After the disappointing results from the 2007 re-introduction, the biologists knew they had to find a way to mitigate nature’s unpredictable weather. Plan B consisted of acquiring permission from the US Fish and Wildlife Service for a 5-year permit to transfer about 4,000 caterpillars from Coyote Ridge, where the population is booming.
This phased introduction will further increase chances of hitting a good weather year that is conducive to population establishment. Mowing and dethatching continue to take place rotationally throughout the butterfly habitat, creating dense fields of dwarf plantain, gold fields, tidy tips, and other nectar sources.
So in February 2011, about 4,000 butterflies were collected and moved to their new home at Edgewood.
The larger number of caterpillars will increase the critical density of adult butterflies. Butterflies judge habitat quality by the presence of others; they need a critical mass to settle down and develop a sedentary tendency. Introducing too few butterflies, as may have been the case in 2007, may increase the likelihood that they will fly away looking for other individuals.