Animal Valentines

Trickery, hermaphroditism and scented dung: For these species, courtship is hardly a long walk on the beach.

• NWF Staff
• Feb 01, 2010

 



Valentine’s Day is a celebration of romance and the art of courtship, and although it’s debatable whether romantic love exists outside the human species (and cynics might say within it), wild animals have courtship nailed down. They might not be giving roses and writing love poems, but they have some amazing rituals all their own:

On warm, romantic summer nights, male fireflies flash their lights while flying—using a code that lets females know what species they belong to—then wait for the females to flash back from hiding places in vegetation. When a female lights up with desire, males zero in on her with hopes of finding a willing mate. But romantics, beware: The female of one firefly species copies the flashes of the females of species different from her own. When a hopeful male shows up, the mimic eats him, then goes on to mate with a male of her own species.


In looking for a mate, male meadow voles—grassland rodents that look like mice with short tails—prefer females that have just given birth. Females are most receptive when males catch them only hours after giving birth. These females will mate after only about 5 minutes of courtship, compared to up to 90 minutes for other females.


The mating inclinations of male bower birds, native to Australia and New Guinea, are every woman’s dream: He’s an excellent carpenter but also a fabulous decorator. He builds a stick structure called a bower and then decorates it to impress eligible females. Often he picks a monochromatic color scheme for his decor, which can include everything from shells, feathers, flowers and even bits of string, plastic and other human-made items. Only if the house and its decor are good enough will a female—and perhaps even more than one—choose him for a mate (an example from which some nonfeathered bipeds might well learn).


Some animals can be both sexes at once. This double-gender condition is called hermaphroditism. Some sea slug species can be male, female or hermaphroditic. With so many sexual options, these slimy mollusks often engage in orgies of 20 or more slugs of various persuasions. Barnacles—marine creatures that live in shells fastened to objects such as reefs or wharfs—are also hermaphrodites. Since they are stuck in one spot, they have a special strategy for sealing the deal. Each barnacle has not one but two penises that can extend as much as 20 times the length of its body. This allows it to reach other barnacles for mating. Often, when one barnacle reaches another with one of its penises, the partner will reciprocate.


When a male Australian cuttlefish feels the urge to get his groove on with the ladies but is thwarted by a bigger, tougher male, he’s got a trick up his tentacles. He can change color and shape to mimic a female and, in this disguise, slip right by the big guy. Females willingly mate with these diminutive but clever fellows right behind the backs of their burlier brethren.


In rhinoceroses, females in mating condition produce specially scented dung piles that signal their readiness. Males will search for these females and fight among themselves over access to females (the rhinos above are competing males). Adult rhinos are usually solitary, socializing only to mate. Pairs stay together two or three days, mating for a half hour at a time several times a day. Young are born about 16 months later.


Through a process that scientists call “parthenogenesis” and the rest of us call “virgin birth,” some animals produce young without ever mating. In these species, females clone themselves via embryos produced by simple cell division of the egg rather than by joining sperm and egg. Without sex, there’s no exchange of genetic information, so the resulting offspring are genetically identical to the mother. A female aphid can produce thousands of little clones of herself this way. In some bee species, queens can produce different kinds of offspring depending on whether their eggs are fertilized: Fertilized eggs all hatch as females, while unfertilized hatch as males. A number of lizard species can reproduce without sex, including the New Mexico whiptail and the largest lizard of all, the Komodo dragon. Some unmated sharks have produced young in captivity.
And now, see how much heart animals put into their lives.

This article is adapted from a blog post by NWF Naturalist Dave Mizejewski.