Species Fact Sheet Taylor's checkerspot butterfly Euphydryas editha taylori
STATUS: ENDANGERED CRITICAL HABITAT: DESIGNATED
Taylor's checkerspot butterfly potentially occurs in these Oregon counties: Benton (Map may reflect historical as well as recent sightings)
The Taylor's checkerspot butterfly (also known as the Whulge checkerspot) became a candidate species in October 2001. An annual review of the species was done in December 2007. On October 3, 2013, the Taylor's checkerspot butterfly was listed as an endangered species under the ESA. More information.
The Taylor's checkerspot is a prairie species once
found throughout grasslands in the Willamette Valley, Puget Sound,
and south Vancouver Island. Historic range and abundance is not
precisely known because exhaustive searches did not occur until
recently. Northwest grasslands were formerly more common, larger
and interconnected - conditions that likely would have supported
a greater distribution and abundance of Taylor's checkerspot.
Before its decline, the checkerspot was documented at more than
70 sites in British Columbia, Washington, and Oregon. These sites
included coastal and inland grasslands (prairies) on southern
Vancouver Island and surrounding islands in British Columbia and
the San Juan Island archipelago, as well as open prairies on post-glacial
gravelly outwash and balds in Washington's Puget Trough and Oregon's
Willamette Valley. In Oregon, there were 14 recorded sites from
which this subspecies had been either collected or observed over
the last century.
Today, the Taylor's checkerspot is extirpated (locally extinct
but exists elsewhere) from British Columbia and all but one locale
in the Willamette Valley. By 1989, fewer than 15 populations remained
in the Pacific Northwest, and as of October 2002, there are only
four confirmed populations, although it may exist at three additional
locales. In Oregon, the checkerspot is found at only one site, in
Benton county, on a grassy bald and powerline right-of-way area
owned by the Weyerhauser Company.
and Life History
Taylor's checkerspot is the darkest subspecies of the Edith checkerspot.
It is a medium-sized, colorfully-checkered butterfly with a wing
span of 5.7 centimeters (2.25 inches). The ventral surface of the
wings are primarily orange with bands of white cells. The dorsal
portion of the wings has a proportionate mix of black, orange, and
white. It is one of the smallest of the Edith checkerspots,
and it has short and stubby wings.
Adults emerge in the spring, during April and May, when they
mate and lay clusters of as many as 1,200 eggs. Larvae emerge
and grow until the fourth or fifth instar. Larvae feeding on wildflowersin Puget Trough have been documented to enter diapause in
mid-June to early July, hibernating through the winter.
Habitat requirements for the Taylor's checkerspot consist of
open grasslands and grass/oak woodland sites where food plants
for larvae and nectar sources for adults are available. These
sites include coastal and inland prairies on post-glacial, gravelly
outwash and balds. Taylors checkerspot larvae have been
documented feeding on members of the figwort or snapdragon family
(Scrophulariaceae), including paintbrush (Castilleja hispida)
as well as native and non-native Plantago spp. in the plantain
family (Plantaginacea). The last remaining population in Oregon
also depends upon P. lanceolata. Within the entire range
of the Taylors checkerspot, prairie habitat was historically
maintained, in part, through periodic burning by Native Americans.
Reasons for Decline
The major limiting factors affecting this species are related
primarily to the significant loss of suitable habitat that is
largely due to agricultural and urban development, encroachment
of trees, and spread of invasive plants which threaten the native
grasslands in which the species is found. Pesticide use and recreational
activities pose a direct threat to the butterflies themselves.
The impact of these threats has led to a smaller and smaller number
of extant (still existing) populations, with the natural instability
of small populations. Most of the remaining checkerspot habitat
sites are a considerable distance from one another, likely well
beyond dispersal distance. Natural re-colonization is unlikely as