Out of curiosity, I started collecting reports of these fatal events and how they occurred (33 events). Out of respect for the victims and their families, I will not include any names or identifying details.
How do Captive Tiger Attacks Occur?
The majority of the tigers involved were kept in zoos (61%) versus as pets (27%) or performing animals (e.g. circus, 12%). As exhibit animals, contact with humans should not be necessary other than through protected contact or with sedation (e.g. from veterinary procedures).
The incident was most likely to happen after the victim entered the tiger's enclosure (73%). The majority of these events involved professionals that work with to around tigers, with a similar number of cases where the person knew the tiger was in the enclosure versus did not know it was there (e.g. due to a gate being unintentionally open). A smaller number of events involved deliberate or accidental trespass by a civilian into the enclosure, or an attack at the perimeter of the enclosure or after the tiger had been removed or escaped.
Victims of a fatal tiger attack have an average age of 33 and are somewhat more likely to be male than female (61%).
Why do Attacks Occur?
Tiger factors: The risk associated with tigers may be especially high as they are considered "pseudo-domesticated". That is they can present very like a domesticated and so relatively safe animal, but then very suddenly show aggressive or predatory behavior. As such, a person might have a relatively long history with an animal in which they have shown no dangerous behavior. This will often lead a person to under-estimate the unpredictability dangerousness of the tiger. This complacency is particularly obvious with inexperienced people being allowed access to a tiger by a private owner -- for example family members including young children or visitors being offered opportunities such as having a photograph taken with a tiger. It should also be recognized that tigers are ambush predators and so their natural pattern of attack is sudden and behaviors leading up to the attack may be brief and subtle.
Environment factors: When it comes to workplace activities, the opportunity for injury is strongly influenced by enclosure design and workplace policies and their enforcement. For example, whether zookeepers are permitted or encouraged to enter the enclosure, and whether the presence of the tiger in the enclosure or an adjoining space is easy to see. In a small number of cases, the enclosure was inadequate to the point that tigers needed to be manually moved or leash-walked between areas or was able to escape. Placing workers under stress and time constraints may also increase their risk-taking behavior such as cleaning enclosures while the animal is still present rather than taking the time to remove them.
Victim factors: In cases where being in the same space as the tiger is part of a performance, the risk of attack is unavoidable. Having direct contact with a large charismatic animal is exciting for the professional and audience -- but interactions of this type are becoming less popular on developed nations for both animal welfare and human safety reasons. When the animal is simply on display and direct contact should not be necessary, one contributing factor to people deliberately entering a tiger enclosure is likely to be that their expertise (e.g. as a zookeeper) causes them to judge they are not at risk and to feel they are able to accurately assess whether the tiger presents any danger. On rare occasions, fatalities have occurred due to deliberate or accidental trespassing by visitors into the tiger habitat including some cases of apparent "suicide by tiger."
Human psychology is generally poor at assessing risks at extremely high or low levels -- in this case, low frequency but high severity. If a tiger is handled with direct contact it may form a calm and friendly relationship with familiar people and provide them with extensive experience of "trustworthy" behavior. However, the tiger's size, reactivity, and predatory nature mean that there is always a risk of sudden attack that can main or kill.
As with other large pseudo-domesticated animals, e.g. elephants, zoos are moving towards not allowing any direct contact between people and captive tigers. While private ownership of tigers is, and should be, discouraged -- most recent fatal events occurred in reputable zoos. As such it seems that a failure to develop and enforce non-contact protocols and provide the resources necessary to implement them in a fail-safe way is the primary cause of captive tiger-related fatalities.
Media reports sometimes indicate that there may be a gap between safety procedures on paper or as known to management, and day-to-day working routines. It is important to not only require non-contact with tigers but to provide the staffing, time, and facilities that allow all necessary work activities to be performed without encouraging the breaking of these rules. Specifically, Activities in any area should only be permitted when the tiger is in another area, the location of the tiger should be visually obvious, gates should not be able to be left open, and people should not work alone in or near the tiger enclosure.
These standards would ideally also be applied to private owners and allowing direct contact between a tiger and a third party, especially a child, should not be permitted. Performers and trainers of tigers used in entertainment are trusted to understand and manage the risk presented by their own direct contact with animals. The extent to which this risk is justifiable for purposes of entertainment is questionable, however it is not dissimilar to other potentially dangerous activities carried out for sporting and entertainment purposes with informed consent.
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