Scientists Find Two New Species of Deadly 'Bird-Catcher' Trees

Rosimar Rivera Colón
Rosimar Rivera Colón

From car windshields to cats, birds around the world face plenty of mortal threats. But as IFLScience reports, avians in Puerto Rico have particularly unique forest foes that until recently were unknown to science. Deep in the island's jungles, researchers have discovered two new species of "bird-catcher" trees, bearing ripe, sticky fruits that—yes—can quite literally trap and kill birds.

As recently described in the journal Phytokeys, the trees—which are members of the genus Pisonia—produce fruits with viscous skins covered in tiny hooks. If a bird perches on the tree, a piece of fruit can stick to its body; when the bird flies off, it takes the fruit with it, potentially dispersing it somewhere else on the island. But if the fruits become too tightly affixed to birds, they can trap and kill their tiny transporters. Their tiny bones sometimes litter the trees' swollen roots, which wrap over rocks and are said to look like elephant feet. 

The trees' discovery has resulted in the long-due recognition of two overlooked female figures in Puerto Rico. The trees were given the names Pisonia horneae and Pisonia roqueae to celebrate the scientific contributions of Frances W. Horne (1873–1967), an American illustrator whose vibrant watercolors depicted hundreds of Puerto Rican plants; and Ana Roqué de Duprey (1853–1933), a Puerto Rican academic, writer, suffragist, and amateur ethnobotanist.

"It only seemed natural to name the two new species after these two extraordinary women who spent decades on large educational projects aimed to divulge botanical knowledge in Puerto Rico," study co-author Jorge C. Trejo-Torres said in a statement. "Just like the two large trees remained unrecognized by science until now, the enormous efforts of these two women, who dedicated part of their lives to botanical work, remained largely unrecognized by the community."


The infructescences of Pisonia roqueae

Jorge C. Trejo-Torres

The 'elephant foot' trunk of Pisonia roqueae

The 'elephant foot' trunk of Pisonia roqueae.

Jorge C. Trejo-Torres

[h/t IFLScience]

New Study Reveals 'Hyper-Alarming' Decline of Rainforest Insect Populations

iStock/jmmf
iStock/jmmf

Climate change is decimating yet another vital part of the world's ecosystem, according to a startling new paper. Rainforest insects are dying off at alarming rates, according to a new study spotted by the The Washington Post. In turn, the animals that feed off those insects are decreasing, too.

In the study, published in Proceedings of the National Academy of Sciences, a pair of scientists from the Rensselaer Polytechnic University in New York and the National Autonomous University of Mexico studied populations of rainforest arthropods (an invertebrate classification that includes insects and spiders) in the El Yunque National Forest in Puerto Rico. They compared the number of insects lead author Bradford Lister found on trips in 1976 and 1977 with the number he and co-author Andres Garcia found on trips they took between 2011 and 2013.

Lister and Garcia used nets and sticky traps to collect insects on the ground and several feet above the ground in the forest canopy. They dried these captured bugs and measured the mass of their haul against the mass of insects found in the 1970s, finding that the modern net sweeps captured only an eighth to a fourth of the insects captured in the '70s. The mass of insects captured by sticky traps on the ground declined by 30 to 60 times what they were a few decades ago. They also tracked populations of lizards, frogs, and birds that live off those rainforest insects, finding that those populations had declined significantly, too, at levels not seen in other rainforest animals that don't rely on insects for food.

Tropical insects are particularly vulnerable to climatic changes, since they can't regulate their body temperature. During the time of the study, average maximum temperatures in El Yunque rose by almost 4°F (2°C). The warming climate is "the major driver" of this decline in arthropod populations, the study authors write, triggering a collapse of the forest food chain.

The paper has other scientists worried. "This is one of the most disturbing articles I have ever read," University of Connecticut entomologist David Wagner, who wasn't involved in the research, told The Washington Post, calling the results "hyper-alarming." Other studies of insect populations have found similarly dire results, including significant declines in butterflies, moths, bees, and other species. One recent study found that Germany's flying insect populations had decreased by as much as 75 percent in the last three decades. Scientists don't always attribute those population losses directly to warmer temperatures (habitat loss, pesticide use, droughts, and other factors might play a role), but it’s clear that insect populations are facing grave threats from the modern world.

Not all insect species will be equally affected by climate change, though. While we may see a sharp drop in the populations of tropical insects, scientists project that the number of insects in other regions will rise—leading to a sharp increase in crop-eating pests in some parts of the world and broadening mosquitos' geographical range.

[h/t The Washington Post]

This 'Time-Traveling Illusion' Is Designed to Trick Your Brain

A team of researchers from the California Institute of Technology (Caltech) have designed an illusion that might trick your brain into seeing things that aren’t there, the New Atlas reports.

Dubbed the Illusory Rabbit, it provides instructions that are simple enough to follow. Start playing the YouTube video below and look at the cross in the middle of the screen while also watching for flashes that appear at the bottom of the screen. Most importantly, you’ll want to add up the number of flashes you see throughout the video. (And make sure your volume is up.)

We don’t want to spoil the fun, so before we explain the science of how it works, check out the video and try it for yourself.

Did you see three flashes paired with three beeps? You’re not alone. This is due to a phenomenon called postdiction, which is a little like the opposite of prediction. According to a paper outlining these findings in the journal PLOS ONE, postdiction occurs when the brain processes information retroactively [PDF]. This occurs in such a way that our perception of earlier events is altered by stimuli that come later. In this case, you might think you missed the flash paired with the second of the three beeps, so your mind goes back and tries to make sense of the missing information. That's why you may see an “illusory flash” in the middle of the screen, sandwiched between the two real flashes.

For this reason, the researchers call the mind trick a “time-traveling illusion across multiple senses” (in this case, vision and hearing). It’s successful because the beeps and flashes occur so rapidly—in less than one-fifth of a second. The senses essentially get confused, and the brain tries to fill in the gaps retroactively.

"Illusions are a really interesting window into the brain," the paper’s first author, Noelle Stiles, said in a statement. "By investigating illusions, we can study the brain's decision-making process.” Researchers wanted to find out how the brain “determines reality” when a couple of your senses (in this case, sight and hearing) are bombarded with noisy and conflicting information. When the brain isn’t sure of what’s going on, it essentially makes up information.

“The brain uses assumptions about the environment to solve this problem,” Stiles said. “When these assumptions happen to be wrong, illusions can occur as the brain tries to make the best sense of a confusing situation. We can use these illusions to unveil the underlying inferences that the brain makes."

[h/t New Atlas]

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