Annual Variations and Seasonal Adaptation of Digestive Tract Morphology in Passer montanus in Wenzhou City,Zhejiang
The morphologies of animal digestive tracts are correlated with food composition.In this study,the annual variations in length and mass of gizzard,small intestine,rectum and total digestive tract in Eurasian tree sparrow(Passer montanus)were measured.The birds were acclimated for 1 week in laboratory before experiments.The digestive tract(giz-zard,small intestines and rectum)of each bird was measured(±1 mm).These organs were then dried to a constant mass.The statistical significance of annual variation in gizzard,small intestine and rectum was assessed using One-Way ANOVA with body mass as the covariate.The results showed the length of total digestive tract in P.montanus was relatively con-stant(P=0.874).Significant seasonal variation was detected in the wet mass(P＜0.001)and dry mass(P＜0.001)of the total digestive tract.Moreover,the birds caught in winter had a heavier digestive tract than those caught in summer.The masses of gizzard,small intestine and rectum(wet:P＜0.001;dry:P＜0.001)in P.montanus were significanty higher in winter with poor conditions than those in summer with favorable conditions.P.montanus would increase the size and mass of the digestive tract to adapt to the increased energy demand and seasonal shifts of diet in winter.This suggested that the adjustments in the capacity and size of digestive tract might play a key role in digestive strategies of P.montanus in natural environment.This study provides basic data for further investigating the survival strategies of wild small birds.
万方数据
维普
