Page 134 - The Origin of Birds and Flight

Hummingbirds possess the fastest metabolic rate of any vertebrate.
Their hearts, which beat 700 to 850 times a minute when the birds are at
rest, begin beating 1,200 times a minute when they hover in the air. In rela-
tion to their size, they expend more energy than a jet plane. If you con-
sumed energy at that same level, your body temperature would rise to 400
degrees Celsius—and in order to meet that energy requirement, you would
have to eat 45 kilograms of sugar every day.
Yet when at rest, these birds reduce their body temperatures from 40 to
15 degrees Celsius and efficiently slow their metabolisms at the same time.
They adopt a particular posture in order to save energy, during which they
puff up their feathers, raise
their beaks up in the air
and reduce their heart beat
to 50 beats a minute. 1
Allah has created these tiny
creatures with a great many superior