Birds, Crabs and Humans

Birds, Crabs and Humans

IMG_2142Florida. What in the world do humans and red knot shore birds have in common? Horseshoe crabs. Really? I remember horseshoe crabs as a kid washing up on the Long Island shore.

These cool looking crabs are one of the few living fossils surviving today, having been around for 450 million years (way, way before dinosaurs). They are close cousins of the spider and look like big scorpions with hard backed shells and a harmless, although scary looking, long tail.

So how are we all connected? The red knot bird relies on the consumption of eggs laid by the horseshoe crab to refuel for their unbelievably long migration from South America to the Arctic (almost 20,000 miles round trip). Humans rely on the blood of the crabs to protect us from bad bacteria (to learn more check out this fascinating PBS documentary (

All intravenous drugs, including shots and vaccines, in the US are required by the FDA to be tested with horseshoe crab blood to detect any foreign bacteria. (Wow, that I didn’t know).The blood, containing copper (making it blue as opposed to the iron in our blood which is red), coagulates when exposed to bad bacteria. Birds, crabs and humans- all interconnected. What an amazing world!

Photo from Wikipedia