Book review from Nance Greenberg: Planting Native to Attract Birds to Your Yard by Sharon Sorenson
A few years ago, Sorenson decided to do a “full-year bird count”. Rather than focusing exclusively on birds that visited her feeders, she spent a lot of time outdoors recording the species she observed (or heard) each week on her three acres of property. What she learned was very interesting:
She counted 114 species of birds but only 29 of them (about one-quarter) visited her feeders
Of the 114 species, 76 were migrating through the area, with a need for high-protein nutrition in spring (i.e., insects) and fats in the fall
Year-round residents were typically raising nestlings, who eat insects rather than seeds
She realized that there is more to attracting birds than simply putting out feeders and feed. Birds utilize plants not only for food but also for shelter, nesting sites, nest materials, safety from predators, and more. Each type of bird she observed needed a particular habitat: the right plantings plus a source of water. She concluded that the more diversified the plantings in a garden, the more species will come to make use of it.
For sure, we should add plants that provide food in the form of berries, seed, fruit and nectar. But the most vital nutrient for birds (just like humans) is protein. Plants cannot provide protein directly. Instead, animals must create it. For us humans, protein comes from cows and sheep munching on grass. For birds, insects provide the equivalent transformation, turning leaves into caterpillars, butterflies, beetles, etc.
Some 96% of songbirds feed their babies bugs (the exceptions being Mourning Doves and American Goldfinches). Experts have found that one brood of babies needs 300 caterpillars per day, so that if the average couple feed two broods over a typical nesting period, that adds up to 8,000 caterpillars! Adult birds also eat bugs during breeding season.
Why native? Turns out that 90% of bugs are plant-specific, breeding and feeding on sometimes a single native plant species. Often non-native plants contain toxins that kill bugs (which is why we buy them in the first place). Native berries, especially in the fall, have more fat content for migrating birds. Native evergreens such as hemlock, pine, cedar, fir and juniper (with American Holly being the best) provide shelter from predators and winter weather.
In Chapter 3 she answers our questions about native plants. A few of them:
What to do when we’re all starting with gardens full of non-natives, including “heritage” plants from relatives and friends? (One answer: reduce that lawn!)
Won’t the garden be too messy? (“Native” does not mean “untended”!)
Aren’t non-natives harmless?
Early leaf-out of non-natives can cause cardinals to establish their territories too early, making them an easy target for predators
Early leaf-out shades out (thus killing off) native plants
Berries low in fat and protein cause poor health and less colorful plumage, making birds less attractive to potential mates
Some non-native berries are actually poisonous (e.g. Nandina berries which kill Cedar Waxwings)
Some non-natives can actually poison the soil around them
Lawn is non-native and may even be toxic to birds if maintained by a lawn service
What type of native to buy?
The straight species from your general region of the country is best
A “cultivar” (sometimes termed “nativar”) is produced by cloning, meaning it has no genetic diversity; sometimes its bird-friendly characteristics have even been bred out
Avoid man-made hybrids – often they don’t produce nectar or seed
Chapter 4 describes how to add natives to an existing garden. Sorenson suggests we start with an inventory of what’s already there, pointing out that many gardens have been invaded by a “Dirty Dozen” of non-natives that should be eliminated immediately. The inventory identifies what is missing, such as shelter or nest materials. Finally, water must be available (and ice-free) all year round. This is a difficult one, but it appears that a neighbor’s pond or stream could suffice.
Chapters 5, 6 and 7 provide descriptions of native trees, shrubs and perennials along with their growing requirements. It’s best to plant shrubs and perennials in masses so that birds can spot their blooms from above. She notes that shrubs are good for small lots, providing nest space, shelter and roosting in winter.
Additional chapters detail how to add water sources, how to eradicate invasives, how to sort through misleading plant labels, and more.