Difference in environmental condition shapes variation in digestive tract length in evolutionary process.In particular,environmental difference results in variation in food resource among different habitats,and thereb...Difference in environmental condition shapes variation in digestive tract length in evolutionary process.In particular,environmental difference results in variation in food resource among different habitats,and thereby affecting energy intake and energy allocation.The digestive theory predicts that animals foraging high indigestible materials of stomach contents can promote the increased gut dimensions.Here,we studied variation in digestive tract and gut length across six Hylarana guentheri populations at different altitudes and latitudes to test the prediction of the digestive theory.We found that altitude and latitude did not affect variation in relative size of digestive tract and gut among populations.We also found that relative size of digestive tract and gut did not be correlated with diversity of prey items,but negatively correlated with proportion of digestible materials.Our findings suggest that individuals foraging less digestible materials display relatively longer digestive tract than individuals foraging more digestible materials.展开更多
Barn Owl (Tyto alba) pellets were collected from nine locations and two districts of Sindh,Pakistan and 937 prey items were recovered from 619 pellets.Rats/mice (59.6%) were the most dominant food items consumed by th...Barn Owl (Tyto alba) pellets were collected from nine locations and two districts of Sindh,Pakistan and 937 prey items were recovered from 619 pellets.Rats/mice (59.6%) were the most dominant food items consumed by the Barn Owl.Shrews (22.3%),bats (1.3%),birds (12.0%),insects (1.3%),frogs (2.2%) and plant materials (1.3%) were found in their diet as well.Study of the pelvic girdle bones of rats/mice,used only for sexing,proved to be a useful device in population dynamics.In the pelvic bone,pelvic symphysis is found only in female rats/mice developed as a result of sex hormones that occur during gestation.Among the diet of rats/mice,males were found to be significantly dominant.Tooth wear patterns on the occlusal surfaces of molariform teeth of the rats/mice were found to provide an effective criterion for establishing age classes of rats/mice.In the present study,adult rats/mice were found to be dominant over sub-adults and old adults.ANOVA showed significant differences in the number of rats/mice and shrews (prey items) and the other prey items/plant materials in the diet of Barn Owls in the district Thatta and district Karachi.Chi-square test disclosed non-significant differences in age and sex categories.展开更多
The diet composition of the Lycian salamander Lyciasalamandra luschani basoglui across both age and sex groups was studied. Specimens were collected from a small island in the Southeast Aegean Sea. The dominant prey g...The diet composition of the Lycian salamander Lyciasalamandra luschani basoglui across both age and sex groups was studied. Specimens were collected from a small island in the Southeast Aegean Sea. The dominant prey group of juveniles consisted of Collembola, while Coleoptera dominated the diet of males and females. The number and size of prey items consumed by males and females of L. luschani basoglui were quite similar, while juveniles ate fewer items of much smaller size. The numerical abundance along with the four measures of the size of prey permitted discrimination among males, females and juveniles. Although discrimination between adults and juveniles is expected due to dissimilarity in body size, discrimination between males and females remains inexplicable despite their similarity in body size. Future studies should be focused on understanding how and why prey choice differs between sexes in L. luschani basoglui.展开更多
基金Financial support was provided by the National Natural Sciences Foundation of China(31772451,31970393)the Science and Technology Youth Innovation Team of Sichuan Province(19CXTD0022)+1 种基金the Key Cultivation Foundation of China West Normal University(17A006)Talent Project of China West Normal University(17YC335)。
文摘Difference in environmental condition shapes variation in digestive tract length in evolutionary process.In particular,environmental difference results in variation in food resource among different habitats,and thereby affecting energy intake and energy allocation.The digestive theory predicts that animals foraging high indigestible materials of stomach contents can promote the increased gut dimensions.Here,we studied variation in digestive tract and gut length across six Hylarana guentheri populations at different altitudes and latitudes to test the prediction of the digestive theory.We found that altitude and latitude did not affect variation in relative size of digestive tract and gut among populations.We also found that relative size of digestive tract and gut did not be correlated with diversity of prey items,but negatively correlated with proportion of digestible materials.Our findings suggest that individuals foraging less digestible materials display relatively longer digestive tract than individuals foraging more digestible materials.
文摘Barn Owl (Tyto alba) pellets were collected from nine locations and two districts of Sindh,Pakistan and 937 prey items were recovered from 619 pellets.Rats/mice (59.6%) were the most dominant food items consumed by the Barn Owl.Shrews (22.3%),bats (1.3%),birds (12.0%),insects (1.3%),frogs (2.2%) and plant materials (1.3%) were found in their diet as well.Study of the pelvic girdle bones of rats/mice,used only for sexing,proved to be a useful device in population dynamics.In the pelvic bone,pelvic symphysis is found only in female rats/mice developed as a result of sex hormones that occur during gestation.Among the diet of rats/mice,males were found to be significantly dominant.Tooth wear patterns on the occlusal surfaces of molariform teeth of the rats/mice were found to provide an effective criterion for establishing age classes of rats/mice.In the present study,adult rats/mice were found to be dominant over sub-adults and old adults.ANOVA showed significant differences in the number of rats/mice and shrews (prey items) and the other prey items/plant materials in the diet of Barn Owls in the district Thatta and district Karachi.Chi-square test disclosed non-significant differences in age and sex categories.
文摘The diet composition of the Lycian salamander Lyciasalamandra luschani basoglui across both age and sex groups was studied. Specimens were collected from a small island in the Southeast Aegean Sea. The dominant prey group of juveniles consisted of Collembola, while Coleoptera dominated the diet of males and females. The number and size of prey items consumed by males and females of L. luschani basoglui were quite similar, while juveniles ate fewer items of much smaller size. The numerical abundance along with the four measures of the size of prey permitted discrimination among males, females and juveniles. Although discrimination between adults and juveniles is expected due to dissimilarity in body size, discrimination between males and females remains inexplicable despite their similarity in body size. Future studies should be focused on understanding how and why prey choice differs between sexes in L. luschani basoglui.
