The Effect of Environmental Enrichment on Sun Bear (Herlarctos malayanus) Behaviour in Captivity

Sains Malaysiana 51(5)(2022): 1283-1291 http://doi.org/10.17576/jsm-2022-5105-01

One of the main concerns for animals kept in captivity is expression of stereotypic behaviour which could indicate stress in the animals. To ensure the welfare of animals are adequate for conservation and to promote species specific behaviour that similar to those in the wild, most of zoos are implementing environmental enrichment. The effect of environmental enrichment on behavioural changes was studied in seven captive sun bears kept in an enclosure at Zoo Negara, Kuala Lumpur, Malaysia. Bear behaviours are divided into three categories: Active, passive, and abnormal behavioural. The study involved three period: baseline, enrichment, and post-enrichment period. The activity budget was recorded as a single animal scan. A total of 210 h of baseline data was collected over 36 weeks at varying times of days. Three different environment enrichment tools were used; buoy with dog food, hidden fruit mixed with honey, and gunny sack filled with cinnamon powder. They were installed in the enclosures for 10 consecutive days on a rotational basis. Both enrichment and post-enrichment observations were done for 210 h using the same methods as in baseline sampling. Baseline data showed greater passive and abnormal behaviours than active behaviour. With the introduction of the enrichment tools, the sun bears displayed decreased passive and abnormal behaviours with an increment of active behaviour. For post-enrichment period, there was no significant difference when compared with the baseline between all behavioural categories. Among three enrichment tools, hidden fruit mixed with honey was the most preferred enrichment followed by buoy filled with dog food and gunnysack with cinnamon powder. It is suggested that foodbased enrichment should be lasting until evening for the sun bear to engaged longer to the enrichment. Although less preferred, cinnamon powder introduction as sensory enrichment was recommended as well. However, it is crucial to ensure that the cinnamon’s odour lasting until late evening, where the bears are ready to enter their night den. It can be concluded that the application of various enrichment tools may help to alleviate abnormal behaviour in captive bears.

Keeping animals in captivity such as in a zoo is one of the widely accepted approaches in the conservation and management of threatened species. These animals will receive veterinary care and free from starvation and predation (Clubb & Mason 2007). Various studies on different animal species indicated that fecundity and survival rates are generally higher in captivity than wild populations (Lahdenperä et al. 2018; Robeck et al. 2015). However, captive animals live in an environment that is totally different from their original habitat (McPhee & Carlstead 2010). For many captive wild species, numerous difficulties exist. One of the main concerns for animals kept in captivity is abnormal behaviour expression such as stereotypic behaviour. It can be one of the indicators of poor animal welfare and often a sign of decreased welfare in an animal (Wolfensohn et al. 2018) as their choice to express natural behaviour has become limited (Clubb & Mason 2007). A comparative study on behaviour between captive and semi-captive sun bear in Sabah showed that captive sun bears exhibited higher stereotypic behaviour compared to semi-captive sun bears (Abdul-Mawah et al. 2021).

Most of the bear species, such as sun bear kept in captivity exhibited abnormal behaviour due to many factors including the size of the enclosure (Berghammer 2008; Tan et al. 2013), barren or unexciting environment (Carlstead & Shepherson 2000; Morgan & Tromborg 2007) and no opportunity for exploration and foraging inside the exhibit (Carlstead & Shepherson 2000; McPhee & Carlstead 2010). Apart from that, anticipatory behaviour towards the bear keeper has also increased the stereotypic behaviour in cubs’ sun bear (Izzat-Husna et al. 2021). The issue has received much attentionfrom the zoo animals’ behaviour literature over several decades (Abdul-Mawah et al. 2021; Izzat-Husna et al. 2021; Shepherdson et al. 2013; Tan et al. 2013; Vickery & Mason 2005). Restrictions in the ability to perform normal species-specific behaviours may lead to stress and frustration and detrimental to their welfare. This is often manifested as alterations to behavioural patterns, such as the development of stereotypical behaviours (Mason et al. 2007). In order to ensure the success of welfare and occupational engagement of animals for conservation and breeding animals in captivity, most zoos are implementing environmental enrichment (Veeraselvam et al. 2013). Environmental enrichment is defined as ‘the provision of stimuli that promote the expression of species-appropriate behavioural and mental activities under stimulating environment’ (Reinhardt & Reinhardt 1998).

Environmental enrichment is widely used to enhance the quality of life for animals in captivity by providing stimuli necessary for psychological, physiological, and behavioural well-being (Swaisgood & Shepherdson 2005). The ultimate goal of environmental enrichment is to improve the ‘quality of life’ of the animals by meeting their physiological and psychological needs (Kuczaj et al. 2002). The use of environmental enrichment simultaneously reduces the stereotypic and abnormal repetitive behaviours and enhances the wellbeing of zoo animals (Carlstead et al. 1991; Kuczaj et al. 2002; Mason et al. 2007). Many forms of enrichment programmes have been utilised and tested according to species and situations that show positive results. For example, a study on the effect of computerised testing on sun bear behaviour in captivity (Perdue 2016) foundthat sun bear preferred interacting with touchscreens than other forms of enrichment. Another study on the environmental enrichment for the captive spectacled bear (Renner & Lussier 2002) shows reduced pacing with the introduction of enrichment such as ice block. Meanwhile, a study on captive sloth bears’ behaviour using various environmental enrichment tools (Veeraselvam et al. 2013) found that abnormal behaviour reduced when the bear was introduced to enrichment tools, such as honey logs. Many studies also showed that environmental enrichment variability could stimulate natural behaviour and prevent animals from expressing abnormal behaviour such as stereotypical behaviour. 

Sains Malaysiana 51(5)(2022): 1283-1291 http://doi.org/10.17576/jsm-2022-5105-01