May 3: Wild fish can tell us apart, and more...
Bone collector caterpillar, dolphins pee on each other, using cars to sample air, and obsidian artifacts
On this week's episode of Quirks & Quarks with Bob McDonald:
It's like something from a horror movie. A creeping, carnivorous creature that in a macabre attempt at disguise and protection, covers itself with the dismembered remains of dead insects. This super-rare caterpillar is one of the strangest insects in the world. It lives on spider webs inside of trees and rock crevices in a 15 square kilometre radius on the Hawaiian island of O'ahu. Daniel Rubinoff, a professor of Entomology at the University of Hawaii, Manoa, and his team have only found about 62 of these caterpillars over the past 20 years. Their research was published in the journal Science.
Researchers observing river dolphins in Brazil were first surprised to see the animals turning on their backs and urinating into the air, and then further amazed to see other dolphins sampling the falling stream. The Canadian and Brazilian team, led by Claryana Araújo-Wang from the CetAsia Research Group, believe this aerial urination may be a way to communicate dominance among males. The research was published in the journal Behavioural Processes.
700 million years ago our planet was frozen from pole to pole during a period known as snowball Earth. Glaciers at that time scoured deep into the continents below like a giant bulldozer, grinding the rock into fine sediments. In a new study in the journal Geology, scientists found that as the glaciers melted, a lot of that loose material was injected very rapidly into the oceans. Brendan Murphy, from St. Francis Xavier University, said this chemical cocktail fertilized the oceans, and set the stage for rise of multicellular complex life on Earth.
Understanding the distribution of bacteria that might be a concern for human or animal health across an entire country is a huge job, but recently, a team from Laval University used a very clever shortcut to gather their data. They collected car air filters from vehicles across the nation, and looked in them to see what they sucked up. They found regional differences in the antimicrobial resistance genes specific to the agricultural activities and environmental factors at each location. Paul George from Laval University was the lead researcher on the study, which was published in the journal Environmental DNA.
Albertan obsidian artifacts are the end point of a widespread Indigenous trade network
Obsidian—volcanic glass used to make super-sharp tools—is found as artifacts from chips to blades to arrowheads at hundreds of sites across the Rockies of Alberta and British Columbia, dating back thousands of years. However, there are no volcanos in the area so archaeologists are using this volcanic glass to chart Indigenous trade routes through North America. New research, led by Timothy Allan of Ember Archeology, has traced the obsidian's point of origin to a site nearly 1,000 kilometers away, suggesting the material travelled over long distances and passed through many hands. The research was published in the Journal of Field Archaeology.
Do his gills ring a bell? Fish can recognize humans
Scientists at a Mediterranean research station kept noticing that particular fish would follow them around whenever they would try and do experiments. To find out if the fish were actually capable of recognizing individual humans, a team from the Max Planck Institute of Animal Behavior in Germany decided to turn this annoying behaviour into a scientific experiment. They found that the fish were indeed capable of remembering which humans had shared tasty treats in the past. The research was published in the journal Biology Letters.
Producer Amanda Buckiewicz spoke to:
- Maëlan Tomasek, a doctoral student at the Max Planck Institute of Animal Behavior and the University of Clermont Auvergne, France
- Katinka Soller, a bachelor student from the Max Planck Institute of Animal Behavior