That time of year thou mayst in me behold
When yellow leaves, or none, or few, do hang
Upon those boughs which shake against the cold,
Bare ruin’d choirs, where late the sweet birds sang.
William Shakespeare, Sonnet 73
Kate Wilhelm‘s novel, Where Late the Sweet Birds Sang, is about how as doomsday approached the Sumners family built a fortified citadel in the Shenandoah valley and prepared to wait it out. as deadly winds swept and polluted destroying plant and animal life, the Sumners were left sterile – so they turned to cloning in the hope that after a number of generations the ability to reproduce would return.