Ontogeny and the influencing factors of bite force and feeding rate of gi-ant pandas(Ailuropoda melanoleuca)
The biting ability of giant pandas(Ailuropoda melanoleuca)holds significant importance in terms of food ac-quisition and male-male competition.Their distinctive dietary preferences and masticatory system render them an ideal species for investigating bite forces.Nevertheless,current studies have predominantly relied on theoretical assessments derived from panda skull morphology,with no empirical animal experimentation conducted.The present study designed a force transducer specifically tailored for giant pandas,and measured body weight,bite forces,and feeding rate in a sam-ple of 46 individuals from various age groups,with a particular focus on juvenile development.The results showed that bite forces at the tip of the incisor of juvenile giant pandas increased rapidly during the dental transitional period,as well as the feeding rate of bamboo shoots.At the end of the dental transitional phase,the bite forces exerted at the incisor point of juvenile giant pandas continued to display a growing trend,albeit at a decelerated rate.Concurrently,the feed-ing rate reached a state of equilibrium.The utilization of a logistic model revealed that age explains 87.56%of the vari-ance observed in the feeding rate among juvenile pandas.As for the comparisons of age groups,the median bite force value exhibited an upward trajectory in tandem with increasing age.The bite force of 8-month to 12-month age group was significantly lower than the bite forces of all the other age groups;the bite force of 13-month to 18-month age group was significantly lower than those of sub-adult,adults and geriatric group;however,there was no significant difference between the latter three groups.The adult group has the highest feeding rate of bamboo shoots and carrots,followed suc-cessively by the sub-adult group,the geriatric groups and the juvenile group.In summary,our study confirmed for the first time the feasibility of measuring bite forces of giant pandas by using force transducer,recorded the developmental process of bite forces and feeding rate of juvenile giant pandas during the dental transitional period,and discussed the ef-fect of age on bite forces and feeding rate,all of which laying a good foundation for future work of giant pandas'feed-ing ecology.
Giant pandaBite forcesFeeding rateAge groupsDental transitional period