Scientists Ask Why There Are So Many Freaking Huge Ants

By Elizabeth Preston | March 18, 2014 10:37 am

big old ant

An ant is not exactly the picture you see in the dictionary next to “rule-breaker.” Colonial ants work together to collect food and generally act in the best interest of the group. Yet certain enormous ants in South America break a basic rule in biology: as you move up the food chain, you should find a smaller group of organisms at each step. These ants are top predators that take up far more than their fair share of space. To find out what their secret is, scientists staked out the forest floor.

“We’re all ant nerds,” says Chad Tillberg, a biologist at Linfield College in Oregon, of himself and his coauthors. So when they started visiting a park in northeastern Argentina and noticed what seemed like a whole lot of Dinoponera australis ants, they thought it might be an illusion created by their excitement. Plus, Tillberg points out, “Dinoponera are huge.” The seven species in this genus, which can be more than an inch long, are some of the largest ants in the world.

There are many plentiful bugs in the rainforest, of course. But an abundance of this particular ant—which locals call hormiga tigre, the “tiger ant”—demands an explanation. That’s because the species is known as a top predator of the soil. Other champion carnivores—like, say, an actual tiger—are rare, compared to the things they eat. Read More

CATEGORIZED UNDER: bugs, environment, math, navigation, top posts

Right- and Left-Handed Birds Help Their Flocks Fly Better

By Elizabeth Preston | March 14, 2014 5:52 am


As they scrub the smeared ink from their wrists yet again, left-handed people must sometimes wonder what the point of all this is. Why do we have a dominant hand, anyway? However arbitrary it seems, we’re not alone in favoring one side over the other—there are all kinds of animals with a preferred paw, claw, or swimming direction. Now flying birds have flapped into the club. In at least one species, birds tend to veer one direction over the other when faced with an obstacle. More than just a pointless impediment to scissors use, “handedness” in birds might keep their flocks flying.

The birds in question are budgerigars, or budgies. Better known to Americans as ordinary pet parakeets, in Australia these birds travel the desert and scrubland in dense flocks. University of Queensland neuroscientist Mandyam Srinivasan says that flying this way without crashing isn’t a trivial task. “Whilst landing on a tree, for example, it would be important to find a clear path,” he says, “as well as avoid collisions with other birds.”

Read More

CATEGORIZED UNDER: birds, navigation, the outback, top posts
MORE ABOUT: Animals, Psychology

Suicidal Algae Help Their Relatives and Harm Their Rivals

By Elizabeth Preston | March 11, 2014 9:25 am


You might say the benefit of staying alive is an actual no-brainer: even brainless lifeforms do their best not to die. For the most part, anyway. When they’re under stress, single-celled organisms may opt to cut up their DNA and neatly implode. A new study hints that by committing suicide in this way, an organism helps its nearby relatives to stay alive—and hurts its rivals at the same time.

In animals with many cells like us, cellular suicide happens all the time, and it helps keep the whole organism in tip-top shape. As embryos, for example, the cells that form our little paws kill themselves off to make fingers. We’re born with a brain that’s too densely connected, and as we grow the superfluous brain cells die to get things in order. Even as adults, our bodies’ regular upkeep includes constantly adding new cells and commanding older ones to die.

If your entire body consists of one cell, the benefit of killing it is less obvious. Yet various single-celled organisms—from fungi to parasites to bacteria—have been shown to off themselves under stress. 

Pierre Durand, an evolutionary biologist at the University of the Witwatersrand in Johannesburg, has been trying to figure out why. In an earlier study with a single-celled algae called Chlamydomonas reinhardtii, Durand grew cells in the liquid where other cells had previous killed themselves (in response to heat stress). The algae grew faster than usual in the suicide liquid. But liquid where cells had been killed from the outside (the researchers tore them apart with sound waves) was harmful to living cells. A cell that dies suddenly leaks toxic contents into its surroundings, but cells that commit suicide apparently don’t—and even leave behind something healthy for other cells to eat. Read More

Pandas v. Horses Fight Goes to Pandas (For Now)

By Elizabeth Preston | March 7, 2014 10:10 am

panda tongue

It was a battle fought in the mountains of southwestern China, where patchy forests sustain the last shreds of the wild giant panda population. All at once, intruders began marching in and helping themselves to the pandas’ food. The incursion happened far from most human eyes, and the pandas that witnessed it  likely didn’t know what to think. It’s not often that one sees a horse in a bamboo forest.

In these woods, the Wolong National Nature Reserve is an important refuge for pandas. About a tenth of the entire wild panda population lives there—although that amounts to only 150 or so animals. They share the space with around 5,000 humans, most of whom are farmers who graze their livestock in designated areas.

A new trend emerged among these farmers in the 2000s as they began to do more business with an adjacent township where horses are reared. Though the Wolong farmers had previously raised cattle, pigs, goats, and yaks, they now began buying horses too.

“We first realized the problem while we were hiking in panda habitat and conducting habitat sampling for our research in 2009,” says Vanessa Hull, a graduate student at Michigan State University. Large areas of forest were “mowed down by horses,” she says. “It was honestly a shock to me.” Read More

CATEGORIZED UNDER: economics, environment, poo, screwups

World’s Tiniest Squid Gives Swimming Lessons

By Elizabeth Preston | March 4, 2014 10:28 am


Learning to walk would be even harder if babies had to do it in jello. This is roughly the problem faced by young Humboldt squid. They start out life at one one-thousandth of their adult size and have to fight against the sticky water molecules surrounding them as they learn how to swim. They deal with it by sometimes swimming like jellyfish instead of squid (and hoping they survive long enough to grow).

Danna Staaf and her colleagues at the Hopkins Marine Station of Stanford University studied the swimming styles of newly hatched Humboldt squid. With a mantle (the bell-shaped part) less than a millimeter long, these might be the tiniest squid in the sea. The researchers picked apart their subjects’ swimming motions in high-speed videos, one frame at a time—sort of like a TV sports commentator analyzing Michael Phelps’s backstroke, if Phelps quadrupled his number of arms and was transparent. Read More

The 5 Creepiest Ways Plant Diseases Mutate Flowers

By Elizabeth Preston | February 25, 2014 10:10 am


Pretty blossoms aren’t immune to the body-morphing, plague-spreading powers of a good microbe. Some of the flowers you admire on a spring day might only be blooming, for example, because they’re hostages of a disease. Plant diseases can’t scatter in sneeze droplets like a human virus can. But they can change the look and behavior of their hosts to make sure they travel as widely—and dangerously—as possible.

1. Replacing pollen with disease bombs

In a new review of flower diseases (title: “Arranging the bouquet of disease”), Scott McArt of the University of Massachusetts at Amherst and his colleagues examined the ways that infectious microbes can alter their host plants. One such microbe is a fungus called Microbotryum violaceum, which infects plants in the carnation family.

Plants are infected with the fungus when pollinating insects visit, carrying spores another infected plant has dusted onto their bodies. The fungus burrows down into the new plant, finds the site of developing pollen, and destroys it. Then it replaces the flower’s packets of pollen with its own spores. Read More

How to Build a High-Altitude Superdog

By Elizabeth Preston | February 21, 2014 9:24 am


No need to start from scratch. Here, someone else already took a wolf and made you a perfectly serviceable sea-level dog. With some  genetic tweaking, you can craft a powerful pet that isn’t bothered by living on an oxygen-starved mountaintop. A few of the same tweaks to your DNA will even let you live there with it.

This is no cockapoo or schnoodle. The Tibetan mastiff and the dog it was bred from, called the Chinese native dog, are ancient breeds, thousands of years old. Tibetan mastiffs live comfortably on the Tibetan Plateau, which with an average elevation of over 4,500 meters is nearly three times as high as Denver. Residents keep the bulky, athletic beasts as guard dogs.

Chinese geneticist Ya-Ping Zhang, along with an international group of coauthors, wanted to know what mutations in canine DNA had created this altitude-loving breed. They gathered DNA from 32 Tibetan mastiffs, along with 20 Chinese native dogs and 14 wolves—the starting material. Read More

MORE ABOUT: Animals, Evolution, Genetics

Urban Bees Build Their Nests with Plastic

By Elizabeth Preston | February 18, 2014 9:23 am

plastic megachile

Scott MacIvor has cracked open hundreds of artificial bee nests. But two he peered inside in Toronto gave him pause. Within their containers, the bees he studies had carefully built homes for their young out of plastic debris. Mixed in with the usual construction materials of leaves and mud, MacIvor could clearly see bits of shopping bag.

These aren’t the hive-dwelling honeybees you know from your backyard. For his PhD research at York University, MacIvor studies so-called solitary bees. Megachile bees live on their own, feeding from and pollinating flowers. Females find a cozy space they can fit into—maybe a hole in a tree, or the inside of a plant stem—and begin building a nest inside it. They lay one egg at a time, tucked away with a little ball of food for when it hatches. Then they wall off the egg and food into a compartment, or cell, and start work on the next one. The adults don’t live long, so the baby bees will be on their own when they hatch.

MacIvor uses pieces of PVC piping to lure solitary bees and study the nests they build inside. It was while observing these traps such as these, which he’d set up around Toronto to study how an urban setting affects the bees, that he discovered some nests that were not exactly traditional. Read More

CATEGORIZED UNDER: bees, environment, top posts, Uncategorized
MORE ABOUT: Animals, Ecology, Pollution

Biologically Accurate Valentines

By Elizabeth Preston | February 14, 2014 8:49 am

Call me, Hallmark.

Lovebugs Read More


Why Stinky Animals Live Alone

By Elizabeth Preston | February 11, 2014 9:10 am

lonely skunk

It’s not the reason you’d guess. They make perfectly pleasant-smelling neighbors. Yet skunks and other animals that use projectile stink as a weapon are apparently destined by evolution to be loners—not because of who they are, but because of who preys on them.

Ted Stankowich, who studies the intersection of evolution, animal behavior and ecology at California State University, Long Beach, promises skunks aren’t offensive to each other. “They try not to get it on themselves,” he says; they spray directed streams of foul liquid only at their attackers. “There’s no social repulsion from other members of [their] species.”

Yet when Stankowich and his coauthors scrutinized the lifestyles of 181 carnivorous mammal species, they found that the stink sprayers are loners. None of these animals—which included stink badgers, grisons, and zorillas as well as skunks—live in groups, the way social animals such as otters, hyenas or foxes do. Read More

MORE ABOUT: Animals, Ecology, Evolution

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Like the wily and many-armed cephalopod, Inkfish reaches into the far corners of science news and brings you back surprises (and the occasional sea creature). The ink is virtual but the research is real.

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