Eastern foxsnake (Elaphe gloydi) (Carolinian)COSEWIC assessment and status report: chapter 13
Technical Summary
Eastern Foxsnake
Couleuvre fauve de l’Est
Range of Occurrence in Canada: Ontario
Extent and Area Information
Simple Minimum Convex Polygon (MCP) computed using Ontario Herpetofaunal Summary records as per COSEWIC methodology adapted from IUCN 2001
(see section Habitat Protection/Ownership and Figure 5 for details)
A 2 km x 2 km grid of cells was overlaid on the distribution of the species and the AO was calculated as the area of all the cells that intersect known occurrences. Occurrences from 1984 to present were used, and from that subset, the dataset was further restricted to those records determined to be valid for distributional analyses (Willson and Rouse 2006). The dataset was considered in 5-year intervals (5 years = ~1 generation) to evaluate both current AO (past 10 years) and trend in AO.
1984; AO=860 km 2
1988; AO=580 km 2
1993; AO=300 km 2
1998; AO=188 km 2
Population Information
Haldimand-Norfolk
Threats (actual or imminent threats to populations or habitats)
- Mortality on roads
- Loss and degradation of habitat especially loss of hedgerows and wetlands
- Persecution by ophidiophobes
- Illegal wildlife trade
Rescue Effect (immigration from an outside source)
[other jurisdictions or agencies] None
Quantitative Analysis
N/A
Current Status
COSEWIC: Carolinian Population - Endangered (2008)
COSEWIC: Species considered as a single unit – Threatened (2000)
COSEWIC: Species considered as a single unit – Threatened (1999)
Status and Reasons for Designation
Reasons for Designation: The species is confined to a few small increasingly disjunct areas that are subject to intensive agriculture, high human populations and extremely high densities of roads. Roads fragment populations leading to increased probability of extirpation. There are no large protected, roadless areas for this species in this region. The species is also subject to persecution and illegal collection for the wildlife trade.
Applicability of Criteria
Criterion A (Declining Total Population):
Not applicable.
Criterion B (Small Distribution, and Decline or Fluctuation):
Meets Endangered B2ab(ii,iii,iv) as the area of occupancy is < 500 km2 and severely fragmented. The AO is declining (ii), the area and quality of habitat are declining (iii) and locations are disappearing (iv) as habitat is lost
Criterion C (Small Total Population Size and Decline):
Total population size not known.
Criterion D (Very Small Population or Restricted Distribution):
Population too large
Criterion E (Quantitative Analysis):
Not applicable.
Eastern Foxsnake
Couleuvre fauve de l’Est
Range of Occurrence in Canada: Ontario
Extent and Area Information
Simple Minimum Convex Polygon (MCP) computed using Ontario Herpetofaunal Summary records as per COSEWIC methodology adapted from IUCN 2001
(see section Habitat Protection/Ownership and Figure 4 for details)
A 2 km x 2 km grid of cells was overlaid on the distribution of the species and the AO was calculated as the area of all the cells that intersect known occurrences. Occurrences from 1984 to present were used, and from that subset, the dataset was further restricted to those records determined to be valid for distributional analyses (Willson and Rouse 2006). Also, the AO was calculated from all observations from the past 10 years (since 1998).
1984 = 276 km 2
1998 = 188 km 2
Population Information
Threats (actual or imminent threats to populations or habitats)
The main threat to these snakes comes from rapidly increasing recreational development along the Georgian Bay coastline and on the shores of the Georgian Bay Islands. Increases in power boats, and roads and traffic are killing more snakes. Housing developments particularly in the southern part of the snakes’ distribution are also destroying their habitat.
Rescue Effect (immigration from an outside source)
[other jurisdictions or agencies] None
Quantitative Analysis
N/A
Current Status
COSEWIC: Great Lakes / St Lawrence Population - Endangered (2008)
COSEWIC: Species considered as a single unit – Threatened (2000)
COSEWIC: Species considered as a single unit – Threatened (1999)
Status and Reasons for Designation
Reasons for Designation: In this region, the species swims long distances often in cold, rough open water where it is subject to mortality from increasing boat traffic. It is uniquely vulnerable to habitat loss because it is confined to a thin strip of shoreline where it must compete with intense road development and habitat modification due to recreational activities. This species’ habitat is undergoing increasing fragmentation as development creates zones that are uninhabitable.
Applicability of Criteria
Criterion A (Declining Total Population):
Not applicable.
Criterion B (Small Distribution, and Decline or Fluctuation):
Meets Endangered B1ab(iii)+B2ab(iii) since the known extent of occurrence (1984 km2) is less than 5000 km2 and the area of occupancy (188 km2) is less than 500 km2. The species’ habitat is fragmented by recreational developments along the species’ coastal habitat. Important shoreline habitat is also being lost to cottage and other development.
Criterion C (Small Total Population Size and Decline):
Numbers not known with reasonable certainty.
Criterion D (Very Small Population or Restricted Distribution):
Population too large
Criterion E (Quantitative Analysis):
Not applicable.
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