Nonnative plants reduce population growth of an insectivorous bird

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 115; no. 45; pp. 11549 - 11554
• Main Authors: Narango, Desirée L., Tallamy, Douglas W., Marra, Peter P.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 06-11-2018
• Subjects: Animal populations; Biological Sciences; Birds; Breeding success; Consumers; Ecosystems; Flowers & plants; Food chains; Food resources; Food webs; Habitats; Historical account; Indigenous plants; Indigenous species; Insects; Introduced species; Landscape; Nonnative species; Plant biomass; Plant communities; Plant populations; Plants (botany); Population growth; Prey; Reproduction; Sustainability; Urban areas; Urban populations; Wildlife; Wildlife habitats; food webs; conservation; native plants; plant–animal interactions; urban ecology
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1809259115

Human-dominated landscapes represent one of the most rapidly expanding and least-understood ecosystems on earth. Yet, we know little about which features in these landscapes promote sustainable wildlife populations. Historically, in urban areas, landowners have converted native plant communities into habitats dominated by nonnative species that are not susceptible to pest damage and require little maintenance. However, nonnative plants are also poor at supporting insects that are critical food resources for higher order consumers. Despite the logical connection, no study has examined the impact of nonnative plants on subsequent population responses of vertebrate consumers. Here, we demonstrate that residential yards dominated by nonnative plants have lower arthropod abundance, forcing resident Carolina chickadees (Poecile carolinensis) to switch diets to less preferred prey and produce fewer young, or forgo reproduction in nonnative sites altogether. This leads to lower reproductive success and unsustainable population growth in these yards compared with those with >70% native plant biomass. Our results reveal that properties landscaped with nonnative plants function as population sinks for insectivorous birds. To promote sustainable food webs, urban planners and private landowners should prioritize native plant species.