Artificial light at night (ALAN) exposes animals to a novel environmental stimulus, one that is generally thought to be maladaptive. ALAN-related health problems have received little attention in non-model species, and we generally know little about the nutritional-physiological impacts of ALAN, especially in young animals. Here, we use a novel application of the acid steatocrit method to experimentally assess changes in digestive efficiency of growing king quail (Excalfactoria chinensis) in response to ALAN. Two weeks after hatching, quail were split into two groups (n = 20–21 per group): overnight-light-treated vs. overnight-dark-treated. When the chicks were 3 weeks old, the experimental group was exposed to weak blue light (ca. 0.3 lux) throughout the entire night for 6 consecutive weeks, until all the chicks had achieved sexual maturation. Fecal samples for assessing digestive efficiency were collected every week. We found that digestive efficiency of quail was reduced by ALAN at two time points from weeks 4 to 9 after hatching (quail reach adulthood by week 9). The negative effect of ALAN on digestion coincided with the period of fastest skeletal growth, which suggests that ALAN may reduce digestive efficiency when energetic demands of growth are at their highest. Interestingly, growth rate was not influenced by ALAN. This suggests that either the negative physiological impacts of ALAN may be concealed when food is provided ad libitum, the observed changes in digestive efficiency were too small to affect growth or condition, or that ALAN-exposed birds had reduced energy expenditure. Our results illustrate that the health impacts of ALAN on wild animals should not be restricted to traditional markers like body mass or growth rate, but instead on a wide array of integrated physiological traits.

夜间人造光（ALAN）将动物暴露于一种新颖的环境刺激中，这种刺激通常被认为具有适应不良性。与ALAN有关的健康问题在非模型物种中很少受到关注，并且我们通常对ALAN的营养生理影响知之甚少，尤其是在幼小的动物中。在这里，我们使用酸脂肪爆击法的一种新应用，通过实验评估生长的鹌鹑（Excalfactoria chinensis）对ALAN的消化效率的变化。孵化两周后，将鹌鹑分为两组（n=每组20–21个）：隔夜光照处理与隔夜黑暗处理。当小鸡三周大时，实验组在整个晚上连续六周暴露于弱蓝光（约0.3 lux），直到所有小鸡都达到了性成熟。每周收集用于评估消化效率的粪便样品。我们发现，从孵化后第4周到第9周的两个时间点，ALAN降低了鹌鹑的消化效率（鹌鹑在第9周达到成年）。ALAN对消化的负面影响与骨骼生长最快的时期相吻合，这表明当精力旺盛的生长需求最高时，ALAN可能会降低消化效率。有趣的是，增长率不受ALAN的影响。随意观察到的消化效率变化太小而不会影响生长或状况，或者暴露于ALAN的家禽的能量消耗减少。我们的结果表明，ALAN对野生动物的健康影响不应局限于体重或生长速度等传统标记，而应局限于多种综合的生理特征。