Seasonal variation in environmental factors is vital to the regulation of seasonal reproduction in primates. Consequently, long-term systematic data is necessary to clarify the birth seasonality and pattern of primate...Seasonal variation in environmental factors is vital to the regulation of seasonal reproduction in primates. Consequently, long-term systematic data is necessary to clarify the birth seasonality and pattern of primates in highly seasonal environments. This study indicated that black-and-white snub-nosed monkeys （Rhinopithecus bieti） at Mt. Lasha exhibited strict birth seasonality with a pulse model. Infants were born with a certain degree of synchronization. Birth distribution showed three birth peaks, and the birth pattern showed a ＂V＂ style in even-numbered years and a gradual increase in odd-numbered years. The beginning date, end date and median birth date were earlier in even-numbered years than those in odd-numbered years. The higher latitude of their habitats, earlier birth date, shorter birth period, fewer birth peaks and stronger birth synchrony might be adaptations for strongly seasonal variation in climate and food resources. After the summer solstice when daylight length began to gradually shorten, R. bieti at Mt. Lasha started to breed during the period with the highest environmental temperature and food availability, which implied that photoperiod may be the proximate factor triggering the onset of estrus and mating. It appears that R. bieti coincided conception and mid-lactation with the peak in staple foods, and weaning with the peak in high quality of foods. Thus, food availability was the ultimate factor regulating reproductive seasonality, and photoperiod was the proximate factor fine-turning the coordination between seasonal breeding and food availability.展开更多
Dear Editor,The common marmoset(Callithrix jacchus),a small New World monkey species,is considered an ideal non-human primate model for studying the evolution and neural mechanism of vocal behavior due to their rich c...Dear Editor,The common marmoset(Callithrix jacchus),a small New World monkey species,is considered an ideal non-human primate model for studying the evolution and neural mechanism of vocal behavior due to their rich call repertoire and vocal communication[1-3].Especially,the early vocal development of marmoset monkeys has attracted much attention,because newborn marmosets have been shown to exhibit a vocal development trajectory.Within two months after birth,marmosets'vocalizations undergo dramatic changes from cries to adult-like mature calls,a process that is influenced not only by inner physical maturation but also by parental care and feedback[4].展开更多
To evaluate the effects of maternal pre-pregnancy body mass index （pre-BMI） and gestational weight gain （GWG） on neonatal birth weight （NBW） in the population of Chinese healthy pregnant women, attempting to gui...To evaluate the effects of maternal pre-pregnancy body mass index （pre-BMI） and gestational weight gain （GWG） on neonatal birth weight （NBW） in the population of Chinese healthy pregnant women, attempting to guide weight control in pregnancy. A retrospective cohort study of 3772 Chinese women was conducted. The population was stratified by maternal pre-BMI categories as underweight （〈18.5 kg/m2）, normal weight （18.5-23.9 kg/m2）, overweight （24.0-27.9 kg/m2）, and obesity （〉28.0 kg/m2）. The NBW differences were tested among the four groups, and then deeper associations among maternal pre-BMI, GWG, and NBW were investigated by multivariate analysis. NBW increased significantly with the increase of maternal pre-BMI level （P〈0.05）, except overweight to obesity （P〉0.05）. The multivariate analysis showed that both pre-BMI and GWG were positively correlated with NBW （P〈0.05）. Compared with normal pre-BMI, underweight predicted an increased odds ratio of small-for-gestational-age （SGA） and decreased odds ratio for macrosomia and large-for-gestational-age （LGA）, and the results were opposite for overweight. With the increase of GWG, the risk of SGA decreased and the risks of macrosomia and LGA increased. In addition, in different pre-BMI categories, the effects of weight gain in the first trimester on NBW were different （P〈0.05）. NBW is positively affected by both maternal pre-BMI and GWG, extreme pre-BMI and GWG are both associated with increased risks of abnormal birth weight, and maternal pre-BMI may modify the effect of weight gain in each trimester on NBW. A valid GWG guideline for Chinese women is an urgent requirement, whereas existing recommendations seem to be not very suitable for the Chinese.展开更多
While most mammals show birth hour peaks at times of the 24-h cycle when they are less active,there are exceptions to this general pattern.Such exceptions have been little explored,but may clarify evolutionary reasons...While most mammals show birth hour peaks at times of the 24-h cycle when they are less active,there are exceptions to this general pattern.Such exceptions have been little explored,but may clarify evolutionary reasons for the diel timing of births.We investigated intraspecific variation in birth hour in wild blue monkeys Cercopithecus mitis stuhlmanni,a diurnal primate,to identify factors that differentiated daytime versus nighttime births.Behavioral and life history data from 14 groups over 14 years revealed that 4%of 484 births occurred during the day.Probability of daytime birth varied with mother’s age,peaking at 15.7 years.Births whose annual timing deviated most from the population’s peak birth months were 5 times more likely to occur during daytime than those that deviated less.There was no evidence that mother’s rank or infant sex influenced birth hour,and mixed evidence that daytime births were more probable in larger groups.Survivorship did not differ significantly for infants born during the day versus night.Prime-aged mothers may be able to handle the consequences of an unusual birth hour more successfully than mothers with less experience or those weakened by age.Daytime birth may be more advantageous in the off-season because nights are colder at that time of year.These findings are consistent with hypotheses relating birth hour to the risk of losing social protection in group-living animals,but are not consistent with those emphasizing risk of conspecific harassment.Patterns of within-species variation can help in evaluating evolutionary hypotheses for non-random birth hour.展开更多
基金Foundation items： This study was supported by the National Natural Science Foundation of China （31160422, 30960084）, China Postdoctoral Science Foundation （2013M542379）, Program for New Century Excellent Talents in University （NCET-12-1079）, and Key Subject of Wildlife Conservation and Utilization in Yunnan Province We thank the directors and staff from the Administrative Bureau of Yunling National Reserve, Lanping County, Nujiang Prefecture, Yunan Province, the residents of Dashanqing village and assistants Qing-Sheng Su and Jin-Fu Zhang.
文摘Seasonal variation in environmental factors is vital to the regulation of seasonal reproduction in primates. Consequently, long-term systematic data is necessary to clarify the birth seasonality and pattern of primates in highly seasonal environments. This study indicated that black-and-white snub-nosed monkeys （Rhinopithecus bieti） at Mt. Lasha exhibited strict birth seasonality with a pulse model. Infants were born with a certain degree of synchronization. Birth distribution showed three birth peaks, and the birth pattern showed a ＂V＂ style in even-numbered years and a gradual increase in odd-numbered years. The beginning date, end date and median birth date were earlier in even-numbered years than those in odd-numbered years. The higher latitude of their habitats, earlier birth date, shorter birth period, fewer birth peaks and stronger birth synchrony might be adaptations for strongly seasonal variation in climate and food resources. After the summer solstice when daylight length began to gradually shorten, R. bieti at Mt. Lasha started to breed during the period with the highest environmental temperature and food availability, which implied that photoperiod may be the proximate factor triggering the onset of estrus and mating. It appears that R. bieti coincided conception and mid-lactation with the peak in staple foods, and weaning with the peak in high quality of foods. Thus, food availability was the ultimate factor regulating reproductive seasonality, and photoperiod was the proximate factor fine-turning the coordination between seasonal breeding and food availability.
基金supported by the STI2030-Major Projects(2021ZD0203900)Shanghai Municipal Science and Technology(22ZR1481500)+1 种基金"Strategic Priority Research Program"of the Chinese Academy of Sciences(XDB32010000)Shanghai Municipal Science and Technology Major Project(2018SHZDZX05).
文摘Dear Editor,The common marmoset(Callithrix jacchus),a small New World monkey species,is considered an ideal non-human primate model for studying the evolution and neural mechanism of vocal behavior due to their rich call repertoire and vocal communication[1-3].Especially,the early vocal development of marmoset monkeys has attracted much attention,because newborn marmosets have been shown to exhibit a vocal development trajectory.Within two months after birth,marmosets'vocalizations undergo dramatic changes from cries to adult-like mature calls,a process that is influenced not only by inner physical maturation but also by parental care and feedback[4].
基金Project supported by the National Natural Science Foundation of China(Nos.81370725 and 81370726)the Natural Science Foundation of Zhejiang Province(No.LQ14H040004)the Key Discipline of Obstetrics of Zhejiang Province,China
文摘To evaluate the effects of maternal pre-pregnancy body mass index （pre-BMI） and gestational weight gain （GWG） on neonatal birth weight （NBW） in the population of Chinese healthy pregnant women, attempting to guide weight control in pregnancy. A retrospective cohort study of 3772 Chinese women was conducted. The population was stratified by maternal pre-BMI categories as underweight （〈18.5 kg/m2）, normal weight （18.5-23.9 kg/m2）, overweight （24.0-27.9 kg/m2）, and obesity （〉28.0 kg/m2）. The NBW differences were tested among the four groups, and then deeper associations among maternal pre-BMI, GWG, and NBW were investigated by multivariate analysis. NBW increased significantly with the increase of maternal pre-BMI level （P〈0.05）, except overweight to obesity （P〉0.05）. The multivariate analysis showed that both pre-BMI and GWG were positively correlated with NBW （P〈0.05）. Compared with normal pre-BMI, underweight predicted an increased odds ratio of small-for-gestational-age （SGA） and decreased odds ratio for macrosomia and large-for-gestational-age （LGA）, and the results were opposite for overweight. With the increase of GWG, the risk of SGA decreased and the risks of macrosomia and LGA increased. In addition, in different pre-BMI categories, the effects of weight gain in the first trimester on NBW were different （P〈0.05）. NBW is positively affected by both maternal pre-BMI and GWG, extreme pre-BMI and GWG are both associated with increased risks of abnormal birth weight, and maternal pre-BMI may modify the effect of weight gain in each trimester on NBW. A valid GWG guideline for Chinese women is an urgent requirement, whereas existing recommendations seem to be not very suitable for the Chinese.
基金the U.S.National Science Foundation(SBE 9523623,BCS 9808273,DGE 0333415,BCS 0554747,DGE 0966166,BCS 1028471),Ford,Leakey,Wenner-Gren and H.F.Guggenheim Foundations,American Association for the Advancement of Science-Women's International Scientific Cooperation Project,and Columbia University,all to M.C.
文摘While most mammals show birth hour peaks at times of the 24-h cycle when they are less active,there are exceptions to this general pattern.Such exceptions have been little explored,but may clarify evolutionary reasons for the diel timing of births.We investigated intraspecific variation in birth hour in wild blue monkeys Cercopithecus mitis stuhlmanni,a diurnal primate,to identify factors that differentiated daytime versus nighttime births.Behavioral and life history data from 14 groups over 14 years revealed that 4%of 484 births occurred during the day.Probability of daytime birth varied with mother’s age,peaking at 15.7 years.Births whose annual timing deviated most from the population’s peak birth months were 5 times more likely to occur during daytime than those that deviated less.There was no evidence that mother’s rank or infant sex influenced birth hour,and mixed evidence that daytime births were more probable in larger groups.Survivorship did not differ significantly for infants born during the day versus night.Prime-aged mothers may be able to handle the consequences of an unusual birth hour more successfully than mothers with less experience or those weakened by age.Daytime birth may be more advantageous in the off-season because nights are colder at that time of year.These findings are consistent with hypotheses relating birth hour to the risk of losing social protection in group-living animals,but are not consistent with those emphasizing risk of conspecific harassment.Patterns of within-species variation can help in evaluating evolutionary hypotheses for non-random birth hour.
