Find Mitchell's satyr information at Animal Diversity Web
Mitchell's satyrs are small, brown butterflies that are unmarked on the upper surface of the wings. Their wings have rows of round, black, yellow-ringed "eyespots" on the undersides of their wings. They have two orange lines that border the undersides of both fore- and hind-wings. Females are slightly lighter in color than males. The forewings of the males range from 1.6 - 1.8 cm; females are larger, ranging from 1.8 - 2.1 cm.
Saint Francis' satyrs are slightly different than Mitchell's satyrs. They are darker, and the eyespots are usually more irregular in shape and they are circled by thinniner rings.
The eggs of both subspecies are greenish-white to cream colored and become tan when they age. The dark head of the larvae is visible one to two days before hatching.
The caterpillars of this species can be different shades of green with white stripes on their sides. Young caterpillars have purple or black heads, and older caterpillars have small, white or green projections on their heads.
Pupae are generally light lime green in color, with some blue. There is also some pale green or whitish speckling. Pupal lengths are 10.5 - 15.5 mm.
The species is only found in the United States. There are two recognized subspecies: Mitchell's satyr and Saint Francis' satyr. Historically there were more than 30 isolated populations of Mitchell's satyr in the states of Michigan, Ohio, Indiana, New Jersey, and possibly Maryland. Currently, there are 19 known populations remaining, 17 in Michigan and 2 in northern Indiana (C. Tansy, USFWS, personal communication, Hyde et al. 2001).
There are 12 known populations of Saint Francis' satyrs in the southeastern United States. The first identified population was discovered in the Sandhills region of North Carolina in 1983. In 1998, intensive survey efforts located 10 more populations in Virginia, and in 2000 one population was discovered in Alabama.
Mitchell's satyrs prefer wetlands such as bogs, fens, and sedge meadows. These habitats contain mostly sedges, with trees such as tamarack and red cedar. These butterflies generally use the areas on the edges of sedge meadows and dense stands of shrubs or tamarack trees.
In North Carolina and Virginia, Saint Francis' satyrs also occur in wetlands dominated by sedges. There is light to moderate grazing by livestock at these sites. There is very limited shrub cover at the Virginia sites, primarily smooth alder (Alnus serrutalata). There are ground water seepages and springs at most sites, and mud or gravel bottom streams in all sites. The dominant plant species is bulrush (Scirpus expansus).
Caterpillars in both subspecies go through five molts before they become pupae. In some populations, the caterpillars become dormant in the fall, and become active again the following spring.
Males spend most of their time looking for females. Males often chase one another. Females are not very active and generally stay within vegeatation. No courtship behaviors have been recorded. Mating and egg-laying generally occur in mid to late afternoon.
Mitchell's satyrs reproduce once per year, Saint Francis' satyrs breed twice per year in North Caroloina, once in Virginia; breeding interval in Alabama unknown.
Flight dates for Mitchell's satyr range from late June through mid-July. In Virginia, Saint Francis' satyrs fly from early to late July. Saint Francis' satyr populations in North Carolina are active from early May through early June and again from late July through late August.
Before they lay eggs, female Mitchell's satyrs must find a sot in the vegetation to lay their eggs. Once they settle on a spot, they either lay their eggs immediately or flutter in the vegetation. If a female decides the spot is good, she'll lay her eggs. If not, she'll try to find another spot.
Females often lay their eggs close to the ground on small plants, under leaves and stems, and even on dead leaves. They generally lay eggs in clusters.
There is no parental care in this species. Females supply their eggs with nourishment, but once they have laid their eggs, they have no further interaction with their offspring.
The lifespan for an adult is approximately three weeks. If they are dormant in the winter, then they may live up to a year at most.
Mitchell's satyrs are most active on warm, overcast days, and and are less active on sunny days, especially if it is very hot. In contrast, Saint Francis' satyrs are active on hot days.
Mitchell's satyrs do not have very large home ranges (less than 0.05 hectares). The average individual appears to use only a small portion of what seems to be suitable habitat in the surrounding area.
Not much is nown about how this species communicates. As in many butterflies, chemical cues may be important in mating, as is vision. Females probably use vision and smell to find good sites to lay their eggs.
Mitchell's satyr larvae appear to feed on a variety of sedges and possibly one or more species of bulrushes (Scirpus spp.). Saint Francis' satyrs are believed to feed on sedges as well, particularly Carex expansus.
Adult Mitchell's satyrs have been observed eating the nectar of mountain mint (Pycanthemum virginianum), black-eyed susans (Rudbeckia hirta), and swamp milkweed (Asclepias incarnata). Adult Saint Francis' satyrs are known to eat the nectar of swamp milkweed (A. incarnata), common milkweed (Asclepias syriaca), yarrow (Achillea millefolium), Queen Anne's lace (Daucus carota), and crown vetch (Coronilla varia).
The role of N. mitchellii in the ecosystem is that of prey for the previously mentioned predators. They may also serve as pollinators to some degree, and the larvae may be significant herbivores on sedge plants.
There are no known adverse affects of Neonympha mitchellii on humans.
Individuals traveling to observe these butterflies contribute to local economies directly, and to the national economy through the purchase of field equipment such as binoculars, field guides, and cameras.
Both Mitchell's satyr and Saint Francis' satyr are listed as endangered by the U.S. Fish and Wildlife Service. Mitchell's satyr is also listed as endangered in the state of Michigan.
Habitat loss is the major cause of their decline. This habitat loss may be caused by 1) development, 2) changes in water use, 3) invasive species, 4) prevention of natural fires and beaver activity. Often, periodic fires are very important and necessary to maintain certain types of ecosystems.
Barb Barton, Special Contributors
Matthew Wund, University of Michigan
George Hammond, Animal Diversity Web, University of Michigan Museum of Zoology
Glassberg, J. 2001. Mitchell's satyr rides again. American Butterflies, 9(3): 16-21.
Hall, S. 1993. A rangewide status survey of Saint Francis' satyr, Neonympha mitchellii francisi (Lepidoptera: Nymphalidae). Report to the US Fish and Wildlife Service, Asheville, NC: 44 pp.
Hall, S. 1994. Supplement to the rangewide status survey of Saint Francis' satyr Neonympha mitchellii francisi (Lepidoptera: Nymphalidae) 1993 field season. Report to the US Fish and Wildlife Service: 26 pp.
Hyde, D., M. Rabe, D. Cuthrell, M. Kost. 2001. Surveys for the recovery of Mitchell's satyr butterfly Neonympha mitchellii mitchellii in Michigan. Final report - 2000. Report to the US Fish and Wildlife Service, Ft. Snelling, MN: 1-97.
Kost, M. 2000. Vegetation characteristics of Mitchell's satyr Neonympha mitchellii mitchellii habitat. Report to the US Fish and Wildlife Service, Ft.Snelling, MN: 1-25.
Legge, J., M. Rabe. 1996. Observations of oviposition and larval ecology in caged Mitchell's satyr butterflies Neonympha mitchellii mitchellii (Lepidoptera: Nymphalidae). Report to the US Fish and Wildlife Service, Ft. Snelling, MN: 17 pp.
McAlpine, W., S. Hubbell, T. Pliske. 1960. The distribution, habits, and life history of Euptychia mitchellii (Satyridae). Journal of the Lepidopterists' Society, 14(3): 209-226.
Opler, P., V. Malikul. 1992. A Field Guide to Eastern Butterflies. NY: Houghton Mifflin Co.
Rabe, M., M. Kost, H. Enander, E. Schools. 2002. Use of a GIS based habitat model to identify potential release sites. Report to the US Fish and Wildlife Service, Ft. Snelling, MN: 34 pp.
Roble, S., C. Kessler, B. Grimes, C. Hobson, A. Chazal. 2001. Biology and conservation status of Neonympha mitchellii, a globally rare butterly new to the Virginia fauna. Banisteria, 18: 3-23.
Shuey, J. 1997. Conservation status and natural history of Mitchell's satyr Neonympha mitchellii mitchellii French (Insecta: Lepidopters: Nymphalidae). Natural Areas Journal, 17: 153-163.
Szymanski, J. 1999.
Szymanski, J., J. Shuey. 2002. Conservation strategy for Mitchell's satyr butterfly at ...(site name deleted). Report to the US Fish and Wildlife Service, Ft. Snelling, MN: 92 pp.
Saint Francis' Satyr Recovery Plan. Asheville, NC: US Fish and Wildlife Service. 1996.
Recovery Plan for the Mitchell's Satyr Butterfly <<Neonympha mitchelli mitchellii>>. Ft. Snelling, MN: US Fish and Wildlife Service. 1998.
Struttman, J. "Butterflies of Michigan, Mitchell's Satyr" (On-line ). Butterflies of North America. Accessed 02/18/03 at http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/mi/131.htm.
US Fish and Wildlife Service Region 3. 1999. "Mitchell's Satyr Butterfly - Endangered Species Fact Sheet" (On-line ). Endangered Species. Accessed 02/18/03 at http://midwest.fws.gov/endangered/insects/mitchell.html.
Hiawatha National Forest, US Forest Service. "Range Map for Mitchell's Satyr Butterfly" (On-line ). Great Lakes Ecological Assessment.
Wilson, T. "Mitchell's Satyr: An Endangered Butterfly Species Found in the Oakmulgee National Forest" (On-line ). Judson Webspinner. Accessed 02/18/03 at http://home.judson.edu/academic/spinner/butterfly/butterflycount.html.
2001. "Mitchell's Satyr Photos" (On-line image). Accessed 02/18/03 at http://www.vireos.com/mitchellssatyr.html.
Michigan Department of Natural Resources. "Mitchell's Satyr Butterfly Neonympha mitchellii mitchellii " (On-line). Michigan Department of Natural Resources. Accessed February 18, 2003 at http://www.michigan.gov./dnr/0,1607,7-153-10370_12145_12204-33013--,00.html.
Struttman, J. 2004. "Butterflies of New Jersey" (On-line). Butterflies of North America. Accessed November 23, 2004 at http://www.npwrc.usgs.gov/resource/distr/lepid/bflyusa/nj/131.htm.
Opler, P., G. Krizek. 1984. Butterflies East of the Great Plains. Baltimore, MD: John Hopkins University Press.
Darlow, N. 2000. Behavior, Habitat Usage, and Oviposition of the Mitchell's Satyr Butterfly, Neonympha mitchellii mitchellii . Report to the US Fish and Wildlife Service, Ft. Snelling, MN: 43 pp..