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Montana Field Guide

Montana Field Guides

Skade's Jumping-slug - Hemphillia skadei

Species of Concern
Native Species

Global Rank: GNR
State Rank: S1S2
(see State Rank Reason below)

Agency Status

External Links

State Rank Reason (see State Rank above)
Species is newly separated by genetic and morphological attributed from the Pale Jumping-slug. Much uncertainty exists in distribution, trends, and the impacts of operational threats including climate change, fire, and forest management practices. Further information is needed to refine the status rank which may be derived from further surveys as well as the analysis of the genetics and morphology of previously collected voucher specimens. The species has a Raw Status Rank 2.5 (S3), but after review of the limited information on the species we have decreased the rank as the species is likely limited in distribution and may face threats to its persistence in the state. Given the limited information on this species we have chosen to assign a split rank of S1-S2 until more information allows us to rank the species with greater uncertainty.
  • Details on Status Ranking and Review
    Skade's Jumping-slug (Hemphillia skadei) Conservation Status Review
    Review Date = 06/07/2019
    View State Conservation Rank Criteria
    Range Extent

    ScoreU - Unknown

    CommentAs this species is newly described, its range extent beyond the initial inventory that discovered it is unknown. The species appears to require cool air temperatures and is likely restricted to the mountains of northwest Montana.

    Long-term Trend

    ScoreU - Unknown. Long-term trend in population, range, area occupied, or number or condition of occurrences unknown


    Short-term Trend

    ScoreU - Unknown. Short-term trend in population, range, area occupied, and number and condition of occurrences unknown.



    ScoreU - Unknown. The available information is not sufficient to assign degree of threat as above. (Severity, scope, and immediacy are all unknown, or mostly [two of three] unknown or not assessed [null].)

    CommentTreat impacts are unknown. Species appears to be restricted to cool montane environments so a warming climate as well as fire and logging will likely have impacts. However, the extent of these impacts on the suitability of occupied habitat and the persistence of the species are unknown at this time. Further research to identify the effects of these threats is needed.

    Intrinsic Vulnerability

    ScoreA - Highly Vulnerable. Species is slow to mature, reproduces infrequently, and/or has low fecundity such that populations are very slow (> 20 years or 5 generations) to recover from decreases in abundance; or species has low dispersal capability such that extirpated populations are unlikely to become reestablished through natural recolonization (unaided by humans).

    CommentSpecies is likely highly vulnerable to threats due to difficulty dispersing between occupied habitat

    Environmental Specificity

    ScoreA - Very Narrow. Specialist. Specific habitat(s), substrate(s), food type(s), hosts, breeding/nonbreeding microhabitats, or other abiotic and/or biotic factor(s) are used or required by the Element in the area of interest, with these habitat(s) and/or other requirements furthermore being scarce within the generalized range of the species within the area of interest, and, the population (or the number of breeding attempts) expected to decline significantly if any of these key requirements become unavailable.

    CommentSpecies is restricted to montane environments with very specific attributes

    Raw Conservation Status Score

    Score 3.5+ -0.5 (environmental specificity) + 0 (trends) + -0.5 (intrinsic vulnerability) = 2.5

General Description
Outer appearance resembles the Pale Jumping Slug (Hemphillia camelus). However, the species is genetically distinct and has four differences in the reproductive system: (1) penis is barrel or acorn shaped in H. skadei and peanut shaped in H. camelus; (2) penis is unpigmented in H. skadei, but has a central band of pigment in the restricted portion in H. camelus; (3) the free oviduct is shorter in H. skadei and longer in H. camelus; and (4) the spermatophore is slender in H. skadei and more robust in H. camelus (Lucid et al. 2018).

Late-season collection of immature specimens is suggestive that the species likely overwinters as immature and mature animals and lives multiple years (Lucid et al. 2018).

Species Range
Montana Range


Range Comments
Only a single occurrence is known in Montana from the western portion of the Cabinet Mountains, approximately 1.6 miles from the Idaho border (Lucid et al. 2018).

Observations in Montana Natural Heritage Program Database
Number of Observations: 1

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

In northern Idaho and Montana this species is typically collected in forested areas with cooler temperatures and most often under logs or rocks; occasionally found on the forest floor surface during wet periods (Lucid et al. 2018).

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Citation for data on this website:
Skade's Jumping-slug — Hemphillia skadei.  Montana Field Guide.  .  Retrieved on , from