The island marble butterfly (IMB) is a rare pierid butterfly currently found only in the vicinity of the americancamp prairie ecosystem, on the southern end of SAN juan island, WA

The U.S. Fish and Wildlife Service (USFWS) awarded a $100,232 Cooperative Agreement under the Endangered Species Recovery Implementation program (CFDA 15.657) to the San Juan Preservation Trust, a private non-profit land conservation organization, to expand and maintain habitat for the federally endangered Island Marble Butterfly (IMB) on San Juan Island, Washington. The project aims to transform approximately 10 acres of degraded pastureland into suitable habitat areas that support IMB and other pollinators, implement seasonal management schemes to maintain proper host plant phenology, and conduct robust monitoring programs to track the butterfly's egg, larval, and adult stages. This effort builds on the Trust's prior experience with IMB habitat creation and species monitoring under USFWS funding. The project is expected to run from August 1, 2024 to December 31, 2026, with the goals of increasing host plant availability, facilitating natural or assisted IMB colonization in the new habitat areas, and establishing a stable or increasing adult breeding population.

IMB is federally endangered under the US fish and wildlife service (USFWS) and is a state candidate species with washington department of fish and wildlife (wdfw). To mitigate for the many threats this butterfly faces, IMB needs a larger, secure, habitat community with a host plant-stimulating management scheme on a seasonal and multi-year rotation, located in a different part of the island and away from the primary population at american camp. This is a new approach to IMB habitat creation and management, building off of lessons learned at small habitat plot sites under state-ledpartnerships, and takes IT to the landscape level. This project will meaningfully expand the prairie and hostplant habitat at one existing site managed by the SAN juan preservation trust (sjpt, a private-non profit landconservation trust), while continuing to maintain three existing habitat patches. Additionally, a robust imbmonitoring program has already been employed successfully by sjpt under prior USFWS funding programs, and sjpt now has the in-house expertise in both habitat creation and species monitoring for the butterfly in its EGG, larval, and adult stages. Successful project outcomes will be measured by 1) host plant availability (correctphenology) through adult flight season 2) transformation of approx. 10 acres of degraded pastureland intohabitat areas that support IMB and other pollinators 3) future natural or assisted colonization of IMB in any ofthe habitat areas 4) larval survival rates into late-instar that are similar to what has been documented inlong-term studies at the core population at american camp and 5) the establishment of a stable or increasingadult breeding population throughout the system.