RANGEWIDE DISTRIBUTION. Historically, the xxxxxx occurred throughout the boreal and temperate forests of North America and its range included southern Canada and most of the northern states as well as peninsular areas that extend south through the eastern states, the northern Rocky Mountains, and the Pacific states (Figure 1). The extirpation of fishers from much of the southern portion of their range that occurred from the late 1800s to the early 1900s resulted in range contraction to ~43% of its historical extent. Efforts to reintroduce fishers in vacant portions of the historical range and improved management of resident xxxxxx populations resulted in xxxxxx recovery and an expansion of the current range to approximately 68% of its historical extent (Figure 1; Xxxxx et al. 2012).
RANGEWIDE DISTRIBUTION. The island marble butterfly was historically known from just two areas along the southeast coast of Vancouver Island, British Columbia, Canada, based on 14 museum records: the Greater Victoria area at the southern end of Vancouver Island; and near Nanaimo and on adjacent Gabriola Island, approximately 56 miles north of Victoria. The last known specimen of the island marble butterfly from Canada was collected in 1908 on Gabriola Island, and the species is now considered extirpated from the province (COSEWIC 2010, p. 6). Reasons for its disappearance from Canada are unknown. Hypotheses include increased parasitoid loads (the number of individual deadly parasites within an individual caterpillar) associated with the introduction of the cabbage white butterfly (Guppy and Xxxxxxx 2001, p. 38) or, more likely, heavy grazing of natural xxxxxxx by cattle and sheep, which severely depressed its presumed larval food plant (XXXX 2015). After 90 years without a documented occurrence, the island marble butterfly was rediscovered in 1998 on San Xxxx Island, San Xxxx County, Washington, at least 9 miles east of Victoria across the Xxxx Xxxxxx (Xxxxxxxxxxxx and Xxxxxx 1999). Subsequent surveys in suitable habitat across Southeast Vancouver Island and the Gulf Islands in Canada (see COSEWIC 2010, p. 5), as well as the San Xxxx Islands and six adjacent counties in the United States (Whatcom, Skagit, Snohomish, Jefferson, Clallam, and Island Counties) (Miskelly and Xxxxxx 2005; Miskelly and Xxxxxxxxxxxx 2007), revealed only two other occupied areas. One of these occupied areas was centered on San Xxxx Island and the other on Xxxxx Island, which is separated from San Xxxx Island by just over 0.5 miles at its closest point. These occupied areas were eventually determined to comprise five populations, as described in detail in the USFWS 2006 12-month finding (71 FR 66292, November 14, 2006). Since 2006, the number and distribution of populations has declined. Four of the five populations that once spanned San Xxxx and Xxxxx Islands have not been detected in recent years, and the species is now observed only in a single area centered on American Camp, a part of San Xxxx Island National Historical Park that is managed by the National Park Service (NPS). The island marble butterfly likely also uses the lands adjoining or near American Camp, as there have been at least two observations of the island marble butterflies flying along the boundaries of these adjoining lands in 2015 (Po...
