Scientists are finding proof that even small habitats can make a big difference. An entomology professor found his 10 acres overrun with non-native and invasive plants. He also noticed that there was never any leaf damage to these plants. So he started experimenting to see what birds and bugs would eat. 96% of birds in North America raise their young on insects, mostly caterpillars. His research on one species of chickadee found that it takes 390 to 570 caterpillars a day to feed 4 to 6 baby chickadees for the 16 days between hatching and fledging. And that adult chickadee forages only about 175 feet from the nest. So I guess "Location, location, location" is a common mantra in chickadee real estate, too. He created a ranking system for plants and trees that host moth and butterfly larvae - number one was oak trees, second was cherry and plum, third was willow. Your trees and shrubs and flowering plants are like bird food factories that ship caterpillars in bulk and deliver fruits and seeds that fuel bird migrations.
So a student set out to compare locales for these birds. She found that the classic suburban yard (weedless grass, 1 or 2 shade trees, non-native foundation plantings) was like a "foreclosed fixer-upper in a bad neighborhood." The properties with native and naturally-occuring plants and less lawn were hosting eight times more birds with better restaurants and accommodations. Another study looked at the fat and energy content of native and non-native fruits that birds eat. The study showed that the birds preferred the native plant fruits which had a much higher fat and energy content than the non-native plants.
But what I really keep going back to is that mama chickadee trying to find 9000 caterpillars in 16 days to feed her hungry, growing brood. I want to be part of that process! I guess I will be out there this fall scouring nurseries for new native plants to enhance the neighborhood...
(Doug Tallamy, the entomologist, wrote a book titled Bringing Nature Home, which I will also have to look up as soon as I can get the fall cleanup under control...)