Help Swallows, Nighthawks, and Flycatchers by Creating an Insect Buffet

Birds that swoop or dart to catch bugs in flight are called aerial insectivores—and they need your help.

By Robyn Bailey, Becca Rodomsky-Bish, and Holly Grant; Illustrations by Vera Ting

May 1, 2024

Illustration of birds flying with insects. — Tree Swallows chase mayflies. *Illustration by Vera Ting / Bartels Science Illustrator 2023.*

This article is adapted from a PDF brochure created by NestWatch. Download the original PDF to print out your own copy or share with others.

Graceful. Colorful. Helpful. You may have seen them in flight, swooping up, down, and all around, on the hunt for their insect prey. Then again, maybe not. Some are nocturnal. Camouflaged. Elusive.

But they all have one thing in common: birds that gulp down insects while flying—whether it’s dawn, dusk, day, or night—are known as aerial insectivores. In North America, this group includes species in the swallow and martin, swift, nightjar, and flycatcher families.

Unfortunately, many aerial insectivore populations have been steeply declining since the 1980s—as have insect populations. So how can we help bring these agile fliers back to our yards, farms, cities, and wild spaces?

Help Insects by Providing Healthy Habitat

Illustration of a shiny blue and white bird flying over flowery field with another blue and white bird perched on a nest box. — Letting open spaces grow up with long grasses and wildflowers creates habitat for flying insects. *Tree Swallow scene by Vera Ting / Bartels Science Illustrator 2023.*

Aerial insectivores eat flying insects as their primary food source year-round. If you have a yard, patio, or outdoor space that you manage, chances are you’re sharing your habitat with both insects and aerial insectivores. The choices you make matter for them. Try these suggestions to improve habitat for nature’s bug-zappers.

Let Grasses Grow Longer

Grasses and wildflowers can provide excellent habitat for insects—especially if allowed to grow longer and wilder than a typical lawn. Meadows provide important habitat for a diversity of insects and safe cover for ground-nesting birds. If you can control the mowing schedule for where you live:

reduce mowing as much as possible to keep insects and nesting birds safer
leave grass at least 3 inches tall so other plants retain their flowers and support pollinators
for large grassy areas, try to avoid mowing during the nesting season for your region (USDA Farm Service Agency)
try to reduce the overall area of grass in your lawn
leave buffer strips or areas with longer grass along lawn edges

Illustration of a brown and white bird with long, slender, pointed wings and a large eye, flies above flowery fields in the evening light — You’ll often find Common Nighthawks near wetlands, where they forage at dawn and dusk for aerial insects. Nighthawks nest in both rural and urban habitats.Illustration by Vera Ting / Bartels Science Illustrator 2023.

Focus On Water Resources

Insects tend to congregate over bodies of water. These irreplaceable “nutrient hotspots” need protection from disturbances like urbanization, agricultural pesticides, and fertilizers. If you have a backyard or farm pond, don’t mow right up to the edge; leave a vegetation buffer around it to provide places for insects to feed, rest, and lay eggs. This will also attract aerial insectivores that may nest nearby.

Cater to Their Needs With Native Plants

Native plants are those that have been growing in your region for thousands of years. Evidence shows that native plants support more insects than non-native or exotic species. Plant-finder tools from Pollinator Partnership and Lady Bird Johnson Wildflower Center will help you determine which plants are native to your region and which can increase your property’s value to birds, insects, and other wildlife.

Save Insects—Avoid Pesticides

Applying broad-spectrum pesticides can harm birds that eat insects, killing many kinds beyond the target species. With fewer insects buzzing through the air, there’s less food to support healthy aerial insectivore populations.

encourage insects in your spheres of influence: turn off the bug zapper and put down the insecticide sprayer
control garden pests by applying soapy water directly to affected plants
use protective clothing and bug spray to keep insects from bothering you, while letting them fly elsewhere

Be Climate Smart

Heat and drought can impair hatching and fledging success of nesting birds. Research shows that aquatic and terrestrial insects are emerging earlier as early spring temperatures get warmer. Some bird species are trying to keep up by nesting earlier, but constraints on the other parts of their life cycle (e.g., migration, replenishing energy reserves) limit just how well they can match the changing pace of insect activity. Using clean energy, lowering your carbon footprint, and supporting policies that help reduce greenhouse gas emissions may delay climate warming.

Give Birds Places to Nest

Helping insects thrive is largely a matter of reducing pesticides and providing vegetation—but birds need dedicated nest sites. Aerial insectivores nest in remarkably diverse locations—in tree hollows and nest boxes, on homes and buildings, on the ground, high on gravel rooftops, in sandy burrows, under bridges and eaves, and in chimneys, for instance. Though these sites can sometimes be inconvenient, tolerating or encouraging them can be a big factor in helping populations recover.

Make Room for Nesting Activities

Three brown fledglings with very long wings cling to a brick wall near their nest. — Chimney Swifts typically nest in urban masonry chimneys as a replacement for large, hollow trees. The noise they create can prompt some homeowners to block the chimneys—but it’s temporary and tolerable. Chimney Swift nestlings take just 14–19 days to fledge. *Photo by Adair Bock / Macaulay Library.*

Offer Them Nest Boxes and Other Nest Sites

For some aerial insectivores, making room for their nesting activities for a few weeks each year may be enough. But for other species, you may need to create new nest sites.

For Tree Swallows and Violet-green Swallows: provide nest boxes in open areas like yards and fields
For Barn Swallows: place a nesting shelf just underneath the eaves of a home, garage, or other building
For Purple Martins: these large swallows rely on actively managed “martin houses” provided by dedicated, passionate people known as Purple Martin landlords
For Common Nighthawks: a flat gravel rooftop is a satisfactory place to nest, while smooth-surfaced rooftops are unsuitable. Maintaining stone rooftops with pea gravel can support more urban Common Nighthawks, and females will return to these sites year after year
Make nest boxes safer by using free-standing poles and attaching predator guards
Leave dead trees standing when possible, as these make desirable natural nest sites.
Download nest box plans for swallows, martins, and many other species via NestWatch’s Right Bird, Right House tool.

Tips for Attracting 9 Kinds of Aerial Insectivores

Tree Swallow

Tachycineta bicolor

Habitat: grassland, lake, marsh, shore

Breeding Range: northern North America

Diet: dragonflies, damselflies, flies, mayflies, caddisflies, true bugs, bees, ants, wasps, beetles, butterflies, moths, spiders.

Nesting period: mid-May to July

Download a nest box plan
Violet-green Swallow

Tachycineta thalassina

Habitat: grassland, lake, marsh, shore, mountain, open woodland

Breeding Range: western North America

Diet: flies, leafhoppers, leafbugs, aphids, flying ants.

Nesting period: mid-May to August

Download a nest box plan
Barn Swallow

Hirundo rustica

Habitat: grassland, lake, shore, town

Breeding Range: near-global distribution

Diet: mainly flies, also beetles, bees, wasps, ants, butterflies, moths

Nesting period: early May to August

Download a nest box plan
Purple Martin

Progne subis

Habitat: desert, town, lake

Breeding Range: North America

Diet: beetles, flies, dragonflies, leafhoppers, grasshoppers, crickets, butterflies, moths, wasps, bees, caddisflies, spiders, cicadas, termites, mayflies.

Nesting period: early April to August

Download a nest box plan
Common Nighthawk

Chordeiles minor

Habitat: grassland, forest, open woodland, town, lake, shore

Breeding Range: North America, parts of Central America

Diet: queen ants, wasps, beetles, caddisflies, moths, mosquitoes, bugs, mayflies, flies, crickets, grasshoppers

Nesting period: late May to August

May nest on the ground or gravel rooftops
Lesser Nighthawk

Chordeiles acutipennis

Habitat: desert, grassland, open woodland, town, lake, shore

Breeding Range: southwestern North America, parts of Central and South America

Diet: flies, mosquitoes, moths, June bugs, leafhoppers

Nesting period: mid-April to August

May nest on the ground or gravel rooftops
Great Crested Flycatcher

Myiarchus crinitus

Habitat: woodlands, particularly with deciduous trees

Breeding Range: eastern North America

Diet: insects and other invertebrates, small berries, and other fruits

Nesting period: May through July

Download a nest box plan
Say’s Phoebe

Sayornis saya

Habitat: open country, sagebrush, badlands, dry barren foothills, canyons, and borders of deserts

Breeding Range: western North America

Diet: insects such as beetles, grasshoppers, crickets, flies, and bees

Nesting period: Mid-April to August

Download a nest box plan
Little brown bat

Myotis lucifugus

Habitat: Open or wooded areas near water; maternity colonies are in attics, bat houses, other human structures, and sometimes hollow trees

Breeding Range: North America

Diet: mosquitoes, midges, caddisflies, moths, hoppers, small beetles, and spiders

Maternity season: pups are born May to June and nurse for 2+ months

Bat house plans