Phoenecia: Land of Purple… Snail Dye

“One of the costliest substances ever produced by man” was actually produced by sea snails (Hexaplex and Haustellum sp.). The Phoenicians (in modern-day Lebanon and Syria) harvested whelks and manufactured a reddish-purple dye called Tyrian Purple. Processing just one pound of the dye required millions of snails and cost almost $100,000 in today’s dollar. The color was prized by the Romans, who used the rare and expensive cloth to designate nobility. Romans named the land that produced the dye “Land of Purple,” or Phoenicia. (1)

As you can probably imagine, destroying millions of whelks for one pound of dye is pretty unsustainable. Over time, populations of the Mediterranean snail declined and were eventually extirpated from the region. The dye industry also collapsed. Even though other sources of purple dyes were found, they paled in comparison to Tyrian purple – literally, since Tyrian purple doesn’t fade in sunlight.

Today, many more species in the Mediterranean are facing extirpation. Almost every sea resource (like snails and other mollusks, turtles, crustaceans) in the area has plummeted to less than half its past population size. (2)

Nature can be an amazing provider, if respectfully and responsibly utilized. Populations of plants and animals produce more than could ever survive, so harvesting a certain number of individuals can actually help many species. But that “certain number” is important. Harvest too much, and the populations we rely upon decline. In harming other species, we ultimately harm our own – a lesson we could learn from the Phoenicians and the snails.

1. McCord, C.P. 1969. The Lowly Whelk and the Lofty Royal Purple Dye. Archives of Environmental Health: An International Journal 18(3) 379-385.
2. Lotze, H.K., M. Coll, and J.A. Dunne. 2011. Historical Changes in Marine Resources, Food-web Structure and Ecosystem Functioning in the Adriatic Sea, Mediterranean. Ecosystems. 14(2): 198-222.

Purring Predators

As agriculture took hold in Middle Eastern societies about 10,000 years ago, archeological evidence of cat domestication appears. When humans began storing grain, any rodent-killing animal was a benefit. But the presence of cats didn’t spread along with agriculture. Egyptians may have revered cats, but other civilizations used weasels or snakes to limit mice. In the painting “Lady with an Ermine” by Leonardo da Vinci, the weasel may symbolize purity or the young woman’s last name (similar to the Greek word for ermine). With all due respect, however, I think the animal may have just been the lady’s pet; weasels were more common pets than cats at that time.

Cats may have been popular in Egypt during the heyday of the Roman Empire, but Greeks and Romans kept weasels as their rodent-killing pets. Cats joined European families around the fourth century but were relatively uncommon until the 1600s (1).

Nowadays, of course, cats are popular pets and internet memes. Their omnipresence is also a major cause of concern to ecologists and bird lovers. In a 2013 research article, Loss et al. estimated our purring pets (and their feral cousins) kill about 2.5 billion birds and 12 billion rodents each year in the U.S. alone (2).

P.s. The adorable cat who posed for this painting is our own 18-year old feline princess, Flea. She’s killed exactly one bird in her life, a fledgling finch who accidentally flew into her mouth. Flea didn’t even bite down; the little bird panicked to death.

1. The Oxford Handbook of Animals in Classical Thought and Life. G.L. Campbell. 2014. Oxford University Press.
2. Loss, S.R. et al. 2013. The impact of free-ranging domestic cats on wildlife of the United States. Nature Communications 4:1396.