In many frog species, the males care for their young. But in a rain forest in Borneo, scientists have discovered a case of unusual paternal devotion. Male smooth guardian frogs scarcely move or eat for days while tending one clutch of eggs, and they seem uninterested in mating with more females. Once hatched, tadpoles clamber on the males’ backs to be ferried to pools of water.

“They are very good fathers,” said Johana Goyes Vallejos, a behavioral ecologist at the University of Kansas and lead author of the study, which was published online November 15 in the Journal of Natural History.

Among frogs, about 10 percent of known species take care of their young. Of that group, half to two-thirds of species rely on males to do the job. For instance, male parental care is common among the brightly colored Neotropical poison frogs of Central and South America. But in species that have been studied in detail, the males often continue to call to females and mate while tending eggs, and they spread their attention over several clutches.

Dr. Goyes Vallejos was drawn to the less glamorous smooth guardian frog: a brown, nocturnal creature about an inch long with back patterns that look like dead leaves. In the 1980s, researchers published two short reports of males “in direct contact” with eggs and carrying tadpoles, but since then, the obscure species had been mostly ignored. “I kind of wanted to go with the one that it seemed that nobody wanted to study,” Dr. Goyes Vallejos said.