| Animal personality,as a series of consistent behavioral differences among conspecifics,has been observed in diverse animal taxa.More and more evidence show that such consistent variance of behavior patterns has important ecological and evolutionary significance for the survival and reproduction of animals,as it can affect the population dispersal,reproductive effectiveness,and the habitat utilization.However,little is known about the mechanisms underlying the generation and maintenance of animal personality.As animal personality has gradually become a hot topic in behavioural ecology,some theories argue that the generation and maintenance of animal personality depends on the state differences among individuals in the same species and the repeatability of animal personality is an outcome of the adaptation to particular states that vary among individuals.In the sense of behavioral ecology,such states may include any characteristics that can affect the costs and benefits of individual behavior.Recently,several studies have begun to focus on whether there are common changes in animal personality and particular states,and whether the state and the personality trait can form any positive feedback,thereby promoting the formation and maintenance of the personality trait.This model presents opportunities for wider testing.From field experiments and ecological perspectives,previous studies with birds as the objects have contributed valuable information for behavioral ecology.However,there is still extensive research space for the analysis of animal personality formation and maintenance mechanisms based on individual states.In this study,laboratory experiment was carried out with two classic personality tests(novel environment test and novel object test)quantifying the exploration,a representative personality trait,in Java sparrows(Lonchura oryzivora).Three states,including the body condition,innate immunity,and the social experience were selected to analyze the relationships with the birds’exploratory behaviour.The main results of this study were as follows:1.Individuals of Java sparrows consistently showed significant variation in exploratory behaviour(ICC(CI)=0.551(0.296-0.734),P<0.001),indicating that exploration of Java sparrows could be used as a personality trait.There was no gender difference in the exploration behavior(t=0.120,df=38,P=0.905).2.There was no correlation between exploratory behavior and body mass index(β=0.049,R~2=0.002,F=0.081,P=0.778),indicating that the formation and maintenance of their personality characteristics do not depend on their physical qualities.3.Exploratory was not related with the concentrations of Nabs Ig M(GLM:estimate±SE=-0.000±0.010,t=-0.076,P=0.940),Ig Y(GLM:estimate±SE=-0.008±0.007,t=-1.198,P=0.239),complements C3(GLM:estimate±SE=-0.006±0.004,t=-1.071,P=0.098),C4(GLM:estimate±SE=-0.009±0.005,t=-1.993,P=0.054),haptoglobin(GLM:estimate±SE=-0.003±0.004,t=-0.581,P=0.565)and corticosterone(GLM:estimate±SE=-0.005±0.004,t=-1.202,P=0.237),indicating that Java sparrows neither exhibited the energy trade-offs between behavior and immunity,nor exhibited the behavioral expression strategies where the immune defense serve as a selective stress.4.Subjects of the solitary and the social group had no significant difference at the beginning(P=0.401),but showed significant difference in their exploration behavior after living under those treatments for one month(P<0.001).The social experience had a carryover impact on the exploration behavior of the birds.After one month of social life,birds’exploration tendencies were significantly higher than their own level before this period of experience(t=-5.407,P<0.001).The interaction between the living context and the stage has a significant impact on the exploration score of Java sparrows(LMM:estimate±SE=-5.200±0.720,t=-7.221,P<0.001),indicating that social experience can affect personality expression.5.There was no significant correlation between the exploration levels of individuals before and after social interaction(r_s=0.224,N=20,P=0.341),indicating that long-term social environment impacts can also reshape the composition of group personality traits.In summary,the expression of exploratory behavior in Java sparrows was not related to their physical fitness or innate immune defense function,indicating that physical fitness and innate immunity were not involved in the formation or maintenance of personality.Social experience had a carryover impact on the subsequent exploration behavior of the birds and increased their exploration tendencies,indicating that social environment could serve as a past experience and affect the future personality expression of animals.The initial exploration level of social individuals could not predict the changes of exploration level. |
