occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (<100 square km (less than about 40 square miles)) Until the 1970s or 1980s the value was G or H. The pre-settlement range of this subspecies is unknown, but by the mid to late 1800s the range northeast to extended into southern New Brunswick Canada (where its presence was probably brief), south at low elevations through New Jersey, well into the Virginias, through the Ohio Valley and probably into Georgia in the mountains. The western historic limit is unclear but was in, or more likely, well to the west of Ohio. Based on habitats used there the more northern and eastern populations in Wisconsin might have been this subspecies or intergrades. Specimens should be evaluated. By 1960 this species no longer occurred in mainland New England except for western Connecticut. The last vouchered Connecticut record was in 1971 and Schweitzer was aware of credible reports several years later but found none at those sites that were checked in the early 1980s. Most populations in New Jersey and New York were gone by 1970. Several Pennsylvania and Michigan populations survived into the 1970s or perhaps 1980s. Some Long Island, New England off-shore island, West Virginia, Maryland, Ohio, and apparently North Carolina mountain populations survived into the late 1980s or (at least the island ones) early 1990s. By 1994 the subspecies had apparently contracted to its current range which is one substantial site in central Pennsylvania and two small colonies in Virginia. Unless it is reintroduced elsewhere or one of the existing metapopulations begins to expand, discovery of new occurrences is not expected.
Comments: The natural habitat is poorly understood but was probably mostly riparian meadows of places kept open by Native Americans. In the late 1800s to 1970s, and probably before that, most populations were associated with anthropogenic habitats such as wet meadows, hay fields, pastures, old fields. Pastures with marshy spots along streams seem to have been typical. More natural, but still more or less anthropogenic, dry sandplain grasslands were used on eastern Long Island and the islands off Massachusetts (but not Block Island), perhaps also on mainland Cape Cod. While most habitats were reportedly wet, or at least adults were usually found in wet places, there seems to have benn some tendancy for longer persistence in drier habitats, and the current Pennsylvania habitat is almost all dry to mesic upland, as were the last well-documented West Virginia site and the last New England Island habitats in large part.
Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
While not migratory, adults, especially females in August and September, disperse and can travel several miles in a day. Adults were also sometimes forced to leave their habitat when mowing or other factors eliminated nectar. Individuals can (or at least did) turn up in odd places, but within its general range, and the subspecies was a frequent colonizer. Except that it was more than six miles in Pennsylvania, the maximum distances adults moved was never documented.
Comments: There has been a myth that this species is associated with birds foot violets (Viola pedata). Most populations of this subspecies were in places where that violet was not present or was a minor component. While birdsfoot violets were used in the few sand plain habitats, V. fimbriatula (main food in Pennsylvania now), V. saggittata, V. lanceolata, V. papilionacea, and undoubtedly others, were also used. Probably any violet in the right habitat is a potential foodplant. Adult nectar is a critical resource, but a great many flowers from red clover to Clethra are used. Late summer composites and milkweeds were probably especially important. Nectar is needed throughout the flight season so most populations depended on multiple sources.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 1 - 5
Comments: As of 2001-2007 one or two in Virginia, one in Pennsylvania, not seen in North Carolina since 1994 so probably not still present. An apparently false rumor of a population in Kentucky circulated in 2002.
250 - 1000 individuals
Comments: Some annual variation. Probably a hundred or so in Virginia and less than 1000 in Pennsylvania most summers.
Populations seem to have been unstable with numerous reports of fluctuations and populations appearing and disappearing suddenly. Overall this was probably a sporadic and uncommon, but not rare, species in most of its range. It is unclear what the pre-settlement range might have been, but if this is a valid taxon, it must have occurrence naturally in the East.
Life History and Behavior
Comments: See full species. At the Pennsylvania site males appear in June, females by late June or early July. Females persist into September. Larvae hatch in the fall, and begin feeding in about April, maturing mostly in June. The pupal stage is brief.
National NatureServe Conservation Status
Rounded National Status Rank: N1 - Critically Imperiled
NatureServe Conservation Status
Rounded Global Status Rank: T1 - Critically Imperiled
Reasons: Catastrophic decline in mid and late 20th century from almost certainly over 1000 populations to near extinction. Three populations are known to still exist and there has been no evidence of any others since about 1994.
Intrinsic Vulnerability: Moderately vulnerable
Comments: Most accounts of this species in the east based on observations in the 1860s to 1960s indicate it was prone to large fluctuations, being at times locally abundant but in other years scarce and sometimes disappearing, and often absent in suitable habitat. The Pennsylvania population is not as vulnerable as the Virginia one because it produces more adults, occupies a fairly large area with several demes, and is being managed.
Environmental Specificity: Moderate. Generalist or community with some key requirements scarce.
Comments: Needs include dozens of hectares of grassland with a lot of nectar and violets but the habitat of this subspecies never really was understood. Very few known occurrences were in natural communities, and there was lot of variation.
Other Considerations: Causes for the near extinction of this subspecies are not fully understood but for various reasons local extirpations were no longer balanced by colonizations by the mid 20th century.
Global Short Term Trend: Relatively stable (=10% change)
Comments: The three known extant populations have been somewhat stable since the mid 1990s.
Global Long Term Trend: Decline of >90%
Comments: More than 99.9% decline since 1900, perhaps an even greater decline between 1800 and 1899. About a 98% decline since 1970.
Degree of Threat: High
Comments: The Pennsylvania population may be secure for the time being but future land use changes on the military base involved could eradicate it quickly. As far as known the Virginia populations are vulnerable to habitat conversion and the other usual threats for this species such as biocides, herbicides, plowing or other incompatible management. It also seems likely extinction of the Virginia populations (or metapopulation) could occur by mere chance annual fluctuations. Some former threats may not apply at these three sites such as inappropriately applied prescribed burning and gypsy moth spraying.
Global Protection: None to few (0-3) occurrences appropriately protected and managed
Comments: The Pennsylvania population probably can be considered protected as well as viable.
Needs: All not yet extinct populations need protection. If this really is a valid taxon, it should be listed under the US Endangered Species Act. If it is not, protection is still warranted in that these are all that remains of this globally rare species over a huge fraction of its documented range.
Names and Taxonomy
Comments: This subspecies is based on Williams' (2002) analysis of wing spot characters and mitochondrial DNA work. Unfortunately by the time this work was done only two or three populations were known extant and the mtDNA work is based entirely on the Pennsylvania population. However, there is no plausible scenario by which this population could be unique from other recently extirpated eastern ones and it differs in several characters from all western samples studied. However, strictly speaking the DNA work only shows the five Pennsylvania individuals are more similar to each other than to western populations and individuals from western states do not necessarily cluster together. However, since the spot characters are almost certainly genetically based, even on these alone this subspecies is better characterized than some among butterflies. Specimens from Ohio, Indiana and Michigan were not included in the wing character analysis even though such are easily available in collections. Whether or not there was some intergradation across this region probably would not have affected the validity of the new subspecies, since interbreeding would be expected in a contact area. However it is impossible from the results presented to rule out a large scale east to west cline rather than two discrete entities (most likely with a small blend zone). Information on variation (or lack of it) within the two "subspecies" would be needed. Although these taxa clearly did differ in habitat acceptance, Williams' statement that in contrast to prairie populations subspecies Speyeria idalia idalia is "typically found in xeric habitats" is inaccurate for almost all former populations and misrepresents what is actually in the references cited. This was largely an inhabitant of damp to marshy, often streamside, habitats. Likewise, there is no evidence that purported foodplant preferences within the genus Viola even exist for this subspecies, let alone differ from prairie populations. See EMG for the species for more on habitats and foodplants. The subspecies designations are provisionally accepted for this database and the name Speyeria idalia idalia applies to all extirpated populations from eastern and southern Ohio to New Brunswick,Canada, to Georgia as well as the two or three extant occurrences in Pennsylvania and Virginia. Among the few places where eastern populations actually did occupy xeric native prairie-like natural communities are Nantucket and Marthas Vineyard Islands off Massachusetts. Examination (by Schweitzer) of six 1980s specimens from those islands shows them to be subspecies idalia based on Williams' spot characters and illustrations. It is presently unclear which subspecies occurred in Indiana, prairie areas of northwestern Ohio, Ontario, or in non-prairie parts of Wisconsin. Those states and provinces may wish to simply track the full species. These comments are by Dale Schweitzer and included some input from Jason Weintraub.