Galápagos penguins forage just offshore, close to their nests, and return to the nest site after the young fledge, so parents and fledglings are likely to encounter one another frequently.

Only one other of the 18 species of penguins is known to do this: the Gentoo penguins. These birds, which inhabit Antarctica and nearby islands, feed their young after they have fledged for about 12 days, probably to give them time to learn how to hunt for themselves.

The Galápagos penguins, the only penguins that live north of the Equator, are endangered, with fewer than 2,000 left in the world. They are not always so self-sacrificing.

“When conditions are good, they can raise two chicks in a season and continue to feed them,” said Dee Boersma, a professor of biology at the University of Washington and the lead author of the study.