Native plants provide birds with more insects, berries and fruit than nonnative plants.
Carolina Chickadee parents have a problem. To successfully rear a brood of five younglings they need to find 6,000 to 9,000 caterpillars in one breeding season (April to early June) to feed their hungry offspring! If you think that is easy, I challenge you to go outside and see how many caterpillars you can pick off the plants in your yard right now. For proper motivation play sounds of hungry baby birds cheeping as you search: Chickadee baby birds feeding.
The large volume of food needed to raise babies means that finding the right nesting area is critical. Over 90% of the food needed are athropods - mostly Lepidoptera larvae (butterfly caterpillars), Hemiptera (true bugs like leafhoppers and aphids), and Araneae (spiders).
Narango et al. 2017 found that native plants hosted more caterpillars than exotic plants. For this study, researchers methodically searched foliage and stems of selected plants to count and collect all the caterpillars. Plants were catalogued as native or non-native. In addition, birds were banded and the plants they foraged on were recorded.
Researchers found that chickadees preferred to search for food in the native plants. Most likely because they get a better return rate of juicy caterpillars and other tasty insects! In non-native trees, searching researchers would find one caterpillar or less. In native trees; such as oak, maple, wild cherry or plums; researchers might find 20 caterpillars or more in five minutes.
Take Home Message
If you want to attract songbirds to your yard plant native trees like oaks, cherries, elms, and maple. Chickadees were more likely to breed in yards with more native plants and tree cover. The researchers noted that the plants and trees that attracted chickadees were also covered in other songbirds including warblers, tanagers, and orioles.
Desiree L. Narango, Douglas W. Tallamy, Peter P. Marra. Native plants improve breeding and foraging habitat for an insectivorous bird, Biological Conservation, Volume 213, Part A, 2017, Pages 42-50, ISSN 0006-3207, https://doi.org/10.1016/j.biocon.2017.06.029. (https://www.sciencedirect.com/science/article/pii/S0006320717305153)