Compared to sparrows in a nonmigratory state, migratory sparrows spent approximately two-thirds less time sleeping.
Niels C Rattenborg, Bruce H Mandt, William H Obermeyer, Peter J Winsauer, Reto Huber,Martin Wikelski, Ruth M Benca 2004, 'Migratory sleeplessness in the white-crowned sparrow (Zonotrichia leucophrys gambelii).',PLoS Biologyhttp://europepmc.org/articles/PMC449897?pdf=render. Retrieved from PLOS CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)