Sunday, August 2, 2015

The pink grasshopper


Mostly in the last couple of years, pink meadow grasshoppers (Chorthippus parallelus) have been sighted by adventurous children in the Belfast hills and JapanNational Geographic's headline was "No, it's not a cocktail" apparently to provide clarification for all those who go on the National Geographic website looking for vintage cocktail recipes. Other headlines were like "No, it's not spraypaint" and "They were tickled pink." Please take a minute to compliment me on my non-sensationalist headline.
If you have red hair and freckles, you know what it's like to be considered a freak of nature. But did you know that the phenomenon that causes red hair in people is thought to be a variation of that which causes funky coloring in other animals? It's called erythrism — an unusual reddish discoloration of anything from hair to skin to feathers. It can sometimes be caused by diet (as in the case of bees feeding on the colorful corn syrup in jars of maraschino cherries and then turning into little pink chubbers). But it's usually caused by a genetic mutation to favor recessive genes, which is the case with this fancy grasshopper:

pink grasshopper
Meadow grasshoppers aren't native to the United States, and are mostly found in the non-arid grasslands of Europe and nearby parts of Asia. They pretty much just run free across the moors and can't be tamed — like the Brönte sisters of bugs.
But it's not easy being pink — these grasshoppers rarely survive to adulthood because they're so visible to predators. Some scientists also suspect that the grasshoppers tend to lose their pink shade as they get older, which would further explain why almost all of the pink grasshopper sightings so far have been of nymphs.

The coolest thing about meadow grasshoppers is that they are a really important model organism for understanding the processes by which species disperse across geographic areas. This is called phylogeography — by looking at where individuals with different genetic variations live now, you can usually figure out what big events happened to their ancestors. In the case of the grasshoppers, we know their wings are totally useless, making geographic dispersal slow and incredibly deliberate.  This limitation explains why the population never moved northward past mountain ranges, and implies that it moved into certain parts of Europe only after glaciers had receded.
Just kidding, the coolest thing about meadow grasshoppers is that when they get scared, they can dive into a pond and cling to the bottom of an underwater plant for several minutes until they're convinced that the danger has passed. The coolest thing about pink meadow grasshoppers is that they've found a really showy way to differentiate themselves from these guys:

a bugs life
Which is a good call, because Hopper is probably the scariest Disney animated villain of all time. Not only is he the Balon Greyjoy of the buggy ecosystem, he's also voiced by Kevin Spacey, which is honestly too much horror for a child to handle. Just ask me, a person who has repressed the entirety of the A Bug's Life experience, with the exception of the short where the old guy plays chess against himself.

Hopper's body creaks when he moves, which is in keeping with the actual sounds made by grasshoppers — a rapid succession of about 35 high-pitched notes which are made by rubbing their hind femur against the edges of their wings like a violin bow. Which is cool, and many have applauded Pixar for the scientific accuracy it strives for in its films, but in this situation I think it's safe to say that a four year-old would rather have a slightly inaccurate portrayal of a bug than they would a villain whose demon body literally creaks like the beams of a haunted house every time he leans forward to menace someone.
Might I remind you: