ABOUT BOM      SPECIES LIST      BUTTERFLY HISTORY      PIONEER LEPIDOPTERISTS      METHODS

 

Sources and Methods

 

                                                             Table 4  No. of Records          Table 5 Atlas/MBC Comparisons

Published literature cited                                                                  

Historical Sources.  The butterfly history of Massachusetts has been documented in unusual detail by some of the nation’s earliest lepidopterists, as well as by many local naturalists and collectors. The present study is fortunate to be able to build on the pioneering work of Thaddeus W. Harris (1795-1856) and Samuel H. Scudder (1837-1911). Thaddeus Harris was America’s first economic entomologist. He taught natural history at Harvard University and made major contributions to the scientific study of North American butterflies.  Interestingly, Henry David Thoreau was one of his students; Thoreau also made early observations about butterflies in the 1850's in Concord, some of which are cited in the species accounts here. Harris’ pioneering Report on the Insects of Massachusetts Injurious to Vegetation first appeared in 1841. Following Harris at Harvard was Samuel H. Scudder, whose magisterial three-volume The Butterflies of the Eastern United States and Canada (Scudder 1899) still stands today as a major scientific contribution. The early specimen collections of Harris, Scudder, and others such as collectors F. H. Sprague, C. Bullard, and C. J. Paine and family, are preserved at the Harvard Museum of Comparative Zoology (partly available at http://mczbase.mcz.harvard.edu ). They are an invaluable resource for knowledge of butterfly distribution, flight time, broods and host plants in 19th and early 20th century Massachusetts.  Butterflies of Massachusetts (BOM) is especially grateful to Rod Eastwood at the MCZ for access to and guidance through this iconic collection.

Thanks to the efforts of many collectors and researchers throughout the twentieth century, Massachusetts butterflies are well-represented in major museum collections. Particularly for lycaenids in the present study, many of these collections have been reviewed, including the American Museum of Natural History (AMNH), the Smithsonian Institution (SI), the McGuire Center at the University of Florida, Yale Peabody Museum, Boston University (BU), University of Connecticut (UConn), Furman University, the California Academy of Sciences, Cornell University, and the University of New Hampshire (UNH), as well as, locally, the Maria Mitchell Museum on Nantucket, the Berkshire Museum, and the Wellesley Insect Collection. Much of this pin label data was compiled in 2010 by a lycaenid and climate change working group at Boston University led by Dr. Richard Primack. BOM is especially grateful to Prof. Primack for kindly providing access to Massachusetts data from these museums.

Supplementing the specimens are the field reports of The Lepidoperists' Society, a venerable organization whose 1959-1985 season summaries have been an invaluable resource. All Lepidopterists’ Society Season Summaries (LSSS) and Correspondence (LSSSC) for this period, supplied courtesy of Mark Mello, as well as their current records, have been incorporated in this study.  The private collections of Mark Mello, David Wagner, Daryll Willis, and Rene Wendell Sr. have also been reviewed.  BOM thanks these individuals, as well as Jeff Boettner, Michael Nelson, Harry Pavulaan, and Robert Robbins for helpful data and comments.

Massachusetts Audubon Butterfly Atlas. Citizen butterfly appreciation and monitoring in Massachusetts began in the mid-1980s, when  the Massachusetts Audubon Society (MAS) undertook the first butterfly atlas in the state. The Society mobilized and trained 150 of the best naturalists of the day to do the field work for the 1986-1990 Atlas. Most of these field workers were not lepidopterists, but were well-taught through training sessions. Using standard methodology, the Atlas collected presence/absence data within a grid based on USGS topographic quadrangles. Each quad was divided into six equal blocks. 186 (100%) of the quadrangles were covered and 723 (65%) of the blocks. The effort extended over five field seasons 1986-1990, and data (sight, photograph, and specimen) were used to assess the spatial and seasonal distribution of butterfly species, as well as broadly indicate their relative abundance. The results were published on line, in the form of maps and species accounts. The Atlas coordinators were Chris Leahy, Brian Cassie, and Richard K. Walton. The species accounts also reviewed historical data for the state from Scudder and other sources, and they remain an important baseline resource. The Atlas is available at http://www.massaudubon.org/butterflyatlas 

Massachusetts Butterfly Club. The Atlas left a legacy of enthusiasm for butterfly observation and monitoring.  At the end of the Atlas period, a core group of the volunteers, led by Brian Cassie, formed the Massachusetts Butterfly Club (MBC) to promote the continued appreciation and documentation of the state’s butterflies. The club began regular field trips, searches for rarities, and migration observation. It continued the important record-keeping function by appointing a records compiler, and sponsored the publication of a semi-annual journal Massachusetts Butterflies. The journal published sightings records and a season summary in its spring issue, and the results of the NABA Counts in the fall issue.

This study, Butterflies of Massachusetts (BOM), uses the 1991-2014 records of the Massachusetts Butterfly Club to provide an overview of the state’s butterfly fauna in the 25-year period following the Atlas.

The club recruited and trained a cohort of new members through a series of Butterfly Institutes held in conjunction with several MassAudubon sanctuaries and other nature centers.  The club gained a cohort of new members in the mid-1990’s as a result of these programs. From the end of the 1990’s through about 2010, the club consisted of a core of about 150 members, most of whom were by this time seasoned butterfly observers, very active in field. Club records for this period reflect their efforts.

The MBC affiliated with the North American Butterfly Association (NABA) in 1995. In 1993 NABA' s founder, Jeffrey Glassberg, published Butterflies Through Binoculars;  this field guide popularized  butterfly-watching nationwide, doing for butterflies what Roger Tory Peterson’s guides had done for birds: make it possible for the serious amateur to identify the great majority of species through close inspection with binoculars. Glassberg’s book became standard reference for MBC members. The club tradition became the observation of butterflies through binoculars and camera, and the building of photo collections rather than the taking of specimens.

Digital Photography.  This important technological advance substantially raised the quality of butterfly observation. Within the MBC, photography became an essential means of resolving identification problems where binocular view was not sufficient. Net-and-release was used only in the earliest years. Small digital cameras fast became essential field equipment. The inspection of enlarged dorsal and ventral views of the same individual often resolved identification problems at least to the species level. The photograph became an accepted form of documentation of a species’ presence at a site. The club produced a photo collection of Massachusetts species on its website, http://www.massbutterflies.org . Many club members, and well as non-member butterfly and nature photographers, maintain their own online photo collections.  Websites of photographers associated with the MBC can be accessed from the club website.

The 'masslep' Listserve.  A second advance of the digital age, the ‘listserve,’ made possible quick communication and easy compilation of records. The advent of ‘masslep’ in 1993 was very important for state-wide record-keeping. Those who posted sightings were predominantly MBC members, but the listserve was organizationally separate from the club, was open to all, and many non-club members participated. It became standard practice that on all club butterfly walks, lists and counts would be made and posted on ‘masslep’.  Most NABA Count results were posted there as well. Individuals began reporting sightings from power lines, sanctuaries, National Wildlife Refuges, state parks, community and private gardens, garden centers – all kinds of sites, wherever butterflies were found. Lists of species seen, with numbers, were the accepted form of posting. Reports of rarities could be quickly disseminated and quickly checked by others. Ease of communication greatly increased the number of enthusiastic observers. Posts on ‘masslep’ became the basis of MBC and BOM records.

But after about 2010, citizen reports of butterflies in the state started to become more fragmented, as new reporting venues emerged.  Posts to 'masslep' continued, but more and more individuals were instead reporting to other online sites, such as Facebook (especially), BAMONA, BugGuide, ebutterfly, and the NABA Sightings page.  Concern among some MBC members about collectors making use of 'masslep' led to location reports for some species being suppressed, or restricted to only a few people, further diminishing the usefulness of 'masslep.'  Season summaries from The Lepidopterists' Society continued to report specific locations, but reports were few, made by only two or three dedicated individuals.  This multiplication of sources of butterfly reports led Butterflies of Massachusetts (BOM) to establish its own recordkeeping, to attempt to incorporate as many sources as possible. The comprehensive BOM database became separate from that of the MBC.

NABA Butterfly Counts.  Some Massachusetts "Fourth of July" butterfly counts date to the late 1980s, when the Count program was administered by the Xerxes Society; these are the Central Berkshire, Concord, and Bristol Counts. In 1990 the Central Franklin Count was begun, as well as the short-lived Lower Pioneer Count. In 1992 the Foxboro Count began, and in 1993 the Southern and Northern Berkshire Counts. In 1993, the administration of the count program was transferred to NABA. In 1996 the Northern Worcester County count was begun, in 1997 the Outer Cape Cod (later, Truro), in 1998 the Northern Essex County, and in 1999 Martha’s Vineyard. The addition of Middleboro in 2000 and Blackstone Valley and Northampton in 2001 made a total of 14 active counts in the state. The creation of three more Cape Cod counts (Barnstable, Falmouth, and Brewster) brought the total to 17 active counts by 2004. (A map of Count locations is available in Massachusetts Butterflies 27: 18, Fall 2006.)  By 2009, only fifteen counts were active. About half of the Counts were organized by staff at Massachusetts Audubon sanctuaries, and the others were led by MBC members. All NABA Count results are included in the records used here.

Analysis using Contemporary Records

The 'citizen science' records used for analysis of the years 1991-2013 are for the most part from publicly available sources. They consist of all sightings posted on ‘masslep’ or published in the journal Massachusetts Butterflies between 1992 and 2013. Also included are the results of all the NABA fourth-of-July and seasonal counts in the state between from the 1980's through 2013.  They also include postings to the Facebook Massachusetts Butterflies group, to the BAMONA website and to the NABA Sightings webpage, plus increasing numbers of private records sent to BOM.

The butterfly reports in the season summaries of The Lepidopterists' Society make up only a very small portion of the dataset, but contribute information on some less common species. Throughout the Atlas and MBC periods, and indeed dating back to the 1960's, collectors associated with The Lepidopterists' Society continued their activities in the state, sometimes resulting in valuable specimen collections such as those of William D. Winter and Mark Mello.

Analysis of distribution and abundance trends covers the years 1992-2010 (sometimes 1991-2010), with additions from 2011, 2012, and 2013 for some species.  1986-90 MAS Butterfly Atlas records, collected under a different protocol,  are treated separately and compared with Club records (see below).  By 1992 MBC/masslep reports had become numerous enough to constitute a good representation of areas across the state. 1992 includes many reports from the Worcester area, from the Berkshire and Central Franklin NABA Counts, and from the large Foxboro NABA Count inaugurated that year. 

In compiling the MBC database, there was some review and oversight by the Club records compiler, who omitted a report if it was judged not reliable.  Overall, the bias was toward inclusion of reports rather than exclusion. The majority of reports in the early period are from group trips led by an experienced Club member, and thus species identifications and the numbers seen were given informal review on the spot before posting to the listserve. Particularly in later years, many reports were accompanied by photographs to confirm the identification. The custom on MBC trips was to provide an actual count of all butterflies seen by the group; however, estimates were made for some very large concentrations of butterflies (migrating Monarchs, for example). 

For this study, the MBC and other records were reviewed carefully to control for duplicate reports. Reports from two observers for the same date and location, and other kinds of duplications were eliminated. In entering the NABA Count reports, town information was retained if possible. NABA Count circles usually encompass more than one town; but entries were re-coded to towns wherever these could be identified. The BOM distribution maps included here are based on the town-level data.

The MBC and other records from these years constitute a high-quality citizen science database, in terms of observer skill, coverage of the area, and amount of time and effort exerted. However, as with most such "opportunistic" citizen science data, there was no systematic accounting of observer effort, whether in terms of hours in the field, miles walked, or number of observers. See "Assessing Detectibility," below, for the implications.

The rapid growth of butterfly observing in the state in the 1990's can be seen in the number of new records entered each year in the MBC database:  they rose from 1,033 in 1991 to some 8,000 in 1999 (Table 4).  Between 2000 and 2009,  participation stabilized at a fairly high level:  new non-duplicate records entered each year varied between 5,000 and 7,000.

Table 4. MBC 1991-2009 Trip Reports and Records used in this study

Year

# Trip reports

# Records

1991*

160

1,033

1992

274

1,239

1993

558

2,279

1994

1,119

4,965

1995

1,190

5,530

1996

837

4,524

1997

555

1,138

1998

1,653

7,234

1999

1,781

8,385

2000

1,380

6,526

2001

1,743

7,242

2002

1,468

5,387

2003

1,477

6,804

2004

1,240

6,368

2005

1,274

5,821

2006

1,519

6,272

2007

1,474

7,154

2008

1,485

6,481

    2009

1,257

6,700

92-09 total

22,284

101,082

*not used in the trend analysis

An important contribution of the 1991-2009 MBC records is that they reflect more diligent searching for rare species than had been possible in the 1986-90 Atlas effort. Thus several resident species which had not been confirmed by the Atlas were subsequently found and documented or re-documented with photographs, for example Bog Elfin, Dion Skipper, Persius Duskywing (confirmed by MA NHESP), Hessel’s Hairstreak, and Two-spotted Skipper. Some Club members were interested in rarities, making targeted trips each year in search of them. Special attention was also given to finding and monitoring such uncommon species as Bronze Copper, Early Hairstreak, Zabulon Skipper, and Hackberry and Tawny Emperors.

Assessing Changes in Distribution

Many published distributional or range maps have been on a fairly large scale. The Butterflies and Moths of North America [BAMONA] website, http://www.butterfliesandmoths.org , begun by Paul Opler and now coordinated by K. Lotts and T. Naberhaus, displays records to the county level, but that is often not helpful and may even be misleading in a state such as Massachusetts which has several quite large counties such as Berkshire, Worcester and Bristol, which differ quite a bit from north to south.  The five-year 1986-90 Massachusetts Audubon Atlas survey was designed to produce more precise distributional maps for this state, based on presence/absence by bloc. These maps are available on the Atlas website. The new BOM maps shown in the species accounts are based on all known Massachusetts sighting records 1991-2013, and show presence/absence by town. They update the Atlas distributions and in some cases indicate major changes from the picture produced by the Atlas. The BOM maps show the species as present in a town even if there is only one report of a single butterfly individual from the town.

The 1991-2013 BOM data include records from all 14 counties in Massachusetts, and from 315 of the 351 towns. There are approximately 1,000 (1142) different locations listed. Reports are distributed throughout each of the 13 major eco-regions of the state (BioMap, 2001). The records are not a systematic sample of the state’s area, as was the Atlas, but they are quite well-distributed geographically, extend over a longer time period and involve a larger number of observers. The representation of towns and regions increased over time, but a few towns have been consistently missed.  In other towns,  some sites have 1990’s records but have not been visited recently, and in still other towns sites have been visited for the first time only in the last few years.

The NABA Counts, considered separately from the MBC and other records, provide a surprisingly good sample of all the state’s regions (Fourth of July Butterfly Count circles Map, Massachusetts Butterflies 27: 18, Fall 2006). Unfortunately, they provide only a midseason snapshot of the butterfly fauna, and miss many early and late-flying species.

Assessing Detectibility Trend from Citizen Science Data

The lack of any systematic accounting of observer effort in these data presents a statistical challenge when trying to extrapolate butterfly population trends. One fairly new approach to accounting for observer effort is to use list-length --- the number of species observed on a trip--- as a proxy for effort.  MBC data was appropriate for list-length analysis, and Dr. Greg Breed, research associate at Harvard Forest, performed these logistic regressions. The resulting analysis was published as Breed, Greg A., Stichter, S., and Crone, E., "Climate-driven changes in northeastern US butterfly communities," Nature: Climate Change, August 19, 2012. Further explanation of the method can be found in that paper;  the results are also reported in the Species Accounts presented here.

A second approach, shown in the charts presented here, uses number of butterfly individuals observed each year per total trip reports for that year, with total trip reports serving as a proxy for observer effort.  Interestingly, both this approach and list-length analysis show the same direction and rough magnitude of change for the majority of species,  

This second approach does not account quite as well for human effort; however, it does not require the elimination of reports containing only one or two species (the list-length analysis omitted any list or report of less than four species).  It also makes use of the numbers of butterflies which participants counted. Of course, there is no measure of the number of people doing the counting, but on a year-to-year basis the total number of participants on MBC trips did not vary enormously.

The charts in each Species Account show trend in frequency of detection of that species over the 18-year time period 1992-2009,  based on MBC observational records. The line shows the two-year moving average. Linear regressions were also run, but are not always shown. Bar charts are used in cases where the number of sightings is too small for trend to be appropriate. Only the highest count for the day and the site was taken in cases of multiple reports and visits to the same site on the same or adjacent days.

In the charts, the number of individuals of that species reported each year is adjusted by the measure of the effort club members made to see butterflies that year. Since there was no routine documentation of the number of observers on each outing, or of how much time they spent looking, effort was measured by number of trip reports for specific locations and dates submitted that year.  A "trip report" was defined as a log (or list) of butterflies (of whatever species) reported for each specific location and date each year, after deletion of any duplicate reports.  Note that "number of trip reports" submitted is not the same as the "number of records" in the database, since a trip report normally contained sightings of several species, each of which becomes a record. The totals of Trip Reports, and of Records, used in the analysis are shown above in Table 4.

 

Comparing the Audubon Atlas and the MBC Records for Relative Abundance

Method.  To see whether a species had become more or less abundant between the 1986-90 Atlas period and the 2000-2007 MBC period, we constructed a scale of relative abundance for MBC data, ranging from Abundant (A), Common (C), Uncommon-Common (UC), Uncommon (U), Uncommon-Rare (UR), Rare (R), and Very Rare (VR), using the total number of butterflies reported 2000-2007 for each species.  Atlas data 1986-1990 were similarly coded, using number of blocs in which a species was confirmed. These measures are strictly useful only for rank-ordering species, but we think they can also support a broader "order of magnitude" interpretation. They can be thought of as meaning "how likely were Atlas and MBC observers to find that particular species in those years?"

There is no correction for effort in either of these numbers, nor is one needed. Effort is a single total quantity for all the Atlas years, and a different total quantity for the MBC years. In the MBC data, the inclusion of the NABA Counts may skew the result slightly. All NABA Counts are in July, so the gross total may underestimate the abundance of species such as elfins, Cobweb Skipper, and Leonard's Skipper, which do not fly in July and are not found on the Counts.  However, the annual Club trips targeting these sought-after early and late-season species may compensate for the "July effect."

For MBC data, the scale was A (>20000), C (5000-20000), UC (1000-5000); U (101-1000), UR (21 - 100), R (2-20), VR (1 sighting). These divisions were to some extent determined by our common-sense usage of the terms. The scale highlights some notable differences between species in the C to A range. For example, the Eastern Tailed-Blue, American Lady, and Silver-spotted Skipper were all near the 5,000 baseline for "medium" or "common" species. By contrast, Common Wood-Nymph, Clouded Sulphur, Red Admiral and Orange Sulphur were four times as numerous; they clustered around the 20,000 mark, and defined what we mean by "abundant."  Still, the Cabbage White was reported to be twice as numerous as even those species, and the numbers of European Skippers, and the estimates of migrating Monarchs, were greater still.

MAS Atlas records were coded as follows: A (150+ records, or blocs confirmed out of the total of 723 blocs searched); C (100-149); U (20-100); R (1-20). The number of Atlas records is usually equivalent to the number of blocs in which the species was recorded, since usually only one record per bloc was entered. The word interpretations accord well with the published Atlas text. This broad scale is intended only to facilitate rough comparisons between the two data sets.

Results. These are shown in Table 5 below and referred to in each Species Account. The comparison suggests some changes in abundance of particular species between the Atlas and MBC time periods.

Abundant species: There are six resident (over-wintering) species which were Abundant in this time period according to both Atlas and MBC records (Table 5):  European Skipper, Cabbage White, Pearl Crescent, Orange Sulphur, Clouded Sulphur, and Common Wood Nymph. They were reported two to three times more frequently than those species labeled Common. None, though, reached the seasonal concentrations reported of Monarchs during their fall migration south in this time period.. A final member of this grouping is Red Admiral, a migrant which does not over-winter; its numbers vary tremendously from year to year, but overall in 2000-2007 the number of reports rank it in this category.

Common species:  The nine or ten Common species, it is well to remember, are not Abundant in the sense used here. Though a few of these were termed "Abundant" by the Atlas, MBC data suggest that the term "Common" is more accurate. In this category are American Copper, Common Ringlet, Little Wood-Satyr, Azures considered as a group, Baltimore Checkerspot, Eastern Tiger Swallowtail + Tiger Swallowtail spp., Peck’s Skipper, Eastern Tailed-Blue, American Lady, and Silver-spotted Skipper.

Uncommon-to-Common species.  There is a large number of species (28) for which the number MBC reports did not reach 5,000 in the years 2000-2007, but did exceed 1,000. They were ranked  Uncommon-to-Common.  Some of these we think of as our "common" butterflies, and the Atlas labeled them as such, but in 2000-2007 they were not actually as numerous as the preceding group: Great Spangled Fritillary, Juvenal’s Duskywing, Dun Skipper, Mourning Cloak, Black Swallowtail, Red-spotted Purple/White Admiral, Spicebush Swallowtail, Viceroy, Long Dash, Eastern Pine Elfin, and Little Glassywing. Other examples of  Uncommon-to-Common species are Banded Hairstreak, Eastern Comma, Question Mark, Northern Broken-Dash, and Brown Elfin. Some in this group are common in appropriate habitats at the right flight time, but not on a statewide basis. Rather than disparaging these species as "common", we should be delighted to see any of them on a butterfly walk, glad to have them with us, and concerned that their populations and habitats be preserved and managed. Two skippers in this group, Hobomok Skipper and Least Skipper, were formerly considered by the Atlas and earlier writers to be "Abundant," but they may have actually declined in numbers over this period.

Three species formerly considered to be rare (Frosted Elfin and Mustard White) or uncommon (Bog Copper), turn out not to be so according to MBC records. Instead they are in the Uncommon-to-Common  range. In general, these are cases where more diligent searches have turned up more locations and more individuals than were formerly known; specifics are discussed in the species accounts. A fourth species, Silvery Blue, may not have arrived in the state at the time of the Atlas; subsequent MBC observations now rank it as Uncommon.

Uncommon species.  The 46 species ranked as Uncommon in MBC sightings are quite diverse. Most were also ranked as Uncommon by the Atlas. Three residents, the Bronze Copper, the Zabulon Skipper, and the Hoary Elfin, and three late season immigrants, the Common Checkered-Skipper, the Fiery Skipper, and the Cloudless Sulphur, were all termed  Rare by the Atlas, but have since been found to be considerably less rare.

Rare species.  Other species the Atlas termed  Rare were still Rare in 2000-2007, but somewhat less so: Early Hairstreak, Hackberry Emperor, White M Hairstreak, Pipevine Swallowtail, Hessel’s Hairstreak, Oak Hairstreak and Two-spotted Skipper. Several resident species not found at all during the Atlas period were by 2007 found or re-found in the state: Hickory Hairstreak, Tawny Emperor, Bog Elfin, and Persius Duskywing. Of the southern-based late season in-migrants, Long-tailed Skipper, Sachem, and Ocola Skipper were seen in greater numbers in the 2000-2007 years than they were earlier. Gray Comma, American Snout, Giant Swallowtail, Checkered White, and Little Yellow remained rare from the 1980’s through 2007. The Regal Fritillary, found by the Atlas in 4 blocs, had by 1992 become extirpated.

 

Table 5. Relative Abundance (Rank) -- MBC/Atlas Comparisons

ENGLISH NAME

MBC

   

ATLAS

     

CHANGE

COMMENT

 

Total reported 2000-7

Code (see text)

 

Blocks

1986-90

Code: 150+=Abundant; 100+=Common; 20-100=Uncomm; 1-20=Rare

Published Status

 

Atlas to MBC

 

Monarch

112958

A

 

156

A

     

 estimates of fall migrating concentrations only

European Skipper

75261

A

 

156

A

abundant + widespread

     

Cabbage White

47256

A

 

187

A

abundant + widespread

     
Pearl Crescent

30628

A

 

194

A

abundant + widespread

     
Orange Sulphur

25536

A

 

169

A

abundant + widespread

     
Red Admiral

21339

A

 

132

C

uncommon to abundant

     
Clouded Sulphur

20929

A

 

175

A

abundant + widespread

     
Common Wood-Nymph

20000

A

 

180

A

abundant + widespread

     
American Copper

11307

C

 

169

A

common

 

downward

 
Common Ringlet

11086

C

 

158

A

abundant + widespread

 

downward

 
Little Wood-Satyr

10432

C

 

157

A

common

     
All Azure species

9614

C

 

179

A

common to abundant

 

downward

Azure species not distinguished in Atlas

Spring Azure

8107

C

 

0

         
Baltimore Checkerspot

6748

C

 

101

C

locally common

     
Peck's Skipper

6114

C

 

158

A

common

     
Eastern Tailed-Blue

5528

C

 

165

A

common

     
American Lady

5205

C

 

171

A

common

     
Silver-spotted Skipper

5005

C

 

160

A

common

     
                   

ENGLISH NAME

MBC

   

ATLAS

     

CHANGE

COMMENT

Bog Copper

4654

UC

 

29

U

locally common

   

short flight period; special habitat

Least Skipper

4223

UC

 

157

A

common

 

downward

 
Great Spangled Fritillary

3976

UC

 

110

C

common

 

downward

most common of the greater fritillaries

Juvenal's Duskywing

3657

UC

 

148

C

common to abundant

 

downward

most common of the duskywings

E. Tiger Sw.+ Can. Tiger Sw.

3412

(UC)

 

173

A

   

(downward)

[provisional]

Dun Skipper

3140

UC

 

142

C

common to abundant

 

downward

 
Mourning Cloak

3062

UC

 

132

C

common

 

downward

 
Eastern Tiger Swallowtail

3014

UC

           

Atlas total includes Canadian Tiger Sw.

Painted Lady

2776

UC

 

24

U-

irregular immigrant

     
Black Swallowtail

2670

UC

 

118

C

locally common to uncommon

     
Red-spotted Purple/White Admiral

2390

UC

 

137

C

common

 

downward

 
Frosted Elfin

2000

UC

 

12

R

rare

 

upward

more searches; better habitat management

Northern Broken-Dash

1761

UC

 

92

U+

locally common

     
Spicebush Swallowtail

1744

UC

 

101

C

fairly common to uncommon

 

downward

 
Viceroy

1738

UC

 

146

C

common

 

downward

 
Banded Hairstreak

1708

UC

 

93

U+

fairly common

 

downward

most common of the hairstreaks

Red-spotted Purple (sub-sp.)

1644

UC

             
Eastern Comma

1555

UC

 

70

U

common

 

downward

more common than Question Mark

Common Buckeye

1490

UC

 

58

U

uncommon to common

     
Summer Azure

1453

UC

 

0

         
Tawny-edged Skipper 

1392

UC

 

78

U

common to locally abund

 

downward

 
Long Dash

1346

UC

 

118

C

common

 

downward

 
Silvery Blue

1331

UC

 

0

        new arrival from north
Hobomok Skipper

1330

UC

 

152

A

common

 

downward

 
Wild Indigo Duskywing

1316

UC

 

45

U

locally common

     
Mustard White

1252

UC

 

5

R

rare/local

 

upward

concentrated in a few Berkshire towns

Eastern Pine Elfin

1222

UC

 

104

C

common

 

downward

 
Little Glassywing

1162

UC

 

101

C

common to very common

 

downward

 
Brown Elfin

1144

UC

 

69

U

locally common

     
Common Sootywing

1119

UC

 

70

U

       
                   

ENGLISH NAME

MBC

   

ATLAS

     

CHANGE

COMMENT

Dusted Skipper

965

U

 

87

U

locally common

     
Broad-winged Skipper

955

U

 

45

U

locally common

     
Edwards' Hairstreak

904

U

 

53

U

       
Delaware Skipper

881

U

 

111

C

common to uncommon

 

downward

 
Dreamy Duskywing

828

U

 

92

U

uncommon to common

   

still more common than Sleepy

Milbert's Tortoiseshell

778

U

 

30

U

locally common

     
Question Mark

725

U

 

95

U+

common

 

downward

 
Appalachian Brown

706

U

 

50

U

uncommon to common

     
Harris' Checkerspot

675

U

 

24

U

uncommon

     
Mulberry Wing

668

U

 

54

U

uncommon

     
Acadian Hairstreak

633

U

 

30

U

uncommon

     
Eyed Brown

601

U

 

79

U

locally common

 

downward

 
Northern Cloudywing

586

U

 

82

U

common

 

downward

still more common than Southern

Striped Hairstreak

543

U

 

94

U+

common

 

downward

now less common than Banded

Crossline Skipper

535

U

 

68

U

uncommon

     
Indian Skipper

509

U

 

48

U

uncommon

     
Coral Hairstreak

475

U

 

65

U

uncommon

     
Cobweb Skipper

460

U

 

33

U

locally common

 

downward

 

ENGLISH NAME

MBC

   

ATLAS

     

CHANGE

COMMENT

Juniper Hairstreak

410

U

 

37

U

uncommon to common

 

downward

 
Canadian Tiger Swallowtail

398

U

 

0

       

 not distinguished by Atlas

Harvester

394

U

 

37

U

local

     
Leonard's Skipper

384

U

 

33

U

uncommon

     
Bronze Copper

354

U

 

10

R

uncommon

 

upward

targeted searches

Compton Tortoiseshell

352

U

 

51

U

locally common

 

downward

 
White Admiral (sub-sp.)

348

U

 

48

U

       
Aphrodite Fritillary

344

U

 

69

U

uncommon to common

 

downward

 
Hoary Elfin

327

U

 

5

R

local

 

upward

not rare

Black Dash

319

U

 

49

U

uncommon to common

 

downward

 
Southern Cloudywing

318

U

 

20

U-

uncommon

     
Cloudless Sulphur

314

U

 

5

R

uncommon

 

upward

not rare

Hoary Edge

276

U

 

28

U

uncommon

     
Meadow Fritillary

275

U

 

31

U

uncommon,local      
Variegated Fritillary

273

U

 

22

U-

rare to uncommon

   

not rare

West Virginia White

262

U

 

29

U-

uncommon to locally common

     
Sleepy Duskywing

261

U

 

27

U-

uncommon

     
Arctic Skipper

255

U

 

31

U

uncommon

     
Common Checkered-Skipper

220

U

 

1

R

rare

 

upward

 overwintering not confirmed

Horace's Duskywing

218

U

 

35

U

common

 

downward

 
Northern Pearly-Eye

218

U

 

72

U

uncommon

     
Gray Hairstreak

215

U

 

67

U

uncommon to common

     
Atlantis Fritillary

191

U

 

20

U-

locally common

 

downward

 
Zabulon Skipper

181

U

 

2

R

rare/local

 

upward

consistent searches

Fiery Skipper

166

U

 

1

R

   

upward

 
Pepper and Salt Skipper

158

U

 

42

U

uncommon

     
Hickory Hairstreak

137

U

 

0

 

not recorded

 

upward

identification problems

Henry's Elfin

118

U

 

29

U

uncommon

     
                   

ENGLISH NAME

MBC

   

ATLAS

     

CHANGE

COMMENT

Tawny Emperor

92

UR

 

0

     

upward

 
Ocola Skipper

83

UR

 

0

 

not recorded

 

upward

 
Early Hairstreak

73

UR

 

5

R

   

upward

 
Hackberry Emperor

71

UR

 

0

 

rare

 

upward

 
White M Hairstreak

68

UR

 

5

R

rare

 

upward

 
Cherry Gall Azure

54

(UR)

 

0

     

upward

 
Pipevine Swallowtail

35

UR

 

12

R

erratic

 

upward

 
Hessel's Hairstreak

34

UR

 

11

R

rare

 

upward

 
Oak Hairstreak

32

UR

 

9

R

rare

 

upward

formerly Southern Hs.

Two-spotted Skipper

23

R

 

3

R

rare

 

upward

 
Common Roadside-Skipper

17

R

 

10

R

rare to uncommon

     
Dion Skipper

15

R

 

1

R

rare

   

less rare

Sachem

13

R

 

0

 

vagrant

 

upward

now found

Persius Duskywing

8

R

 

0

     

upward

now found, but rarely

Long-tailed Skipper

7

R

 

1

R

vagrant

   

less rare

Bog Elfin

5

R

 

0

 

not recorded

 

upward

now found

American Snout

4

R

 

6

R

rare

     
Checkered White

4

R

 

0

 

not recorded

 

upward

now found, but rarely

Gray Comma

4

R

 

4

R

rare

     
Queen

3

R

 

0

         
Brazilian Skipper

1

VR

 

0

 

not recorded

     
Giant Swallowtail

1

VR

 

0

 

not recorded

     
Little Yellow

1

VR

 

1

R

   

downward

 
Zebra Swallowtail

1

VR

 

0

 

not recorded

     
Falcate Orangetip

0

   

0

 

not found

     
Regal Fritillary

0

EX

 

4

R

   

downward

extirpated

Columbine Duskywing

0

EX

 

0

 

not found

   

extirpated

ENGLISH NAME

MBC

   

ATLAS

     

CHANGE

COMMENT

 

Total reported 2000-7

Code (see text)

 

Blocks

Code: 150+=Abundant; 100+=Common; 20-100=Uncomm; 1-20=Rare

Published Status

 

Atlas to MBC

 
                   

 

© Sharon Stichter 2010, 2011, 2012, 2013, 2014

page updated  11-21-2014

 

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