Annual variation in the reproductive hormone and behavior rhythm in a population of the Asian short-toed lark: Can spring temperature influence activation of the HPG axis of wild birds?

Differential cell stress responses to food availability by the nestlings of Asian Short-toed Lark (Calandrella cheleensis)

“…In addition, their response usually results in a concomitant reduction in the synthesis of antibodies, thus synthesizing more HSPs to mitigate stress has been found in passerine birds to be traded-off against mounting humoral and cell-mediated immune responses (Morales et al 2006). The result of our previous study on the Asian Short-toed Lark showed that the survival rate of the nestlings in 2014 and 2016 when the peak of nestling hatching mismatched with the peak of nymph abundance peak was significantly lower than that in 2015 when the two peaks thoroughly match (Zhang et al 2017), which suggests that overexpression of HSPs could be related with lower nestling survival. As a bird species living in the harsh weather condition, the nestlings of Asian Short-toed Lark have to cope with the marked weather variation by cell stress response, and poor food condition could impose additional stress to make HSPs overexpression, which consequently could result in negative effect on the nestling survival.…”

“…Because there is only one significant nymph abundance peak once a year in the study area (Chen and Gong 2005;Guo et al 2009), and the hatching time of nestlings has to be synchronized with the time of nymph abundance peak. According to our previous study, the species displays significantly within year individual variation in the timing of breeding behavior (Zhang et al 2017;Zhao et al 2017). Although there was an obvious hatching peak in one breeding season, there were some nestlings hatched outside this peak (Zhang et al 2017).…”

“…According to our previous study, the species displays significantly within year individual variation in the timing of breeding behavior (Zhang et al 2017;Zhao et al 2017). Although there was an obvious hatching peak in one breeding season, there were some nestlings hatched outside this peak (Zhang et al 2017). In addition, the synchronization between the nestling hatching peak and nymph abundance peak varied with the spring temperature.…”

“…Asian Short-toed Lark (Calandrella cheleensis) is the most common passerine species living on the grasslands of northeastern Inner Mongolia of China (Tian et al 2015;Zhang et al 2017). The breeding of the species begins in mid-April and ends in mid-June, and the grasshopper nymph (Orthoptera) is the main component (about 80%) of the nestlings' diet (Tian et al 2015).…”

“…In addition, the synchronization between the nestling hatching peak and nymph abundance peak varied with the spring temperature. In 2014 and 2016, the peak of nestling hatching was asynchronized with the nymph abundance peak for the extremely high and low spring temperature, and nestling's food shortage induced by such mismatch could finally reduce the survival rate of nestlings (Zhang et al 2017). Therefore, this species is an appropriate species to study the effect of food availability on the physiological status of nestlings.…”