Carl Bergstrom, Biologist
The ABILITY to plan for the future is generally thought to be one of the skills that set humans apart from animals. However, according to a recent article tweeted by biologist Carl Bergstrom, ravens have shown evidence that they may the first non-primate that plans for future events. The study, published in Science, found that ravens cache food items in precise locations where they might need them in the future. They also showed the cognitive ability to use tools to acquire food. The ravens were given stones they could use to open weight-triggered boxes that contained food. When given the stones in isolation, they stored them until they were presented with the food boxes as much as 17 hours later. In a separate test, ravens were taught that certain items could be used as tokens and be traded for food. They were then given these “tokens” along with a large group of other useless items (again in isolation). Many hours later, the scientists showed them food, and noticed that the ravens knew exactly which tokens to fetch to get food. So far, scientists have believed only primates such as chimpanzees and orangutans have the ability to select, store, transport and utilise tools. The researchers said the new findings contrast “all of the previous studies in future planning, which have focused on naturally occurring behaviour” among animals.
Fire ant hazard
Jonathan Eisen, Biologist
When Hurricane Harvey was forecast, most Texas residents thought they knew what was heading towards them. They stocked food items, placed precious items above ground level, and took other precautions. But the victims of one of the worst storms in modern American history are facing a threat they never anticipated: floating colonies of aggressive fire ants. When the tunnels of their colonies get flooded, entire fire ant colonies — ants, eggs, larvae and all — form huge rigs with their bodies that float on water and will latch on any dry surface they find, according to an article tweeted by biologist Jonathan Eisen. And to the horror of Houston residents treading these floodwaters, the fire ants have been latching on to them. “The fire ants emerge from the soil, form a loose ball, float, and flow with the water until they reach a dry area or object they can crawl up on,” explains Paul Nester, a biologist at Texas A&M University. Scientists said the ants are able to float because they have a “hydrophobic” wax layer on their body that allows them to repel water. They use this repelling nature to link their limbs and form massive chains of pancake-like floating discs. An important thing to note, the article adds, is that fire ants are to regular ants what wolves are to golden retrievers. They’re highly aggressive, territorial, venomous creatures whose stings have known to be fatal for humans many times. Texas A&M experts warned residents to avoid contact “at all costs” with such ant rafts.
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