Listen to the whole show (pop up player) or
use this link to download an mp3.
Falling Flowers and Rising Rats
 Rat raiding rice crop, courtesy S. Belmain
|
The local farmers call it a flood; some even call it an 'act of God'. Once every 50 years, the bamboo forests of Northeastern India, Bangladesh and Burma flower at the same time and release pear-sized seeds that eventually fall to the ground. The resulting 80 tonnes of seed per hectare, over thousands and thousands of hectares, are a major food source for rats. The rat population swells to the point where the bamboo seeds eventually run out, and farmers' crops are next in line. As there is little farmers can do to stop the millions of rats, famine takes hold. The fact that is it a 50-year cycle is, in itself, a problem for scientists studying this phenomenon.
Dr. Steve Belmain, a rodent Ecologist with the Natural Resources Institute at the University of Greenwich in Medway, England, says with so few people having knowledge of these events from the previous cycle, he has to separate local folklore and legend from fact, in trying to understand what is happening. Planting crops earlier, better trapping methods, and improved fencing around crops are all strategies currently being put in place. The present cycle began in 2004 and may last for another year or two, in some places.
Related Links
Listen to this item (pop up player) or
use this link to download an mp3.
Wildfires Burn Deep
 Courtesy US Fish & Wildlife Service
|
As the climate changes, wildfires in places like Alaska and Western Canada are burning more fiercely and emitting more greenhouses gases into the atmosphere. This change has been recorded over the past ten years by
Dr. Merritt Turetsky from the Department of Integrative Biology at the University of Guelph. In Alaska, in particular, longer snow- free months and a depletion of the permafrost has resulted in wildfires taking their toll on not just tress, but also burning deeper into the carpet of moss, plant litter and organic matter on the forest floor. The fires unlock carbon stored up in these peatland soils over thousands of years. More severe burning also raises health issues for humans, as fire emissions contain mercury and particulate matter that can result in respiratory problems.
Related Links
Listen to this item (pop up player) or
use this link to download an mp3.
Snakes on a #&%*$$!! Rope!
Last week, we spoke to a researcher about his study of how snakes glide down from trees by literally slithering through the air. But that had us wondering, how do the snakes get into the trees in the first place? By remarkable coincidence,
Dr. Bruce Jayne, a professor in the Department of Biological Sciences at the University of Cincinnati, has just published research that helps explain how snakes climb. Dr. Jayne performed experiments looking at how boa constrictors climbed ropes of different thickness - the herpetological equivalent of the fearsome gym-class rite of passage, the rope climb. Dr. Jayne found that the snakes were surprisingly good climbers, but had to use different strategies to ascend ropes of different diameters.
Related Links- Paper in Journal of Experimental Biology
- News article in JEB
- News from the University of Cincinnati
- Dr. Jayne's videos of snake locomotion
Listen to this item (pop up player) or
use this link to download an mp3.
Rainforests and the Rise of Reptiles
 Tropical Rainforest, photo Dave Kimble
|
During the Carboniferous Period, 300 million years ago, North America and Europe formed one continent that lay at the equator. It was covered in steamy rainforest. But a sudden global warming resulted in a collapse of these rainforests. As the Earth ultimately cooled and the air dried, the rainforests fragmented into pockets - or islands - of treed forests.
Sarda Sahney, a Canadian PhD student in the Department of Earth Sciences at the University of Bristol in England, says fossil evidence supports the idea that this, in turn, resulted in a burst of reptile biodiversity. Amphibians were at a disadvantage because their habitat was drying up; but reptiles were able to thrive and adapt to these islands of forest in relative isolation. This ultimately paved the way for the rise of reptilian dinosaurs,100 million years later. Among the fossil sites that she studied were the Joggins Fossil Cliffs in Nova Scotia.
Related Links
Listen to this item (pop up player) or
use this link to download an mp3.
Light Flight
 Time Lapse photo of wing rising - courtesy Nature Photonics/G Swartzlander
|
An airfoil is a remarkable device that harnesses the force of air coming at it from one direction to generate motion - lift - in another direction. This is the basic principle behind sails, wings and propellers, which use the flow of air or water over a shaped airfoil to create a pressure difference, which in turns provides force in a new direction.
Dr. Grover Swartzlander, a professor of Imaging Science and Physics at the Rochester Institute of Technology, has discovered an interesting way to do an analogous thing with light - creating what is basically an optical wing. Light doesn't travel around the wing, though; it travels into it and is refracted. As the refracted light changes direction, there is a small change of momentum, so that the wing is pushed opposite to the direction the light is refracted - and the light provides lift. The technology may provide a new way to steer solar sails for space travel..
Related Links
Listen to this item (pop up player) or
use this link to download an mp3.
Theme music bed copyright Raphaël Gluckstein, Creative Commons License by-nc-nd-2.0
Saturdays at noon, Mondays at 11:00 p.m., Wednesdays at 3:00 p.m. (in some markets only)
Rat raiding rice crop, courtesy S. Belmain
We're coming to Halifax in early June for our annual Quirks Question Roadshow, and we want to see you there. Stay tuned to this space for details.
Saturdays at noon, Mondays at 11:00 p.m., Wednesdays at 3:00 p.m. and Fridays at 5:00 a.m. (ET)
podcasts 
facebook 
twitter 
rss