As native grasslands are lost to agriculture and other development, the survival of the Taylor’s checkerspot butterfly hangs in the balance.
Because of the checkerspot’s sensitivity to changes in its habitat, it is considered a keystone species — an environmental indicator for the health of the entire ecosystem. The Taylor’s checkerspot is the darkest subspecies of the Edith’s checkerspot and has a wingspan of less than six centimetres. Adults emerge in April and May, when they mate and lay clusters of as many as 1,200 eggs. The larvae that emerge pause their development in mid-June to early July and hibernate through the winter.
The Taylor’s checkerspot needs open grassland with sparse vegetation and wet conditions that support the food sources larvae need, such as marsh speedwell, thymeleaf speedwell or plantago (an introduced species). Nectar-producing wildflowers such as wild strawberry must also be nearby to feed the adults. These conditions are often found in natural Garry oak ecosystems (which are now rare), although areas cleared by human activities have also supported checkerspot populations.
The Taylor’s checkerspot once was widespread in the San Juan Islands, southern Vancouver Island and the surrounding islands of British Columbia, as well as on coastal and inland grasslands, open prairies and gravelly outwash areas of Puget Sound, Washington and Oregon. It was believed to have disappeared from Canada until 2005, when 15 Taylor’s checkerspot butterflies were observed on Denman Island in B.C.’s Gulf Islands. According to one study, there are only 14 sites in the Pacific Northwest with checkerspot populations that contain more than 50 individuals.
The native grasslands these butterflies favour are particularly vulnerable to agricultural use, urban development and the encroachment of trees and invasive plants. At one point, there were 100,000 hectares of suitable habitat in western Washington alone. Today only a few acres remain. Pesticides, fire suppression and drought also threaten this species.
Recommended Recovery Actions
The federal multi-species Recovery Strategy for Garry oak ecosystems calls for a number of conservation measures that will benefit Taylor’s checkerspot, including protecting habitat, identifying food plants and developing techniques for establishing new populations.
What We Are Doing
Find out how Wildlife Preservation Canada is helping save native pollinators, including Taylor’s checkerspot, and how you can make a difference.
Federal Species at Risk Profile: Taylor’s Checkerspot
Garry Oak Ecosystem Recovery Team