Plus-Hex CLINICAL
Introduction
In most mammal species , bonding occurs between adult individuals where social groups exist [ 1 ] . Having relationships with other adults in the group serves to increase the individual ' s chance of survival and mating opportunities [ 2 ] . Across species , the presence of a social partner has been shown to lead to more favourable outcomes in relation to an individual ' s response to stress and , therefore , their general health levels [ 3 – 5 ] .
In a long observational study of wild cavies , Asher et al . [ 6 ] observed that the animals preferred to live in small , single-male groups . Domestication and selective breeding have played a part in changing the innate behaviour of the domestic guinea pig [ 7 ] . Domestic guinea pigs are adapted to living in less turbulent or volatile environments and will display lower levels of exploration and risk-taking behaviours than their wild ancestors , and this is paired with lower cortisol responses when faced with a stressful situation [ 7 ] .
Domesticated guinea pigs show increased socio-positive and courtship behaviours compared with their wild predecessors . As such , literature on best practice for housing guinea pigs recommends housing guinea pigs in pairs or single-male groups [ 8 , 9 ] . Further research found that within these groups , females preferred close relationships with the boar rather than with other females in the herd [ 6 ] .
Materials
• MacBook computer
• GoPro camera × 2
• Pen , paper , highlighter
• Stopwatch
• Enclosure : The experiment was conducted in an enclosure ( 146 cm × 74 cm ) ( Figure 1 ) made with temporary fencing . An X marked a spot 25 cm from one end of the enclosure , indicating the starting place for the novel item , and another X marked a spot 25 cm from the other end of the enclosure , indicating the starting place of the guinea pig ( s ). The enclosure was lined with fleece and situated in a room far enough away from the guinea pig ' s regular housing to ensure that there was no visual , olfactory or auditory contact between the active test subject and the rest of the herd .
• Novel Item A ( NIA ): An imitation male mallard duck ( approximately 12 × 15 × 9 cm ) made from recycled high-density polyethylene .
• Novel Item B ( NIB ): A purple yoga block ( approximately 22.5 × 13.5 × 7.5 cm ) made from 95 % foamed polyethylene and 5 % foamed EVA .
Research focusing on stress responses in guinea pigs has shown that the presence of a herd mate reduces cortisol levels in female guinea pigs when they are placed in a stressful situation [ 10 ] . This supports previous research proving that females preferred to be close to the boar rather than other females within their bonded groups . Stress cortisol responses were reduced in the presence of the boar more than they were in the presence of any female from the group . The cortisol levels of male guinea pigs in similarly stressful environments are reduced in the presence of a bonded partner , but not in the presence of an unbonded or unknown guinea pig [ 11 ] .
There is limited published research into the effect of the presence of a herd mate on observable guinea pig behaviour during a potentially stressful or novel experience . This study focused on identifying how the presence of a herd mate affects explorative behaviour . Creating environments where guinea pigs feel comfortable enough to explore their surroundings in a veterinary setting may lead to better patient outcomes through increased locomotion and foraging behaviours .
The study hypothesised that the presence of a bonded male will increase explorative behaviour in female guinea pigs when presented with a novel stimulus . For the purpose of this study , explorative behaviour included any behaviour where the guinea pig was observed to be seeking auditory , visual , olfactory or physical information about its environment .
Figure 1 . The enclosure in which the experiment was conducted .
Participants
The herd of eight guinea pigs ( Table 1 , page 30 ) lived in a shared enclosure . They all joined the herd at different times and were considered bonded . Since joining the herd they all had the same lifestyle and routine , with similar amounts of time in and out of the enclosure and being handled . They had comparable exposure to novel sounds , sights and scents . They ate the same diet , consisting of hay , Burgess Excel pellets and a variety of fresh greens , herbs , vegetables and fruits .
Volume 39 ( 4 ) • August 2024
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