Borneo’s Camponotus cylindricus ants are a little touchy: if they encounter a foreign ant in their territory, they will latch onto its legs with their jaws and then quite literally blow themselves up, spraying a sticky yellow substance over the unlucky intruder. Not exactly the most level-headed reaction, but an effective one for defending the ant’s territory. A recent study in the journal Acta Zoologica describes how these volatile buggers release their noxious lather: by squeezing themselves to death with their abdominal muscles.
Archive for the ‘The Wide (& Strange) World of Animals’ Category
Green, Glowing Kittens Contribute to HIV Research, Look Adorable
These wee green kittens not only glow, they’re resistant to the feline version of HIV.
Scientists exploring possible treatments for HIV have, purely as a byproduct of their methods, earned themselves a spot in today’s science blog postings: They’ve made glowing kittens.
Sneaky Toad Tadpoles Use Chemical Weapons Against Their Growing Competition
Think you’re a survivor? You’ve got nothing on the cane toad, former native of Central and South America, now scourge of Australia. To snuff out their competition for resources, cane toad tadpoles will actually cannibalize nearby cane toad eggs. And all those eggs the tadpoles are too full to gobble up? Well, researchers recently learned that the hardy amphibians have that covered, too: cane toad tadpoles release chemicals into the water that stunt the growth of developing embryos.
Scientists already knew that cane toads communicate with pheromones and use these chemical signals to locate tasty eggs. They also wondered if the pheromones have another, more insidious, purpose. Biologists at the University of Sydney set up a simple experiment to find out. They placed cane toad eggs in 20 containers filled partially with water; in 10 of those containers, they added tadpoles and separated them from the eggs with mesh screens.
Kinky Skinks Show That Size Matters in Speciation
When a male’s bits don’t fit with a female’s bits, you wind up with reproductive malfunction. But shape isn’t everything, as a team of researchers recently discovered while watching hundreds of skink lizards court and spark.
Most studies looking at how genitalia mismatch contributes to new species take the concept literally: if the bits don’t fit together like lock and key, matings will be unsuccessful. And if the mismatch between the gear of two groups is bad enough, they will form separate reproductive populations, and, eventually, species. But the idea, which was first tossed around more than 150 years ago, has been discounted as a possible source of new species. Differently sized or shaped genitalia is such a big change that it’s likely to come after many other speciation triggers, like mutations or long separations between populations divided by mountain ranges.
Bad News for Roosters: If You Aren’t King of the Henhouse, Your Ejaculate Will Be Ejected
WHAT? Noooooooo!
If you haven’t heard about the corkscrew kookiness that is duck genitalia by now, you need to check that stuff out ASAP.
Ducks’ twisting vaginas and telescoping penises are well-known part of an evolutionary arms race between the sexes that’s been going on for millennia, with each side trying to exert control over which males’ sperm fertilize the female’s eggs—a battle that, especially in birds, is fierce, occasionally violent, and weird as all-get-out. The most recently discovered example of what biologists deem “sexual conflict,” a little behavior hens have developed called sperm ejection, upholds that fine tradition.
Showy Male Birds—You Live Life Like a Candle in the Wind
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
Shrimp Couples Use Sponges as Gingerbread Houses
Up-close views of Typton carneus‘s shear-like tools.
In Hansel and Gretel, two ravenous children stumble upon a house made entirely of sugary goodness, and begin to chow down with abandon. But the kids’ journey quickly turns sour, as the owner of the house, a wicked witch, tries to cook them for dinner.
While the story seems to be a cautionary tale, it turns out that finding and living in an edible house can actually be pretty sweet—at least in the animal kingdom. Researchers in Prague have now learned that some tiny shrimp in the Belize Barrier Reef dine on fire sponges, their homes, by first tearing off pieces of tissue with claws not unlike those of Edward Scissorhands.
Extroverted Elephants Change Their Best Friends Over Time
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.
Stealthy Whales Cut the Chit-Chat to Hide from Hungry Predators
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.]
Image: NOAA
Studly Fish Aren’t Born, They’re Made—Sometimes Overnight
Some people like to say that men are always ready (and eager) for sex. Whether or not that’s true for humans, Stanford University researchers have recently learned that it is the case for certain male fish. Downtrodden male African cichlids, whose reproductive systems are so suppressed that biologists thought the fish couldn’t produce sperm, can successfully spawn within hours of rising to power, according to a new study published in the journal Proceedings of the Royal Society B.
Like many other animal species, a single leader—the biggest, baddest male—runs each group of African cichlids. This alpha male, which often sports vibrant blue scales, monopolizes the females and beats down other, weaker males in the community. (High school, anyone?) Because of this sexual exclusion, subordinate males suffer a noticeable pallor, decreased levels of reproductive hormones, and severely shrunken testes. Essentially, the fish trade sperm production for growth spurts, in hopes of someday overtaking the alpha male. Why waste energy making sperm if you can’t use it, right?
