Who’s your daddy? If you’re a giant salamander, he’s the one who fanned your nest with his tail, of course. A recent article in the Journal of Ethology describes paternal care behaviors in the giant salamander, newly captured on video by a team of researchers from Japan and the USA.
These notable behaviors included the male’s fanning the nest with his tail—likely to oxygenate the nest—and also vigorously “agitating” the eggs, which is theorized to assist with embryonic development. The researchers also identified a third, more counter-intuitive way that male salamanders cared for their eggs—by eating them. While it doesn’t sound like the most fatherly way to act, the salamanders that were videotaped only consumed eggs that were whiter than normal, thus probably diseased or dead. This might allow them to focus their care on more viable potential offspring.
This research is particularly notable because very few amphibian species display male parental behavior. In fact, male care of eggs and offspring is extremely uncommon in most of the animal kingdom, with birds being one of the most notable exceptions—in fact, the vast majority of bird species show some male parental care. In 2009, researchers captured video footage of male care behaviors in the Sprague’s Pipit, a ground-nesting prairie bird. In this species, males care for their young by bringing prey for them to eat and removing their waste from the nest.
Quite a few frog and fish species also display this kind of “exceptional” fathering. This 1990 article describes the extensive paternal care shown by the green dart-poison frog. After the female lays her clutch of eggs, the male frog fertilizes them and begins looking for a quiet, safe pool to house his future offspring, returning periodically to check on the eggs. When the tadpoles finally hatch, they wriggle up onto his back, and he carries them to their new home.
The male cardinalfish is similarly concerned with transporting and protecting his young, though, as one might guess from the evocatively titled “Breathing with a mouth full of eggs: Respiratory consequences of mouthbrooding in cardinalfish,” His means of doing so (for 1-2 weeks!) is a bit more inconvenient than a “froggyback ride.” Clearly, it’s not always fun and games when you’re a dad who cares.