Sensory enrichment - visual
When it comes to visual enrichment, similar to auditory, it can be both positive and negative. The key here is to provide the correct type of visual enrichment that stimulates positive behaviours rather than more negative ones. In this quick post we will take a look at some of the visual enrichment options and what to consider when creating visual captive tiger enrichment.
Tigers are visual, so it’s important to create visually interesting objects and enrichment items for tigers to use. These types of enrichment overlap somewhat between the different enrichment sectors. For instance, colourful items can be used to gain the tiger’s attention. However, as tigers are dichromats [1] they don’t see as many colours as humans and are specifically not able to differentiate between reds and greens.
Other visual options include making hanging items. These can be made light enough to move in the wind, which will catch the attention of the tiger and encourage them to interact. These types of enrichment toys are great for encouraging tigers to play or simulate hunting behaviours such as grabbing, tugging and pulling.
Visual enrichment can also involve providing a line of sight to other animals, such as conspecifics or prey species. However, little is known about this area and there are ethical considerations such as causing stress to the prey animals.
The ability to see other tigers, but unable to engage with them is known to increase pacing behaviour [2,3]. Visual barriers can be used to reduce pacing caused by catching sight of conspecifics [2,3]. However, the reason for the increase in pacing when seeing another tiger is unknown. This type of pacing could be due to stress or agonistic behaviours towards the other tiger [2], or the result of frustrated interaction behaviour [3]. If the latter is true, blocking access could actually cause poorer welfare especially as another study [4] showed that tigers housed together decreased the amount they paced indicating a possible preference to be with a conspecific. Therefore, it is important to determine the relationship between the tigers to know whether providing a line of sight to other tigers will be beneficial enrichment or not.
Another possibility is to add mirrors to an enclosure that will enable the tiger to catch sight of itself and interact in that manner. A number of animals have been introduced to mirrors including elephants and chimpanzees, with the animals using them to great effect. Again though, the reaction of each tiger needs to be studied to ensure that the mirror isn’t causing stress.
As a result, more research needs to be done in this area to ensure the visual access to other species are not only welfare oriented for tigers in general but will also match the specific tiger receiving the enrichment.
References
1. Fennell, J.G., Talas, L., Baddeley, R.J., Cuthill, I.C. and Scott-Samuel, N.E. (2019). Optimizing colour for camouflage and visibility using deep learning: the effects of the environment and the observer’s visual system. Journal of the Royal Society. https://doi.org/10.1098/rsif.2019.0183
2. Bashaw, M.J., Kelling, A.S., Bloomsmith, M.A. and Maple, T.L. (2007). Environmental effects on the behaviour of zoo-housed lions and tigers, with a case study of the effects of a visual barrier on pacing. Applied Animal Welfare Science. 10(2), pp. 95-109 doi: 10.1080/10888700701313116.
3. Miller, L.J., Bettinger, T. and Mellen, J. (2008). The reduction of stereotypic pacing in tigers (Panthera tigris) by obstructing the view of neighbouring individuals. Animal Welfare 17(3), pp. 255-258
4. De Rouck, M., Kitchener, A.C., Law, G. and Nelissen, M. (2005). A comparative study of the influence of social housing conditions on the behaviour of captive tigers (Panthera tigris). Animal Welfare. 14, pp. 229–238
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