Think it’s tough to catch 151 Pokémon Go monsters? Imagine trying to collect more than 15,000. That’s what botanists studying the trees of the Amazon rain forest have been attempting for more than 300 years. So far, intrepid explorers have found a total of 11,676 tree species, a team of ecologists reported. The team combed through hundreds of thousands of digital records from museums around the world. The oldest samples were collected in 1707, the most recent in 2015. According to Hans ter Steege, a tropical forest ecologist, 4,000 tree species may still be hidden in museum drawers, not yet digitized, or remain undiscovered in the Amazon. “We will certainly not catch them all,” he said.

The mirrors behind Rembrandt portraits

Francis O’Neill was always astounded by Rembrandt’s technical accuracy. “I thought, ‘What sort of magic has this guy imbued in himself?’ ” said O’Neill, who produces art and teaches in Oxford, England. In a paper published in the Journal of Optics, O’Neill lays out a theory that Rembrandt set up flat and concave mirrors to project his subjects — including himself — onto surfaces before painting or etching them. His research suggests that some of Rembrandt’s most prominent work may not have been done purely freehand, as many art historians believe.

Newborn ducklings judge shapes, color

It pervades our thinking processes, from situations as simple as choosing which socks to wear to more nuanced scenarios. The ability to make inferences from same and different, once thought unique to humans, is present in creatures generally seen as unintelligent: newborn ducklings, according to a study published in Science. Researchers took day-old ducklings and exposed them to a pair of moving objects. Then they exposed each duckling to two new pairs of objects. The researchers found that about 70 percent of the ducklings preferred to move toward the pair of objects that had the same shape or color relationship as the first objects they saw.

New York Times