Scientific Name: Limenitis weidemeyerii
Taxonomy Group: Arthropods
Last COSEWIC Assessment: May 2012
Last COSEWIC Designation: Special Concern
SARA Status: Schedule 1, Special Concern
Image of Weidemeyer's Admiral
The Weidemeyer's Admiral is a relatively large butterfly with a wingspan of 55 to 72 mm. It is mostly black with bold white bands on both wing surfaces and with extensive greyish white markings on the underside of the hind wings. Near the white band are small, relatively inconspicuous, red markings. The species' caterpillars can be olive-green with a mostly tan thorax (the segment behind the head), or greyish mottled with grey and white patches. Further back, there is a whitish-tan saddle on the middle of the dorsal surface and a whitish band on each side. The head is red-brown with small tubercles on the top. The pupae are blackish-brown with tan on the head and thorax and some areas of whitish and tan, a black streak on the dorsal surface, and slight greenish mottling.
Distribution and Population
This admiral is widely distributed in the western interior of the United States. In Canada, the only known resident population occurs along about 80 km of the Milk River valley in southern Alberta. The Canadian population, estimated at a maximum of 1800 to 3200 individuals, is naturally fragmented (reflecting the distribution of its habitat), but is probably stable.
Admirals use the woody riparian (along river banks) vegetation along the Milk River and its tributaries. Within the species' range, this vegetation naturally occurs as patches in a wide expanse of arid native grassland, badlands and croplands. The butterflies are typically associated with deciduous treed and shrubby areas which provide the necessary habitat ingredients: larval host plants, moisture and nectar sources for adults, and elevated perches for mate-locating by males.
Little information has been published on the biology of the Weidemeyer's Admiral. In Alberta, adult admirals have only one flight period per year, mostly from mid-June to mid July. Males may be territorial. They engage in both patrolling and perching types of mate-locating behaviour. They tend to patrol early in the day and later settle into perching sites. Females are seen less frequently as they spend much of their time in shrubs. They lay greyish-green eggs, placed singly on the upper side of the leaf tips of host plants, such as saskatoon, aspen, willow and wild cherries. The caterpillars eat the leaves of these plants. They hibernate through the winter. The following summer, they pupate and emerge as adults which feed on tree sap, flower nectar and carrion and also obtain moisture from mud. The Weidemeyer's Admiral can hybridize with other admiral species/sub-species where their ranges meet, but tends not to hybridize in areas of range overlap. Even though the Canadian population is patchily distributed, the species is very mobile. Genetic exchange between populations in these patches and with those in the United States is probably quite extensive.
The species is at the northern edge of its range and is presumably limited by climate. It is restricted to suitable habitat which is naturally patchy and limited within the butterfly's restricted range. The human population is sparse in this remote are, and urbanization is not a factor. The areas occupied by the butterfly are unlikely to be cultivated, but high intensity livestock grazing could potentially be detrimental to the species.
Federal ProtectionMore information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
In Canada the Weidemeyer's Admiral has a very restricted range, but portions of it are protected in a provincial park, an ecological reserve and a natural area.
Provincial and Territorial Protection
Recovery Progress and Activities
Summary of Progress to Date Conservation strategies for individual ranches have been developed and implemented on some private ranches which contain habitat of the Weidemeyer’s Admiral. Summary of Recovery Activities Meetings are being held to inform the public about species at risk, such as the Weidemeyer’s Admiral. Workshops are being held with land owners to discuss management practices that would be beneficial for this butterfly.
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
6 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Management Plans (1 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Recovery Document Posting Plans (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
Recovery Document Posting Plans
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