Even kings and queens that have six legs and live underground aren’t immune to royal machinations. In one Asian termite species, queens choose to shut their mates out of the picture when it’s time to breed a successor. They simply clone themselves to make new queens. To keep the king’s genes away, the queen makes special eggs that have no entrances for sperm—all their drawbridges are pulled up tight.
The lives of Reticulitermes speratus termites are worthy of an HBO series. The story starts when a new colony is founded by a single termite pair, the king and queen. They mate in the usual way and fill the colony with workers, their offspring. No one reproduces except for the royal pair. Everyone in this humble kingdom of dirt knows their places.
The queen can live for more than 11 years, and as she ages, the order of things starts to get muddy. Read More
If you were assigned to watch a dozen dwarf mongooses on the savannah, would you know how to keep them safe? Or would half of them get snatched by snakes before you finished checking the dictionary to make sure they weren’t really a dozen mongeese? Luckily these animals don’t need us to watch their backs. Volunteers within their ranks take turns watching out for predators, and they know how to monitor a range of risk factors while doing their jobs.
Dwarf mongooses (Helogale parvula) are squirrel-sized carnivores in East and Central Africa. They live and breed in social groups, with lower-ranking animals helping to raise a dominant pair’s young. While they’re out in the open, some members will spontaneously go on “sentinel” duty. They’ll stop what they’re doing, find higher ground (a tree branch, the top of a termite mound), and spend a few minutes watching for predators. If they see anything, the mongooses have different alarm calls to tell the group what type of danger approaches.
Sentinels are crucial for dwarf mongooses because they mostly eat bugs, and it’s hard to keep an eye out for predators while you’ve got your face in the dirt. Dwarf mongooses have plenty of predators, too, say University of Bristol graduate student Julie Kern and behavioral ecologist Andrew Radford. At the scientists’ study site in South Africa, the little mammals are vulnerable to wildcats, jackals, civets, servals, honey badgers, larger mongooses, monitor lizards, five kinds of snake, and fourteen birds of prey. (Still want to babysit?) Read More
What—just because they’re called gut microbes, you’ve been keeping them in your colon? How unoriginal.
This is Bankia setacea, also called the Northwest or feathery shipworm. Humans usually pay attention to shipworms only when they perform their namesake activity: burrowing face-first into our boats or docks and eating their way through. Shipworms are bivalves, like clams or scallops, but their shells are shrunken into a set of rasping tools at each worm’s front end.
Animals that subsist on wood usually need help. Studies of termite guts, as well as wood-eating fish and beetles, have found specialized bacteria that break down the tough plant materials the animals themselves can’t. Even humans and other omnivores and carnivores get a digestive hand from microbes. The abundant bugs in our intestines play a role in breaking down our food and getting the nutrients out.
Yet the digestive tract of Bankia setacea is weirdly empty. Read More
Like many new mothers, a female elephant seal puts herself on a strict diet after giving birth. She dives into the Pacific and spends two months eating everything she can find. It’s only by working hard at building up her blubber stores that she can get back her ideal body.
Northern elephant seals (Mirounga angustirostris) spend 9 to 10 months of the year at sea. Twice annually, the animals haul their enormous bodies ashore. In the winter, they gather on beaches in Mexico and Southern California for breeding and mating. Females deliver their pups and nurse them; males defend “harems” of dozens of mates and work on impregnating them again. While on land, the seals fast. Then they go back to the ocean, abandoning the babies to their own devices. In the spring, the seals return to the same beaches to molt, shedding their fur and even some skin before spending the rest of the year in the ocean.
During their travels, northern elephant seals may migrate as far as Alaska. They make dives almost half a mile deep, pursuing squid, fish, and other animals unfortunate enough to be in their paths. But to regain the body mass that they lost while fasting on land, they have to bank their calories. Energy that they save while swimming can be spent on longer dives. Energy gained from a stomach full of squid can be used to hunt some more.
Taiki Adachi, a graduate student in the polar science department at Tokyo’s Graduate University for Advanced Studies, wanted to learn how a migrating seal’s increasing blubberiness affects its swimming. Read More
If we’re lucky, this is behavior we haven’t seen since high school. The coolest individuals can’t stand to see others gaining social status, so they cut down any peers who are starting to elevate themselves. Ravens have to live with this behavior all the time. When the top-dog birds see others building new relationships, they attack these birds or put themselves in the middle. They may as well be spreading rumors or defacing each other’s lockers.
Wild ravens living in Austria were the ones to reveal this behavior to scientists. The ravens, a group of about 300 birds in the Austrian Alps, have discovered that a local zoo is a convenient source of food. So the wild birds hang around the captive animals year-round (they especially like the wild boar enclosure) and steal their provisions. Because of this, they’re used to seeing humans nearby.
For years, scientists have been capturing these birds, marking them with colored leg bands, and studying their social behavior. Now University of Vienna cognitive biologist Jorg Massen and his coauthors asked whether the most dominant birds might be sabotaging those lower down in the group.
The raven social ladder goes like this: Read More
The first time a colony of Antarctic penguins sees a towering human striding toward them, it must be like First Contact. They’ve never seen a species our size on land before, or anything that moves like we do. Even after penguins have interacted with researchers, the approach of a human is a physiologically stressful experience. To avoid stressing out their subjects so much, some researchers are experimenting with remote-control rovers. They’re hardly natural, but it turns out penguins don’t mind a motorized, four-wheeled intruder nearly as much as they mind us.
Stressing out penguins is bad for researchers, not just for birds. A panicked penguin can alter the data scientists are gathering, and may disturb its neighbors in the process. One way scientists are trying to bother animals less is by using tiny, under-the-skin transponders rather than the usual tags. These transponders are similar to the chip that a vet might implant in your dog. The only trouble is that the tag has to be read from close range: if you can’t hide a scanner where the animals are likely to walk past it, someone has to walk around and scan each bird like a box of cereal at the grocery store checkout.
Yvon Le Maho of the University of Strasbourg and his colleagues are trying to solve this problem with a rover. Read More
When a new developer comes to town and starts aggressively building up the empty property around your home, you can get mad—or you can move in. That’s what tiny crustaceans in the Georgia mudflats have done. Facing an invasive Japanese seaweed, they’ve discovered that it makes excellent shelter, protecting them from all kinds of threats. And where the crustaceans went, a whole ecosystem has followed.
Jeffrey Wright is an ecologist who studies invasive species at Australian Maritime College in Tasmania. He traveled all the way to the southeastern United States to study Gracilaria vermiculophylla, a Japanese seaweed that’s made a name for itself by crashing both coasts of North America as well as northern Europe. Wright had previously studied a similar seaweed in Australia, and was eager to see how this ecosystem compared.
In Georgia and South Carolina, Gracilaria has moved into marshy coastal areas, taking over the mudflats that appear at low tide near the mouths of rivers. Read More
Scientists love the data they get by attaching electronic tags to animals, but these devices can be a literal drag. For animals that fly or swim, tags can mess up their mechanics and force them to spend more energy. That’s what scientists expected to see when they studied dolphins with data loggers suction-cupped to their backs. To their surprise, they found instead that these dolphins refused to work any harder at all.
When scientists attach a data-logging tag to an animal, they try to disturb the animal as little as possible. Tags on birds, for example, are limited to a certain percentage of the bird’s mass. But there are fewer guidelines for animals that aren’t birds, writes Julie van der Hoop, a graduate student in the MIT–Woods Hole Oceanographic Institute joint program. And much of the research on tag drag in marine mammals has been done with computer modeling, not actual animals.
Van der Hoop and her coauthors wanted to see how tags affect real, swimming dolphins. Working with Dolphin Quest Oahu, the researchers engineered a setup that would let them measure how tags changed dolphins’ energy use. Read More
Yes, fish. These aquarium lap-swimmers and pursuers of flaked food aren’t known for their joie de vivre. Yet in one hobbyist’s tanks, scientists say they’ve captured a rare instance of fish playing around.
James Murphy is a herpetologist at the Smithsonian National Zoological Park. Although he professionally studies reptiles and amphibians, he keeps fish as a hobby. It was one of his cichlids—a 5-inch fish of the species Tropheus duboisi—that first caught his attention by inventing a game. A weighted thermometer sat at the bottom of the fish’s tank, and the fish would repeatedly whack this thermometer with its head and let it bounce back. The behavior was hard to miss: the sound of the fish knocking the thermometer around could sometimes be heard from the next room.
Although examples of playful mammals are plentiful, such behaviors are harder to find in other groups of animals. Play examples in fish are especially controversial and difficult to come by, say Murphy and his coauthors, Gordon Burghardt and Vladimir Dinets of the University of Tennessee, Knoxville. To make sure that what they were seeing was really play, the authors checked it against a list of five criteria: Read More