Mike Singer, associate professor of biology; Tim Farkas ’08, MA ’10 and Christian Skorik ’09, MA ’10 are the authors of “Tritrophic Interactions at a Community Level: Effects of Host Plant Species Quality on Bird Predation of Caterpillars,” published in the March issue of The American Naturalist. Researchers at the University of California at Irvine also contributed to the report.
Researchers report that a tree is not a tree is not a tree when it comes to birds foraging for tree-feeding caterpillars. With help from a small army of students, the scientists ran a field experiment in Connecticut forests over two years, involving hundreds of tree branches either bagged with garden variety, bird-proof netting or left open to foraging birds. They found that disparities in caterpillar growth between different tree species, such as black cherry and American beech, changed a caterpillar’s risk of becoming bird food. On balance, nutritious trees like black cherry can increase a caterpillar’s risk of being taken by foraging birds by 90%. This neat pest-control system works because the most nutritious tree species harbor the greatest numbers of caterpillars, offering up the easiest pickings for birds. For tree-feeding caterpillars, however, no tree is completely safe. Even without the risk of being in a crowd, nutritionally poor trees like American beech can slow down a caterpillar’s growth and prolong its exposure to bird predation.
Read more about the study in this past Wesleyan Connection article.