Baby birds can't eat seeds and berries. They need caterpillars and other soft insects. Caterpillars and other insects need native plants. They are not adapted to live on plants imported from Europe and Asia, or even other parts of the US. In other words, birds need insects, and insects need native plants.
Grow native plants. Avoid pesticides and leaf blowers.
Grow native plants. Avoid pesticides and leaf blowers.