| differences in the reproductive hormone rhythm of tree sparrows (passer montanus) from urban and rural sites in beijing: the effect of anthropogenic light sources. | the pervasiveness of anthropogenic light in urban environments has increased the exposure to light of many animals. since photoperiod is a regulator of the timing of reproduction in most temperate region birds, such light sources could potentially change the timing of reproduction. we compared the luteinizing hormone (lh), testosterone (t), and estradiol (e2) levels of tree sparrow (passer montanus) populations sampled at two urban and two rural sites in china, and also performed a controlled ph ... | 2014 | 24861803 |