Endocrine response of early-hatching Asian Short-toed Lark nestlings exposed to cold temperature in a high-latitude grassland habitat  

作　　者：Jing Shang Liang Zhang Xinyu Li Shuping Zhang 

机构地区：[1]Key Laboratory of Ecology and Environment in Minority Areas(National Ethnic Affairs Commission),Minzu University of China,Beijing 100081,China [2]College of Life and Environmental Sciences,Minzu University of China,Beijing 100081,China

出　　处：《Avian Research》2021年第4期750-758,共9页鸟类学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.32071515)。

摘　　要：Background:In high latitude grassland habitats,altricial nestlings hatching in open-cup nests early in the breeding season must cope with cold temperature challenges.Thyroid hormones(triiodothyronine,T_(3)and thyroxine,T_(4))and corticosterone play a crucial role in avian thermoregulation response to cold.Investigating the endocrine response of altricial nestlings to temperature variation is important for understanding the adaptive mechanisms of individual variation in the timing of breeding in birds.Methods:We compared nest temperature,ambient temperature,body temperature,plasma T_(3),T_(4)and corticosterone levels in Asian Short-toed Lark(Alaudala cheleensis)nestlings hatching in the early-,middle-,and late-stages of the breeding season in Hulunbuir grassland,northeast China.Results:Mean nest temperature in the early-,middle-and late-stage groups was-1.85,3.81 and 10.23℃,respectively,for the 3-day-old nestlings,and 6.83,10.41 and 11.81℃,respectively,for the 6-day-old nestlings.The nest temperature significantly correlated with body temperature,plasma T_(3),T_(4)and corticosterone concentrations of nestlings.Body temperature of 3-day-old nestlings in the early and middle groups was significantly lower than that of the late group,but there was no significant difference between the nestlings in the early and middle groups.The T_(4)and T_(3)concentrations and the ratio of T_(3)/T_(4)of both 3-and 6-day-old nestlings in the early-stage group were significantly higher compared to the middle and late groups.The corticosterone levels of 3-day-old nestlings were significantly higher in the early-stage group compared to the middle-and late-stage groups.Conclusion:Nestlings hatching early responded to cold temperature by increasing thyroid hormones and corticosterone levels even in the early days of post hatching development when the endothermy has not been established.These hormones may play a physiological role in neonatal nestlings coping with cold temperature challenges.

关 键 词：Endocrine response of early-hatching Asian Short-toed Lark nestlings exposed to cold temperature in a high-latitude grassland habitat 

分 类 号：Q958[生物学—动物学]