Ben Franklin, ecologist

Breeding male Brewer's blackbird.

— Photo by JerryFriedman 

“In New England, they once thought blackbirds useless, and mischievous to the corn. They made efforts to destroy them. The consequence was, the blackbirds were diminished; but a kind of worm, which devoured their grass, and which the blackbirds used to feed on, increased prodigiously; then, finding their loss in grass much greater than their saving in corn, they wished again for their blackbirds.”

— Benjamin Franklin (1706-1790), a U.S. founding father and polymath. He was born and raised in Boston, which he left at 17 to move to Philadelphia.