Mild spring temperature rising affects the anti-oxidation and immune functions of Asian Short-toed Larks

Background Predicting the possibility of severe effects of global warming on animals is important for understanding the ecological consequences of climate change on ecosystem. Spring is the season during which birds have to physiologically prepare for the subsequent breeding period, and unusual spring temperature rising probably becomes a heat stress to the birds which have adapted to the low spring temperature. Therefore, it is necessary to understand the physiological effect of spring warming on the temperate birds.

Methods Using the activities of blood anti-oxidative enzymes (SOD, CAT, GPx) and the concentrations of serum immunogloblins (IgA, IgY, IgM) as indicators, we compared the anti-oxidative and immune functions of Asian Short-toed Larks (Calandrella cheleensis) captured between 10 and 15 March, 2015 and housed under conditions of 21 ℃ and 16 ℃.

Results The SOD activities of birds in 21 ℃ group were significantly lower than those in 16 ℃ group on all the treatment days. The CAT activities of the birds in 21 ℃ group were significantly lower than those in 16 ℃ group on the 1st, 5th, 13th, 17 treatment days. The GPx activities of the birds in 21 ℃ group were signifthicantly lower than those in 16 ℃ group on the 1st, 13th and 17th, but significantly higher on the 21st treatment day. The IgA, IgY and IgM concentrations of birds in 21 ℃ group were significantly lower than those in 16 ℃ group on all the treatment days.

Conclusions This study shows that spring temperature rising negatively influences antioxibative and humoral immune functions, which indicates that spring climate warming might reduce the fitness of the temperate passerine birds which have adapted to the low spring temperature.