Here’s the latest lesson from the ant world: kidnapped babysitters may not be the most reliable. Evolutionary myrmecologist Susanne Foitzik studies a species of ants that, instead of using its own workers to raise its young, kidnaps larvae from another species and puts them to work as babysitters. But, she’s found, the free labor has a price.
For male Houbara bustards, extravagant sexual displays come with a price: rapid sexual aging. By studying over 1,700 North African Houbara bustards, researchers in France have learned that the birds, by age six, already begin producing smaller ejaculates with a large number of dead and abnormal sperm. The more showy the bustard, the quicker he burns himself out. As lead researcher Brian Preston said in a prepared statement:
This is the bird equivalent of the posers who strut their stuff in bars and nightclubs every weekend. If the bustard is anything to go by, these same guys will be reaching for their toupees sooner than they’d like.
[Read more about these peculiar birds and see a video of one of their seductive dances at the BBC.]
Image courtesy of Frank. Vassen / Flickr
While there are many different specific personality types, people are often categorized as either introverted or extroverted. Some like to keep to just a few close friends, rarely leaving their small comfort zones, while others are more outgoing, collecting friends wherever they go; most of us fall somewhere the middle. But we’re not the only mammals with this type of social diversity. Researchers in Sri Lanka have now found that many female Asian elephants—previously believed to be kind of antisocial—are social butterflies, changing their circle of friends as the seasons pass. Moreover, they maintain close ties with pals even after extended periods of separation.
To avoid enemy crafts, naval submarines will often run silently, shutting down nonessential functions and cutting crew chatter. Now, an international team of researchers has found that Blainsville’s beaked whales also go into stealth mode to avoid being eaten by their mortal enemies, orcas.
While they normally click, buzz, and whistle to one another in the deep, the aquatic mammals stop all gab when they enter waters shallower than about 550 feet, presumably because killer whales typically hunt in shallow water. This is surprising considering that the beaked whales spend only 40 percent of their lives in the deeper waters—scientists expected that the animals would need frequent communication to maintain social ties.
Makes you wonder: How often do the whales leave the deep to get away from all the gossiping?
[Read more at BBC.]
The Japanese white-eye is one of the most
popular airplane models for snails.
The airplane is, arguably, one of the greatest inventions of humankind, shortening travel times and bringing disparate cultures together. But it turns out that we’re not the only ones to take advantage of flying vehicles. Researchers in Japan have now learned that a certain land snail, Tornatellides boeningi, can quickly travel great distances by hitching a ride in the guts of birds.
The concave-eared torrent frog.
Wouldn’t it be nice if we could hear each other over the low-frequency roar of jetliners and subway trains? For some rodents, bats, and marine mammals, environmental noise doesn’t normally pose a problem, as they can communicate at ultrasonic frequencies (greater than 20 kHz, just above our maximum hearing range). There are also a couple of amphibians that exhibit this trait, but in an odd twist, researchers have now learned that female concave-eared torrent frogs are deaf to the ultrasonic components of the males’ calls.
The concave-eared frog is a tree-loving native of the Huangshan Mountains in China. In choosing this woodsy area, the nocturnal amphibians must put up with one minor annoyance: streams that produce constant ambient noise. In 2006, Jun-Xian Shen, a biophysicist at the Chinese Academy of Science in Beijing, and his research team discovered that the frogs get around this sonic clutter by adding ultrasonic frequencies to their normal calls (pdf). The frogs were the first non-mammalian vertebrate found to do this, and scientists have since learned that Borneo’s hole-in-the-head frogs (yes, that’s the actual name) also chirp in ultrasonic frequencies. After finding these ultrasonic noises, researchers wanted to know what they were saying with these super-high-pitched croaks.
A prophetic story from The Onion in 2003 seems to be coming true: our pets and even lab and wild animals are becoming obese alongside humans:
Amid a barrage of commercials for new diet dog and cat foods, many owners say that their pets are being held to impossibly high animal-body standards perpetrated by the media. “I don’t care what anyone says, my Sassy looks good,” said Janice Guswhite.
Back in the non-satirical world, the findings are alarming. A study of over 20,000 animals from 12 different populations, published in Proceedings of the Royal Society B, found that over the last 20 years the animals in every population they studied have been growing significantly tubbier, paralleling the human obesity epidemic.
Not only pets are fattening up–the group also studied wild animals living near humans and animals living in labs and zoos. All of them have been chubbing-out over the last two decades. This could mean we are thinking about the obesity epidemic all wrong, lead author David Allison told Nature News:
Apparently it’s hard to teach an old frog a new trick: landing on its legs. As painfully demonstrated in the video below, the primitive frog family Leiopelmatidae prefers to belly-flop.
From the heroic Flipper to the charismatic Willy, dolphins and whales have made some splashy supporting actors. And since they often seem almost as smart and interesting as their human costars, perhaps it’s not surprising that a new movement is afoot to grant these animals “human rights.”
Research on everything from whale communication to “trans-species psychology” hints that the glowing portrayals of these fictional animal friends have some basis in reality. If cetaceans—marine mammals including whales, dolphins, and porpoises—can act like humans, even using tools and recognizing themselves in a mirror, shouldn’t they have the same basic rights as people?
That’s what attendees of a meeting organized by the Whale and Dolphin Conservation Society (WDCS) said yesterday, where a multidisciplinary panel agreed on a “Declaration of Rights for Cetaceans: Whales and Dolphins.” Read More
Male cichlid fish apparently don’t like what they see in the mirror–in fact, they dislike their own reflections even more than enemy fish, according to new research published in Biology Letters.
“[The] fish readily attack other males as well as mirror images of themselves, posturing and lunging with the same aggression… the reflection-fighting males show heightened activity in [the amygdala,] a part of the brain associated with fear and other negative reactions in vertebrates, [Stanford University researchers] have found. Tangling with a real male doesn’t stir up that response.”