A doubling in worm size could adversely affect species of worm eaters that primarily feed on small, thin worms. These seeds are larger, fatter worms that can be more difficult to catch and digest, and may not fit in your mouth or be more difficult to break down. Worm-eater species that eat earthworms may be positively impacted by the change, as more food is available and larger prey is easier to catch and digest.
Worm-eater species that feed on a variety of worms of varying sizes may not be affected at all, as they have the flexibility to adjust their diets to accommodate new worm sizes. Both-eating birds can do so as the average worm size increases, as long as smaller worms are still available. Overall, the effects of worm size changes on worm eaters depend on the specific dietary habits and physical characteristics of each species. However, those that rely on small, thin worms may be adversely affected. Those who can adjust their diets to accommodate different worm sizes may not be affected at all.