A Species Few Have Observed
When you think of rare wildlife in the Credit River Watershed, butterflies may not be the first thing that comes to mind. Yet one species may hold the title of our watershed’s rarest butterfly: the meadow fritillary (Boloria bellona).
To date, the meadow fritillary has been observed only six times within the watershed and all six records come from the same location.
The meadow fritillary belongs to the brushfoot butterfly family (Nymphalidae), which also includes familiar species such as monarchs, white admirals and mourning cloaks. Within this family, it’s part of a group known as the fritillaries. If you’ve spent time in a pollinator garden, you may already know one of its relatives: the great spangled fritillary (Speyeria cybele), a common visitor to native wildflower plantings.
Like other fritillaries, the meadow fritillary has bright orange wings marked with dark brown or black patterns. Looking more closely reveals the details that set it apart. The undersides of its wings are mottled orange and brown with patches of frosted white, creating a distinctive appearance noticeable when you look closely.
A Secretive Life Among the Violets
Much of the meadow fritillary’s life remains hidden from view.
Its caterpillars feed on native violets but they do most of their feeding at night and are rarely observed. Adult females lay their eggs individually on nearby vegetation rather than directly on violet plants. Once the caterpillars hatch, they must find their own way to the host plants that will sustain them.
As winter approaches, the caterpillars seek shelter in leaf litter, where they overwinter curled inside fallen leaves until warmer temperatures return.
In Ontario, meadow fritillaries produce two or three generations each year. Records from local observations show adults flying in spring, midsummer and late summer, with sightings documented in May, July and August.
Why Are Meadow Fritullarys So Rare?
Interestingly, field guides often describe the meadow fritillary as one of Ontario’s most common lesser fritillaries.So why does it appear to be so uncommon in the Credit River Watershed?
One possibility is that it’s more widespread than our records suggest. Butterflies can be difficult to find, and some species are easily overlooked. However, after years of intensive surveying through CVC’s Butterfly Blitz program, it seems likely that meadow fritillaries would have been detected in more locations if they were regularly occurring across the watershed.
Another possibility is that suitable habitat has become less common over time.
The meadow fritillary depends on open habitats that support native violets and a diversity of flowering plants. Across southern Ontario, many of these habitats face pressures from development, changing land use and natural succession. The species is also affected by broader challenges facing insects, including pesticide use and landscaping practices that provide limited habitat and food sources.
Records from the Ontario Butterfly Atlas suggests that meadow fritillary populations may be declining in other parts of southern Ontario as well.
Supporting Butterflies Through Habitat Conservation
The good news is that many actions that benefit the meadow fritillary are already part of ongoing conservation work across the watershed.
Protecting and restoring natural areas, supporting sustainable gardening practices, enhancing habitat connectivity and promoting biodiversity all help create conditions that support butterflies and other pollinators.
An important part of this work is recognizing that healthy watersheds need a variety of habitat types. While tree planting remains a valuable tool for restoring forests and improving ecological health, some species depend on open habitats such as meadows, grasslands and wetlands. Conserving and managing a balance of habitat types helps ensure that species with different needs can thrive across the landscape.
To better understand these needs, we’ re beginning work to identify local butterfly species of conservation concern. This project will help highlight areas that provide important habitat for locally rare butterflies and support future conservation planning.
How You Can Help
The next important meadow fritillary observation could come from anyone exploring the watershed.
If you spot an unfamiliar butterfly, consider taking a photograph and sharing your observation through iNaturalist. Citizen science observations help researchers and conservation organizations better understand where species occur, how populations change over time and what habitats they depend on.
For rare species like the meadow fritillary, every observation matters. The more we learn about where it lives, the better equipped we are to protect the habitats it needs to survive.
And who knows? You could discover the watershed’s seventh meadow Fritillary record.
Learn more about butterflies in the Credit River Watershed.
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By Laura Timms, Program Manager, Natural Heritage Management