Each step of the training procedure was done slowly and carefully to avoid a dangerous flight reaction. Both nyala and bongo will orient their heads and ears towards a novel sound, such as movement of the crate doors. If the sound continues, the animal will either tolerate it or bolt and attempt to flee. Habituating the animals to the sound of the sliding doors is the most critical part of the training. Great care was taken to avoid triggering a flight reaction. The reason why horns are often broken off when animals are forcefully manually restrained is due to a massive flight reaction due to fear.

• On the first day of training to door movement, movement of the door was stopped the instant the animals oriented towards it. Each day the doors were moved a bit more until the animals completely tolerated them and they could be pulled open quickly.
  • It is extremely important to avoid triggering a massive fear flight reaction which would cause an animal to hit a wall or fence. Research has shown that if an animal's first experience with a new place is either painful or frightening, it will refuse to enter it again (Miller, 1960). Practical experience with cattle and sheep has shown that when the animals are first put in a new corral or squeeze chute, painful procedures should be avoided. If pain or high levels of fear are associated with the first encounter with the new facility, it will be extremely difficult to get the animals to enter in the future (Grandin, 1993, 1996; Hutson, 1993). This is due to a strong conditioned fear response. Extinguishing this fear response can be very difficult, because fear conditioning is a very primitive learned response that takes place is a subcortical neural pathway (LeDoux, 1994). A neural connection is made which bypasses the cortex (thinking part of the brain). For example, if an animal was scared by a big red truck and it bolted and hit the fence, it will get an instant fear reaction when it sees a big red truck in the future. It is much easier to train an animal to tolerate a big red truck by slowly and gradually introducing them to one than to attempt to unlearn a fear response after the animal has been badly frightened by one.
  • Prey specie animals such as nyala or bongo are extremely wary of novelty because in the wild, a sudden novel event is often a sign of danger. Sudden novel events are very stressful (Danzer and Mormede, 1983; Moberg and Wood, 1982); however, animals can be trained to tolerate novelty if it is introduced slowly and gradually. Introduction of novelty must be done more slowly and gradually in a wild prey species animal, such as bongo because they have a greater flight response than a domestic ruminant, such as cattle.

  • The people training the nyala and the bongo also had a good understanding of the concept of flight zone (Hediger, 1968; Grandin, 1987). The flight zone is the animal's personal space. The size of the flight zone is affected by both genetics and previous experience. It varies from none in a completely tame animal to many meters in a wild one. When a person enters the flight zone, the animal will move away. Both nyala and bongo will face a person who is outside their flight zone. If the flight zone is penetrated in a confined space, such as a barn or stall where there is insufficient space for the animal to move away, it may panic and crash into a wall or attack a person. This is due to fear.

  • The nyala at the Denver Zoological Gardens were tame enough so that the handler could enter the stall with the animals in it. For the bongo, the handler had to remain outside the stall until an animal was restrained inside the crate.

• To condition the animals to walk through the crate, treats were placed on the floor. The next step was to train the animals to enter the crate with the forward door closed. The first few times the rear door is closed, the animal is immediately released through the front door. The next step is habituating the animals to stand restrained in the crate with both doors closed for five to ten minutes. During this time they were continuously fed treats. It is important to get the animals fully patterned to standing and eating quietly in the carte before any attempt is made to touch them. Since the bongo is more vigilant and wary of novel sights and sounds than the nyala, extra time was required to habituate the bongo to opening the access holes in the crate.
  • After an animal has learned that a particular situation is safe, it will tolerate some aversive stimuli. Miller (1960) found that rats will tolerate gradually increasing shocks to get a food reward. A relatively long training period was used to get the nyala and bongo into an established routine of being locked in the crate to receive treats before any manipulation of the leg was attempted. Experiments with cattle have shown that the animals are reluctant to change an established routine (Grandin et al., 1994).

• The next step was to habituate the animals to touching and manipulation of the rear leg. For the nyala, firm touches were used, and for the bongo, the initial touches were very light. Gradually, the animals were habituated to increasingly hard pinches to simulate blood sampling from the recurrent tarsal vein. The middle door was used to make the crate smaller so that the leg of a small animal would be near the bleeding hole. There was a critical point during habituation to manipulation of the leg where the treats were changed from being an enticement to being a reward for standing still. The handler training the animal had to differentiate between a dangerous flight fear response and learned avoidance behavior such as twitching or kicking. The animals were taught that they would be given a treat after they stood still. A large flight fear response is most likely to occur during the early phases of habituation to the crate and door movement. There were great individual differences between the animals. Voice commands were used with the bongo after they were habituated to standing in the crate. "Good girl" or "good boy" were spoken when they were rewarded with a treat, and a sharp "no" was spoken when they misbehaved. The word "steady" was said in a soothing voice when they appeared to get nervous. After the animals were accustomed to hard pinches, blood samples could be drawn.