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| Chestnut-backed Chickadee Photo by Christine Southwick |
By Christine Southwick
Our backyard birds evolved using the canopies of trees. Their feet are made for perching on tree limbs, landing and sleeping on branches, finding bugs on leaves, or for launching from tree perches. Indeed, these birds form the world’s largest group of birds, called Passerines, or perching birds.
Sure trees give birds places to rest, raise their young, and find food, but why do we need tree canopy in our neighborhoods? What exactly is tree canopy anyway?
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| Varied Thrush, female, February 2011 Photo by Christine Southwick |
Tree canopy is the layers of leaves/needles, branches, and stems of trees that cover the ground when viewed from above. Tree canopy is not only pretty, it is functional. Tree canopy delays rainwater from reaching the ground during storms, thus slowing runoff. This allows sediments to settle and stay out of our creeks and lakes; and reduces, sometimes even prevents, flooding. Tree leaves/needles also filter our air, making the air cleaner and healthier for us to breath. In the summer tree canopy helps keep houses and roads from over-heating, and in the winter helps keep these areas warmer. Studies have even found that cities with more tree canopy are safer places to live.
Evergreens, like our Western Cedars, Douglas Firs, Yews, and all those pines and spruces provide year-round filtering protection for the birds and for us. A sentinel force, if you will. Evergreens are long-lived, grow tall, offer multi-layered canopy per tree, and increase the value of your property, and the neighborhood’s.
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| Band-tailed Pigeon Photo by Christine Southwick |
Dark-eyed Juncos, Varied Thrushes, and Townsend’s Warblers huddle under/in evergreen branches during snows, ice storms, and cold windy weather. Anna’s Hummingbirds often build their nests under an overhanging evergreen branch before deciduous trees leaf.
Many birds depend on evergreens: Chestnut-backed Chickadees need, and are found in, yards and forests with evergreens. Downy, Hairy, and Pileated woodpeckers find their food in the bark of evergreens—their bills and tongues have evolved to access specific bugs, and excavate their nests. Red-breasted Sapsuckers drill sap-wells in evergreens for year-round feeding. Red-breasted Nuthatches and Brown Creepers are also evergreen aficionados. Merlins and Band-tailed Pigeons need tall evergreens for their roosts and their nests—lack of these large trees is one reason for the decline of our native Band-tailed Pigeon.
Deciduous tree canopy, especially from fruiting trees, is certainly valuable to birds, and our own sense of completeness; but it is the evergreens that work year-round protecting our environment and those who live here. Maybe that’s why Washington is, “The Evergreen State”.
Christine Southwick is on the Board of the Puget Sound Bird Observatory and is their Winter Urban Color-banding Project Manager. She is a National Wildlife Federation Certified Wildlife Habitat Steward, having completed their forty hour class. We're happy that she is sharing her expertise with us about the birds in our backyards.
This excellent article directly relates to the current discussion taking place at te Shoreline City council regarding the importance of deciduous and conifers. I hope council members read this!
ReplyDeleteChris,
ReplyDeleteYou are a treasure! What an outstanding article. And thanks for all your work to educate us about birds and wildlife!
In the 15 years we have lived in our Shoreline home we have seen a huge loss of nearby tree canopy, especially conifers. Only a few of them were hazard trees, often they were viewed as "messy" or blocking sunlight. Shoreline City Council should work hard to promote educating the public about our trees (thinning a conifer vs removal, for example). After all, isn't that the reason many of us moved to Shoreline in the first place?
ReplyDeleteThank you so much for discussing the multidimensional aspects of our canopy. I have recently come to realize that too many actually think of it only in terms of the color green on a flat page like the simple square foot coverage of circle.
ReplyDeleteIn reality, it is a dynamic, living system that has height, width and depth; reaching up, out, down while engaging in ongoing interactions with the insects, birds, soil biota, and the weather.
How we think about our canopy will determine how we treat it. Thanks for helping us think about it as the "sentinel" it truly is.
Christine, can you write about how one can become a National Wildlife Federation Certified Wildlife Habitat Steward?
ReplyDeleteBetter yet, contact the Wa state Fish & Wildlife Backyard Certification program. National Wildlife Federation is currently embroiled in a controversial alliance with Scott's Miracle Gro.
ReplyDelete