Apr 19: What the dinos did, and more...
Baby bird disguises, seals can sense oxygen, fruit flies play, and scaring krill with penguin poop
On this week's episode of Quirks & Quarks with Bob McDonald:
There's not a more vulnerable creature in nature than a baby bird. Tiny and immobile, they're easy pickings for predators. But the chicks of the white-necked jacobin hummingbird have evolved a unique defence. They disguise themselves as poisonous caterpillars to discourage those that might eat them. Jay Falk, an NSF postdoctoral fellow at the University of Colorado and Scott Taylor, director of the Mountain Research Station and associate professor at the University of Colorado, studied these birds in Panama. Their research was published in the journal Ecology.
Seals can dive at length to tremendous depth thanks to some remarkable adaptations, like the ability to collapse their lungs, and radically lower their heart rate. Chris McKnight, a senior research fellow at the University of St Andrews Sea Mammal Research Unit in Scotland, led a study looking to see if tweaking oxygen and C02 levels changed the seals' dive times. The researchers discovered that the seals have the unique ability to measure the oxygen levels in their tissues, so they can anticipate when they need to return to the surface before they get into trouble. The research was published in the journal Science.
As the joke goes, time flies like an arrow, fruit flies like a banana. Researchers recently demonstrated that fruit flies enjoy more than just aged produce. Using a custom carousel built to fly scale, scientists found that some, but not all, of their fruit flies would play on it, enjoying an activity that had nothing to do with the necessities of life. This brings up the possibility of variability in personality for fruit flies. Wolf Hütteroth is an associate professor at Northumbria University, Newcastle and was part of the team, whose research was published in the journal Current Biology.
Krill, the small, shrimp-like creatures that swarm the world's oceans and are particularly abundant in southern oceans, play a big role in marine food webs, connecting microscopic organisms with many of the oceans' larger animal species. Researchers in Australia investigated how krill respond to predator cues, like the smell of their feces. Nicole Hellessey, from the University of Tasmania, said the mere whiff of penguin feces affects the Antarctic krills' feeding behaviour and causes them to take frantic evasive action. The study is published in the journal Frontiers in Marine Science.
Dinosaur bones can tell amazing stories about these prehistoric beasts, but how do we piece together how they behaved? A new book dives into the many lines of evidence that can shed light on the behaviour of these extinct creatures. From fossils, to tracks they left behind, to their modern day descendents, paleontologist David Hone from Queen Mary University of London explores how scientists develop robust theories about how dinosaurs lived in his new book, Uncovering Dinosaur Behavior: What They Did and How We Know.
