The Power of the Secondary Reinforcer
(Expanding your List of Reinforcers)
By Barbara Heidenreich
First presented at The International Association of Avian Trainers and Educators Conference 2008



The power and role of the secondary reinforcer is often underestimated. Traditionally food has been the reinforcer of choice in training animals for conservation education programming. While food reinforcers can be extremely useful, secondary reinforcers have proven to be valuable when animals are satiated on food reinforcers. Secondary reinforcers can also help increase motivation by increasing reinforcer variety and allowing for novelty in reinforcers. They also provide a reinforcer that may retain its reinforcing value for long periods of time before an animal is satiated. By including secondary reinforcers in the repertoire, trainers may find alternative means to influence behavior and in turn expand their training skill set. Video examples will be provided to demonstrate the important role secondary reinforcers can play in animal training.

Primary and Secondary Reinforcers

The Cambridge Center for Behavior Studies defines primary and secondary reinforcers as follows: Primary reinforcers are reinforcers the effectiveness of which does not depend on its contingent relation to another reinforcer. This can be a stimulus, such as food, water, or sexual activity that usually is reinforcing in the absence of any prior learning history. They are sometimes described as reinforcers which are necessary for the survival of the species. The list of primary reinforcers is typically very, very small.

Secondary reinforcers are reinforcers that are dependent on their association with other reinforcers. They are also called conditioned reinforcers. They are a stimulus that initially has no reinforcing properties but, through occurring simultaneously with unconditioned or strongly conditioned reinforcers, acquires reinforcing properties. They are also called learned reinforcers. The list of secondary reinforcers can be endless.

Typically animal training relies heavily on the use of primary reinforcers, usually food, to increase desired behavior. Food is an extremely effective reinforcer under certain conditions. It has also been shown that given the choice to use their adaptations to acquire food, animals will choose to do so (contrafreeloading). Food also allows for quick repetition of behavior. It is useful if the list of secondary reinforcers is small or non existent. Food can also be paired with other items to expand the list of secondary reinforcers. It can help trainers avoid the use of negative reinforcement to increase behavior when applied well. (Heidenreich 2006) There are many benefits to using food as a reinforcer. However by adding a long list of secondary reinforcers to the training repertoire, trainers may find additional means to influence behavior that can be extremely powerful.

Examples of Reinforcing Alternatives to Food

One obvious application of the use of secondary reinforcers is when motivation for food reinforcers is low. Certainly one option is to consider means in which to create a higher level of motivation for food reinforcers. These can include the following strategies: reserve favorite foods for training, offer food in portions throughout the day and train before feeding, feed until satiated several times a day in training sessions, use small pieces of food to avoid satiation in the session, avoid over feeding, and train just before normal feeding time. (Heidenreich 2006)

However another option is to start looking for the plethora of other things that seem to stir up some motivation in the training subject. The following are examples in which secondary reinforcers were used to reinforce desired behavior.

Contact with a preferred person as a reinforcer:
At one facility contact with a preferred person was used as a reinforcer to train a Sun Conure to step up onto new people. This was done by having the preferred person place the bird on a table and step away. In order for this clipped bird to have contact with the preferred person, the conure would step up onto a new person. The new person would then offer the bird an “elevator ride” to the preferred person. This reinforced the behavior of stepping up onto a new person. Over time staff members were able to phase out using the preferred person as the reinforcer. This is because the new person was being paired with a positive reinforcer and soon contact with the new person also became reinforcing.

Tactiles as a reinforcer:
Tactiles often have a great many applications as reinforcers. A yak with an apparent longing for contact would crowd keepers as they entered her enclosure. Although the yak’s body language indicated her intentions had to do with play, her size made it unsafe for the keeper to be a play mate for this animal. To give the keepers a means to redirect the yak to safer activities, it was decided to target train her. The yak had no interest in food reinforcers at the time of the training session. Furthermore her problem behavior also indicated that she wasn’t seeking food reinforcers. It was decided to offer a scratch on the neck when she presented desired behavior. The yak responded immediately. Within one session she was walking to a target to touch it with her nose, all for some tactile reinforcers.

Annual vaccinations can present challenges in that they often mean capture and restraint for animals. An Emu that responded well to tactile reinforcers was successfully injected without restraint simply by pairing tactile reinforcers with the procedure.

A young Blue Throated Macaw’s training regime often involved using food to reinforce behavior in the first half of the training session. The bird was reinforced with preferred food reinforcers until satiated. At this point tactile reinforcers were introduced to allow continued training. Tactile reinforcers were successfully used to train the bird to be comfortable with restraint in a towel and to also reinforce lying on her back.

Enrichment items as a reinforcer:
A zoo trained two Jackson’s Hornbills to participate in education programs. These highly inquisitive birds often found many seemingly ordinary objects quite stimulating. Observing the birds’ elevated interest in novel objects, the trainers began using enrichment items as reinforcers for desired behavior, such as entering a kennel, and flying to the trainer.

Sun Conures housed in an interactive aviary presented problem behavior of flying into the guest entry way in order to perch and chew on ceiling fans. To address this behavior, keepers looked for behaviors that typically preceded the problem behavior. In this case, the birds would often perch on a specific rope in anticipation of the door to the entry way opening. When keepers noticed the conures on this perch, they cued the birds to fly to the hand. Once on the hand the birds were offered various small parrot safe toys to destroy. Being that the reinforcer for going in the entry way was opportunities to chew other items, it was deemed enrichment items/toys were the preferred reinforcer for the undesirable behavior and could be used to reinforce acceptable behavior of flying to the hand.

Although not often considered a toy or enrichment, lures used for hawks, eagles and falcons are classic examples of secondary reinforcers. These items are usually initially paired with food. Over time the food is no longer attached to the lure. However the bird will still respond to the lure. Often the bird is reinforced with food for giving up the lure. The drive to capture prey also facilitates the lures reinforcing value.

Scent as reinforcer:
Mammal species often respond well to scent as a reinforcer. A Tamandua that was used in education programs was required to receive a generous diet to address a medical condition. This often made food reinforcers have less value in training. However the scent of a female Tamandua and vinegar proved to be powerful for reinforcers for this animal. Both have been used to reinforce behaviors such as climbing on a branch during presentations and returning to his kennel when cued.

The opportunity to go for a walk as a reinforcer:
The opportunity to pass through a doorway to go for a walk was paired with a pat on the back from a man for a New Guinea Singing Dog that would recoil from men. This same reinforcer was used to train a penguin to wear a harness. After each approximation of attaching the harness a door was opened that lead the bird one step closer to the highly enriching out doors.

Bath as a reinforcer:
To train an ostrich to walk from its enclosure to center stage the opportunity to bathe in fine dust was used as a reinforcer. The bird did not have access to the dust inside of its enclosure. Walking from point A to point B was easily reinforced with the bath, and also provided an interesting experience for the audience.

Activity itself as the reinforcer:
Also apparently reinforcing is the opportunity to be express activity. Skilled flying parrots often present a flight pattern that appears to support this idea. This flight pattern often involves the parrot quickly tilting its body from side to side in flight. It is also often accompanied by quick swoops and maneuvers through obstacles in the flight path.  This exuberance for movement can also be observed in confined hoof stock when they are first given access to large spaces.

Excitement as a reinforcer:
Some parrots seem to respond enthusiastically to people making loud noise or vocalizations. At a Parrot Behavior and Training Seminar in Canada, a Blue Fronted Amazon would pin his eyes, fan his tail and make noise along with me when I approached him talking in an animated voice. His interest in food was much reduced, but his response to my jubilant praise was quite encouraging. I decided to use this to reinforce the training of a new behavior. The behavior I chose was to teach him to lift his foot on cue. When I would approach him, he would offer his foot perhaps in anticipation of the opportunity to step up. Immediately when his foot went up, I reinforced with animated comments of “good boy.” He joined in with his own vocalizations, eye pinning and tail fanning. After a number of repetitions of this, he was eagerly lifting a foot on cue.

The list of potential secondary reinforcers can be very long.  It depends on the individual animal in training and under what circumstances. But by being open to the possibilities, trainers may find that there are so very many reinforcers to consider.

Pitfalls to Avoid

Whenever training an animal, it is critical to read and interpret body language. This can be especially important when attempting to use a novel type of reinforcer. While animated vocalizations worked well with the Blue Fronted Amazon in Canada. Vocalizations can create undesirable responses in some individuals. For some parrots loud animated reactions lead a bird to a heightened level of arousal. It is in this stage that some birds can cross into a realm of aggressive behavior. This may be attributed to the fact that excitement and aggressive behavior occur in the same portion of the brain. A chemical cascade of sorts may heighten a bird’s arousal to a level that produces undesirable results. Therefore it is important to be very selective as to when to use animated praise to reinforce. Often it is preferable to use it to train a behavior in which the animals does not come in contact with the trainer.  For some animals, a human talking is so arousing that it may require that trainers do not talk during sessions.

In addition using attention that seems to reinforce courtship behaviors may be problematic. While a parrot may show a preference for regurgitating on its perceived human partner, encouraging this behavior may create a bird that prefers to only interact with one person and behave aggressively towards other. For some facilities this may not be a concern, but for programs that require many people to interact with an animal, it is recommended they focus on reinforcing non courtship behaviors. This may mean also paying attention to an animal’s response to touching. Touch may still be in the repertoire of reinforcers, but perhaps it is limited to areas that do not encourage reproductive behavior.


Food is not the only reinforcer. For many animals these reinforcers can include attention, companionship, toys, touch and more. Adding these additional reinforcers to the repertoire gives professionals greater flexibility and mileage when training. By examining the potential list of secondary reinforcers, trainers can take advantage of all the tools in the training toolbox.


Cambridge Center for Behavior Studies online resource

Heidenreich, B.E. (2006).Managing the Deliverance of Food to Create Motivation Proceedings Mid Atlantic States Association of Avian Veterinarians.
