Late Migration
By Margaret Renkl
Guernica, 6 December 2016

Every monarch in the world is hatched on the leaf of a milkweed plant somewhere in the continental United States, and almost all of them spend winters on fir-covered mountains in central Mexico, in clumps so thick that tree branches can crash to the forest floor from their weight.

But this March, a storm brought such shattering winds and rain to their Mexican wintering grounds that millions of butterflies died before they could return to the US to breed.