When billions of cicadas erupt from the ground, the natural world experiences a phenomenon known as a resource pulse. This mass emergence, often occurring on a 13- or 17-year cycle, temporarily floods the ecosystem with an immense, easily accessible food source. For a few weeks, the landscape is dramatically altered by the sheer volume of these insects, creating a temporary disruption in the local food web. Local predators must adapt their diets to take advantage of this fleeting abundance.
Squirrels as Opportunistic Cicada Predators
Squirrels are opportunistic omnivores and readily consume cicadas during an emergence. When an easier, more abundant option appears, they consume food sources outside their typical diet of nuts and seeds. Cicadas represent a slow-moving, defenseless meal that requires little effort to catch compared to burrowing for a buried nut.
Observation shows squirrels actively hunt the insects, often consuming dozens in a single morning. They target both soft, newly emerged nymphs and harder-shelled adult cicadas. Squirrels often discard the adult cicada wings, which are largely indigestible chitin. The scattering of transparent remnants is a common sign of a squirrel’s recent meal.
Understanding the Nutritional Appeal
Cicadas are particularly attractive to squirrels and other wildlife due to their rich nutritional profile. Compared to a typical diet of plant matter, these insects function as a high-protein supplement. Studies show cicadas contain high-quality protein, around 21 grams of crude protein per 100 grams, a value comparable to or slightly higher than that found in eggs. They also offer a beneficial blend of fats, including healthy polyunsaturated fatty acids. This sudden, concentrated source of both protein and fat provides essential energy and building blocks for animals, helping squirrels quickly build up reserves.
Broader Ecological Context of Cicada Emergence
A mass cicada emergence is a significant ecological event that affects the entire local food web. Many animals, including various bird species, raccoons, opossums, and even domestic pets, participate in the temporary feast. This enormous availability of prey causes a temporary shift in the foraging habits of generalist predators.
The ecological impact extends beyond the predators, creating a trophic cascade. When birds switch to eating cicadas, the predation pressure on their usual prey, such as caterpillars, is significantly reduced. This allows caterpillar populations to increase, which leads to greater defoliation and damage to host trees.
The sheer number of cicadas employs a biological strategy known as predator satiation. Despite the intense feeding frenzy, the overall cicada population is not significantly impacted, and animals quickly revert to their normal diets once the emergence period ends.