Jan 25: Solving the mysteries of our solar system, and more
Hawaiian crow comeback, desert ant navigation, pterosaur tails, and gophers rebuilding
On this week's episode of Quirks & Quarks with Bob McDonald:
The world's most endangered crow, the Hawaiian crow or or ʻalalā, is making tentative steps towards a comeback. After going extinct in the wild, only 120 birds remain in captivity, in two facilities operated by the San Diego Zoo Wildlife Alliance. Over the years, researchers have attempted reintroductions in the bird's native habitat on the Big Island of Hawaii, but those efforts have all been unsuccessful. Recently, several organizations partnered together to try something different — reintroducing the birds to a different island than their native home. We spoke with Conservation Program Manager Bryce Masuda about the release, and why he has high hopes for their latest attempt.
The great flying reptiles of the dawn of the age of dinosaurs, the pterosaurs, took flight with delicate but flexible internal tail structure that allowed it to work like a kite. Scientists used recently developed technology to enable them to see a lattice-like structure in the soft tissue in the early pterosaur soft tissue that was otherwise invisible to the naked eye. Natalia Jagielska, a paleontologist at the Lyme Regis Museum in Dorset, England, said their kite-like tail vane would have stood upright and could have functioned as a display and to help them in flight. The study was published in the eLife journal, Evolutionary Biology.
After Mt. St. Helens exploded in 1980 it left a shattered, ash-covered, barren landscape behind. But the one-time reintroduction of gophers to one area led to a remarkably fast recovery of plants and other fauna. Forty-years later, changes to the environment are still being documented by Mia Maltz, assistant professor of Microbial Ecology and Soil Earth at the University of Connecticut, and her team. They published their research in the journal Frontiers in Microbiomes.
Desert ants that navigate the endless sands of the Sahara use the Earth's magnetic field to find their way, which is not unusual. But unlike other animals like birds and turtles they don't appear to have an internal compass that aligns north and south. Instead they are unique in that they use a more subtle cue – the polarity of the magnetic field. A study looking at this led by Pauline Fleischmann, a post-doctoral researcher at the University of Oldenburg in Germany was published in the journal Current Biology.
The thousands of small celestial bodies in our solar system are now a bit less mysterious, thanks to several recent discoveries.
One group of astronomers have traced back the origins of 84 per cent of all known meteorites that have pummeled Earth to just a few young asteroid families in the asteroid belt. Michaël Marsset, from the European Southern Observatory in Chile, said collisions in the asteroid belt create a collisional cascade that produces fragments, some of which end up raining down on Earth as meteorites. Two of their papers were published in the journal Nature and a third in Astronomy & Astrophysics.
Another group of astronomers have identified two populations of stealthy dark comets that are something in between a comet and an asteroid. They've found fourteen of these objects whose orbital motion is comet-like, but which lack a visible tail like regular comets. Davide Farnocchia, a navigation engineer at NASA's Jet Propulsion Lab, said they've found two types of these unusual solar system bodies: larger ones in an elliptical orbit out to Jupiter and smaller ones in orbit around Earth. Their study was published in the journal PNAS.
