Black swallowtail, butterfly count, Rice Lake Plains, ON (Photo by NCC)

Black swallowtail, butterfly count, Rice Lake Plains, ON (Photo by NCC)

Bringing back the butterflies

Pearl crescent, butterfly count, Rice Lake Plains, ON (Photo by NCC)

Pearl crescent, butterfly count, Rice Lake Plains, ON (Photo by NCC)

Butterflies are one of those species that’s hard not to like. Their beautiful colours, delicate flight patterns and non-aggressive nature (at least toward humans) makes them popular with nature lovers and even those who prefer to spend most of their time indoors. Ask anyone who says they don’t like bugs, and butterflies will usually be the exception.

Butterflies are also important indicators of the state of our ecosystems. Their presence or absence can tell us a lot about the environment around us. In central Ontario, butterfly populations have been a useful barometer to track our progress in restoring the rare tall grass prairie mosaic of the Rice Lake Plains. That’s why each year, with the help of Conservation Volunteers, the Nature Conservancy of Canada (NCC) conducts butterfly counts on our properties.

Located north of Cobourg, Ontario, the rolling hills of the Rice Lake Plains were once dominated by massive black and white oaks and grasses. Big bluestem, Indian grass and switchgrass once grew more than two metres high. Today, remnant examples of these habitats still exist, but they are badly fragmented and overgrown with non-native species. These remaining areas are priorities for conservation and restoration because they are refuges for species at risk, including many grassland birds, insects and the eastern hog-nosed snake.

Butterfly milkweed, Rice Lake Plains, ON (Photo by NCC)

Butterfly milkweed, Rice Lake Plains, ON (Photo by NCC)

Butterflies really are the cherry on top when it comes to restoration. The decline of certain butterfly species (such as the Karner blue) is a direct result of the loss of rare ecosystems, such as those found in the Rice Lakes Plains.

This small oasis was once part of a larger mosaic of native savannah species species that are necessary for the life cycle of many rare butterflies. Periodic natural disturbances such as fire and grazing were the “spring cleaning” events that kept savannah ecosystems in check. When these natural process were halted, through human activity and development, the tall grass prairies were engulfed by forests and taken over by invasive species, causing some butterflies to disappear.

Reversing these changes is where NCC comes in. Thanks to a three-year, $663,200 Grow Grant from the Ontario Trillium Foundation made in late 2017, NCC has been able to ramp up restoration efforts of important tall grass prairie and oak savannah habitat in the Rice Lake Plains Natural Area. With the help of volunteers, we have planted thousands of wildflowers, such as butterfly milkweed, along with native prairie grasses. We also planted a shrub called New Jersey tea, which is the required food for the threatened mottled duskywing butterfly. The Ontario Government Career Ready Fund (that, in part, funds our summer conservation technicians) and the Ministry of Natural Resources and Forestry Species at Risk Stewardship Fund have also contributed to moving restoration efforts ahead.

Through removing invasive species, reintroducing regular disturbances, such as prescribed burns, and planting native grassland species, NCC is working hard to get the butterflies back. Every time we see a species-at-risk butterfly, we take it as a sign that we are doing it right!

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