Strangely enough, it makes sense: A study of red junglefowl, a close relative of chickens, found that males can “adjust the speed and effectiveness of their sperm by allocating more or less seminal fluid to copulations.” The determining factor in this remarkable change of speed is how attractive the male finds the female. According to Discovery News (not to be confused with DISCOVER):
The study…adds to the growing body of evidence that males throughout many promiscuous species in the animal kingdom, including humans, can mate with many females, but chances of fertilization are greater when the female is deemed to be attractive.
Desirable female red junglefowl are easy to identify.
“Female attractiveness is determined by the expression of a sexual ornament — the comb — which is phenotypically and genetically correlated to the number and mass of eggs females lay,” according to study co-authors Charlie Cornwallis of the University of Oxford and the Royal Veterinary College’s Emily O’Connor.
To collect their data, the researchers collected natural ejaculates from dominate and subordinate red junglefowl that had just mated with either an “attractive” or “unattractive” female. What the dedicated won’t do for science.
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The muriqui have a reputation as being one of the gentlest, most social of the primates—so much so that they’ve been dubbed the “hippy monkey.”But even the sweetest of animals will turn murderous when deprived of basic needs—in this case, sex. New Scientist reports that a gang of six muriqui was spotted pulling a “Lord of the Flies” on an older male:
The victim, an old male, died an hour after receiving savage bites to his face, body and genitals. The observations, published this week in the American Journal of Primatology, show how lifestyles may dramatically alter the behaviour of a species.
So why would these peaceful creatures, close relatives of spider monkeys found only in the Atlantic forests of Brazil, turn to such savagery? NS explains:
The muriqui’s peaceful reputation stems mainly from northern populations that feed on abundant leaves, and where males patiently queue to mate with females.
But in the southern population where the attack took place, fruit is more widely available than in the north, and this may provide a clue to the assault, says Mauricio Talebi of the Federal University of São Paulo-Diadema, Brazil, who led the research.
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A recent survey of the animal kingdom has found that, like humans, animals just wanna have fun.
To anyone who’s ever spent time with a dog, it may seem obvious that animals can enjoy play for the sake of it—though this hasn’t been so well documented in the scientific realm. Jonathan Balcombe, a research scientist with the Physicians Committee for Responsible Medicine, has now gathered a list of ways that animals get pointless pleasure, and published it in the journal Applied Animal Behavior Science. A few examples:
- Herring gulls play “drop-catch,” tossing around clams and other small, hard objects.
- Hippos go to the spa. When a hippo wants to unwind at the freshwater springs, they relax with their legs spread out and mouth wide open, and let the surrounding fish suck off parasites, flaky skin, fungus, and other blemishes. Sometimes they get so relaxed that they fall asleep.
- Dolphins use vibrators. They’ve been caught making low-pitched buzzing clicks near each others’ private areas, and researchers say it seems to be an enjoyable experience.
- Certain birds have been caught masturbating, while goats, hyenas, primates, bats, and sheep appear to engage in oral sex.
In order to have fun, animals must have a brain that can process the pleasure. Some aren’t so lucky: Sponges and jellyfish aren’t conscious enough to really know what fun is.
Humans aren’t the only species that use pearly whites to judge the fitness of a mate: Apparently teeth are also important to a certain species of whales. The beaked whales have earned the reputation as the most bizarre whales in the ocean, spending the majority of their lives foraging for food and living in seclusion. For years, scientists have wondered why these strange whales have tusks, especially since it hinders their bite.
It turns out these seeming-unnecessary teeth are important for mating—a discovery that marks the first time scientists have found a secondary sexual characteristic (like antlers) that shaped evolution in a marine mammal.
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At a bar, intoxicated people may fall victim to the notorious “beer goggles” effect. Now, researchers have discovered that in the fish world, pollution can have the same effect as a six-pack of Heineken.
Scientists already know that female African cichlids are partially blind, and have evolved into a new species over the past 30 years. The cichlids in Lake Victoria’s polluted waters are vanishing, causing “the largest human-witnessed mass extinction of vertebrates.” And now, pollution is also causing closely-related species of cichlids to interbreed, all because they can’t see each other.
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