Related Clues:

• Wither away
• Become extinct
• Go extinct
• Become extinct, e.g.
• Go from endangered to extinct
• Cease to exist
• Expire one by one
• Gradually expire one by one
• Spotted thing gets sick, as doomed species do
• Reduce in number, as something that's spotted and rotten
• Cross the great divide one by one, removing violins from field of vision