People passionate about nature

A Snapshot of Butterflies in Southeast Manitoba - Parts 1 & 2

A citizen science project to record butterfly species and numbers

By Richard Staniforth, Larry de March, Deanna Dodgson and Peter Taylor

Part 1 - Introduction

Five full field seasons have now passed in a five-year project to record butterfly species and numbers in southeast Manitoba. It started with records reported to the Yahoo discussion group Manitobanaturetalk, but later included sightings from group field trips and from individuals who contributed sightings directly to the authors.

Above: Butterfly enthusiasts concentrate on a basking Northern blue on a trail near Chatfield, 29 June, 2016.  Photo by Garry Budyk

Manitobanaturetalk was one of over ten million discussion boards once hosted by Yahoo! Inc. It was set up in 2006 for sharing information on all Manitoba natural history subjects after the success of Manitobabirds, which had been set up 6 years earlier (membership of more than 700). Although Manitobanaturetalk garnered less interest than did Manitobabirds (64 members and, as is typical of online forums, about 10-15% very active) those who participated actively were enthusiastic, knowledgeable naturalists eager to share sightings both in their posts and in the field. Yahoo closed down most features of their groups at the end of 2019, but a number of groups including Manitobanaturetalk have migrated to which can be found here.

Manitobanaturetalk proved to be an excellent forum for collecting data and photographs of the diverse flora and fauna of Manitoba. During the existence of Manitobanaturetalk, there have been numerous postings of arthropods, rather fewer of mammals, reptiles and amphibians, and even fewer of fungi and plants. Butterfly and dragonfly records and their photographs were particularly numerous, likely because of their relatively large size and visibility, and they generated considerable discussion.

In 2014, we kept a casual list of “first-date-of-the-year” records for any butterfly species that were reported. By the end of the year we had records for 83 species. The enthusiasm of Manitoban naturalists encouraged us to record all butterfly sightings the following year and then to continue recording for a further 4 years.

Above: Common milkweed is well known as a larval food plant for Monarchs, but is also a nectar source for many other butterflies, like this group west of Milner Ridge on 16 July, 2019. Clockwise from upper right: Atlantis Fritillary; two male Northern Crescents (wings closed and open); unidentified crescent (probably an aberrant female Northern); Acadian Hairstreak.  Photo by Peter Taylor

The data included species, numbers of individuals, observation dates, locations, and observer names. Photographic documentation was obtained for all species, and for multiple observations in most cases. Excluding numbers of Cabbage white (Pieris rapae), whose numbers were sometimes described as “in the thousands”, 5575 individuals and 84 species of butterflies were recorded in 2015; 6509 individuals of 93 species in 2016, 15,992 individuals of 88 species in 2017, 8790 individuals of 84 species in 2018 and 9844 individuals of 86 species in 2019, for a combined total of 107 species, comprised of 46,710 individual insects.

To some extent the numbers of species depended on observers’ travel history and habitat coverage. Consequently, we decided that we would restrict our area of interest to the area of greatest coverage which was southeast Manitoba and the results reported below reflect that decision.

The study area was limited by the Ontario and U.S. boundaries to the east and south, respectively, and in the north by the latitude of Bloodvein. The western boundary is an irregular line that runs from Bloodvein to Watchorn in the Interlake, then along the eastern and southern shores of Lake Manitoba to Delta, and finally south to the international border.

In a series of short articles, we will present an overview of some of our findings. Each article will cover a different taxonomic unit or part thereof, depending on the number of species in that unit. The first article, presented here, covers Swallowtails (Papilionidae) and Whites and Sulphurs (Pieridae). Articles covering the Gossamer wings (Lycaenidae), Brushfoots (Nymphalidae), Spreadwing skippers (Pyrginae) and Grass skippers (Hesperiinae) will appear in future editions of the Newsletter.

As well as furnishing a lot of data and photographs, our field trips have left us with many indelible memories, especially from the period of peak butterfly diversity around the beginning of July. A combination of sunshine after recent rain with abundant roadside flowers can yield some fine spectacles of assorted puddling and nectaring butterflies along little-used rights-of-way. Provincial roads west of Chatfield (PR 419) and south of East Braintree (PR 308), and gravel roads in and near Agassiz Provincial Forest, were especially rewarding.

Above: These White admirals and Canadian tiger swallowtails are “puddling”, i.e. drinking, in this case from wet sand in Sandilands. 15 June, 2012.  Puddling also occurs on dung and carrion.  Butterflies obtain minerals and amino acids from this activity.  Photo by Larry de March

More detailed information will be published elsewhere and we will let you know where after the publications are accepted.


Part 2 - Swallowtails, Whites and Sulphurs

Old World Swallowtail
(3 reported)
Black Swallowtail
(284 reported)
Canadian Tiger Swallowtail
(2015 reported)
Clouded Sulphur
(1000s reported)
Orange Sulphur
(482 reported)
Pink-edged Sulphur
(395 reported)
Large Marble
(134 reported)
Mustard White
(154 reported)
Cabbage White
(1000s reported)
Checkered White
(5 reported)
Western White
(22 reported)

Above: Photo 2.1. Black Swallowtail male on Dandelion - Ste Geneviève, 16 May, 2012 by Richard Staniforth

Our three kinds of Swallowtails are part of a mostly tropical family of very showy butterflies (Papilionidae) and include the largest butterfly in the world, the Queen Alexandra’s Birdwing Butterfly of Papua New Guinea. The Old World Swallowtail just reaches southward into the northern edge of our area, where we have only 3 records. It is generally uncommon anywhere in our province.

The Black Swallowtail (see photo 2.1 above) is more familiar to us in the south. It has two peaks of abundance, in early June and in late July, indicating two broods. Its yellow and black banded caterpillars feed on plants of the Carrot family (Apiaceae); such as carrot, celery, celeriac, dill, fennel, parsnip, and parsley. The presence of these magnificent insects is well worth the loss of a few vegetable leaves in our yards! The Tiger Swallowtail is one of the largest North American butterflies. It has yellow with black striped wings and is our commonest swallowtail, in fact, it is often seen in large numbers which gather at rain puddles on gravel roads in forest regions. Elsewhere, such as in gardens and parks, its large size, its yellow coloration and its distinctive flight pattern of flap, flap, glide makes it easy to identify.

Above: Photo 2.2. Pink-edged Sulphur male on Red Clover - St. Labre, 5 July, 2014 by Richard Staniforth

Manitoba’s yellow butterflies and white butterflies belong to one family, the Pieridae. We had three species of yellows or sulphurs and five species of whites reported from within the boundaries of our area in southeast Manitoba. Members of this butterfly family usually perch with their wings closed over their thoraces and abdomens. Our three sulphurs are difficult to distinguish from each other and usually require a very close observation or photograph.

The Clouded and Orange Sulphurs are most often seen over fields of legumes, such as clover or alfalfa, on which the caterpillars feed. Orange Sulphurs are seen later in the summer because they depend to some extent on immigrants arriving from the south. The Pink-edged Sulphur (see photo 2.2) is found in boreal regions and over the Canadian Shield where its caterpillars feed on various species of blueberries, and not legumes as do the other species. The Pink-edged Sulphur is poorly named because other species also may have pink edges to their wings especially when freshly emerged from their chrysalids. This species is flies mostly in the month of July, each year.  Two additional species of sulphurs, the Giant Sulphur and the Christina Sulphur, have been recorded in locations near the boundaries of our area, “southeast Manitoba”, but none of us found either of them within it.

Above: Photo 2.3. Western White female - Interlake Forest Centre, Hodgson, 31 August, 2011 by Richard Staniforth

Our five species of white butterflies test our identification skills! The commonest is the Cabbage butterfly which may appear in their thousands over fields of crucifers (Brassicaceae), such as cabbages and canola on which their caterpillars feed. They cause significant damage to garden crops such as cabbages, kale, Brussels sprouts and kohlrabi by leaving an unsightly mess of frass (droppings) and damaged foliage. This species and the European Skipper are the only non-native butterflies in Manitoba.  In England it is known as the “Small White”. Though much less common as a rule, the Western (see photo 2.3) and Checkered Whites can also damage crops at times. The Mustard White feeds on legumes but is a woodland butterfly, its cruciferous foodplants are Bitter and Rock cresses (Cardamine and Arabis species). The last of our “whites” is the beautiful Large Marble, so named because of its “marbling” of green markings on the lower sides of the wings (see photo). Like the Mustard White, this spring-flying species feeds on wild cruciferous plants but is not a pest of crops.


Acknowledgements: We wish to thank the following people for their sightings which in many cases filled in gaps in coverage by the authors (alphabetical within groups): Michael Loyd, Jim Reist, and Bob Shettler for major contributions and G. Budyk, A. Drabyk, S. Hébert-Allard, L. Holbert, A. Jacobs, L. Klassen, R. Koes, B. Krosney, D. Martin, R. Mooi, D. Neufeld, R. Parsons, J. Pelechaty, D. Raitt, J. Rodger, N. Schmidt, J. Smith, R. Smith, D. Staniforth, J. Swartz, M. Waldron and J. Yatsko for additional