What do birds eat? A trophic and taxonomic analysis of breeding bird diets in North America based on citizen scientist images

Bird populations are declining throughout North America, especially among Neotropical migrants and grassland birds.  Poor habitat quality is one cause of such declines. Because 96% of all terrestrial bird species rear young on insects, we can restore breeding habitats by planting the plants that produce the insects birds prefer. Here we report data from a citizen science project to identify which insects bird species feed young. Data were produce from 1300 images taken by bird photographers throughout the U.S.  Most bird guilds rear young on insect herbivores, primarily smooth skinned caterpillars.