Doug Tallamy, Desiree Narango and Peter Marra* have provided more definitive data about the importance of native trees and shrubs for the livelihood of insect-eating birds. In this case, their research focused primarily on the Caroline Chickadee (Poecile carolinensis). In their report Nonnative plants reduce population growth of an insectivorous bird printed in Proceedings of the National Academy of Sciences of the USA (PNAS) Doug and his team concluded:

“We monitored reproduction and survival of Carolina chickadees within residential yards and found that when nonnative plants increased, both insect availability and chickadee population growth declined. We also found that populations could only be sustained if nonnative plants constituted <30% of plant biomass. Our results demonstrate that nonnative plants reduce habitat quality for insectivorous birds and restoration of human-dominated areas should prioritize native plants to support local food webs.” (PNAS) [Read more…]