Scientists already knew starfish have superpowers. They can regenerate entire lost limbs or organs; some can even regrow a whole body from one arm. And these animals have just revealed another bizarre ability. To two Danish students, it first appeared as the power to really wreck an experiment.
At the University of Southern Denmark, students Frederik Ekholm Gaardsted Christensen and Trine Bottos Olsen were asked to tag some starfish. The task was simple: inject the Asterias rubens with microchips, the same kind that veterinarians implant in pet dogs. This would let researchers easily identify individual starfish later on. The technique had already been used successfully in sea urchins.
Starfish came to the university from local fishers who had caught them by accident. The students injected the tags into the animals as directed. But within days, those same tags showed up at the bottom of the tank. Somehow, the starfish were expelling the foreign objects from their bodies. Read More
How long could you survive as a tortoise? Sure, the basic rules are easy: Eat plants. Hide in your shell. Slow and steady wins the race. But a tortoise in danger has to make some quick decisions. Especially if it’s been flipped onto its back, slow and steady isn’t good enough. The tortoise’s best strategy, in fact, depends on its age.
Ana Golubović, a biologist at the University of Belgrade in Serbia, is interested in how the behavior of turtles and tortoises changes over their lifetimes. Baby tortoises are small and fairly soft. As they age, their shells harden and the reptiles grow—and grow, and grow. The older the tortoise, the bigger it is. (You can even estimate a tortoise’s age by counting rings on its shell, like a tree trunk.)
This means an adult tortoise can rely on its shell in ways that a younger one can’t. Golubović notes that not only do juveniles have softer shells, but they get no protection from their parents, and they’re bite-sized to some predators. So a young tortoise that gets attacked and flipped is more vulnerable than its better-armored elders are. Read More
You snooze, you lose paternity. That’s the message of a new study on wild birds in Germany. Males that wake up the earliest are able to sneakily mate with other birds’ partners. Males that sleep in, meanwhile, get stuck raising young that aren’t their own.
Great tits (Parus major) appear monogamous at first glance. They stick with one partner and cooperate to raise their young. But, like many other birds that scientists call “socially monogamous,” they sleep around. Great tit nests often contain eggs from more than one father.
North Dakota State University biologist Timothy Greives knew from previous studies that songbirds often use the early morning for their trysts. This could mean that males who are true early birds have a better chance of finding extra partners—and guarding their own partners from other males. Supporting this idea, a study in blue tits showed that males have greater mating success outside their home nests if they start singing earlier in the morning. Read More
What’s a scientist to do with 1.2 million photos, most of grass but some containing valuable data about endangered animals? Turn the whole thing over to the public, if you’re the creators of Snapshot Serengeti. This project caught the attention of tens of thousands of volunteers. Now their work has produced a massive dataset that’s already helping scientists in a range of fields.
Amputees often feel eerie sensations from their missing limbs. These “phantom limb” feelings can include pain, itching, tingling, or even a sense of trying to pick something up. Patients who lose an eye may have similar symptoms—with the addition of actual phantoms.
Phantom eye syndrome (PES) had been studied in the past, but University of Liverpool psychologist Laura Hope-Stone and her colleagues recently conducted the largest study of PES specifically in patients who’d lost an eye to cancer.
The researchers sent surveys to 239 patients who’d been treated for uveal melanoma at the Liverpool Ocular Oncology Centre. All of these patients had had one eye surgically removed. Some of their surgeries were only 4 months in the past; others had taken place almost 4 and a half years earlier. Three-quarters of the patients returned the surveys, sharing details about how they were doing in their new monocular lives. Read More
Let’s say you’re clever enough to build and use tools, but your species hasn’t learned how to manufacture pants. So you can’t store your hard-won tools in your pocket, or in a belt or box. What to do? One species of crow is showing scientists how it answers that question—and how it changes its strategy based on how likely its tools are to go missing.
New Caledonian crows, native to islands in the southwest Pacific Ocean, are renowned tool makers and users. They prey on bugs that live inside branches and plants. To fish out their prey, the birds use sticks or leaves, which they may trim and tweak to fashion into hooks.
Humans have sometimes noticed these birds trapping their tools under one foot while they munch on a bug, or stashing tools in convenient holes. It makes sense—after going to the trouble to MacGyver a fishing hook out of a plant, you wouldn’t want to lose it either. And when the birds do lose their tools, they can look distinctly peeved. Watch the bird at the beginning of this video drop its stick and fly off in a huff: Read More
One thing you won’t find in the story of the Very Hungry Caterpillar is the part where after transforming into a butterfly, he mates with a female who has a Very Hungry Reproductive Tract waiting to devour his sperm. She has a special digestive organ just for this purpose. It’s so powerful that it could even compete with the gut that let the caterpillar, in his more innocent days, chew through those five oranges.
This sperm-hungry organ is called the bursa copulatrix. In female butterflies and moths, it’s a few zigzags away from the vagina. The sex organs of these insects are absurdly complex; a drawing of the female anatomy looks a lot like a road map. Until now, no one was sure how the bursa copulatrix—one mysterious cul-de-sac on this map—really worked.
To learn more about it, University of Pittburgh graduate student Melissa Plakke turned to a common butterfly: the cabbage white, or Pieris rapae. Each female butterfly in this species can mate with many males. And this starts to explain why their sex organs are so complicated. Read More
Earlier this month, while I was busy taking screenshots of autofill suggestions for medical searches on Google, something shocking happened: Inkfish had its five-year anniversary.
Five years!! It’s about twice the lifespan of a pet hamster. It’s closer to three times the lifespan of a common octopus. In that time I’ve written 519 posts, had three different online homes, and somehow managed to learn almost no HTML.
To mark the occasion, I dug through my analytics and found the most-viewed story from each year of Inkfish’s existence. Read More
The squash bug mating orgies that biologist Christine Miller began noticing in gardens around Gainesville were nothing unusual. Dozens of insects were crowded together, the petite males along with the bulkier females, to search for partners. The unusual thing was that some males were copulating with females of the wrong species—apparently, they found them irresistible.
When Jen Hamel arrived at Miller’s University of Florida lab to do her postdoctoral research, she took up the mystery of the swinging squash bugs.
Although they’re related, the two insect species don’t seem to have viable offspring together. And mating with the wrong species can be more than just a waste of time. “There is potentially a big waste of energy for a female,” Hamel says, if she lays eggs that aren’t fertilized because she’s been dallying with the wrong males. The insects could also miss out on opportunities to mate with the right partners, and females might risk damage to their genitalia or reproductive tracts. So what are these bugs doing together? Read More
Sure, there are faces only a mother could love. And then there are faces no mother loves, because they belong to animals that fend for themselves from birth. The babies we find cutest—no matter what species they are—may have evolved to look that way because they need a parent’s attention. That means even a crocodile can tug on our heartstrings.
Konrad Lorenz, an Austrian zoologist, proposed in the mid-20th century that human infants are cute for a reason. He said evolution has created adorable babies so that their parents will take care of them. When we see a face with big eyes, a big head, and a tiny nose and mouth, we can’t help but feel affection, he argued. It’s easy to look at a wide-eyed puppy or kitten and imagine that other animals have evolved in the same way. Read More