Winged barometers

Dr. Paul Catling speaks about butterflies at the Picton Library on Saturday.

What butterflies tell us about the natural landscape

It is rare to observe the juniper hairstreak in Canada—except, it seems, in Prince Edward County. In fact, more than half of the Canadian population of this olive-coloured butterfly species may be found in the County’s particular habitat, according to Dr. Paul Catling.

Catling is a research scientist and naturalist with Agriculture and Agri-FoodCanada—a federal ministry. He came to prominence in Prince Edward County last spring, when he presented expert evidence about the nature of the rare and sensitive alvar habitat at Ostrander Point to an Environmental Review Tribunal.

He told the Tribunal it was a mistake to construct 500-foot industrial wind turbines in this habitat—the massive footings and road system needed to support this development would forever disrupt the delicate balance in this rare place—a nesting and breeding area for an unusual number of endangered species, including the Blanding’s turtle and the whippoorwill.

The soil cover on the alvar is thin— non-existent in patches. This means it serves as host to particular types of grasses, wildflowers and hardy shrubs. The area is defined by vast open meadows of grasses, red cedar and juniper. It is also a great habitat for butterflies.

Catling has prepared and written a book about PrinceEdwardCounty’s butterflies. He spoke to a capacity crowd at the Picton Library on Saturday afternoon to launch his book, A Field guide to Butterflies of Prince Edward County and the surrounding region, and sign copies.

“Not very many counties have their own guide to the flora and fauna,” said Catling. “But some of Prince Edward County’s natural landscape is remarkable.”

More than 80 species of butterfly have been recorded in the County—most reside here, ten species migrate through on their way to and from nesting sites. They come with colourful and fanciful names including orange sulphur, red admiral and meadow fritillary.

The giant swallowtail is the largest butterfly species in Canada, with a wingspan of up to 11 centimetres (a little over four inches). Giant swallowtails have been sighted at a variety of locations across Prince Edward County, but is a relative newcomer to the area.

Catling noted that it has only been a couple of decades since the first sightings of these large Lepidoptera. Climate change has likely played a role— but Catling suggests the explanation is more nuanced. He noted that agricultural land was used more intensively in the past 100 years—leaving very little untouched.

“Wood was used for everything,” said Catling.

But as farming has evolved, and become more specialized, low yield land is giving way to meadows, woodland and the prickly ash. The foliage of the prickly ash is a favourite of the giant swallowtail caterpillar.

Catling says there are easy things we can do, either individually or as a community, to preserve natural habitat for these winged creatures.

“Reduce cutting along the margin of the roadside,” said Catling. He acknowledges that some must be cut back for safety and visibility—but there is no need to shear grass to the fenceline.

He tells the story of his neighbour, Bob who lives down the street in suburban Ottawa.

Bob cuts his lawn early each spring, but then allows a one by 20 metre strip along the front of his yard to grow until late August. It now features a wide mix of grasses and wild flowers. It has become a magnet for butterflies all summer long.

Once the butterflies have gone and the plants have dropped their seeds, Bob trims his butterfly patch.

Catling believes it is important to monitor and observe butterflies as they dart around County meadows. They are, in his view, a barometer for the health of the environment around us—a highly sensitive warning system. But their signals are increasingly crowded out by technology, our devotion to instant communication and increasingly urban lifestyles.

“We are becoming increasingly detached from nature,” warned Catling. “So too have our children.”

Catling has committed that all the proceeds from the sale of the book will go to the Prince Edward County Field Naturalists to protect the natural landscape

A field guide to Butterflies of PrinceEdwardCounty and the surrounding region by Paul Catling is available at Books & Company in Picton. Copies can also be ordered online at: saveostranderpoint.com.