Rare, Threatened, & Endangered Invertebrates

Edwards’ Hairstreak
(photo by Bryan Pfeiffer)

Tidewater Mucket
(photo by Ethan Nedeau)

Roaring Brook Mayfly nymph
(photo by Don Chandler)

Spatterdock Darner
(photo by Bryan Pfeiffer)

Invertebrates, smaller organisms lacking a backbone, are the dominant form of life on earth both in diversity and biomass (living weight). It is estimated that Maine alone hosts over 16,000 inland species of invertebrates, comprising approximately 95% of the State's animal life. Whether insects (butterflies and bees), crustaceans (crayfish and fairy shrimp), mollusks (snails and mussels), or arachnids (spiders and mites) -- to name just a few groups -- Maine’s invertebrates are both fascinating in their diversity of form and function, and critically important for sustaining natural ecosystems. The famous Harvard biologist Edward O. Wilson refers to invertebrates as “the little things that run the world” because of their life-sustaining services in crop pollination, soil enrichment, seed dispersal, waste recycling, biological pest control, and food chain support. On this last point, consider for example, that most of Maine’s more conspicuous wildlife -- birds, bats, amphibians, reptiles, and fish -- are insectivorous for at least a portion of their life history.

In part because of the essential ecosystem services provided by invertebrates, MDIFW takes its charge to conserve all of Maine’s “wildlife” (defined as any organism in the animal Kingdom) seriously. At least 18 native species of wildlife are known to have become extinct historically within Maine’s borders, including nine insect species (1 beetle and 8 butterflies and moths). We may never know the true ecosystem effects and expense of these losses, but MDIFW is committed to preventing further species extinctions in Maine. One of the tools the State uses to prioritize its efforts at invertebrate conservation is the Maine Endangered Species Act, where the conservation status of species is assessed and those in danger of extinction afforded extra protection.

Maine's current Endangered and Threatened Species List includes 21 invertebrate species: eight butterflies, three freshwater mussels, two beetles, two dragonflies, two moths, two mayflies, one land-snail, and one bumble bee. To learn more about these species and Maine’s other vulnerable wildlife, visit the state list of Endangered, Threatened and Special Concern species.