Father's Day may be about warmth and fuzziness to humans, but in the animal kingdom, dads can often be general deadbeats at best and murderous baby killers at worst.
Particularly among fish, it's not uncommon to find dads that will even eat their own young, either the eggs or the ... well, you get the idea. Outside of fish, it's not terribly common to find dads eating their own offspring (filial infanticide, in fancy terms), although some adult male animals, such as lions, will kill a conquered male's offspring in order to flex its dominance muscles and also free up some breeding time for the (now-childless) ladies in the pride.
With apologies to all the great dads out there in the animal kingdom, let's take a look at a few of nature's harsher papas.
The male grizzly bear, for starters, from a distance, can look like quite the charmer, but children of the same species might beg to differ. The giant creatures have been known to kill young cubs for much the same reason as lions: to force the mother to mate with him.
As we noted, dads eating their own offspring is largely a "fish thing." Largemouth bass, for example, are omnivorous, eating all kinds of things -- other bass, waterfowl, frogs and the like. They've also been known to eat their own young.
Male lions won't be winning any Father's Day awards. Once they, ahem, do the necessary things to sire some children, they pretty much leave the rest to the lioness. The male doesn't acknowledge any rearing responsibilities, and while he won't kill his own children, he will kill his pride predecessor's cubs, to assert his own dominance and also to create time in the female's calendar for his gene-prolonging advances.
The male lion had better be prepared for a fight, though, as mother lions are known to be fierce protectors of their cubs.
Gobies are a pretty large family of fish (shown here, a sharknose goby). One rather icky thing the males will do is eat the eggs of their offspring. They're in charge of fanning mounds of eggs in a burrow, to keep them oxygenated. But if mom leaves the burrow, the dad can lose control over the mound's structural properties and then decide "eh, why not eat them?"
Good news/bad news here. Pipefish can be pretty good dads, in the sense that they will stoop to the chore of carrying fertilized eggs. So far, so good, right? Unfortunately, they end up eating half of them.
The polar bear has taken on an "Awwwww" quality among humans that can belie its native ferocity, borne of the life it has to lead to survive. Sure, they're cute, but only from a very safe distance. If you tried to pet one it would pay you back the kindness by mauling you to shreds.
Polar bears were documented in several cases devouring cubs in Svalbard, Norway. When food sources are depleted, male polar bears don't seem too troubled with the idea of eating young ones of their kind.
Like lionesses, however, momma polar bears often won't let their children be sacrificed without a fight.
This is one damsel who's not in distress. Damselfish, which can grow up to around 1 foot long, usually live in tropical coral reefs. They'll eat algae, plankton and little crustaceans. The male Cortez Damselfish is a dad from a dark fairy tale; it will eat about a quarter of its clutch, especially the ones that are undersized.
Burying beetles of both sexes have a rather disturbing tendency to eat some of their new larvae when there just isn't enough food on hand to feed everyone.
Bottlenose dolphins are so cute! Right? Indeed, but they have also been observed killing porpoises just for what seems to be the fun of it. Not satisfied with porpoises, they can also kill young members of their own species, the purpose for which remains unclear.
Gray langurs hail from India and live in groups dominated by a single male, with several females. The male has to be tough enough to hang onto the alpha title, and if he's challenged and loses, the infants of the group's females are killed, though only in the brief time after the victory has been secured. The new alpha male kills, but does not eat, the poor infants.