The impact of food enrichment on the behaviour of turtles in captivity : An observational study of McCord’s snake-necked turtle (Chelodina mccordi) and Vietnamese pond turtle (Mauremys annamensis)

Abstract: McCord’s snake-necked turtle (Chelodina mccordi) and Vietnamese pond turtle (Mauremys annamensis) are two critically endangered species of fresh water turtles originating from Asia. The aim of this study was to evaluate how the two species of aquatic turtles responded to food enrichment, if feed enrichment could reduce the stereotypic behaviour displayed by the McCord’s Snake-necked turtles and if behavioural signs associated to good welfare increased in response to food enrichment. There are many different definitions of animal welfare. In this study, emphasis was put on the importance to look at species-specific behaviours and the response of the individual when assessing welfare. Few enrichment studies have been made on reptiles when compared to mammals. Two types of enrichments were used and evaluated through direct observation with focal sampling and video observation in this study. The enrichment, “The Egg”, was a dog toy designed to contain treats, which could fall out of the toy when the animal manipulated it physically. The other enrichment was an automatic feeder, which expelled small amounts of feed multiple times during the one-hour long observations. Behavioural changes varied between individuals. On a group level, there was a significant difference (p<0.05) in the stereotypic behaviour “swim against glass” for the Vietnamese pond turtles. The behaviour was performed at longer durations when enrichments were used compared to normal feeding. A reduction of the stereotypic behaviour was seen in the McCord’s snake-necked turtles when “The Egg” was used. The automatic feeder produced a decrease in foraging behaviour and increased stereotypic-, aggressive- and same-sex sexual behaviour for multiple individuals. More individuals displayed behavioural changes indicative of good welfare when “The Egg” was used compared to when the automatic feeder was used.