Most of us relax when we sleep, but hummingbirds can take it one step farther. If their energy reserves get really low, they can enter a state of torpor.
Torpor – Noun
Pronounced: tȯr-pər
1a: a state of mental and motor inactivity with partial or total insensibility.
b: a state of lowered physiological activity typically characterized by reduced metabolism, heart rate, respiration, and body temperature that occurs in varying degrees especially in hibernating and estivating animals.
from: https://www.merriam-webster.com/dictionary/torpor
Their breathing becomes shallow and irregular and they can slow their heartbeats to 50 beats per minutes. Talk about a deep sleep! They can stay in this state for 8 to 14 hours. It could take up to an hour to get back up to normal speed the next day.
HUMMINGBIRD: A Star Touched Story
Plagued by memories not her own, a young hummingbird struggles to decipher the visions and powers that set her apart from her fellow birds. But the road to awareness is fraught with danger that could doom her to repeat history. One step toward understanding. One stride toward survival. One leap toward flying free from the past.
STAR TOUCHED

Sometimes it’s hard to be who you are meant to be.
Especially when your powers can get you killed.
Eighteen-year-old Tatiana is running from her past and her star-touched powers eight years after a meteor devastates earth’s population.
Her power to heal may be overshadowed by more destructive abilities. Fleeing the persecution of those like her, Tatiana seeks refuge in a small town she once visited. But this civil haven, in a world where society has broken down, is beginning to crumble.
Only by harnessing the very forces that haunt her can Tatiana save her friends…and herself.