Similar to humans, captive animals need stimulation to prevent boredom.
Positive reinforcement training sessions
One of the ways that tigers can be kept mentally stimulated is through training. This needs to be a planned and targeted session that encourages the tiger to perform specific behaviours [1] such as blood taking or standing on scales. Studies with big cat keepers has shown that most believe training is more beneficial to tigers (more so than any of the three handling options) specifically when it comes to medical procedures or check-ups [1]. In fact, while a good bond with the keeper is essential, protected contact or contact alone is not enough as it is less likely to offer structure or even target aspects that will improve the tiger’s well-being [1]. Performing training allows a bond to be built while also sending positive messages to any visitors. However, training should not be used as a substitute for environmental enrichment but rather used alongside it.
This type of training can cover a range of different activities such as getting the tiger to stand on weighing scales, standing on hind legs to enable checks of the body and learning to lie close to the cage side to have blood drawn from the tail. These types of training programs double up in encouraging the tiger to learn, but also in providing a vastly less stressful environment resulting in a reduced need for sedation as the tiger will remain still for a number of veterinary procedures. As such training is a great way to reduce fear within human-animal interactions [2].
Generally, training has been shown to afford animals learning opportunities and are thus enriching [2,3]. However, it is important to bear in mind that once an activity is learned, it can cease to be enriching resulting in the necessity to continue training different behaviours.
Training can also provide control [1] and choices within the animal’s environment as the tiger is able to leave if they choose [1]. It can also aid in coping with challenges within the environment [2].
Encouraging hunting behaviours
As we have touched upon in other sections of enrichment, novel objects are a great way to occupy a tiger’s time in captivity as they provide something new to investigate and explore. Novel objects can be used to encourage natural behaviours, particularly those centering on promoting hunting behaviours. Simply placing something novel into the environment will also provide mental stimulation. However, it is important to introduce objects carefully and slowly so as not to cause alarm or stress. This is where a good knowledge of the individual tiger also comes in handy.
Novel Objects
For tigers, this can include the use of large Boomer balls, barrels, tyres and other types of PVC toys including floating toys or tubes. These objects, if placed hanging up can help the tiger emulate prey take down. Boomer balls left loose to roll around or floating in bodies of water will also help to promote this – tigers will often launch on top of them much as they would their prey. The size of the ball can vary too – bigger balls emulating larger prey, with smaller balls encouraging more chasing and carrying. It’s important that any smaller balls are not too small to risk being swallowed.
In captivity, tigers are generally unable to perform natural hunting behaviours. This means that they don’t use their full body in the same way as their wild counterparts. Some of the behaviours that wild tigers perform a lot are dragging, carrying or pulling behaviours. This occurs around a kill where the tiger will often drag/carry its prey to a safer spot to eat.
Tyres and other smaller toys such as cardboard tubes can be used to emulate dragging or carrying behaviour.
Hard to get
Another aspect of cognitive enrichment is about encouraging the tiger to figure out how to get food, and that’s where feed poles can come in (we covered this in nutrition enrichment). However, there are other methods that can be employed to make it harder for tigers to get hold of their food.
One cause of stereotypical pacing in tigers is thought to stem from the inability to perform appetitive foraging behaviours. This type of behaviour is the active search for an external stimulus i.e. prey. Tigers in the wild spend a large portion of their day searching for food [4], which, if they are successful, the appetitive behaviour is met with the behaviour culminating in consuming the prey. If the tiger’s hunt is unsuccessful, then the active search continues. And it is here that the captive setting can cause problems.
In captivity, tigers never have to hunt. This means that appetitive behaviour is always unsuccessful in captivity due to regulated feeding times and so on. It is thought that this thwarting of the natural appetitive search is one cause for stereotypical pacing behaviours seen in captive tigers [5]. Keepers will often observe a higher amount of pacing prior to feeding. Often characterised as anticipatory pacing, it is suggested that this behaviour happens because there is a high motivation to forage [4,6].
Artificial prey – As live prey cannot be used in most countries around the world, it’s possible to simulate prey instead. One study using artificial squirrels and rabbits successfully encouraged the tigers to hunt, stalk and chase the “prey’ to be rewarded with chunks of meat when they successfully capture the prey. The system utilised the entire enclosure to encourage the tiger to explore and was only set off at random times with a varying sequence of events [7].
Feeding boxes - Tigers are opportunistic hunters which means they will take and eat any type of prey that comes along – big or small. Studies have shown that puzzle feeders can be used for mental stimulation. Feed boxes have been used to great effect in Amur tigers, reducing pacing time and encouraging foraging behaviours [5]. Providing food in smaller quantities at varying times and in different hiding places will encourage the tiger to perform these wild-type behaviours. Food can also be hidden in tubes, hollowed-out balls, and even hidden under things encouraging the tiger to search.
Pulleys and bungees - Continuing the trend of making it harder for the tiger to simply walk off with their dinner instantly, carcasses can be hung by pulleys or bungee cords to make the tiger work for their food. In this way, the tiger is encouraged to use their neck muscles to pull on their “prey”. A study using bungee-carcass enrichment did promote active behaviour without causing stress [8].
Lures – Some facilities have taken things further by developing ways to encourage the tiger to actively chase prey. This can be done with standard lures - food on a rope dragged across the enclosure (Cheetahs have been provided enrichment using a greyhound lure for instance) or with more advanced options. Some facilities have taken to using motorised cars with prey attached. The keeper can operate the car attempting to stay one step ahead of the pursuing tiger. While some may complain that this is not natural enrichment, the aim is to recreate the tigers’ natural behaviour and not to cater to visitor sensibilities [9], and this achieves the former very well.
Zip lines - Zip lines are also a great way to encourage natural behaviour as food can be attached to the wire and winched out to the tiger in the enclosure. Tigers are encouraged to chase and jump for it or climb up parts of the enclosure (caves and platforms are created for this purpose) in order to get hold of the meat. On top of that, a variety of food and toys, such as this wooden spool can be hung from it, making this a very versatile piece of enrichment.
However, Stichting Leeuw has taken this to another level. The first of its kind, the hunting simulator is a series of pulleys attached to a mechanism that the keeper can operate to move the meat randomly throughout the enclosure space. The meat and movement of the stimulator is carefully adjusted to meet the needs of the predator taking part, modifying the height, speed and duration of the hunt in order to provide the best stimulation to the big cat. The stimulator also offers variation as cats will quickly recognise if the prey is following the same pattern and may become lazy. Elaborate devices stimulating hunting opportunities have been shown to decrease pacing and increase hunting behaviours including moving more, jumping, pouncing, rolling and even being more visible to the public [7,10,11].
Efficient cognitive enrichment doesn’t have to be expensive or extremely elaborate, as long as keepers take the time to get to know the personalities of their tigers. Even a low budget can go a long way as long as the right amount of time and effort is put into enrichment development. We encourage thinking outside the box and utilising what is available, always with the tiger’s welfare in mind.
References
Szokalski MS, Litchfield CA and Foster WK 2012 Enrichment for captive tigers (Panthera tigris); Current knowledge and future directions. Applied Animal Behaviour Science 139(1-2): 1-9
Westlund, K. (2014). Training is enrichment -And beyond. Applied Animal Behaviour Science. 152 1-6 https://doi.org/10.1016/j.applanim.2013.12.009
Melfi, V. (2013). Is training zoo animals enriching? Applied Animal Behaviour Science 147, 299-305 DOI:10.1016/j.applanim.2013.04.011
Lyons J, Young RJ and Deag JM 1997 The Effects of Physical Characteristics of the Environment and Feeding Regime on the Behavior of Captive Felids. Zoo Biology 16: 71–83
Jenny S and Schmid H 2002 Effect of feeding boxes on the behaviour of stereotyping Amur Tigers (Panthera tigris altaica) in the Zurich Zoo, Zurich, Switzerland. Zoo Biology 21: 573-584
Shepherdson, D.J., Carlstead, K., Mellen, J. and Seidensticker, J. (1993). The influence of food presentation on the behavior of small cats in confined environments. Zoo Biology 12: 203-216.
Markowitz, H. and LaForse, S. (1987). Artificial prey as behavioral enrichment devices for felines. Applied Animal Behaviour Science. 18(1) 31-43 https://doi.org/10.1016/0168-1591(87)90252-8
Ruskell AD, Meiers ST, Jenkins SE and Santymire RM 2015 Effect of Bungee-Carcass Enrichment on Behavior and Fecal Glucocorticoid Metabolites in Two Species of Zoo-Housed Felids. Zoo Biology 34: 170-177
Robinson, M.H. (1998). Enriching the lives of zoo animals, and their welfare where research can be fundamental. Animal Welfare.7(2): 151-175
Bashaw MJ, Bloomsmith MA, Marr MJ and Maple TL 2003 To hunt or not to hunt? A feeding enrichment experiment with captive large felids. Zoo Biology 22:189–198
Markowitz H, Aday C, Gavazzi A. 1995. Effectiveness of acoustic ‘‘prey’’: environmental enrichment for a captive African leopard (Panthera pardus). Zoo Biology 14:371–9