Cicadas, known for their distinctive buzzing sounds, emerge periodically from underground after years of development. During these emergence events, these insects become a readily available and abundant food source for many animals, including birds. This natural phenomenon provides a temporary food supply for various avian species, influencing local ecosystems.
Birds That Consume Cicadas
Many bird species consume cicadas, including insectivorous birds like American Robins, Blue Jays, Northern Cardinals, and European Starlings. Songbirds such as sparrows, bluebirds, gray catbirds, and mockingbirds also eat them. Even raptors, including American Kestrels and Red-tailed Hawks, prey on cicadas when abundant.
Birds employ various hunting strategies to capture these insects. Ground-feeding birds like robins and grackles often forage on the ground or in low vegetation where cicadas are emerging or have fallen. Other species, such as cuckoos, woodpeckers, and orioles, may hunt them in trees where adult cicadas congregate. Aerial insectivores, like falcons, might catch cicadas in flight.
Nutritional Benefits for Birds
Cicadas offer significant nutritional advantages for birds. They are rich in protein, crucial for muscle development and provides a substantial energy boost. They also contain fats, iron, and various vitamins, making them a comprehensive food source. Some studies indicate cicadas can contain over 50% protein by dry weight and provide all nine key amino acids.
This abundant and nutritious food supply impacts bird breeding success during emergence years. Bird populations with access to large numbers of cicadas may experience increased clutch sizes, higher nestling body mass, and improved survival rates for their young. The easy availability of cicadas means adult birds can spend more time at the nest, incubating eggs and protecting their chicks, rather than extensively foraging for food. This temporary food bonanza can boost local bird populations in the years following a major cicada emergence.
Cicada Survival Mechanisms
Despite being a food source for birds, cicadas have evolved several strategies to ensure their survival. One recognized mechanism is “predator satiation,” where an overwhelming number of cicadas emerge simultaneously. This sheer abundance means that while many individuals are eaten, predators become full, allowing a large proportion of the cicada population to survive and reproduce. Emergence densities can exceed 1.5 million individuals per acre, making it impossible for predators to consume them all.
Cicadas also spend most of their lives underground as nymphs, some for 13 or 17 years, feeding on tree root fluids. This long underground dormancy protects them from surface predators for extended periods. Their synchronized emergence, often occurring in prime-numbered year cycles (like 13 or 17 years), is hypothesized to minimize the chances of their emergence aligning with the shorter, more regular population cycles of many predators. Male cicadas produce loud calls, primarily to attract mates, but these sounds may also deter or distract some predators.