笼养普通朱雀适应北方冬季气候的体温调节特征

Thermoregulatory Characteristics in Winter-acclimatized Common Rosefinch Carpodacus erythrinus

内温动物的能量代谢和体温调节表现出普遍的季节性适应,这对于动物的能量分配、存活和繁殖等具有积极意义。本研究中,利用陆生动物呼吸代谢测量系统,测定了在北方适应了3年(2018至2020年)的普通朱雀(Carpodacus erythrinus)冬季代谢产热特征,以期理解该物种对北方冬季气候的响应。结果发现,普通朱雀冬季基础代谢率(以单位时间耗氧量表示)为(6.5±0.3)ml/(g·h);热中性区为20~35℃,环境温度低于下临界温度时,代谢率随环境温度降低显著升高,环境温度高于上临界温度时,代谢率随环境温度升高显著增加。体温在环境温度为10~25℃时,保持相对稳定,为(42.9±0.15)℃;环境温度为5℃时体温降低,高于30℃时,体温升高。最小热传导(0.25±0.02)ml/(g·h·℃),热传导随环境温度上升显著增加。与已有关于普通朱雀的研究报道相比较,本结果表明,普通朱雀在冬季代谢产热增加,以维持较高体温;热中性区变宽,下临界温度下调,以节省体温调节的能量支出;体温维持较高水平以抵抗寒冷,当气温过低时,适当降低体温,以减少直接能量消耗。

Seasonal adjustments of metabolic thermogenesis is common in endotherms,which is important to energy allocation,survival,reproduction and other aspects of these animals.To understand the response of thermoregulation to climate change,we used a continuous flow respirometry system to determine thermoregulatory characteristics including body temperature,basal metabolic rate,thermal neutral zone and thermal conductance in the winter-acclimatized Common Rosefinch Carpodacus erythrinus,which were captured in breeding ground and in captivity for 3 years(2018﹣2020).The results analyzed by one-way ANOVA showed that their body temperatures(T_(b))maintained at 42.9±0.15℃,when the air temperature(T_(a))ranged between 10﹣25℃;and T_(b) increased when the T_(a) upper this range,and decreased to 41.6±0.13℃at the T_(a) of 5℃(Fig.1).The resting metabolic rate increased significantly with the descending of T_(a) when the T_(a) lower than 20℃,and when T_(a) exceeded 35℃.Metabolic rate maintained lowest and stable when the T_(a) ranged between 20-35℃(Fig.2),therefore,this temperature range should be the thermal neutral zone(TNZ)in this bird,with the basal metabolic rate(BMR)of 6.5±0.3 ml/(g·h).Thermal conductance increased with the upgrade of T_(a)(Fig.3)and with the least value of 0.25±0.02 ml/(g·h·℃).Compared to the previously reports,our results indicated that the Common Rosefinch changed their TNZ wider and increased metabolic thermogenesis to maintain their higher T_(b) in winter,and could survival in the temperate conditions with abundant food.