Butterflies occupy a happy spot in the human psyche. Only our most exuberant songbirds are as closely identified with the warm, colorful passion of summer. We tend to think of butterflies—quite rightly—as inhabitants of sunny meadows filled with wildflowers. But butterflies live in a broad spectrum of habitats including forests, heathlands, bogs, swamps, even salt marshes—anywhere, in fact, where their caterpillar food plants and sources of nectars for adults are found. In addition to their aesthetic appeal, butterflies are among nature's most fascinating creatures. Did you know that:

• One hundred three species of butterflies occur regularly in Massachusetts and another 27 species have been recorded as rare vagrants or have become extinct in the state.
• Several species of Massachusetts butterflies such as the Mourning Cloak overwinter as adults—quite possibly in the walls of your house!
• One species, the Harvester, is a carnivore, its caterpillar gorging itself on wooly aphids and then hiding under a pile of discarded aphid skeletons.
• A few species eat poisonous plants as caterpillars and become unpalatable to predators like birds. Other, non-poisonous species gain protection by mimicking the color patterns of toxic ones and faking out their would-be attackers.
• There are currently seven species of butterflies on the Massachusetts Endangered Species List.

This new addition to the Mass Audubon website is intended to be a gateway through which you can enter and explore the world of Massachusetts butterflies—their identification, distribution, habits and conservation.

The website is based on data collected during the Massachusetts Butterfly Atlas Project (see "About the Atlas"). Future additions and improvements to the website are anticipated in the near future including:

• The ability to search the database of butterfly records accumulated during the Atlas project
• Updated distribution records reflecting the substantial collecting performed by members of the Massachusetts Butterfly Club since the completion of the Atlas in 1990
• A mechanism for continued updates and comparisons of past and current butterfly distributions
• An extensive bibliography of butterfly taxonomy, distribution, and ecology

On this website, you will find links to the Massachusetts Butterfly Club as well as other butterfly resources. We especially appreciate the contributions of the members of the Butterfly Club, many of whom generously contributed their photographs, in making this website a reality. We particularly welcome photographs for species not currently depicted or updates to species accounts.

Recommended Citations for the Massachusetts Butterfly Atlas

• When citing the atlas as a whole:
  
  Leahy, C.W., B. Cassie, and R. K. Walton (eds). 2006. Massachusetts Butterfly Atlas 1986-1990, Massachusetts Audubon Society (www.massaudubon.org/butterflyatlas).
• Example for citing individual species accounts:
  
  Cassie, B. 2006.Pipvine Swallowtail, Battus philenor Linneaus 1771. In: Leahy, C.W., B. Cassie, and R. K. Walton (eds), Massachusetts Butterfly Atlas 1986-1990, Massachusetts Audubon Society (www.massaudubon.org/butterflyatlas).

If you have comments or suggestions for improving this website, please e-mail us at butterflyatlas@massaudubon.org.

Heading Illustrations (L to R): Spicebush Swallowtail, Eastern Tiger Swallowtail caterpillar, Monarch.