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HOSTED BY

The Cambridge Water Department, Biodiversity Builders, Biodiversity for a Livable Climate, The Boston Birding Festival, Earthwise Aware, Green Cambridge, Mystic Charles Pollinator Pathways Group, Native Plant Community Gardeners

The Boston Birding Festival is co-hosting The 2024 Cambridge Moth Ball, a night of moths, community science, and moth photography. And, in addition to moths, we’ll have some extra special guests, entomologist and moth scientist Téa Montanga of the University of Massachusetts and award-winning nature photographer, Billy Hickey, 2024 Artist-in-Residence at Mount Auburn Cemetery in Cambridge, MA.

Get all the details on the 2024 Cambridge Moth Ball and register In advance.

WHy Birders Should Care About Moths

Many of us think of moths as pests. They eat our sweaters, attack our pantries, and destroy our vegetable gardens and crops. We often fight back with toxic chemicals like naphthalene and pesticides.

But while “pest” moths can be destructive and annoying, thousands of other moths are incredibly beneficial, beautiful, and essential to healthy ecosystems. Even “pest” moths can often be managed and diverted.

Moths are in the order Lepidoptera, which includes butterflies—the moth’s glamorous descendants. Like butterflies, moths are shape-shifters and undergo metamorphosis. They hatch from eggs into larvae or caterpillars that spend most of their time eating and growing. When the timing is right, moth caterpillars spin a cozy cocoon, usually underground or in leaf litter, or sometimes attached to the side of a structure, and pupate—a process of reorganizing their bodies before emerging as winged adults. Adult moths typically live only a few days and are focused on mating and egg-laying.. Some never eat anything, others nectar on flowers, especially night blooming flowers.

North America is home to more than 800 butterfly species and 12,000 moth species. In Massachusetts, there are at least 2,800 known moth species. If you take a closer look, we think you’ll be amazed.

Birds need moths for food.

If you want birds in your backyard or your city park, you need to appeal to moths. Birds, as you might guess, eat moth caterpillars—and they eat a lot. Birds consume an estimated 400–500 million tons of insect prey annually—much of that moths.

Many species of adult birds rely heavily on moth caterpillars for food. For warblers, cuckoos, and vireos, moth caterpillars can make up more than half of their diet. But where moths shine is with baby birds. Moth caterpillars make the best baby bird food. They provide an easily acquired, appropriately fatty, protein-rich, easily digestible meal for young birds. Ninety-six percent of North American terrestrial birds are dependent on moth caterpillars. Even seed and fruit-eating birds feed moth larvae to juvenile birds.

According to Doug Tallamy, a professor of entomology and wildlife ecology at the University of Delaware and author of Nature’s Last Hope, a single pair of breeding Carolina Chickadees must find 6,000 to 9,000 caterpillars to rear one clutch of young. Our northeastern birds aren’t any different and the lesson is the same: if you can’t attract caterpillars, you can’t attract many species of nesting birds.

To attract moth caterpillars, you need native plants. Nearly all caterpillar species avoid non-native flora. By planting native species, you help generate caterpillars for birds. If there is enough food available, birds will do the work of maintaining insect populations without the need for any other interventions. If there aren’t enough, birds will pass you over for a fuller buffet and the bugs in your garden will thrive.

Even adult moths make for a tasty treat. Insectivores like swallows, swifts, flycatchers, and nightjars consume vast numbers of adult moths. The Eastern Whippoorwill, a species in sharp decline in our state, has a diet that’s about 60% moth. Common Nighthawks also hunt large quantities of moths.

As moth populations decline, their decline contributes to the decline of many bird species. It used to be that when you watched a Red Sox game you could see the silhouettes of Chimney Swifts and Common Nighthawks catching moths in the lights above the Green Monster—even if you were watching on TV. But that local wonder is much rarer now as populations of these birds—and these moths—have declined.

As birders, we’re naturally interested in understanding what’s going on with moths so we can do better for birds.

Birds (and humans) need moths to pollinate plants to produce seeds and fruits.

Pollination means fruits, nuts, and seeds, and for many birds that means food. And moths are spectacular pollinators.

Moths are active after dark, pollinating plants—including many night-blooming plants—after other pollinators quiet down. Moths spread pollen around just as well as bumble bees. In fact, nocturnal moths visit more plant species than daytime super-pollinators (such as bees) do. Some moth species actively pollinate plants by stuffing pollen into the plant’s pistil with their claws. While some moths are generalists and visit a wide variety of plants, others have evolved to rely on a single plant species or group of species and as a result have become essential to their survival. California’s rare Joshua Trees, for example, rely on a single moth for pollination.

Birds and other animals need the shelter of trees.

Many moths species live in out forests and woodlands and play a key role in pollination of trees and the development of forests. But an out-of-control moth population can quickly devastate woodlands. Tent caterpillars, for example, can strip a tree of leaves, create what foresters call “top kill” and weaken a centuries-old tree permanently. Fortunately, birds like cuckoos can eat 100 tent caterpillars in a single sitting. Baltimore Orioles, better known for their love of grape jelly slices, also chow down on tent caterpillars.

Experts estimate that the mortality for moth caterpillars hovers at about 99 percent. That means about 99 in every 100 caterpillars becomes a snack.

That extraordinary level of consumption is essential to forest health—a healthy mix that makes it possible for birds, caterpillars, and forests to exist in balance.

By keeping caterpillars in check, birds help keep trees and forests healthy and ensure there will be food for future generations of hungry caterpillars. This relationship also helps maintain a lush canopy that benefits other creatures including mammals, other insects, and reptiles. Bats, for example, are especially enthusiastic consumers of moths. A healthy tree canopy also protects soil from erosion and supports soil organisms and microbiomes. The trees, especially those of the boreal forests, also fix carbon, reduce greenhouse gasses, and cool the planet.

Moths and Humans Need Each Other.

Yes, they do eat our sweaters, but moths also matter to humans and have long-inspired artistic expression, scientific curiosity, and invention.

One important impact moths have had is in research. Moths have long given scientists and researchers an accessible pathway for learning about the dynamics of ecosystems and complex biological relationships, and have been widely used ‘model’ organisms for scientific studies. For centuries moths have helped scientists understand phenomena like animal navigation, biomimicry, evolution, embryology, genetics, population dynamics, and biodiversity conservation.

For birders, moths present an excellent opportunity to sharpen observational skills. Moths are fascinating in their own right, offering a different window into nature experiences. National Moth Week has turned thousands of people into moth watchers, eager to learn more about the big hairy moths that show up on their porches or the luminous green moths that flutter through a park at night and the many forms of intricate camouflage. Identifying moths can be more complicated than identifying birds—there are more of them, they are smaller, and they come out of night, and most of them don’t sing. Studying the details of a moth makes us all better at looking and noticing in general.

Moths can also be quite cooperative and be encouraged to sit quietly while you enjoy their furry crowns or colorful wing spots or get them to pose for glamor shots. Some birders also find that moths make it a little easier to learn about trees and flowering plants, which leads to a better understanding of bird habitat preferences and the ecology of those habitats. Backyard birders especially can benefit from moth observation. Learning how to bring more moths to your yard to attract birds is more effective than stocking up on bird seed. Plus, squirrels rarely eat moths.

The more we know about moths, the more we appreciate New England’s complex ecological connections and intricate food webs—and how our own choices from the plants we put in our gardens to the pesticides we use or choose not to use, affect those dynamics and their impact on biodiversity.

The Boston Birding Festival has a habitat and ecosystem philosophy when it comes to birding. We appreciate that moths are an amazing part of what makes an ecosystem good for birds. A diverse and healthy habitat means more birds. It means more wildness in our lives and more awe. We’re proud and excited to be part of Cambridge’s first Moth Ball and look forward to helping make it an annual event.