"March"-ing Animals

Ever heard of the "March of the Spiny Lobster?" I hadn't either until I started researching The Jungle Store's animal fact page for Lobsters. That is when I stumbled across the term. Having grown-up near the coast of Maine, Spiny Lobsters were the "less desired" species and I'd never learned much about them. Now, they seem quite fascinating.

The "March" happens in late October, early November, off the shores of the Bahamas. Autumnal storms roll in, rapidly dropping temperatures and agitating the waters. When the storms end, the generally solitary Spiny Lobsters gather by the hundreds, even the thousands, and form long, single-file columns, marching side-by-side. With each troop numbering as many as 60 lobsters, they form a living chain with the lobster behind in constant physical contact with the lobster in front. The leader of each column changes often, but there is no pattern to which lobster will lead next. Their marching formation seems to be a defensive imperative, providing protection in numbers as they cross the open sandy bottom to reach deeper water. Whether fearless or highly motivated, the lobster columns let nothing deter them. They will crawl over divers who lie down in front of them, and even march over "leaders" who slow down or falter.

Scientists are not sure why the Spiny Lobsters march. There seems to be no connection to mating, food resources or maturation process (i.e., juveniles changing habitats once they become adults). The most favored hypothesis attributes the exodus to lobsters simply seeking warmer, less turbulent waters.