COSEWIC Status Appraisal Summary on the Northern Bobwhite Colinus virginianus in Canada – 2013

Endangered
2013

COSEWIC — Committee on the Status of Endangered Wildlife in Canada

COSEWIC status appraisal summaries are working documents used in assigning the status of wildlife species suspected of being at risk in Canada. This document may be cited as follows:

COSEWIC. 2013. COSEWIC status appraisal summary on the Northern Bobwhite Colinus virginianus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xiii pp.

Production note:
COSEWIC would like to acknowledge Sue Chiblow for writing the status appraisal summary on the Northern Bobwhite (Colinus virginianus) in Canada, prepared under contract with Environment Canada. This status appraisal summary was overseen and edited by Jon McCracken, Co-chair of the COSEWIC Birds Specialist Subcommittee.

For additional copies contact:

COSEWIC Secretariat
c/o Canadian Wildlife Service
Environment Canada
Ottawa, ON
K1A 0H3

Tel.: 819-953-3215
Fax: 819-994-3684
COSEWIC E-mail
COSEWIC Website

Également disponible en français sous le titre Sommaire du statut de l’espèce du COSEPAC sur le Colin de Virginie (Colinus virginianus) au Canada.

© Her Majesty the Queen in Right of Canada, 2013.
Catalogue No. CW69-14/2-31-2013E-PDF
ISBN 978-1-100-22492-3

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COSEWIC
Assessment Summary

Assessment Summary – May 2013

Common name
Northern Bobwhite

Scientific name
Colinus virginianus

Status
Endangered

Reason for designation
Owing to habitat loss, this grassland bird’s population has declined dramatically over historical levels and shows no sign of recovery. There is only one viable population remaining in Canada, located on Walpole Island, Ontario. The status of this species is complicated by the presence of introduced pen-reared birds whose genetic composition is believed to pose a threat to the remaining native population.

Occurrence
Ontario

Status history
Designated Endangered in April 1994. Status re-examined and confirmed in November 2003 and May 2013.

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COSEWIC
Status Appraisal Summary

Colinus virginianus
Northern Bobwhite
Range of occurrence in Canada: Ontario

Status History

Designated Endangered in April 1994. Status re-examined and confirmed in November 2003 and May 2013.

Evidence (indicate as applicable):

Wildlife species:
Change in eligibility, taxonomy or designatable units: no

Explanation:
no change

 

Range:
Change in Extent of Occurrence (EO): unknown
Change in Area of Occupancy (IAO): unknown
Change in number of known or inferred current locations*: unknown
Significant new survey information: no

Explanation:
In Canada, the Northern Bobwhite is still located predominantly at Walpole Island, Ontario (Figure 1). No directed surveys have been done there since the last status assessment. Virtually all records of birds that are now detected elsewhere in southern Ontario are believed to be of captive-bred origin. Such birds are raised and released for sport hunting, have poor viability in the wild, and do not maintain self-sustaining populations.

* Use the IUCN definition of “location”

 

Population Information:
Change in number of mature individuals: unknown
Change in total population trend: unknown
Change in severity of population fragmentation: no
Change in trend in area and/or quality of habitat: no
Significant new survey information: no

Explanation:
No targeted surveys have been done since the last status assessment, so it is unknown if the number of mature individuals has changed. The southern portion of the Wallaceburg Christmas Bird Count (CBC) circle covers part of Walpole Island. Northern Bobwhites were recorded on this CBC on most years from 1986 to 2003, with numbers ranging from 2 to 33 birds. However, from 2004 to 2010, no sightings of the species have been reported within this count area, suggesting that the local population has continued to decline. There is, however, local community knowledge that the species continues to persist at Walpole Island First Nation. This includes a report of two birds on 31 May 2006 (Mike Burrell) and three to five birds on 5 June 2012 (Joshua Vandermeulen).

The extent and quality of prairie and savannah habitats at Walpole Island First Nation have declined and are continuing to do so (COSEWIC a,b).

 

Threats:
Change in nature and/or severity of threats: no  

Explanation:
No change. The amount of prairie and savannah habitat at Walpole Island First Nation has been reduced by conversion to agriculture, housing and other land uses (COSEWIC 2010a,b).  Periodic fire is necessary to maintain prairie and savannah habitats. While regular fires still occur at Walpole, their frequency is decreasing as more houses are built in prairies and savannah habitat. In addition, the non-native and invasive subspecies of Common Reed (Phragmites australis ssp. australis) is invading meadow marshes and moist prairies at Walpole Island First Nation (COSEWIC 2010a,b) and is degrading bobwhite habitat. 

Dilution of the native gene pool of bobwhites through repeated reintroductions from non-native, pen-reared stocks has been continuing in many parts of southwestern Ontario, including regions surrounding Walpole Island First Nation (Hubert pers. comm. 2012).

 

Protection:
Change in effective protection: no

Explanation:
The Northern Bobwhite is listed as Endangered nationally and receives protection under the Species at Risk Act. It also receives protection under Ontario’s Endangered Species Act, 2007. The species is now believed to be found only at Walpole Island First Nation.

 

Rescue Effect:
Change in evidence of rescue effect: no

Explanation:
no change (rescue is not possible).

 

Quantitative Analysis:
Change in estimated probability of extirpation: no

Details:
no change (a quantitative analysis has not been done).

 

Summary and Additional Considerations: [e.g., recovery efforts]
The population located on Walpole Island is the only known population in Canada. A recovery strategy for the species has been compiled and is in draft form.

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Acknowledgements

Thanks to Chris Risley for providing the contacts within government who have knowledge on the Northern Bobwhite, and to the co-chairs and members of COSEWIC’s Birds Subcommittee for giving the author the learning opportunity to conduct this research. Thanks also to Jon McCracken for offering his expertise.

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Authorities Contacted

Austen, Madeline. Head, Species at Risk Unit. Canadian Wildlife Service – Ontario Region. Downsview, ON.

Badzinski, Debbie. Bird Population Biologist, Bird Studies Canada. Port Rowan, ON.

Cannings, Russell. British Columbia Rare Bird Alerts. Naramata, BC.

Hubert, Patrick. Avian Biologist. Ontario Ministry of Natural Resources, Peterborough, ON.

Jacobs, Clint. Species at Risk, Walpole Island Heritage Centre. Walpole Island First Nation.

Jong, Catherine. Species at Risk Biologist, Aylmer District, Ontario Ministry of Natural Resources. Aylmer, ON.

Lozon, Jake. Acting Stewardship Coordinator, Rural Lambton Stewardship Network, Ontario Ministry of Natural Resources.

Risley, Chris. Birds and Mammal Species at Risk Biologist, Ministry of Natural Resources, Species at Risk Branch. Peterborough, ON.

Sutherland, Don. Zoologist, Natural Heritage Information Centre, Ontario Ministry of Natural Resources. Peterborough, ON.

Tuininga, Ken. Species at Risk Biologist, Canadian Wildlife Service – Ontario Region. Downsview, ON.

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Information Sources

Brennan, L.A. 1999. Northern Bobwhite (Colinus virginianus). The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online.

Cadman, M.D., D.A. Sutherland, G.G. Beck, D. Lepage, and A.R Couturier, eds. 2007 Atlas of the Breeding Birds of Ontario, 2001-2005. Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources and Ontario Nature, Toronto, xxii + 706 pp.

COSEWIC. 2010a. COSEWIC assessment and status report on the Showy Goldenrod Solidago speciosa (Great Lakes Plains and Boreal Populations) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xiv + 23 pp.

COSEWIC. 2010b. COSEWIC assessment and status report on the Dense Blazing Star Liatris spicata in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. ix + 23 pp.

Hubert, P. pers. comm. 2012. Presentation attended by J. McCracken. 9 February 2012. Ontario Ministry of Natural Resources, Exeter Rd., London, ON.

James, R.D and R. Cannings 2003. COSEWIC update status report on the Northern Bobwhite Colinus virginianus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 20pp.

Ontario’s Biodiversity: Species at Risk. Northern Bobwhite.

Page, A.M. and M.J. Austen. 1994. Status report on the Northern Bobwhite Colinus virginianus in Canada. Committee on the Status of Endangered Wildlife in Canada, Ottawa.

Recovery Progress and Activities. Species at Risk Public Registry. Government of Canada. (last accessed May 2012).

Response Statement for Northern Bobwhite. 2004. Species at Risk Public Registry. Government of Canada. (last accessed May 2012).

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Figure 1. Global range of the Northern Bobwhite

Map showing the global range of the Northern Bobwhite in North America (see long description below).

Adapted from Page and Austen 1994.

Description of Figure 1

Map showing the global range of the Northern Bobwhite in North America, where it is primarily found from southeastern Wyoming east to Massachusetts south through eastern Mexico to western Guatemala. In Canada, the Northern Bobwhite is native only to southwestern Ontario.

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Figure 2. Breeding distribution of the Northern Bobwhite in Ontario in two time periods (2001-05 and 1981-85)

Map with grid overlay showing the breeding distribution of the Northern Bobwhite in Ontario (see long description below).

Based on the Ontario Breeding Bird Atlas (reproduced from Cadman et al. 2007).

Description of Figure 2

Map with grid overlay showing the breeding distribution of the Northern Bobwhite in Ontario. Squares with black dots are those in which the species was found in the first atlas period (1981-1985), but not in the second (2001-05). Those with yellow dots are occurrences in the second atlas, but not the first. Occurrences in both periods are confounded by records of non-native, released domestic stock, particularly in squares away from the vicinity of Lake St. Clair.

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Technical Summary

Colinus virginianus
Northern Bobwhite
Range of occurrence in Canada: Ontario

Demographic Information

Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines(2008) is being used) 2 – 3 yrs
Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?Unknown
Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]Unknown
(decline suspected)
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations].
- Breeding Bird Survey results for the Lower Great Lakes-St. Lawrence Plain (including the northern USA) indicate a decline of 47% from 2000 to 2010. Breeding Bird Atlas data for Ontario indicate a 65% decline between 1985 and 2005, but this estimate is confounded by the inclusion of non-native, pen-reared stock.
Unknown
rate of decline
[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].Unknown
[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.Unknown
Are the causes of the decline clearly reversible and understood and ceased?No
Are there extreme fluctuations in number of mature individuals?No

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Extent and Occupancy Information

Estimated extent of occurrenceLess than 5000 km2
Index of area of occupancy (IAO)
(Always report 2x2 grid value).
Less than 500 km2
Is the total population severely fragmented?No
Number of locations*One
Is there an [observed, inferred, or projected] continuing decline in extent of occurrence?Unknown but likely
Is there an [observed, inferred, or projected] continuing decline in index of area of occupancy? Unknown but likely
Is there an [observed, inferred, or projected] continuing decline in number of populations?No
Is there an [observed, inferred, or projected] continuing decline in number of locations*?No
Is there an observed, inferred, or projected continuing decline in area, extent and quality of habitat?Yes
Are there extreme fluctuations in number of populations?No
Are there extreme fluctuations in number of locations*?No
Are there extreme fluctuations in extent of occurrence?No
Are there extreme fluctuations in index of area of occupancy?No

* See Definitions and Abbreviations on COSEWIC website and IUCN 2010 for more information on this term.

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Number of Mature Individuals (in each population)
PopulationN Mature Individuals
Number of mature individualsUnknown; last estimate for Walpole was 230 birds; no new information since then.
Total230 (maximum)

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Quantitative Analysis

Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years].Not done

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Threats (actual or imminent, to populations or habitats)

  • Continued loss of agricultural grasslands and native prairie habitat
  • Degradation of habitat through increase in size of individual cultivated fields
  • Loss of fencerows, and loss and increasing isolation of bushy cover
  • Food sources depleted through insecticides and herbicides
  • Increasing predator (house cat, raccoon, fox, coyote, skunk, opossum) populations
  • Dilution of native gene pool through repeated reintroductions from non-native stocks

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Rescue Effect (immigration from outside Canada)

Status of outside population(s)?
IUCN lists the species as “near threatened.” All populations in the adjacent U.S. are showing statistically significant declines over both the long term and short term.  

Is immigration known or possible?
Unlikely

The Northern Bobwhite is a non-migratory species, which greatly impedes immigration.

Would immigrants be adapted to survive in Canada?
Yes

Is there sufficient habitat for immigrants in Canada?
Declining

Is rescue from outside populations likely?
No

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Status History

Designated Endangered in April 1994. Status re-examined and confirmed in November 2003 and May 2013.

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Status and Reasons for Designation

Status:
Endangered

Alpha-numeric Code:
B1ab(iii)+2ab(iii); D1

Reasons for Designation:
Owing to habitat loss, this grassland bird’s population has declined dramatically over historical levels and shows no sign of recovery. There is only one viable population remaining in Canada, located on Walpole Island, Ontario. The status of this species is complicated by the presence of introduced pen-reared birds whose genetic composition is believed to pose a threat to the remaining native population.

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Applicability of Criteria

Criterion A (Decline in Total Number of Mature Individuals):
Not applicable as there is insufficient information available to estimate reliable population trends.
Criterion B (Small Distribution Range and Decline or Fluctuation):
Meets B1ab(iii)+2ab(iii) for Endangered because extent of occurrence is <5000 km2, area of occupancy is <500 km2, there are fewer than 5 locations, and there is a continuing observed decline in area, extent and quality of habitat.
Criterion C (Small and Declining Number of Mature Individuals):
Not applicable as there is insufficient information to estimate current population trends.
Criterion D (Very Small or Restricted Total Population):
Meets D1 for Endangered because the population is estimated to consist of <250 adults.
Criterion E (Quantitative Analysis):
Not performed.

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COSEWIC History
he Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC Mandate
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC Membership
COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

Definitions (2013)

Wildlife Species
A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.
Extinct (X)
A wildlife species that no longer exists.
Extirpated (XT)
A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.
Endangered (E)
A wildlife species facing imminent extirpation or extinction.
Threatened (T)
A wildlife species likely to become endangered if limiting factors are not reversed.
Special Concern (SC)*
A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.
Not at Risk (NAR)**
A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.
Data Deficient (DD)***
A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.

* Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.
** Formerly described as “Not In Any Category”, or “No Designation Required.”
*** Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” (insufficient scientific information on which to base a designation) prior to 1994. Definition of the (DD) category revised in 2006.

The Canadian Wildlife Service, Environment Canada, provides full administrative and financial support to the COSEWIC Secretariat.

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