Effects Of Repeated Encounters On Behaviors And Physiological Status In Male Striped Hamsters (Cricetulus Barabensis) And Striped Field Mice (Apodemus Agrarius)

We examined the body mass and physiological states related to solitary lifestyle and dominant-subordinate relationships in male striped hamster(Cricetulus barabensis).and male striped field mouse(Apodemus agrarius) Wild adult hamsters and mouse were captured from farmland of mountainous area in the southwest of Shandong province and caged singly in the laboratory during the breeding season.The experimental hamsters and mouse were subjected to 4 weeks staged dyadic encounters and the faeces were collected every day for 28 consecutive days by pairing two unfamiliar and weight matched males in a neutral arena.In order to determined dominant or subordinate status,aggressive behavior,defense,social and nonsocial behaviors were quantified everyday.Animals were then autopsied and their physiological and reproductive state assessed.Our results suggested that 1) the frequency of social behavior and aggressive behavior were significantly higher in dominant male than in subordinate male,while the frequency of defendable behavior was lower in dominant male than in subordinate male;as the time passing,the frequency of social behavior was reduced.2)increase of body mass could not be depressed by repeated encounters of male hamsters;decrease of body mass could not be depressed by repeated encounters of male mouse;3) adrenal gland index of subordinate male hamsters increased significantly;4) the faecal GC concentrations performance were related to the repeated encounters's time and the individual social status;5) the dominant individual maintained the high testosterone level,which favored its aggressive behavior and obtained the dominant status;6) the cortisol suppressed the testosterone secretion within all treatment groups, caused the testosterone to fall to the low level.