Maine Butterfly Survey

MBS Background & Introduction

Because of their short generation times, sensitivity to environmental insults and often narrow habitat requirements, insects can be effective sentinels of environmental change.  As the specter of global warming looms, wildlife biologists and ecologists need to be able to monitor the direction and rate of changes in plant and animal populations.  The use of any group of organisms to monitor population changes requires a firm baseline of information against which changes can be judged.  Acquiring a solid baseline of the distribution and abundance of Maine butterflies (including the skippers) is one of the primary objectives of the Maine Butterfly Survey (MBS).

 With over 115 species native to Maine, butterflies contribute a colorful and conspicuous component to our state’s biological diversity.  Butterflies play an important role in terrestrial and wetland ecosystems by serving both as pollinators of many wildflowers and prey (both caterpillars and adults) to larger species ranging from dragonflies to birds.  Butterflies are also widely recognized for their value as ecological indicators of ecosystem stress due to such factors as climate change pollution, and habitat loss.  Their potential economic contribution in terms of “watchable wildlife” is difficult to estimate, but clearly no other group of insects has attracted as much attention from amateur naturalists and ecotourists, a group whose ranks increasingly include bird watchers armed with close-focusing binoculars.  Many neighboring states and provinces (Vermont, Connecticut, Massachusetts, New Brunswick) have compiled atlases of their butterfly fauna.  Despite growing local interest in butterflies and their conservation, baseline information for the group has been mostly lacking in Maine.

 In 2005, Phillip deMaynadier and Reggie Webster published “A Baseline Assessment and Conservation Status of the Butterflies of Maine”.  [A copy can be downloaded the MBS website (Baseline Report)] Based on nearly 9,000 records and the addition of 11 previously undocumented butterflies and skippers to the state list, this report summarizes all of the known records of Maine butterflies and skippers in national and regional museums, in private collections and in published material.  Prior to this assessment, one of the most valuable sources of information on the distribution of Maine butterflies is Brower’s 1974 publication, “A List of the Lepidoptera of Maine - Part I. The Macrolepidoptera” published as a Technical Bulletin by the University of Maine-Orono.  This publication summarizes the distribution of butterflies that Brower and a small group of other collectors had documented since the 1930’s.

We encourage all MBS participants to download a copy of Webster and deMaynadier (2005).  This document provides a color photograph for 34 rare species, along with current information on identification, geographic range, abundance, habitats, life cycle, nectar sources and conservation status.  Importantly, a map for all 114 (now 115) Maine species is shown, indicating confirmed presence in the 711 Maine townships.  Here is the map for the Monarch (Danaus plexippus).

Even for such an easily identified species that is believed to be common in Maine, we have very few townships where the occurrence of the Monarch has been recently documented with either a specimen or a photograph.  We have much to learn about the distribution and status of Maine butterflies!

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