4039 Pill Bugs and Horseshoe Crabs

Sunday, May 17, 2015

I read a lot.  Most of the day, in fact.  But even though I keep buying books, most of them are in the "to read" stack.  Most of my reading is on the internet.  I start with something, and start following links, and next thing I know hours have passed.

Earlier today Daughter asked if we could feed the baby bird pill bugs.  I started looking, and ended up fascinated.  Did you know that pill bugs (a.k.a. roly-poly, sowbug, wood louse) aren't insects at all?  They are crustaceans, descended from trilobites, and directly related to horseshoe crabs.  They breathe with gills. That's why they need to stay in moist areas.  They, along with the horseshoe crabs, evolved many eons ago, when there was more copper in the oceans than iron, so their blood is copper-based, not iron-based, and so their blood is blue, not red.

Birds do love to eat them, but rarely find them because they stay in dark places, and are active at night.

However, pill bugs suffer from a parasite that warps their minds.  The parasite eggs are in bird poop.  When the pill bugs eat the bird poop, the eggs hatch inside them and take over their brains, causing them to go out in the open in daylight, where birds find them and eat them.  The parasite grows in the birds from the larval stage to the adult stage, mate, lay eggs in the birds' digestive tract, and then the eggs are pooped out, to be eaten by more pill bugs.

So yes, we can feed the baby bird pill bugs, but only those captured in dark places.  None found out in the open.

Cool, huh?

(Earthworms have the same parasite, with the same life cycle, but it doesn't take over their brains.  The parasite is dangerous for baby birds because the first stage of the parasite is spent in the bird's trachea, where they grow into wormy things, and then when it gets to adult stage it moves to the esophagus, and if there is a large infestation, it can impede the bird's breathing.  So it's not a good idea to feed baby birds worms.  Which I don't understand, because parent birds feed chicks worms all the time.  Another interesting note - chickens won't touch a pill bug.)
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