Eastern persius duskywing: COSEWIC assessment and status report: chapter 13

Technical Summary

Erynnis persius persius

Eastern Persius Duskywing
Hespérie Persius de l’Est

Ontario


Extent and Area Information

Extent of occurrence (EO) ( km2 )
None known
Specify trend (decline, stable, increasing, unknown)
Past decline
Are there extreme fluctuations in EO (> 1 order of magnitude)?
Not applicable
Area of occupancy (AO) (km 2 )
None known
Specify trend (decline, stable, increasing, unknown)
Past decline
Are there extreme fluctuations in AO (> 1 order magnitude)?
Not applicable
Number of extant locations
None known
Specify trend in # locations (decline, stable, increasing, unknown)
Not applicable
Are there extreme fluctuations in # locations (>1 order of magnitude)?
No
Habitat trend: specify declining, stable, increasing or unknown trend in area, extent or quality of habitat
Habitat is still being destroyed, yet rehabilitation is occurring in some areas. Overall, a large decline in habitat extent and quality has occurred over the last several decades


Population Information

Generation time (average age of parents in the population) (indicate years, months, days, etc.)
One year
Number of mature individuals (capable of reproduction) in the Canadian population (or, specify a range of plausible values)
None known
Total population trend: specify declining, stable, increasing or unknown trend in number of mature individuals
Declined over the past fifty years, with no individuals known to occur in the last 18 years
If decline, % decline over the last/next 10 years or 3 generations, whichever is greater (or specify if for shorter time period)
Declined to presumed extirpation 18 years ago
Are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)?
No
Is the total population severely fragmented (most individuals found within small and relatively isolated (geographically or otherwise) populations between which there is little exchange, i.e., ≤ 1 successful migrant / year)?
No extant population known
List each population and the number of mature individuals in each
None extant known
Specify trend in number of populations (decline, stable, increasing, unknown)
Declined to presumed extirpation
Are there extreme fluctuations in number of populations (>1 order of magnitude)?
No


Threats (actual or imminent threats to populations or habitats)

  • Habitat loss and degradation due to:
    • fire suppression
    • tree planting
    • herbivory of host plants
    • agriculture, urban development and resource extraction
  • Pesticide spraying


Rescue Effect (immigration from an outside source): No

Does species exist elsewhere (in Canada or outside)?
Yes, in US
Status of the outside population(s)?
Declining and rare
Is immigration known or possible?
Unknown and unlikely
Would immigrants be adapted to survive here?
Yes
Is there sufficient habitat for immigrants here?
Possibly


Quantitative Analysis

None performed


Current Status

COSEWIC: Endangered (2006)

Status and Reasons for Designation

Status: Endangered
Alpha-numeric code: B1ab(iii)+2ab(iii); C2a(i); D1

Reasons for Designation: This lupine-feeding butterfly has been confirmed from only two sites in Canada. It inhabits oak savannahs in southern Ontario, a habitat that has undergone substantial declines and alterations. Larval host plant populations have been greatly reduced. There have been no confirmed records of this butterfly for 18 years, but unconfirmed sight records suggest that the species might still exist in Canada.


Applicability of Criteria

Criterion A (Declining Total Population):
Not applicable, no decline data.

Criterion B (Small Distribution, and Decline or Fluctuation):
If any individuals of the species persist, the EO is certainly much less than 5000 km2 B1. The AO is certainly much less than 500 km2 – B2. This species occurs at fewer than 5 locations – a. There is a continuing decline – b. In habitat (iii)

Criterion C (Small Total Population Size and Decline):
There are fewer than 2500 mature individuals and there is likely a continuing decline in the number of mature individuals – 2 with a population structure such that no population contains more than 250 mature individuals – a(i)

Criterion D (Very Small Population or Restricted Distribution):
There are fewer than 250 mature individuals – D1.

Criterion E (Quantitative Analysis):
Not available.

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