Many people look forward to the return of songbirds to their yards in Spring. Hearing chickadees, wrens, cardinals, phoebes, and many other birds sing is a cheerful reminder that the grip of winter is loosening. Unfortunately, two recent studies have shown that songbird populations have been declining over the last decade. Research conducted by Doug Tallamy, a professor of Entomology at the University of Delaware, has drawn a clear connection between the bird population decline and recent popular landscaping practices. If you want to support birds in your own yard, it’s helpful to understand that connection and then make your own landscaping choices accordingly.
In Dr. Tallamy’s book, Bringing Nature Home: How to Sustain Wildlife with Native Plants, he explains that if you don’t have native plants in your landscape, you can’t have baby birds in your landscape. Why?
While some adult songbirds can eat seeds, 96% of terrestrial birds feed their young caterpillars, spiders and other soft bodied bugs (Peterson). It’s the only food these baby birds can eat.
Caterpillars are plant eating (herbivores) and they have co-evolved over thousands of years to eat native plant foliage. For example, caterpillar mouth parts and digestive systems have evolved to work with particular native plants called ‘host’ plants. No native plants means no caterpillars which means your yard is a protein desert for baby birds.
Bird parents work extremely hard when they have nestlings and any excess energy use can be detrimental. Adult chickadees need 350 to 570 caterpillars per day to feed an average clutch of nestlings. All of this food needs to be within 160 feet of the nest because over the 16 day period until fledging, they are delivering those caterpillars in up to 150 feedings a day.
So if you would like to support birds and give them a chance to bring up young in your landscape, here are three easy steps you can take include:
-Plant native plants. There are hundreds of beautiful trees, shrubs, and herbaceous plants to choose from in Central Virginia so if you want a rank ordered list based on the number of butterfly and moth species (and therefore, caterpillars) they each support visit www.nwf.org/NativePlantFinder and enter your zip code. For example, native oak trees are a host plant for over 500 different species of butterfly and moth caterpillars while a blueberry bush supports 250. Non-native plants host zero.
-Reduce the size of your lawn. Large swathes of lawn create long commutes for parent birds as pure grass is a non-native monoculture that doesn’t provide any food. As a bonus the more native trees and shrubs you introduce into your landscape, the less mowing you will need to do this summer.
-Don’t spray pesticides. Poisoning caterpillars and other soft bodied insects means you are reducing the food supply and may be introducing toxins to young birds through their diet. Another positive of not using pesticides is that any butterfly caterpillars that aren’t used for lunch or dinner will eventually increase your gardens’ butterfly population.
For more ways to support birds in your home landscape download the National Wildlife Federation’s Garden Certification Walk-through Checklist located at www.nwf.org/certify. Whether you choose to apply for certification or not, the free checklist lets you review your own landscape.
The U.S. Census Bureau states that the vast majority of land in the lower 48 States is privately held. For the land east of the Mississippi, that private ownership number is 85.6%. Therefore, saving our songbirds and allowing them to successfully raise their young can’t just be done through public parks. Homeowners will need to help. And, of course, by helping birds you’ll be helping yourself to a Spring serenade.
Cathy McCarthy is a certified Master Gardener through the Virginia Cooperative Extension and a member of the Goochland Powhatan Master Gardener Association. If you are interested in learning more about GPMGA programs or how to become a master gardener volunteer please visit gpmga.org.