Sustaining Songbirds with Native Plants
Importance of Native Plants
Biologically speaking, plants are classified as producers - absorbing energy from the Sun and converting that energy into biomass (mostly sugars) that consumers (insects and animals) in turn utilize to fuel their own energy needs. Plants the world over act as the very foundation of their respective ecosystems. Without the plants that are native to a respective region, the ecosystem ceases to function. This is the problem we are currently facing on a global scale; foreign species from continents oceans away have been so heavily utilized in the ornamental horticultural industry that they are completely dismantling local ecosystems. While human development and agriculture are the leading causes of habitat loss, the effect is compounded when humans follow up that destruction by replacing the flora that once existed with these foreign species. This is because the primary consumers of plants are insects who have evolved for millenia with their respective host plant species and are unable to feed off of this exotic flora.
How does this affect songbirds, you might ask? As adults, songbirds feed on a variety of food sources including insects, berries, fruit, nuts, and seeds. The problem arises during nesting season, during which time all songbirds (save a few varieties such as Doves) feed their chicks a diet exclusively of insects. These creatures are highly nutritious, being high in protein and fats which are required to fuel the quick growth and development of songbird chicks in order to successfully grow and leave the nest. The most sought after food item during this time happens to be the soft-bodied larvae of butterflies and moths who tend to be extremely host specific to their respective native plants. Without these native host plants, there can be no caterpillars, which often leads to songbird chicks starving within their nests. By making the conscious effort to include native plants in our human-dominated landscapes we are ensuring that the local food-web continues to function as nature intended, allowing for all of the ecosystem services that come along with a healthy ecology.
Native Plants' Function Through the Seasons
While we’ve expressed the crucial role of native plants during the chick-rearing season this is not the only time songbirds rely on these native plants. Throughout the year songbirds and other wildlife rely on the native plant communities they have evolved with for millennia. Even in the earliest days of Spring, before growth has started, you can observe songbirds utilizing last year's growth in their effort to construct their nests for the upcoming breeding season. This is where proper maintenance of your own yard plays an important role for successful nesting. Allowing stalks, stems, blades of grass, seed fibers, etc. from last year’s growth to remain within your garden throughout the spring you are providing songbirds with the literal “building blocks” for their own nests. When we perform “spring cleanups” and dispose of this valuable material, they lose out, and have to spend even more energy searching for these materials. Even material not often thought of as nesting material can be crucial depending on the species, with Ruby-Throated Hummingbirds utilizing Mosses, Lichens, and Spiderwebs to construct their own nests.
Besides feeding off the insects that are hosted by our native plants, many songbirds also utilize the fruit or seeds from our native plants to feed on as adults. This is especially so for migrating species during the late Summer and Fall, who will gorge on native berries, fruit, seed, and nuts on their journey Southward. Berries of Amelanchier, Aronia, Cornus, and more all fuel these migrations while other species like Ilex and Quercus provide food not only for migrants but also sustenance for species that reside locally through the resource-scarce days of the Winter.
Furthermore, our native species provide the shelter and nesting opportunities that are best suited for our native wildlife. The short stature of a Flowering Dogwood, for example, provides the perfect habitat for an American Robin to build a nest, providing the multitudes of “crotches” within its canopy for anchoring a nest, while hosting insects to be fed on through the summer, as well as berries to be feasted on in the Fall. Similarly our native thicket-forming species and brambles offer protection to our native wildlife from predators. Many songbirds will dive into a thorny bramble, such as a Virginia Rose, to escape an overhead Hawk, while rabbits will similarly shelter or nest within these structures as well. I’ve even witnessed my own resident American Robins showing a clear preference for perching within the protection of a native Hawthorn tree, where they can let their guard down and preen themselves within the safety of the characteristically large thorns of the Hawthorn.
Our native trees also play a huge role in the success of our woodland wildlife. Members of the Oak, Cherry, and Willow families have some of the highest insect hosting capabilities available for our region, with Oaks specifically hosting over 520 butterfly and moth species locally. While providing hosting opportunities for insects, they also provide fruit or nuts for wildlife, but also something very special: shelter and a place to raise young. Largely dependent on the success of local Woodpecker populations (which in turn depends on native trees and the insects that feed on them), many of our woodland species are known as cavity-nesters and utilize the abandoned hollows previously excavated by their fellow birds. Many people are hesitant to plant large shade trees, and to allow dead branches or dead trees, known as snags, to persist within our suburbs and cities, yet they are integral to the breeding success of some of our more favorite songbirds such as Chickadees, Wrens, and Nuthatches. Without these trees and the long-term ecosystem services they provide, these songbird species will continue to decline. Always consult an arborist concerning the possibility of safely leaving a snag standing.
Benefits and Detriments of Supplemental Feeding
While I’ve touched on the benefits and necessity of native plants for songbirds, I’d also like to take a moment to discuss the negatives of supplemental bird feeding. It’s ironic that we insist on never feeding most wildlife but are so open and passionate about feeding songbirds. While there may be some short-term benefits for local bird populations who are lacking the proper native plant support required for their actual survival, feeding songbirds is mostly to benefit humans and our continued need to be connected to Nature. I will argue in favor of feeding Songbirds as an introduction to Nature, especially for young children. Sometimes observing wildlife at a close proximity, as with a feeder, is a great way to spark that lifelong interest in Nature and conservation. Unfortunately, like many other nature- or conservation-based activities, bird feeding has been commercialized in what can only be described as another form of “green-washing.”
There are many negatives to supplementing songbirds with “bird seed” that are often not discussed, mostly because the $2.2 Billion a year bird-feeding industry doesn’t want such information to be known. The following detrimental issues are my own reasoning for no longer offering up supplemental food to my own backyard birds.
Communicable Disease: Bird feeders bring many birds (of many species) together in densities not normally found in nature. While Chickadees, Nuthatches, Titmice, and Woodpeckers all form loose mixed-flocks during the winter months, they would not all be feeding from (and coming into contact with) the same feeding apparatus as the myriad of other songbirds that visit our feeders. This creates optimal conditions for the spread of communicable disease from bird flu, and bird lice, to conjunctivitis (as can often be observed in House Finch populations).
Food-borne Illness: many bird feeders create prime conditions for the proliferation of molds, mildews, and bacteria to spread throughout the seed which can seriously injure or kill our local songbirds. Summer heat and humidity, coupled with rain, often lead to moldy seed, unless the proper protection from the elements is taken. Periodic sterilization is always recommended but cannot be done often enough to truly prevent the soiling of these foods/food surfaces as well as prevent the spread of communicable disease, as mentioned above.
Invasive Species: Supplemental bird feeders often support non-native, invasive bird species at a time when lack of natural resources would control their numbers and provide a reprieve from their invasive tendencies. House Sparrows and European Starlings in particular are extremely territorial, often evicting and killing our native songbirds from their own nests or cavities during the breeding season. Similarly, House Finches (native to the southwest) and Pigeons are top spreaders of communicable diseases that in turn can affect our related native Finches and Mourning Doves. Most seed mixes on the market are filled with “filler seed” that are preferred by these non-native species allowing them to proliferate and compounding their negative environmental impacts.
Loss of Habitat: Agriculture is the leading cause of habitat loss around the world. Many people don’t make the connection that “bird seed” is an agricultural crop, with millions of acres of land being destroyed and cultivated just for the purpose of marketing birdseed to homeowners. It stands to reason, that if even half the energy and land devoted to growing bird seed crops was instead set aside to actually provide habitat (and the natural food resources that come with it) we would all be in a better position. We hang and fill bird feeders in our towns and cities to support adult songbirds exclusively, all the while robbing rural birds of the habitat they need for survival. It also helps to remember that farmers don’t like losing crops to pests, and will defend their crops with pesticides, herbicides, as well as lethal controls against the very birds we are trying to protect. Think: when was the last time you purchased an organic bag of bird seed?
Increased Predation: Due again to the unnaturally high densities of songbirds bird feeders and bird feeding stations create, increased predation is also something to consider when feeding songbirds. Many backyard birders become distressed when a Cooper's Hawk finally discovers the smörgåsbord of distracted songbirds squabbling over their bird feeder. This is especially true in winter where it has become an annual occurrence for multiple birds of prey to converge on the suburbs to enjoy the easy pickings offered up at feeders.
Vermin: Mismanaged feeders also come with the added risk of attracting vermin such as non-native rodents like house mice or Norway rats, which in turn come with their own batch of diseases and pests (like fleas) that also negatively affect humans. Being the reason your neighborhood has a rodent problem is never good exposure, especially if you also happen to have a large native garden, which then runs the risk of your neighbors associating your plantings with pests.
A word about suet. Suet is a popular offering for songbirds that enjoy eating insects, nuts, and other high-protein/high-fat foods. Woodpeckers, Chickadees, and Nuthatches will all readily accept suet offered in a feeder or even simply smeared on a tree trunk. Suet is one of the few bird foods offered that is not purposely produced for songbirds being a byproduct of another industry. Suet is simply rendered beef fat, providing a great way to prevent waste from the beef industry. Due to how Suet is produced, and it’s origins as a byproduct of another industry, no land is devoted specifically to producing it and so this is a great option for birders who are looking to provide some food to songbirds. Again, feeder cleanliness is of great importance, and it helps to avoid suet brands that incorporate “fillers” into their suet products like milo, cracked corn, or millet. Try to find plain (or even make it yourself), or opt for varieties that include nuts, fruit, or insects, rather than seeds which will simply attract House Sparrows and European Starlings who directly compete with our native Woodpeckers and other cavity-nesters come spring. The use of a special “cling-type” suet feeder can help dissuade these pest birds, as will upside-down suet feeders that have recently entered the market.
While feeding songbirds has been a beloved pastime and hobby for generations the world over, today’s multitude of environmental crises pose a unique challenge for our songbirds. It is time to truly support our backyard songbirds throughout the year - the way Nature intended - as a long-term solution, rather than a short-term fix. Remove non-native and invasive plant species from your own property and replace them with ecologically appropriate and highly functional native plants that will support your songbirds through the seasons, for years to come. Together, we can all Grow a Better Bird Feeder.
Clockwise from Top-Left: Eastern Bluebird feeding on Rhus ; American Goldfinch feeding on Liatris; Female Blackbird collecting Typha fiber for nesting, Gray Catbird feeding on a caterpillar within Prunus; Tennessee Warbler feeding on Aphids on Asclepias; American Goldfinch feeding on Heliopsis; Black-Capped Chickadee feeding on Rhus; Yellow-Rumped Warbler feeding on Myrica.