@article{Shi2019, 
author = {Mei Shi and Yun Fang and Jin-ming Zhao and Siegfried Klaus and Yingxin Jiang and Jon E. Swenson and Yue-Hua Sun},
title = {Egg laying and incubation rhythm of the Chinese Grouse (Tetrastes sewerzowi) at Lianhuashan, Gansu, China},
year = {2019},
journal = {Avian Research},
volume = {10},
number = {1},
pages = {23},
keywords = {Body mass, Chinese Grouse, Environment temperature, Incubation pattern, Nest attentiveness},
url = {https://www.sciopen.com/article/10.1186/s40657-019-0161-x},
doi = {10.1186/s40657-019-0161-x},
abstract = {BackgroundIncubating birds must balance the conflict between thermal needs of the developing embryos and their self-maintenance needs for energy. The Chinese Grouse (Tetrastes sewerzowi) lives in high mountain conifer forests and faces energy stress, cold environment, and predation pressure. Females might adjust incubation rhythm to adapt to these constraints.MethodsTwo methods were used to investigate egg laying and incubation pattern of the Chinese Grouse; 25 nests were monitored by data loggers and 12 nests by infrared video cameras.ResultsFemale Chinese Grouses usually laid an egg every 2 days. The incubation period was 28-31 days. Overall incubation constancy for Chinese Grouse was 93%. The females took 5.0 recesses per day and 34% of all 1696 recesses were taken in the crepuscular period. The average recess duration was 20.3 min. Females took more and shorter recesses in the latter part of incubation. The females who allocated more time to foraging had a higher reproductive success.ConclusionsProbably due to its high egg/body mass ratio, the Chinese Grouse has a long laying interval of 49 h. We suggest that, due to energy stress, females have relatively more recesses and they increase the number of recesses as incubation progresses. To compensate for the embryos' thermal needs, they extend the incubation period and shorten the recess duration in this cold environment.}
}