the quality of life of the creatures that give us so much pleasure. I hope bird training will become a priority in your facility.
The following people and/or facilities are responsible for the indicated training examples in this paper, accompanying PowerPoint and/or video presentations:
Barbara Heidenreich- Animal Training and Consulting Services www.ATandCS.com and staff members of listed facilities
Parrots and People: www.parrotsandpeople.org
Cockatoo step up onto hand
Macaw step onto scale
Macaw trained to accept inhalant
Conure conditioned to accept towel
Conure conditioned to accept tactile exam (keel, preen gland, feet, wings, vent check, etc)
Conure conditioned to accept stethoscope exam
Conure trained to open mouth
Conure trained to go into a crate
Amazon Parrot conditioned to accept nail filing in protected contact situation
Amazon Parrot conditioned to accept foot examination in protected contact situation
Amazon Parrot conditioned to accept keel and breast muscle palpitation in protected contact situation
Dallas World Aquarium: www.dwazoo.com
Manatee stationing and conditioning for blood draw
Saki Monkey targeting and sit on scale
Jabiru Stork stationing and stand on scale
Cock of the Rock, Bell Bird, Green Aracari, Spangled Cotinga, Troupial stand on scale
Bell Bird, Green Aracari, Spangled Cotinga, Troupial go into transport cage
John Ball Zoo: www.accesskent.com/visiting/zoo/zooindex.htm
Chicken targeting hand to step onto scale
Dr. Renato Lenzi - Dolphin Discovery www.dolphindiscovery.com
Macaws conditioned to accept wing and nail trim
Macaws conditioned to accept tactile exam
Macaws conditioned to accept cloacal swab
Macaws conditioned to accept stethoscope exam
Macaws conditioned to accept blood draw
Macaws conditioned to accept simulated radiograph procedure
Macaws conditioned to accept simulated ultrasound procedure
Peta Clarke -Taronga Zoo www.zoo.nsw.gov.au/index.htm
Condor conditioned to accept eye drops
Cathi Wright -Oregon Zoo www.zooregon.org
Condor stationing on a scale
Matt Schmitt- Houston Zoo http://wild.houstonzoo.org/Public/index.asp
Aggressive Hornbill stationing while keeper enters exhibit
Heather Leeson - Moody Gardens www.moodygardens.org
Conure trained to accept oral medication through a syringe
Cockatoo conditioned to accept swab or gauze pad application
Sun Bittern, Guan, Fairy Bluebird trained to come off exhibit and go into crates
Alison Sinnott- Utica Zoo www.uticazoo.org
Macaw conditioned to accept cloacal thermometer insertion
Jenny Schaefer and Keri Caporale -Seaworld San Diego www.seaworld.com
Fish Eagle conditioned to accept intramuscular injection and bandage change to feet
Bird Keeping Staff - Caldwell Zoo www.caldwellzoo.org
Macaw conditioned to accept wing stretched out
Barn Owl on scale
Animal Care Staff – Disney’s Discovery Island (facility permanently closed)
Hornbill trained to shift to separate holding
Animal Lodge Animal Care Staff - Disney’s Animal Kingdom http://disneyworld.disney.go.com/waltdisneyworld/parksandmore/parkindex?id=TPAnimalKingdomPrk
Storks and cranes trained to station on tubs for feeding, shifting and weighing
Animal Care Staff- John Ball Zoo www.accesskent.com/visiting/zoo/zooindex.htm
Chimps presenting chest for stethoscope exam
Andy Schleis SAIC- Biosolutions www.saic.com/biosolutions
Flock of 400 Finches, Budgerigars, Cockatiels and Rosellas trained to go into crates
I would like to thank the following for their support and input in the development of this paper: Parrots and People for the use of their parrots as training subjects (www.parrotsandpeople.org), Dr. Renato Lenzi and his staff at Dolphin Discovery, Peta Clarke and Mathew Kettle at Taronga Zoo, Cathi Wright and Shannon LaMonica at the Oregon Zoo, Matt Schmitt at the Houston Zoo, Heather Leeson and Kat Fowler at Moody Gardens, Jenny Schaefer at Seaworld San Diego, Andy Schleis and Scott Klappenback of SAIC- Biosolutions and Christine Barth of Disney’s Animal Kingdom Lodge.
Barth, C. (2003) Stepping up the Training Process: The Benefits of Stationing East African Crowned Cranes and Marabou Storks. International Association of Avian Trainers and Educators Proceedings. Portland, OR.
Canoine, V., Hayden, T., Rowe, K., Goymann, W. (2002) The Stress Response of European Stonechats Depends on the Type of Stressor. Behaviour 139, 1303-1311.
Caporale, K., Schafer, J. (2003) Focused Behavioral Plan for African Fish Eagles. International Association of Avian Trainers and Educators Proceedings. Portland, OR.
Friedman, S. (2002) Alternatives to Breaking Parrots: Reducing Aggression and Fear through Learning. Stop PDD Virtual Conference: PsittaScene.
Lacinek, T., Scarpuzzi, M., Force, D., & McHugh, M. Sea World’s Husbandry Program Update (1999). Animal Training. Successful Animal Management through Positive Reinforcement. Chicago: Shedd Aquarium. 160-163.
Selye, Hans (1978, 1976) The Stress of Life. New York: McGraw-Hill.
Silervin, B. (1998) Behavioural and Hormonal Responses of the Pied Flycatcher to Environmental Stressors. Animal Behaviour. Volume 55. 1411-1420.
Mazur, J. E. (2002) Learning and Behavior. Prentice Hall.
Phillips, M., Grandin, T., Graffam, W., Irlbeck, N., Cambre, R. (1998)
Crate Conditioning of Bongo (Tragelaphus eurycerus) for Veterinary and Husbandry Procedures at the Denver Zoological Gardens. Zoo Biology, 17, 25-32.
Ramirez, K. (1999) Animal Training. Successful Animal Management through Positive Reinforcement. Chicago: Shedd Aquarium.
Wissman, M. (2003) Causes and Cures: Anesthetizing During Grooming. Bird Talk. January, 2003.
Animal Training and Consulting Services- Barbara Heidenreich www.ATandCS.com
International Association of Avian Trainers and Educators www.IAATE.org
American Zoo and Aquarium Association www.AZA.org
Animal Behavior Management Alliance www.theABMA.org
Disney’s Animal Kingdom training program www.animaltraining.org
“Don’t Shoot the Dog” by Karen Pryor (1999 Bantam Publishers) www.clickertraining.com
“Animal Training. Successful Animal Management through Positive Reinforcement: by Ken Ramirez 1999 (Shedd Aquarium Publishers) www.sheddnet.org.
The Cambridge Center for Behavioral Studies www.behavior.org
Marian & Bob Bailey Operant Conditioning and Behavior Analysis Workshops