Dicamptodon copei

In geographic contact with Dicamptodon tenebrosus in northern Oregon, but no hybridization occurs; see Good (1989) for information on relationships among Dicamptodon species.

This species occurs in a small range in Washington and northwestern Oregon. There are many occurrences, but populations are isolated and exhibit limited gene flow. They are threatened by multiple activities that increase stream temperatures, siltation, and alter stream flow patterns, as well as by the effects of climate change.

This species occurs from the northwestern corner of the Olympic Peninsula, Washington, south through the Willapa Hills and Coast Range to the Nehalem River watershed in northwest Oregon, and in the Cascade Range from Mt Rainier National Park south and east to Wasco County, Oregon, USA (Nussbaum 1983, Stebbins 1985, Jones and Corkran 2002, Foster and Olson 2014). It is mostly absent from intervening lowlands in the Puget Trough and Willamette Valley, with a few intervening sites in Clark and Cowlitz Counties, Washington (Foster and Olson 2014). The range extent of these areas, excluding intervening lowlands, is 31,983 sq km (Foster and Olson 2014). The combined range extent, including intervening unoccupied areas, is 35,271 sq km (ORBIC 2022). The species has been documented from Clallam, Jefferson, Grays Harbor, Mason, Pacific, Wahkiakum, Cowlitz, Lewis, Clark, Skamania and Pierce Counties in Washington, and in Hood River, Wasco, Clackamas, Multnomah, Clatsop, Washington and Tillamook Counties in Oregon (Foster and Olson 2014). It is found from near sea level to about 1593 m (Foster et al. 2015).

There are 581 discrete (not overlapping) observation records (Foster and Olson 2014). Many of these would combine into single element occurrences. The observations occur across 164 6th field watersheds (Foster and Olson 2014). There are possibly over 100 occurrences in Washington (J. Fleckenstein, pers. comm., 1997). There are approximately 40 occurrences in Oregon (ORBIC 2022).

Activities that alter microhabitats or create barriers to dispersal are likely to negatively impact this species. Forest management and stream-road culverts are the greatest threats, primarily due to habitat alterations that impede dispersal, increase stream siltation from erosion, and increase in-stream temperatures after canopy removal (Foster and Olson 2014, Foster et al. 2015). Timber harvest could disturb stream channel habitat, increase stream temperatures to unsuitably high levels, and result in siltation, which may detrimentally affect food resources. However the effect of timber harvest appears to vary by location and methods used (Corn and Bury 1989, Steele et al. 2002, Foster and Olson 2014). Culverts and road construction and maintenance can increase stream sedimentation and present barriers to dispersal and gene flow (Foster and Olson 2014).

Cope's giant salamanders have been identified as having moderate-to-high vulnerability to climate change due to reduced summer stream flow and elevated water temperature (Washington Department of Fish and Wildlife 2022). Warmer or more variable stream temperatures will affect life history characteristics and may make streams uninhabitable, altering distribution, particularly in the southern portion of the species' range (Trumbo et al. 2013, Foster and Olson 2014, Washington Department of Fish and Wildlife 2022). Increasingly frequent high flow events may adversely affect Cope's giant salamanders (Foster and Olson 2014). Large stand replacing fires may increase under climate change, resulting in increased stream temperatures, sediment inputs, and debris flows (Foster and Olson 2014, Washington Department of Fish and Wildlife 2022). Chemical use for vegetation management, fire retardants, and pest control can directly affect Cope's giant salamander, and this threat is of particular concern on state and private lands (Foster and Olson 2014).