Enrichment Evaluation Guide

We all want the best for the animals in our care. To make the environment more challenging, more complex and more stimulating to perform certain behaviours, we use environmental enrichment to achieve these aims. Sometimes, when you use a particular enrichment item to stimulate a specific response, the enrichment will not immediately be used. Does this mean the enrichment attempt has failed? No, not necessarily. It can be that the animal uses the enrichment item mostly in the absence of a keeper and you don’t see its effectiveness. On the other hand, when you use enrichment, and it is used multiple times by the animal, have you then completed your goal? Maybe you give enrichment to stimulate a particular behaviour, and the animal(s) use it to perform another behaviour. Thus, the simple fact that an animal interacted with the enrichment does not indicate that the enrichment item improved its well-being. 

Why is evaluating enrichment important?

Evaluation of enrichment can assist the animal care staff in making decisions whether to continue with the enrichment strategy, make adjustments and improvements, or to discontinue the enrichment initiatives. Previously, and even today, much enrichment is developed on a ‘trial and error’ basis, whereby stimuli are randomly added to an enclosure. Off course, before you start applying enrichment, you have to set aims what you want to achieve with your enrichment effort. But, without the resultant behaviour(s) being observed, it is not clear whether these changes to the animals’ environment have a positive, negative, or indeed, any effect at all. Furthermore, with the limited time zookeepers usually have for enrichment, it mustn’t be wasted on ineffective enrichment. Therefore, since enrichment is provided to enhance the animals’ behavioural welfare, it is vital to know whether it is working and as even importantly, not having the opposite effect and decreasing their well-being. 

How can enrichment be evaluated?

The evaluation of enrichment is a three-step process, consisting of documenting your enrichment, evaluate this documentation and observer you enrichment initiatives, and readjusting when necessary. How to assess your enrichment is depending on the aim of your enrichment strategy. 

What are the aims of your enrichment?

Enrichment is done for, and not limited by one, specific reasons. When developing an enrichment plan, these goals need to be specified. These goals can vary per species, per exhibit with multiple species (mixed-exhibits), or even per individual. Frequently used goals for enrichment include:

  • Reduction in abnormal or stereotypic behaviour(s);
  • Increased time and diversity of foraging behaviour;
  • Increased diversity of (species-specific) behaviours;
  • Increased diversity of enclosure space use;
  • Increased activity; 
  • Increased physical fitness;
  • Increased adaptability;
  • Provide a more stimulating environment.

Not every aim is easily measured. Especially the last three goals mentioned above are hard to not measured at all. When you have set clear goals, it is essential to track your enrichment efforts daily. On the one hand, to confirm enrichment is implemented as planned, and secondly to see trends and developments related to your enrichment initiatives. One crucial aim that always needs to be observed and documented is enrichment safety.  

Enrichment documentation

Documentation can be as simple or complex as necessary. Depending on if a data ‘snapshot’ is acceptable, or more details are required to assess if enrichment is a success. There are three main types of documentation.

  • A simple type of documentation: This is mostly done in the form of a calendar. Hereon everyday information is written, such as which enrichment is given and the scoring of enrichment used. This can also be achieved using daily reports in, for example, ZIMS.
  • A detailed type of documentation: This is a more detailed report of the animal’s level of involvement with an enrichment item. This can be done in many forms, but often exist that multiple criteria are scaled and ranked daily to assess the success of each enrichment item.
  • A complex type of documentation: This type of observation is mostly used for research purposes or extensive observation. Within this type of documentation, often observation software, or some degree of digital data collection, is used. Good examples of this kind of software are BORIS (free) or ZooMonitor (free for accredited institutions). 

Whatever type is chosen to document your enrichment, it needs to reflect the process, including the goal(s) and objective(s) of the enrichment. A great resource on evaluating environmental enrichment, and how to measure it, is provided by Dr Amy Plowman in ‘a keeper’s guide to evaluate environmental enrichment‘.

Enrichment measured and evaluated

When the collected data is evaluated, it will determine whether there are any identifiable trends and that goals are met. Questions can be answered, such as: Was enough enrichment provided? Did the enrichment items cause any social problems? How were the animals’ anticipation and predictability on the enrichment? Did the enrichment meet its goal(s), by increasing or decreasing specific behaviours? When you did extensive observation and documentation, you can analyse this data and present it in graphs and spreadsheets. When you answered the relevant questions, there is one final question to be answered: Is this enrichment strategy and effort sufficient to meet its goal? When the answer is ‘No’, then you need to readjust your enrichment strategy.  

Readjusting your enrichment

When using the S.P.I.D.E.R. framework, the enrichment program can be continuously changed to suit the animals’ behavioural needs. This will be necessary because the animals’ environment is continually changing too. Think of the social group structure, building of new exhibits (but when you do, think of integrating enrichment into the exhibit), or when behavioural problems arise. Based on any enrichment plan, the following questions can be asked when readjustment is needed:

  • Does the enrichment need to be provided differently?
  • Should the enrichment item be offered for a longer or shorter duration?
  • Should the enrichment be offered more or less frequently?
  • Should the enrichment be offered in larger or smaller quantities?
  • Should the enrichment item be improved or replaced?

When readjusting the enrichment plan, it allows the enrichment to be refined and improved, and therefore make the enrichment more effective. Because environments are ever-changing, it is often the case that change is useful both for the enrichment and for the animal’s well-being. 

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