Red Knots on PBS

PBS will air a documentary film on the ecology of horseshoe crabs and red knots:

With its armored shell, ancient anatomy, and 350-million-year lineage, the horseshoe crab almost seems too inconspicuous to stir up controversy. Yet this humble creature is at the very center of a collision between three completely different species.

For many decades, humans have harvested the horseshoe crab for use as fishing bait. Since the 1970s, we have even used horseshoe crab blood for medical purposes. But now we may have gone too far. Horseshoe crab numbers have declined significantly in the past few years. And, naturally, so have their egg numbers.

This is especially important to a small shorebird that is a global traveler of the most impressive kind. The red knot makes one of the longest migrations of any animal -- a journey that takes it from one end of the earth to the other. To accomplish this feat, it relies on the eggs of the horseshoe crab. Without these eggs, the red knot is in danger.

In the film "Crash: A Tale of Two Species," filmmaker Alison Argo tells the story of nature's amazing ability to create fragile connections among the most unexpected creatures, and of our potential as humans to destroy those connections -- or restore them.

WNET will broadcast Crash on Sunday, February 10, at 8:00 pm.