Lost cripples can result in lead being invested by predatory birds and mammals, as well.
Good point! There have been mass goose and duck kills in certain areas of Minnesota over the years blamed on the ingestion of lead shot. Seems to be a problem with deer meat from deer killed with lead-based ammo as well.
https://www.outdoorlife.com/is-game-meat-shot-with-lead-safe-to-eat/