Grandmothers used to warn youngsters against being “a jack of all trades, and a master of none,” and with good reason, at least in the animal kingdom, according to research by Mike Singer, associate professor of biology, associate professor of environmental studies.
Singer’s decade of research in the ecosystems of Connecticut forests reveals that caterpillars with finicky feeding habits avoid predation from birds, whereas those that feed generally on many plants become meals for baby birds. The “specialist” bugs are much better at survival.
Singer and five collaborators published these findings in the prestigious Proceedings of the National Academy of Sciences June 16.
“Dietary specialization of herbivores drives the dynamics of this food chain,” Singer explained. Caterpillars with generalized diets are less likely than specialists to be camouflaged or to display warning colors or features to avian predators.
A familiar example of a dietary specialist is the caterpillar of the Monarch butterfly, which feeds exclusively on milkweed plants. This caterpillar accumulates toxins from its food-plants, rendering it unpalatable to birds and other predators. The toxic caterpillar is distinctively striped and colored as a warning to its enemies.