Western Tanager - Food Habits

Food Habits

Western tanager obtain their food by foliage gleaning and hawking. The degree to which each of these methods is used apparently varies across locations. For instance, in a California mixed conifer-oak forest consisting mainly of white fir, Douglas-fir, incense-cedar, and California black oak, about 47% of western tanager foraging observations were gleaning, about 40% were hawking, while lunging and hovering occurred in about 6% and 7% of observations, respectively. In contrast, in the mainly Douglas-fir dominated communities of interior British Columbia, gleaning constituted 93.2% of western tanager foraging observations. Hawking only occurred in 3.7% of observations and hovering in 3.1%.

Western tanagers primarily glean from foliage. In the mixed conifer-oak woodland of California, 45% of western tanager foraging observations were foliage gleaning. Western tanagers gleaned from twigs in 10% of observations and from branches in 5% of observations. Hawking constituted the remainder of western tanager foraging observations. In British Columbia, 88.3% of gleaning observations occurred on foliage, 10.5% on branches and twigs, and 1.2% on trunks.

Western tanagers eat fruits (~18%) and a wide range of insects (~82%). Fruits include hawthorn apples (Crataegus spp.), raspberries (Rubus spp.), mulberries (Morus spp.), elderberries (Sambucus spp.), serviceberries (Amelanchier spp.), and wild and cultivated cherries (Prunus spp.). Western tanagers have been observed foraging on Perry's agave (Agave parryi) nectar. Reports of western tanager eating Eucalyptus (Eucalyptus spp.) nectar, Russian-olive fruits, and human-provided food, including bird seed and dried fruit, were summarized in. Western tanagers are major consumers of western spruce budworms (Choristoneura occidentalis), and they have been observed eating Douglas-fir tussock moth larvae (Orgyia pseudotsugata). Hymenopterans, mostly wasps and ants constituted 75% of insects in western tanager stomachs in August. The other insects were beetles (Coleoptera, 12%), mainly click beetles (Elateridae) and woodborers (Bupestridae), true bugs (Hemipterans, 8%), grasshoppers (Orthoptera, 4%) and caterpillars (Lepidoptera, 2%).