Leaf choice in black-and-white snub-nosed monkeys Rhinopithecus bieti is related to the physical and chemical properties of leaves

To understand the effects of the chemical and physical properties of plant leaves on food choice in Rhinopithecus bieti, we collected mature leaves of nine food and five non-food plant species at the southernmost part of the species＇s range. Chemical properties such as fat, ash, crude protein （CP）, total phenolics （TP）, and fiber content including neutral detergent fiber （NDF）, acid detergent fiber （ADF）, lignin, celluloses and hemicelluloses, and physical toughness were measured. R. bieti tended to choose leaves with lower fiber content, higher ash, a higher ratio of CP/ADF, and lower toughness. No difference was found for fat, crude protein, total phenolics, hemicelluloses and lignin between food and non-food leaves. Even though the ratio of CP/ADF is generally regarded as a good indicator for colobine food choice, the difference in the ratio of CP/ADF between food and non-food leaves was only the result of differences in ADE Since positive correlations were found between ADF and tough- ness from all leaves （both food and non-food species）, and toughness of leaves was likely easier for R. bieti to sense than fiber content via mastication, the toughness of leaves may function as a predictor of food choice in this species [Current Zoology 56 （6） 643-49, 2010].

Avoidance of potentially harmful food cannot be socially transmitted between rats

The social transmission of food preferences （STFP） is a behavioural task of olfactory memory, in which an observer rat learns safe food odours from a demonstrator rat, and shows preference for this odour in a subsequent choice test. However, previous studies have failed to detect the transmission of information about food study, we tested how demonstrators＇ health affects the exchange of of potential danger and food aversion using STFP test. In this odour information and whether observers can learn danger information from an unhealthy demonstrator. As expected, the observer rat formed an odour preference after interacting with a demonstrator rat that had just eaten food containing a new odour, however, odour preference rather than aversion was also formed after interacting with a demonstrator rat injected with LiC1 （used to induce gastric malaise）. Furthermore, anaesthetized demonstrator rats and half-anaesthetized demonstrator rats, which showed obvious motor deficits suggesting an unhealthy state, also socially transmitted food preferences to observers. These results suggest that the social transmission of food preferences task is independent of a demonstrators＇ health, and that information about dangerous foods cannot be transmitted using this behavioural task.