Tanagers are striking songbirds, recognized by their vibrant plumage, found exclusively in the Americas. They exhibit a varied diet, adapting their foraging habits to the seasonal availability of different food sources. The nutritional needs of a tanager shift dramatically between the demands of the breeding season and the extensive energy requirements of migration. Their sophisticated strategy balances high protein intake with carbohydrate and fat consumption.
The Essential Insect Diet
The breeding season represents a time when the tanager’s diet is overwhelmingly focused on protein-rich invertebrates. During this period, insects form the bulk of their meals, providing the amino acids necessary for egg production and the rapid growth of nestlings. Tanagers consume a wide array of arthropods, including beetles, cicadas, grasshoppers, ants, and caterpillars. The sheer volume of insects eaten is impressive; one Scarlet Tanager was once recorded consuming hundreds of tent caterpillars within minutes.
Foraging techniques are specialized to capture different types of prey within the forest canopy. Tanagers often engage in “gleaning,” methodically picking stationary insects and spiders from foliage, bark, and branches. They also perform “sallying” or “hawking,” darting from a perch to snatch flying insects like flies, dragonflies, and wasps directly out of the air. When catching large insects, such as dragonflies, some species like the Western Tanager will first clip the wings, head, or legs before consumption.
Plant-Based Supplements: Fruits and Nectar
While insects dominate the summer diet, plant matter becomes a highly significant food source during migration and wintering periods. This shift provides the concentrated sugars and fats needed for long-distance flight and maintenance when protein demands are lower. Small, soft-fleshed fruits and berries are preferred, as these are easy to consume and digest.
Specific fruits commonly eaten include mulberries, serviceberries, elderberries, and various wild cherries. These fruits offer readily available carbohydrates and fats, which are essential for building up the fat reserves that fuel migratory journeys. Tanagers also occasionally sip nectar from flowers or feed on tree sap. In wintering grounds, the availability of fruit, such as that from the Strangler Fig in Central America, can be a primary factor in their diet.
Seasonal and Species-Specific Dietary Shifts
The annual cycle of a tanager dictates a major change in its foraging focus, moving from a breeding-season insectivore to a migratory frugivore. During the spring and summer, the diet is approximately 80 to 90 percent insects, prioritizing the protein needed for reproduction. In contrast, the autumn migration and wintering months see a substantial increase in fruit consumption, providing the high-energy density required for sustained flight and cold weather survival.
Dietary specialization also separates different tanager species in North America. The Summer Tanager exhibits a remarkable preference for stinging insects, earning it the nickname of a bee and wasp specialist. They possess a unique behavior of capturing wasps, then repeatedly beating the insect against a branch and wiping the stinger off before swallowing the prey. The Western Tanager, found in the coniferous forests of the West, frequently includes pine seeds and conifer buds in its diet, particularly in the non-breeding season.