Undesired Animal/Keeper Interactions in Zoo Exhibits


Zoos are charged with keeping, caring for, and educating the public about many potentially dangerous animals which requires them to design systems and processes to balance three key priorities:

  • Caring for the animals in their exhibits
  • Providing the best possible visitor experience for those who come to see the animals
  • Minimizing the risk that these dangerous animals could impose to keepers, zoo staff and the general public

These priorities can come into conflict when the keepers are dealing with their safety and the perceptions of visitors. For example, over-constraining animals for the safety of zoo staff would have negative impacts on both animal care and the visitor experience. No one wants to visit a zoo that feels like a prison and many animals need freedom to move about in large spaces for their general well-being. The challenge is to manage the risks to zoo staff without an undue burden on either of the other two goals.


Trajectories Company advisors recently partnered with an AZA-accredited public zoo to examine this challenge regarding two specific animal environments: big cats and elephants. These two environments pose an elevated level of risk—together they account for over 55% of injuries and over 90% of deaths caused by animals to zoo staff.1 The modeling team used Trajectories methodology to model the very different systems and processes in each environment to identify potential areas for reducing this risk to keepers working with big cats and elephants.

The model focused on the risk of two primary types of undesired animal/keeper interactions in zoo exhibits:

  • Unintentional Shared Space Events
    o Any event in which staff and animals are unintentionally sharing the same physical space at the same time, either from an animal gaining access to somewhere it should not be, or from a human entering a space to which an animal still has access.
  • Unwanted Contact Events
    o Any event in which an animal makes direct physical contact with a staff member that the staff member did not intend to occur.

The team sought to use Trajectories to model the various errors, mechanical failures, and other initiating events which can cause either unintentional shared space or unwanted contact between zoo staff and animals in the big cat and elephant enclosures. They then analyzed what (if any) defenses exist within the current systems and processes in each of the two environments to prevent such initiating events from progressing to undesired outcomes. This model was specific to the facilities, systems, and procedures in place at the partner zoo, but many of the findings and opportunities are likely applicable to any similar institution.


The Trajectories® model revealed five key lessons about the risk of shared space and unwanted contact in these environments:

  • For a shared space event to occur in the zoo’s big cat facilities, a door that should have been locked has to be somehow unlocked. This can occur via simple errors (e.g., forgetting to lock a door), more complex errors (e.g., unlocking a door that should have remained locked because the keeper missed an animal or an unlocked door into the space during visual checks), or mechanical failure (e.g., a broken padlock). Risks of such events increase significantly for any door which a single zookeeper can open or close on his or her own (i.e., doors without two locks, or with two locks but a common key).
  • Other unwanted contact events in the big cat facilities can occur any time someone approaches too closely to a mesh barrier when there is an animal on the other side, enabling the animal to reach through the mesh and attack. Current defenses against such risk rely on situational awareness (e.g., clearly marked lines indicating danger zones) and are completely ineffective against potential unintentional approaches (e.g., tripping and falling into the mesh).
  • Shared space events in the elephant enclosure are more complex, because elephant barriers allow humans to pass through without having to unlock anything (they can simply step through the bars), and the size and layout of elephant enclosures means any single keeper is generally unable to visually inspect everywhere an elephant might be located prior to entry—even in the barn, it is possible for an elephant to have access to stalls down the line and difficult for keepers to see the status of gates between him or her and a given animal. Risk of shared space events in such an environment comes from the lack of situational awareness about an animal’s location and the status of gates between animal areas.
  • Unintentional shared space with elephants can occur via another form of human error such as when a keeper or other staff member is up on a wall around a yard, or on a platform or a similar elevated position, and he or she trips or slips and falls into the yard. There are few defenses against such errors; current systems rely on keepers to be careful during such activities.
  • The risk of unwanted contact in the elephant enclosure comes primarily from elephants’ large reach where their trunks can grab or strike people from an extended distance. There is a risk of such events any time a keeper is within trunk reach of an animal, either intentionally (i.e., during routine animal care like medical activities) or unintentionally (i.e., walking through a danger zone without realizing an animal is present). Once within range, all that it takes for such an event is for the animal to do something unexpected like lash out.


Eliminating Single Keeper Operations in Big Cat Facilities: as much as staffing allows, preventing any single individual from being able to open or close a barrier within big cat facilities would significantly reduce the existing risk of unintentional shared space events between zoo staff and big cats. Any implementation of redundant processes like a “two locks, two keys” system for every door needs to include careful assessment and monitoring of compliance with associated procedures: such systems fail if the two individuals share keys, or the second individual does not conscientiously conduct independent checks prior to unlocking his or her lock. It is important to note that compliance is crucial for such a system to be effective.

Minimizing Big Cat Reach-Through: installing barriers too small for animals to reach through (e.g., plexiglass or smaller mesh secured to the primary mesh barrier), anywhere it is feasible within animal care and visitor experience requirements would reduce or eliminate the animals’ ability to attack if someone trips and falls or otherwise inadvertently enters the danger zone at low cost to the zoo. Note that this secondary barrier does not have to be strong enough to stop a determined animal, that is what the primary mesh is for. It just needs to be enough to stop impulsive attacks of opportunity.

Implement Elephant Situational Awareness Systems: keepers need the ability to know where elephants are and, ideally, the status of gates and barriers between elephant locations and other enclosure areas prior to entry through any gate. The specific form of such a system requires balancing resource requirements against reliability. A computerized tracking system (or high-tech camera system) which monitors the elephant’s location and gate status in real time, which keepers could reference prior to entering any space, would be extremely reliable, but also have a high cost of implementation and maintenance. A less costly alternative would be mandatory positive animal counts via radio, with confirmation of animal locations and gate status prior to entry This option would be much less resource intensive, but its reliability would be completely dependent on compliance rates. There are of course other potential solutions to the problem, but it is one that every zoo with an elephant exhibit should examine carefully.

Employ Anti-Fall Equipment When Working In Elevated Positions: wearing harnesses and safety lines short enough to prevent a fall and adding railings wherever possible without significant impact on visitor experience, would reduce the potential for shared space events which result from keepers falling into elephant enclosures.

Strengthen Precursor Strategies Against Unwanted Contact During Elephant Care: conducting deliberate assessments to determine if keepers can reduce direct interaction as much as possible while still meeting a high standard of animal care would limit the opportunity for unwanted contact events. The increased use of working walls and static squeezes, for example, do not eliminate animals’ opportunities to act unexpectedly, but greatly reduce the ways they can do so and improve the keepers’ abilities to recognize and manage such behaviors before they result in harm.

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