Photo Credit: Dan Marschalek
Photo Credit: Emily Perkins, SDMMP
Photo Credit: Emily Perkins, SDMMP
| Historically present | |
| Currently present >2000 |
Goal: Protect, enhance, and restore Harbison's dun skipper occupied habitat, historically occupied habitat, and the landscape connections between them to create resilient, self-sustaining populations that provide for persistence over the long-term (>100 years).
Management units: 3, 4, 5, 6, 8, 11
In 2017 and 2020, conduct host plant (San Diego sedge), adult, larval and hibernaculum surveys, and habitat assessments for Harbison's dun skipper that were initiated in 2013 in the MSPA (see Table of Occurrences) to further document the butterfly's current distribution and population size, define habitat requirements, and to assess habitat and threats at survey sites.
| Action | Statement | Action status | Projects |
|---|---|---|---|
| SURV-1 | Search for Harvison's dun skipper adults, butterfly hiberniculum, larvae and host plants (San Diego sedge) at known occupied habitat, historically occupied habitat and in suitable potential habitat, to determine the extent of the butterfly's range, population sizes, and to better understand habitat relationships. Use a standardized protocol to collect habitat and threats covariate data at each site for developing and prioritizing management actions. | In progress | |
| SURV-2 | Submit project metadata, datasets, analyses and report with management recommendations to the MSP Web Portal. | In progress |
| Criteria | Deadline year |
|---|---|
| Harbison's Dun Skipper Surveys and Reports Completed in 2018 and 2021 | 2021 |
| Threat Name | Threat Code |
|---|---|
| Altered fire regime | ALTFIR |
| Altered hydrology | ALTHYD |
| Climate change | CLICHN |
| Invasive animals | INVANI |
| Invasive plants | INVPLA |
| Urban development | URBDEV |
Management units: 3, 4, 5, 6, 8, 11
In 2017, in conjunction with adult surveys and the marking study for Harbison's dun skipper (see Table of Occurrences), capture adult butterflies and collect non-lethal genetic samples (i.e., legs) to analyze population genetic structure, dispersal and connectivity between populations, and genetic diversity. Use the analytical results to develop management recommendations to improve connectivity and to maintain or enhance genetic diversity at Harbison's dun skipper occurrences.
| Action | Statement | Action status | Projects |
|---|---|---|---|
| RES-1 | Use genomic sequencing techniques (e.g., RAD-Seq) to analyze large amounts of Harbison's dun skipper DNA sequences to estimate gene flow, effective population size, and genetic diversity of butterfly occurrences to inform management actions. | In progress | |
| RES-2 | Evaluate Harbison's dun skipper movement patterns at multiple scales by considering the results of genetic data analyses at a larger scale between drainages and across the MSPA, in contrast with results from the marking study characterizing intra-habitat, local scale movements within a drainage. Use these results to develop and prioritize management recommendations to include in the Harbison's Dun Skipper Management Plan. | In progress | |
| RES-3 | Submit project metadata, datasets, analyses and report with management recommendations to the MSP Web Portal. | In progress |
| Criteria | Deadline year |
|---|---|
| Harbison's Dun Skipper Genetic Study and Report Completed in 2017 | 2021 |
| Threat Name | Threat Code |
|---|---|
| Loss of connectivity | LOSCON |
Management units: 3, 4, 5, 6, 8, 11
In 2017, conduct a marking study of adult Harbison's dun skippers during the flight season to determine connectivity within habitat patches in a watershed. Design the study to obtain information on local movement patterns, flight season phenology, demography, detection probabilities, longevity, individual behavior, nectaring sources, and relationship between maximum counts and local population size. The results of this study should be used to develop specific management recommendations to be incorporated in the Harbison's Dun Skipper Management Plan.
| Action | Statement | Action status | Projects |
|---|---|---|---|
| RES-1 | Include within the study a site that supports a large, relatively stable population as determined from previous surveys. Capture and mark individuals at the selected site and then revisit and survey 2-3 times per week during the flight season to search for marked individuals and to capture and mark previously unmarked individuals. Locations of all individuals when captured for marking and at all subsequent resightings will be recorded. | In progress | |
| RES-2 | The marking study complements the genetics study by providing genetic samples from individuals captured for marking. Both studies are important at evaluating Harbison's dun skipper movement patterns at multiple scales. The results of genetic analyses represent a larger scale between drainages and across the MSPA, in contrast with results from the marking study that characterize intra-habitat, local scale movements within a drainage. These results should be used in developing and prioritizing management actions in the butterfly's 2018 management plan. | In progress | |
| RES-3 | Submit project metadata, marking study datasets, analyses and report to the MSP Web Portal. | In progress |
| Criteria | Deadline year |
|---|---|
| Harbison's Dun Skipper Marking Study and Report Completed in 2017 | 2021 |
| Threat Name | Threat Code |
|---|---|
| Loss of connectivity | LOSCON |
Management units: 3, 4, 5, 6, 8, 11
In 2017, develop habitat suitability models for Harbison's dun skipper, the host plant (San Diego sedge), and oak woodlands under current and future climate change scenarios, and conduct fire risk modeling with different management scenarios to identify potential fire and climate refugia. The results of this modeling will be considered in the development of monitoring and management plans.
| Action | Statement | Action status | Projects |
|---|---|---|---|
| DEV-1 | Submit project metadata, modeling datasets, results and report to the MSP Web Portal. | In progress |
| Criteria | Deadline year |
|---|---|
| Harbison's Dun Skipper Current and Future Climate Habitat Models and Report Completed in 2017 | 2021 |
| Threat Name | Threat Code |
|---|---|
| Altered fire regime | ALTFIR |
| Climate change | CLICHN |
| Invasive animals | INVANI |
| Invasive plants | INVPLA |
| Urban development | URBDEV |
Management units: 3, 4, 5, 6, 8, 11
In 2017, prepare a 5 year Harbison's Dun Skipper Management Plan that includes the results from butterfly surveys and habitat assessments, genetic and marking studies, and climate and fire modeling to characterize habitat quality at occupied occurrences and unoccupied suitable habitat important for enhancing connectivity, expanding populations or that could serve as fire and climate refugia. The plan should include an overall management strategy, identification and prioritization of sites where management is needed, and specific management recommendations for each site. It should also include actions to reduce fire risk at prioritized occurrences and specifications for monitoring the effectiveness of implementing high priority management actions.
| Action | Statement | Action status | Projects |
|---|---|---|---|
| PRP-1 | Work with the Butterfly Working Group consisting of species experts, scientists, wildlife agencies, land managers and other stakeholders to develop prioritized management actions. | In progress | |
| PRP-2 | Submit project metadata and Harbison's Dun Skipper Management Plant to the MSP Web Portal. | In progress |
| Criteria | Deadline year |
|---|---|
| Harbison's Dun Skipper Management Plan Completed in 2017 | 2021 |
| Threat Name | Threat Code |
|---|---|
| Altered fire regime | ALTFIR |
| Altered hydrology | ALTHYD |
| Climate change | CLICHN |
| Invasive animals | INVANI |
| Invasive plants | INVPLA |
| Urban development | URBDEV |
Management units: 3, 4, 5, 6, 8, 11
Beginning in 2018, implement highest priority management actions identified in the Harbison's Dun Skipper Management Plan.
| Action | Statement | Action status | Projects |
|---|---|---|---|
| IMP-1 | Submit project metadata, management datasets, and report to the MSP Web Portal. | waiting for precedent action |
| Criteria | Deadline year |
|---|---|
| By 2022, =1 High Priority Management Action Implemented from the Harbison's Dun Skipper Management Plan | 2021 |
| Threat Name | Threat Code |
|---|---|
| Altered fire regime | ALTFIR |
| Altered hydrology | ALTHYD |
| Climate change | CLICHN |
| Invasive animals | INVANI |
| Invasive plants | INVPLA |
| Urban development | URBDEV |
Management units: 3, 4, 5, 6, 8, 11
Beginning in 2018, monitor effectiveness of implementation of highest priority management actions identified in the Harbison's Dun Skipper Management Plan.
| Action | Statement | Action status | Projects |
|---|---|---|---|
| IMP-1 | Submit metadata, management effectiveness datasets, analyses, and report to the MSP Web Portal. | waiting for precedent action |
| Criteria | Deadline year |
|---|---|
| Effectiveness of High Priority Management Actions Determined | 2021 |
| Threat Name | Threat Code |
|---|---|
| Altered fire regime | ALTFIR |
| Altered hydrology | ALTHYD |
| Climate change | CLICHN |
| Invasive animals | INVANI |
| Invasive plants | INVPLA |
| Urban development | URBDEV |
Management units: 3, 4, 5, 6, 8, 11
Beginning in 2019, implement high priority MSP 2018 Wildfire Ignition Reduction Plan measures developed for Harbison's Dun Skipper to reduce the probability of ignition at most at-risk occurrences.
| Action | Statement | Action status | Projects |
|---|---|---|---|
| IMP-1 | Submit project metadata, management datasets, and report to the MSP Web Portal. | waiting for precedent action |
| Criteria | Deadline year |
|---|---|
| By 2023, =1 High Priority Management Action Implemented for Harbison's Dun Skipper from the MSP 2018 Wildfire Ignition Reduction Plan | 2021 |
| Threat Name | Threat Code |
|---|---|
| Altered fire regime | ALTFIR |
Management units: 3, 4, 5, 6, 8, 11
For at least the first 3 years following a wildfire, monitor recovery of Harbison's dun skipper occurrences and habitat affected by fire. Use a standardized postfire protocol to document the butterfly's distribution and abundance over time and to characterize habitat recovery and threats following a wildfire. Postfire monitoring should encompass occupied dun skipper sites and unoccupied sites that are important for enhancing connectivity or for future population expansion. The postfire monitoring should identify and prioritize management actions to assist in recovery of Harbison's dun skipper populations and important habitat patches.
| Action | Statement | Action status | Projects |
|---|---|---|---|
| IMP-1 | Prepare and implement a postfire habitat monitoring protocol and sampling design to determine the status of Harbison's dun skipper occurrences and characterize oak woodland and host plant (San Diego sedge) recovery following wildfire. Use the monitoring results to identify management actions to ensure postfire recovery of high quality habitat as identified in the Harbison's Dun Skipper Management Plan. | On hold | |
| IMP-2 | Submit project metadata, Harbison's dun skipper postfire survey and habitat monitoring data, annual reports with management recommendations, and a final report documenting project methods and results to the MSP Web Portal. | On hold |
| Criteria | Deadline year |
|---|---|
| At Least 3 Years of Postfire Monitoring of Harbison's Dun Skipper and Habitats with Annual Management Recommendations | 2021 |
| Threat Name | Threat Code |
|---|---|
| Altered fire regime | ALTFIR |
Management units: 3, 4, 5, 6, 8, 11
For at least the first 3 years following a fire, implement management actions identified by postfire monitoring as necessary to protect and recover Harbison's dun skipper occurrences and habitat impacted by wildfire.
| Action | Statement | Action status | Projects |
|---|---|---|---|
| IMP-1 | Implement management actions to restore oak woodland and host plant habitat destroyed by wildfire. These management actions may include planting oaks, host plants, and native nectaring plants. Control invasive plants to to =20% absolute cover to reduce postfire invasion of nonnative plants and to allow postfire recovery of native plants by reducing competition for water and light. Manage erosion and human use impacts while habitat is recoverying. | On hold | |
| IMP-2 | Submit project metadata and management actions to the MSP Web Portal. | On hold |
| Criteria | Deadline year |
|---|---|
| At Least 3 Years of Postfire Management in Harbison's Dun Skipper Habitats | 2021 |
| Threat Name | Threat Code |
|---|---|
| Altered fire regime | ALTFIR |
| Invasive plants | INVPLA |
|
Harbison's Dun Skipper Surveys and Monitoring
SANDAG-funded surveys for Harbison's dun skipper adults were conducted to assess year to year variation in population size. Field visits were used to document use including plants used for nectar sources, as well as obtain non-lethal genetic samples. A rapid habitat assessment was conducted at each site which included general woodland tree species composition, condition of San Diego sedge plants, and recording potential threats to the Harbison's dun skipper.
|
|
San Diego County Harbison's Dun Skipper (Euphyes vestris harbisoni) Habitat Conservation and Management Plan
This plan provides a summary of what is known regarding the Harbison's dun skipper, including life
history, historic and current distribution, movement patterns, suitable habitat, and threats. A thorough
understanding of the species is necessary to make appropriate adaptive management recommendations
in an attempt to alleviate the current threats to the species. To develop this plan, we:
1. Reviewed existing data, including historic Harbison's dun skipper locations, recent (2013-2017)
survey data, property ownership to identify conserved lands for potential surveys, management,
and acquisitions, and
2. Consulted with the wildlife agencies and other stakeholders to ensure that the most current
information regarding Harbison's dun skipper biology, management, regulations, conserved
lands, and potential acquisitions were included.
|
|
SR 94 Wildlife Infrastructure Plan
Proposed road improvements to SR 94 provide an opportunity to mitigate the potential barrier effects of the highway. This project identifies where improvements to existing infrastructure on SR-94 could improve connectivity across the South County preserves, using Best Management Practices from the scientific literature; recommends wildlife movement monitoring to identify where new crossings are needed; and identifies where additional conservation would enhance the integrity of South County linkages. The review prioritizes infrastructure improvements of 35 existing undercrossings inspected by wildlife experts in the field along 14.6 miles of SR-94 where the highway bisects conserved lands. The majority of the recommendations for infrastructure improvement focus on increasing the diameter, and thus the openness ratio (cross-sectional area divided by length), of the undercrossing itself, removing vegetation and debris blocking the undercrossing, restoring habitat in the approach to the undercrossing, and installing fencing to both (1) keep animals off the highway and (2) funnel wildlife to the undercrossings.
|
Endemic to San Diego and Orange County in scattered disjunct colonies [1,2,3; cited from 2]. Range is restricted in part by the distribution of the larval host plant, Carex spissa, the San Diego Sedge, which has limited and spotty distribution from San Luis Obispo County, CA to Baja California Norte, Mexico [4; cited from 1].
Occurrences found in Hollenbeck Canyon Wildlife Area, Crestridge Ecological Reserve, San Diego National Wildlife Refuge, Sycuan Peak Ecological Reserve, Otay Ranch Preserve, Boden Canyon Ecological Reserve, Hellhole Canyon Ecological Preserve, Cleveland National Forest, Pamo Valley, Hodges Reservoir Open Space, Barrett Reservoir Open Space, Turner Lake Watershed, Sage Hill Preserve, and Daley Ranch Open Space Preserve.
None.
Typically found in chaparral or riparian areas that have narrow canyons or drainages. Must be a seep or spring present for the host plant to grow. Oak riparian seems to be preferred location providing enough shade and sun for the butterfly to bask [5]. Butterfly found only in areas with Carex spissa [6; cited from 1].
There are four subspecies of Euphyes vestris: E. v. metcacomet to the east, E. v. vestris to the west, E. vestris kiowah to the north, and E. vestris harbisoni to the south [5].
Single-brooded with flight extending from late May through mid-July [2]. Adult’s primary flight period is late June. Males will patrol canyons not far from the host plant. Females will perch on Carex spissa while basking in the late morning/early afternoon sun [5].
Adults emerge in late spring/early summer, with specimens recorded from May to July. Females deposit pale yellow-green eggs with a red ring and red dot on the underside of host plant leaves. Larvae emerge shortly after and feed near the base of the plant. Second and third instar larvae construct a shelter (hibernaculum) by attaching two to four leaves together where they can be found when not foraging. Fourth, but occasionally third, instar larvae overwinter in these hibernacula. Pupation also occurs in these hibernacula, although larvae will construct more than one shelter. Immediately prior to pupation, the upper end is filled with a white, cotton-like substance, with pupation lasting 18-21 days [7].
Remain close to their only known larval food plant, San Diego sedge (Carex spissa). Will often visit nearby nectar sources [7]. Previously published nectar sources are: morning glory, red thistle, loosestrife, and rarely golden yarrow and black mustard. Dun skippers are known to nectar on white, pink, and purple flowers [8].
No information.
Threats to the species include habitat loss and fragmentation, wildfires, drought, water quality, the Goldenspotted Oak Borer (Agrilus auroguttatus), and grazing. Loss of coastal wetlands is well documented but the loss of inland riparian and drainages is not well documented [5,7].
[1] U.S. Fish and Wildlife Service. 1993. Endangered and threatened wildlife and plants; 90-day finding for a petition to list four California butterflies as endangered and continuation of status reviews. Federal Register 50: 38549-38552.
[2] Brown, J. W. and W. W. McGuire. 1983. A new subspecies of Euphyes vestris (Boisduval) from southern California (Lepidoptera: Hesperiidae). San Diego Society of Natural History.
[3] Orsak, L. J. 1977. Butterflies of Orange County. Center for Pathobiology: Miscellaneous Publication no. 3, Museum of Systematic Biology: Research Series no. 4, University of California Irvine, Irvine, California.
[4] Munz, P. 1974. A Flora of Southern California. University of California Press, Berkely, California. 1086 pp.
[5] Faulkner D. K. and M. W. Klein. 2012. Sensitive Butterflies of San Diego County, California. Booklet from San Diego’s sensitive butterflies: a workshop focusing on nine local species. 72 pp.
[6] Brown J. W. 1982. Only where the Carex grows. Environment Southwest 498:22.
[7] Marschalek, D. and D. Deutschman. 2015. Initial Investigation of Critical Biological Uncertainties for Harbison’s dun skipper (Euphyes vestris harbisoni) on Conserved Lands in San Diego County. San Diego State University, San Diego, California. Report to the California Department of Fish and Wildlife.
[8] Opler P. A., K. Lotts and T. Naberhaus. 2016. Butterflies and moths of North America. Available from: <http://www.butterfliesandmoths.org>. Accessed 07 Sept 2016.