by Steve Hagenbuch, Conservation Biologist
Most of us have at one time or another giggled at the sight and feel of an earthworm wriggling in the palm of our hand. There is also a notion that worms are “bird food” and therefore must be good, right? Not necessarily. Each of the 19 known species of earthworms found in Vermont are non-native. While the majority of these originated in Europe, the three most impactful to forests are snake, or jumping, worms from Asia.
Snake worms alter forest soil structure and quickly consume leaf litter. As a result, it can be difficult for tree seedlings and other forest shrubs to germinate and become established. In these situations, a dense and diverse layer of understory vegetation, critical nesting habitat for birds such as Black-throated Blue Warbler, may not develop. Combine this effect with an over-abundant white-tailed deer population, which actively browse vegetation in this forest layer, and the issue becomes even greater.
