As other researchers reported in 2009, the brain and eyes of the opah are even
warmer than the rest of the body, thanks to a small countercurrent heat exchanger at the base of its skull.
Despite their hostile environment, Red - throated Loon chicks did not use more energy
than what was predicted by their
body mass, possibly because
of how they limit their energy expenditure — they regularly
rest onshore, and very young chicks are brooded by their parents to help keep them
warm.