Giant, tree-dwelling rat discovered

NEW RODENT SPECIES

Mammalogist Tyrone Lavery first heard stories about ‘vika’, a giant, coconut-cracking, tree-dwelling rat from the Solomon Islands, in 2010. After years of searching for the elusive animal, he has finally confirmed its existence, making it the first new rodent species to be described from the islands in more than 80 years.

For years, the only non-anecdotal evidence he had that vika was real was a “really big rodent pellet, too huge to be from a black rat (the common rat which was introduced to the island),” that he discovered on a hike in 2012.

Just as he began to worry that the animal had gone extinct, a local conservationist gave him a call: a 46-cm-long, orange-brown rat had been collected from a felled tree.

“To finally have vika in the hand was a very special feeling,” says Tyrone, a postdoctoral researcher at The Field Museum in Chicago, Illinois, USA, and lead author on the paper that describes Uromys vika, published in the Journal of Mammalogy.

By the time Tyrone examined the animal, almost all of its soft tissues had decomposed. But the cranium was complete, and his examination of it, along with the partial skeleton, hair and mandible, and the results of a DNA analysis, showed that this was indeed a new species. The rat was not weighed before it decomposed, but Tyrone thinks that an adult Uromys vika probably reaches between 500 gm and one kg.

EVOLUTIONARY CHANGES

How pumpkins and squash came to be

Dear Watermelon, it’s been nice hanging out with you over the summer. But the seasons are changing, and it’s time I move on to pumpkins and squash. It’s not you, it’s me. You’re light, and sweet, and perfect for the summer. But as it starts to cool off, I just need the warm spices that go so well with that buttery hunk of pumpkin meat. Don’t be sad. I’ll see you again next summer.

Many of us have gone through this with the plants of the cucurbitaceae family. And although bittersweet, the opportunity to appreciate their diversity wouldn’t have been possible if it weren’t for an ancient event in plant evolution. About 100 million years ago, the genome of a single melon-like fruit copied itself. Over time, this one ancestor became a whole family of plants with different colours, shapes, sizes and flavours, like pumpkins, squash, watermelons and cucumbers, according to a recent paper published in the journal, Molecular Biology and Evolution.

The researchers compared the genomes and evolutionary trees of a number of plants including cucumbers, melons and gourds. Millions of years of environmental changes allowed the fruits to lose genes over time and tailor their own codes to become what we know them as today.

PLAYFUL EXPLORATION

Using objects as tools

Researchers have discovered that New Caledonian crows and kea parrots can learn about the usefulness of objects by playing with them — similar to human baby behaviour. The study, led by researchers at the Universities of York and St Andrews, UK, demonstrated that the two types of birds were able to solve tasks more successfully if they had explored the object involved in the task beforehand. It has long been thought that playful exploration allows animals to gather information about their physical world, in much the same way that human infants learn about their world through play. In one of the first direct tests of this hypothesis, scientists studied two bird species, the New Caledonian crow and the kea parrot, to understand how they interact with objects before, during and after a task involving that object. 

DOCUMENTARY

Chasing Coral

Directed by Jeff Orlowski, the documentary Chasing Coral focuses on the world’s oceans on a journey to reveal a mysterious phenomenon happening beneath the surface. Shot over three years, the documentary follows Richard Vevers, an underwater photographer, and scientist and Zackery Rago to document the world’s dying coral reefs. Chasing Coral was shot over three years, with expeditions to coral reefs around the world.

The imagery is an ominous warning of the planet’s future along the current course; at the same time, it is a celebration of the most biodiverse ecosystem on the planet. To watch the documentary, visit www.chasingcoral.com.