The latest I and the Bird is up at The Birdchaser’s place, and one post really jumped out at me, from Audubon Birdscapes:
Impact of Native Plants on Bird and Butterfly Biodiversity in Suburban Landscapes.
The post in question shares notice of a paper of the same title in the Feb. 2009 issue of the journal Conservation Biology. The abstract (emphasis mine):
Managed landscapes in which non-native ornamental plants are favored over native vegetation now dominate the United States, particularly east of the Mississippi River. We measured how landscaping with native plants affects the avian and lepidopteran communities on 6 pairs of suburban properties in southeastern Pennsylvania. One property in each pair was landscaped entirely with native plants and the other exhibited a more conventional suburban mixture of plants—a native canopy with non-native groundcover and shrubs. Vegetation sampling confirmed that total plant cover and plant diversity did not differ between treatments, but non-native plant cover was greater on the conventional sites and native plant cover was greater on the native sites. Several avian (abundance, species richness, biomass, and breeding-bird abundance) and larval lepidopteran (abundance and species richness) community parameters were measured from June 2006 to August 2006. Native properties supported significantly more caterpillars and caterpillar species and significantly greater bird abundance, diversity, species richness, biomass, and breeding pairs of native species. Of particular importance is that bird species of regional conservation concern were 8 times more abundant and significantly more diverse on native properties. In our study area, native landscaping positively influenced the avian and lepidopteran carrying capacity of suburbia and provided a mechanism for reducing biodiversity losses in human-dominated landscapes.
IOW, more native plants=more bugs=more birds in your yard — 8 times more for bird species that aren’t doing so well regionally. This probably applies to landscaping outside of SE Pennsylvania just as much.