Cedar Waxwings and many other bird species are sustained by the berries of the Winterberry Holly during the colder months. Photo: <a href="https://www.lilibirds.com/" target="_blank" >David Speiser</a>
Cedar Waxwings and many other bird species are sustained by the berries of the Winterberry Holly during the colder months. Photo: David Speiser

Plants for Birds

Birds, like people, have a few basic needs that must be met in order for them to survive, and thrive: 
  • Food
  • Shelter
  • Safe places to raise young
  • Safe passage during migration
In New York City, we can help provide all these things by enriching the landscape for birds. In our highly managed greenspaces, which plant species we choose to include can have a strong impact on the health and diversity of our land bird population, and on our ecosystem in general. 
 
Some birds, like the Northern Cardinal and Red-bellied Woodpecker, are year-round residents in our parks. Others, like the Blackburnian Warbler or Acadian Flycatcher, just stop through during migration. Some migrants, such as the Baltimore Oriole or Blue-gray Gnatcatcher, stay to nest in New York City’s larger parks. And some species that breed far north of us, like the White-throated Sparrow and Golden-crowned Kinglet, come south to spend the winter here. But all these birds can benefit from the planting choices we make in our city’s public and private greenspaces. Plants provide sustenance and rest during migration; nesting sites and protein-rich food for their chicks in the breeding season; and shelter and a fat-rich diet to make it through the cold winter. And by planting for birds, we also enrich our habitat for pollinating insects and many other kinds of wildlife.
The Advantages of Native Plants
In recent decades, research by scientists such as entomologist Doug Tallamy has demonstrated how important it is that we choose the right plants for our parks and gardens. Native plants, meaning plant species that have grown in our area for millions of years and have co-evolved with our birds and other wildlife, provide the richest habitat for birds, year-round. To a large extent, the advantage of native plants for our birds is related to food: native plants provide richer, and more abundant, nourishment for birds throughout their life cycle. 
 
What food do birds get from native plants? Native plants provide fruit, nuts, and seeds; nectar; and insects
 

A Blue Jay with an acorn. Photo: Douglas Tallamy
A Blue Jay with an acorn. Photo: Douglas Tallamy
Fruit, Seeds, and Nuts
While many plant species, both native and non-native, provide fruit and nuts for birds, research has shown that native plants tend to provide the higher-fat-content fruit that our birds need to fuel their long migration flights. The red berries of our native Spicebush, for example, are about 50 percent fat1. Long distance migrants like thrushes and tanagers need that high-calorie diet to sustain their migration—while fruit-bearing shrubs like Winterberry Holly and Northern Bayberry sustain birds through the winter. 

Trees such as oaks, hickories, and pines feed birds through the year with their rich nuts. And native grasses such as Bushy Bluestem, and wildflowers like goldenrods, produce countless seeds that nourish birds through the winter. 
 

A male Ruby-throated Hummingbird perched among native Coral Honeysuckle flowers. Photo: Will Stuart
A male Ruby-throated Hummingbird perched among native Coral Honeysuckle flowers. Photo: Will Stuart
Nectar
In the late summer, NYC birders know to head for patches of blooming Cardinal Flower and Jewelweed (a.k.a. Spotted Touch-Me-Not) in our parks. Hungry, migrating Ruby-throated Hummingbirds are sure to show up there to sip the plants’ rich nectar. In recent years, observant birders have also discovered hummingbirds nesting in the Jamaica Bay Wildlife Refuge —where the tiny, feisty birds are likely sustained by the pendulous, orange-red blooms of native Trumpet Creeper. Native flowers bloom at just the right times for migrating and breeding hummingbirds.
Carolina-Chickadee_Douglas-Tallamy.jpg” caption = “A Carolina Chickadee delivers a caterpillar to its young. Photo: Douglas Tallamy
Carolina-Chickadee_Douglas-Tallamy.jpg” caption = “A Carolina Chickadee delivers a caterpillar to its young. Photo: Douglas Tallamy
Insects
In urban and suburban areas of the U.S., it is estimated that approximately 80 percent of plantings are non-native species. Many of these plant species were chosen precisely for a quality that makes them care-free for gardeners, but poor food sources for native birds: non-native plants often have leaves that are inedible to our native insects. Most native insects can only eat native plants, with which they have evolved over millions of years. 
 
The difference between native and non-native plants in this regard can be stark: Doug Tallamy’s research has shown that native oak trees support more than 550 different species of butterfly and moth caterpillars. The non-native Ginkgo tree? Just 5 species. More than a 100-fold difference! And as it turns out, that 100-fold difference in bugs is of huge importance to birds.
 

A Wood Thrush feeds insects to its nestlings. Photo: Douglas Tallamy
A Wood Thrush feeds insects to its nestlings. Photo: Douglas Tallamy
Both Adult and Baby Birds Eat Bugs
While a landscape of non-native “pest-free” plants like the Ginkgo may be attractive to gardeners, it can be a food-free landscape for birds. Many migrating songbirds and flycatchers eat insects, and if they don’t find adequate food on their long and energy-intensive journeys, they may not survive. (Migrating warblers, tanagers, and orioles that flock to our parks’ oak trees in the spring are not eating acorns! They are eating countless caterpillars and other insects, too small for us to see.) Just as critically, 96 percent of North American land bird species feed insects to their chicks. 
 
This is the case for all sorts of birds: from Scarlet Tanagers to Northern Cardinals to Ruby-throated Hummingbirds to American Kestrels! Though as adults, some of these birds may primarily eat seeds or nectar, as growing nestlings, they require the protein provided by insects. Caterpillars, in particular, are the go-to “baby bird food”: in the 16 days between hatching and fledging, a clutch of Carolina Chickadee chicks can down more than 9,000 of them. If we consider again that a native oak may host 500 caterpillar species vs. 5 for the non-native Ginkgo, we can see how important native plants are to birds, and to all wildlife.
 

A landscape rich with native plants. Photo: Douglas Tallamy
A landscape rich with native plants. Photo: Douglas Tallamy
Restoring Our Landscape for Birds
Many of our city’s parks are dominated by invasive, non-native plant species. The current understanding of the importance of native plants to birds provides a clear path of action for those who want to help birds. More native plants equals more native birds. Tallamy's research has confirmed that native landscaping can be a simple and powerful tool in increasing bird diversity and abundance: In a study of suburban properties in southeast Pennsylvania, for example, eight times more Wood Thrushes, Eastern Towhees, Veeries, and Scarlet Tanagers (all species of conservation concern) were found in yards with native plantings as compared with yards landscaped with typical non-native ornamentals. 

Thanks to New York City’s Local Law 11, passed in 2013 by the City Council, only native species may be planted in park zones designated as “natural areas” (about one-third of NYC Parks-managed lands), and the incorporation of native plants in other areas is encouraged. A walk through any large park in the City today will reveal native plantings, and regular efforts are made to remove invasive species. The restoration of large tracts of New York City land does not come cheaply, however, and long-term maintenance is often not taken into account in restoration planning. In order to be successful, restoration projects require long-term funding that includes explicit post-project monitoring and maintenance. It’s important that parks management understand that well-maintained, bird-friendly native plant habitats are important to the public. 
How You Can Plant for Birds
Choosing bird-friendly native plants for your community garden, yard, terrace, or even your window box can provide host plants for butterflies and moths, and enrich the environment for birds. A number of excellent, locally created resources are available to provide native plant suggestions and guidance on creating a native plant habitat for birds. 

Entomologist Doug Tallamy’s research has been behind much of our current understanding of how important native plants are for birds, and why. He has published several excellent books, below. You can also find more information about his research and publications on his Bringing Nature Home website. 

Citations
1)    Smith, S.B, DeSando, S.A., and Pagano, T. 2013. The Value of Native and Invasive Fruit-Bearing Shrubs for Migrating Songbirds. Northeastern Naturalist 20(1):171-184.

Citations:

1)    Smith, S.B, DeSando, S.A., and Pagano, T. 2013. The Value of Native and Invasive Fruit-Bearing Shrubs for Migrating Songbirds. Northeastern Naturalist 20(1):171-184.