Species Profile

Western Yellow-bellied Racer

Scientific Name: Coluber constrictor mormon
Taxonomy Group: Reptiles
COSEWIC Range: British Columbia
COSEWIC Assessment Date and Status Change: November 2015
COSEWIC Status: Threatened
COSEWIC Status Criteria: A3cd+4cd
COSEWIC Reason for Designation: The Canadian distribution of this snake is confined to arid valleys of south-central British Columbia, an area with intensive agricultural development and an expanding human population and tourism industry. While relatively little is known of this elusive snake, it likely faces similar threats as other large snakes with which it shares its habitat (Western Rattlesnake, Great Basin Gophersnake). Migratory behaviour of snakes between overwintering dens on valley slopes and lowland foraging habitats, together with increasing numbers of roads and traffic volumes, make populations particularly sensitive to road mortality and habitat loss and fragmentation. Life history characteristics, such as small clutch size and infrequent reproduction by females, increase vulnerability of populations to disturbance, persecution, and changes in land use.
COSEWIC History of Status Designation: Designated Not at Risk in April 1991. Status re-examined and designated Special Concern in November 2004. Status re-examined and designated Threatened in November 2015.
SARA Status: Schedule 1, Special Concern
Date of Listing (yyyy-mm-dd): 2006-08-15

Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.

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Quick Links: | Description | Distribution and Population | Habitat | Biology | Threats | Protection | National Recovery Program | Documents

Description

The racer species complex (Coluber constrictor) has a broad distribution throughout North America, with three subspecies occurring in Canada: Eastern Yellow-bellied Racer (Coluber constrictor flaviventris), Western Yellow-bellied Racer (C. c. mormon), and Blue Racer (C. c. foxii; addressed in a separate status report). Racers are long, slender snakes with whip-like tails. The Eastern and Western Yellow-bellied Racers are olive-green to blue-grey with cream to bright yellow undersides, from which the name “Yellow-bellied Racer” is derived. Juvenile racers have dark saddle-shaped dorsal markings that fade as the snakes mature. Their sleek body form helps make them extremely fast, while their colouration provides excellent camouflage. In Canada, racers are at the northern extent of their global distribution, where they are of high conservation value as such populations often possess unique ecological adaptations. Racers are non-venomous and harmless to humans. They feed mainly on rodents and insects and are beneficial to local ecological processes. (Updated 2016/12/19)

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Distribution and Population

Racers are broadly distributed across North America, but the Eastern Yellow-bellied Racer and Western Yellow-bellied Racer have more restricted ranges. In Canada, the distribution of the Eastern Yellow-bellied Racer extends into three discrete river valleys in southern Saskatchewan and one in southeastern Alberta. The Western Yellow-bellied Racer is restricted to the arid south-central interior of British Columbia, where it occurs in five discrete river valleys. (Updated 2016/12/19)

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Habitat

In Canada, racers overwinter in communal rock dens. Western Yellow-bellied Racers may also use rodent burrows or other refuges and hibernate singly, as shown for the sympatric Great Basin Gophersnake. Rock dens are often located on south-facing slopes of steep river valleys, and suitable sites appear to be a limited resource within the landscape. During the active season, racers move from their dens into grassland foraging areas in adjacent lowlands. While Eastern Yellow-bellied Racers occur in mixed-grass prairie, Western Yellow-bellied Racers most frequently occur in Ponderosa Pine and Bunchgrass habitats. Both subspecies forage in riparian and valley bottom habitats. (Updated 2016/12/19)

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Biology

In more southern areas of their range in the United States, female racers mature at 2 - 4 years of age and produce one clutch of eggs per year, although, depending on body condition, some may reproduce only every second year. Limited data are available on the age of maturity and survivorship of racers in Canada. The generation time is presumed to be 7 – 8 years. Racers mate after emerging from their winter dens in spring. Females lay a clutch of 3 – 12 eggs, which hatch in approximately 2 months (usually August or September), at which time neonates find their way to a den to hibernate for the winter. Individuals often exhibit strong fidelity to specific hibernacula. The diet of juvenile Eastern and Western Yellow-bellied Racers consists mainly of insects, including crickets and grasshoppers. Adult racers will also take larger prey such as small mammals, reptiles, birds, and amphibians. (Updated 2016/12/19)

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Threats

Both Eastern and Western Yellow-bellied Racers are vulnerable to habitat loss and fragmentation. These snakes exhibit a high degree of fidelity to specific hibernacula, nesting sites, and summer foraging areas, and appear not to tolerate significant disturbance to these habitats. Racers are limited by the availability of suitable den sites and are unlikely to be able to relocate to other areas if dens are destroyed. Large geographic distances or habitat-barriers isolate small subpopulations, further decreasing the probability of individuals dispersing between sites. Both subspecies are regularly killed on roads, but the threat of road mortality varies greatly across their ranges, being considerably greater for the western subspecies. The overall threat impact was rated as “high” for the Western Yellow-bellied Racer and “medium” for the Eastern Yellow-bellied Racer according to the COSEWIC threat calculator. (Updated 2016/12/19)

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Protection

Federal Protection

The Western Yellow-bellied Racer is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.

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Documents

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.

13 record(s) found.

COSEWIC Status Reports

  • COSEWIC assessment and update status report on the Eastern and Western Yellow-bellied Racers, Coluber constrictor flaviventris and Coluber constrictor mormon in Canada (2016-10-13)

    The racer species complex (Coluber constrictor) has a broad distribution throughout North America, with three subspecies occurring in Canada: Eastern Yellow-bellied Racer (Coluber constrictor flaviventris), Western Yellow-bellied Racer (C. c. mormon), and Blue Racer (C. c. foxii; addressed in a separate status report). Racers are long, slender snakes with whip-like tails. The Eastern and Western Yellow-bellied Racers are olive-green to blue-grey with cream to bright yellow undersides, from which the name “Yellow-bellied Racer” is derived. Juvenile racers have dark saddle-shaped dorsal markings that fade as the snakes mature. Their sleek body form helps make them extremely fast, while their colouration provides excellent camouflage. In Canada, racers are at the northern extent of their global distribution, where they are of high conservation value as such populations often possess unique ecological adaptations. Racers are non-venomous and harmless to humans. They feed mainly on rodents and insects and are beneficial to local ecological processes.

Response Statements

  • Response Statement - Western Yellow-bellied Racer (2017-01-11)

    The Canadian distribution of this snake is confined to arid valleys of south-central British Columbia, an area with intensive agricultural development and an expanding human population and tourism industry. While relatively little is known of this elusive snake, it likely faces similar threats as other large snakes with which it shares its habitat (Western Rattlesnake, Great Basin Gophersnake). Migratory behaviour of snakes between overwintering dens on valley slopes and lowland foraging habitats, together with increasing numbers of roads and traffic volumes, make populations particularly sensitive to road mortality and habitat loss and fragmentation. Life history characteristics, such as small clutch size and infrequent reproduction by females, increase vulnerability of populations to disturbance, persecution, and changes in land use.
  • Response Statements - Western Yellow-bellied Racer (2005-11-15)

    This snake occurs in five valleys in south-central British Columbia. It is susceptible to habitat loss and fragmentation from agriculture and urban development, especially as this species is particularly intolerant of urbanization. The ongoing expansion of the road network and traffic volumes increases mortality and further fragments the habitat. Pesticide applications in agricultural areas may impact the snakes both directly and via contamination of their insect prey. It is unlikely that there is a significant rescue effect because of extensive loss of habitat contiguous to the United States border.

Management Plans

  • Management Plan for the Western Yellow-bellied Racer (Coluber constrictor mormon) in Canada (2015-12-30)

    The Racer is a relatively thin snake that is typically less than 1 m in length. Adults are uniform grey or olive and have a yellow belly; young have a series of brown, saddle-like cross bands across the back that become fainter as the snakes mature. Racers are harmless to humans and feed mainly on insects. Racers occur in the south and central interior of British Columbia, a range that includes at least 5 discrete areas near Trail, Grand Forks, and Midway; and within the Okanagan/Similkameen and Thompson/Fraser watersheds.

Orders

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2005 (2005-08-12)

    2005 Annual Report to the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
  • COSEWIC Annual Report - 2015-2016 (2016-10-13)

    Over the past year COSEWIC re-examined the status of 25 wildlife species; of these, the majority (68%) were re-assessed at the same or lower level of risk. Of a total of 45 species assessed, seven were assigned a status of Not at Risk (two re-assessments and five new assessments). To date, and with the submission of this report, COSEWIC’s assessments now include 724 wildlife species in various risk categories, including 320 Endangered, 172 Threatened, 209 Special Concern, and 23 Extirpated (i.e., no longer found in the wild in Canada). In addition, 15 wildlife species have been assessed as Extinct, 54 wildlife species have been designated as Data Deficient, and 177 have been assessed and assigned Not at Risk status.

Permits and Related Agreements

  • Explanation for issuing permit(#SARA-PYR-2009-0115), persuant to the provisions of section 73 of SARA (2009-08-17)

    The proponents will conduct ground surveys of species at risk including, amphibian visual encounter surveys, Oregon forestsnail ground searches, Badger burrow searches, Pacific water shrew habitat ratings, Spotted bat roost searches, snake foraging surveys, Monarch surveys (visual searches for larvae and adults), Great basin spadefoot egg mass surveys and Snake den surveys. No traps will be set and animals will only be handled where it is necessary for species identification and photo documentation. All animals will then be immediately released in the habitat where captured. No animals will be marked.

Consultation Documents

  • Consultation on Amending the List of Species Under the Species At Risk Act: November 2005 (2005-11-16)

    The Government of Canada proclaimed the Species at Risk Act (SARA) on June 5, 2003 as part of its strategy for the protection of wildlife species at risk. Attached to the Act is Schedule 1, the list of the species that receive protection under SARA, hereinafter referred to as the 'SARA list'. Canadians are invited to comment on whether all or some of the species included in this document should be added to the SARA list.
  • Consultation on Amending the List of Species under the Species at Risk Act: Terrestrial Species - January 2017 (2017-01-16)

    The Government of Canada is committed to preventing the disappearance of wildlife species at risk from our lands. As part of its strategy for realizing that commitment, on June 5, 2003, the Government of Canada proclaimed the Species at Risk Act (SARA). Attached to the Act is Schedule 1, the list of the species provided for under SARA, also called the List of Wildlife Species at Risk. Extirpated, Endangered and Threatened species on Schedule 1 benefit from the protection afforded by the prohibitions and from recovery planning requirements under SARA. Special Concern species benefit from its management planning requirements. Schedule 1 has grown from the original 233 to 521 wildlife species at risk. In 2016, on the recommendation of the Minister of the Environment, the Governor in Council approved listing proposals for 44 wildlife species. It is proposed that 23 species be added to Schedule 1, 18 be reclassified or have a change made to how they are defined (two wildlife species are being split into four), one species  be removed from Schedule 1, and another two species not be added. Listing proposals were published in Canada Gazette, part I for a 30-day public comment period and final listing decisions for all 44 species are expected in the first half of 2017.Please submit your comments byMay 11, 2017, for terrestrial species undergoing normal consultationsand byOctober 11, 2017, for terrestrial species undergoing extended consultations.For a description of the consultation paths these species will undergo, please see:Minister of Environment response to COSEWIC species at risk assessments: October 13, 2016 The COSEWIC Summaries of Terrestrial Species Eligible for Addition or Reclassification on Schedule 1 - January 2017

Related Information

  • Environment and Climate Change Canada’s Species at Risk Act (SARA) Listing Plan 2016 to 2018 (2017-09-29)

    The status of wildlife species is assessed by an independent panel of expert Canadian scientists, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). 149 terrestrial species were assessed as at-risk by COSEWIC between 2009 and 2016 and are eligible for listing under the Species at Risk Act (SARA) to be considered by the Governor-in-Council (GIC) on the recommendation of the Minister of the Environment: 86 species would be new additions, 54 currently listed species would be reclassified and 9 species would be updated to reflect changes in their recognized designatable units. A three-year listing plan has been developed to address all 149 terrestrial species and listing decisions for most species are anticipated by the end of 2018. Making amendments to Schedule 1 of SARA is a two-step process. The first step is for the GIC to propose an amendment through an order in council published in the Canada Gazette, Part I, for a 30-day public comment period. The second step is for the GIC to make a final decision on whether or not to make amendments to Schedule 1 of SARA, taking into consideration comments received during the 30-day public comment period. The amendments are made through an order in council published in the Canada Gazette, Part II. Both orders are accompanied by a Regulatory Impact Analysis Statement (RIAS) which presents the implications of listing the species or changing their status. Publishing this plan on the Species at Risk Public Registry is intended to provide transparency about the Government of Canada’s plan to make listing decisions under the Species at Risk Act. NOTE: The information presented below is intended to provide openness and transparency with respect to when terrestrial species might be considered for listing under Schedule 1 of the Species at Risk Act. It is intended to assist anyone who may wish to provide comments on such listing considerations. Given any number of factors can affect the timing of a listing decision; the Plan is subject to change. Accordingly, the Plan will be periodically updated.

Recovery Document Posting Plans

  • Environment and Climate Change Canada's Three-Year Recovery Document Posting Plan (2016-07-06)

    Environment and Climate Change Canada’s Three-Year Recovery Document Posting Plan identifies the species for which recovery documents will be posted each fiscal year starting in 2014-2015. Posting this three year plan on the Species at Risk Public Registry is intended to provide transparency to partners, stakeholders, and the public about Environment and Climate Change Canada’s plan to develop and post these proposed recovery strategies and management plans. However, both the number of documents and the particular species that are posted in a given year may change slightly due to a variety of circumstances. Last update December 2, 2021
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