Species Profile

Prothonotary Warbler

Scientific Name: Protonotaria citrea
Taxonomy Group: Birds
COSEWIC Range: Ontario
COSEWIC Assessment Date and Status Change: November 2016
COSEWIC Status: Endangered
COSEWIC Status Criteria: C2a(i); D1
COSEWIC Reason for Designation: In Canada, this species breeds only in deciduous forest swamps in the Carolinian region of southwestern Ontario. The population is small, fewer than 30 individuals, and at risk of decreasing further. This warbler is vulnerable to degradation of breeding habitat from wetland drainage, forest harvest, development, invasion of European Common Reed, and loss of tree canopy cover due to dieback caused by Emerald Ash Borer. Loss of mangrove wintering habitat to aquaculture and coastal development in Central and South America poses additional threats.
COSEWIC History of Status Designation: Designated Special Concern in April 1984. Status re-examined and designated Endangered in April 1996. Status re-examined and confirmed in May 2000, April 2007, and November 2016.
SARA Status: Schedule 1, Endangered
Date of Listing (yyyy-mm-dd): 2003-06-05

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: | Photo | Description | Distribution and Population | Habitat | Biology | Threats | Protection | Recovery Initiatives | Recovery Team | National Recovery Program | Documents

Prothonotary Warbler Photo 2

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Description

The Prothonotary Warbler is a small bird about 14 cm long. It is one of North America’s most dazzling songbirds. The plumage of males and females is similar, but the males are more brightly coloured. Both males and females have golden yellow heads and breasts, olive green backs, and blue-grey wings and tails. White tail spots are quite prominent. This species is easily confused with the yellow warbler and the blue-winged warbler. The Prothonotary Warbler can be distinguished from the former by its dark wings and white-spotted tail and from the latter by its lack of white wing bars or black eye line.

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Distribution and Population

This species is very rare in Canada, but is actively monitored by a combination of amateurs and professionals. Many occupied sites are prone to blinking on and off. This level of annual fluctuation makes it difficult to ascertain whether there has been a true change in occupied range, but such a change seems unlikely. Fewer than 10 locations are occupied in Canada in any given year (e.g., no more than 8 in 2015). Numbers have remained stable or declined slightly in Canada since the previous status report, from 28- 34 mature individuals (COSEWIC 2007) to 28 in 2015. As such, the population trend has changed from the steep decline reported in the previous status report. See Appendix A for details. The North American population estimate has been adjusted slightly since the last status report. Based on new analysis techniques, the continental population is now estimated at about 1.6 million mature individuals (Blancher et al. 2012), versus an estimated 1.8 million birds in the previous COSEWIC report. However, this is mostly just a change in the manner in which estimates are derived. Based on the Breeding Bird Survey (Sauer et al. 2014), the long-term North American trend was -1.1% per year from 1966-2013 (95% CI = -1.6 to -0.7). The short-term 10- year trend was -0.5% per year from 2003 to 2013 (95% CI = -1.7 to 0.7), which is equivalent to a decline of no more than 17% over the decade. Figure 1 depicts the North American population trend. In Canada, there has been a major and ongoing deterioration in the quality and extent of breeding habitat in the last decade caused by invasive species, notably European Common Reed (Phragmites australis ssp. australis) and Emerald Ash Borer (Agrilus planipennis). [Updated 2018-02-19]

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Habitat

In Canada, this species breeds only in deciduous swamp forests or riparian floodplain forests. The forests it occupies are typically dominated by silver maple, ash and yellow birch. The species nests in naturally formed tree cavities or cavities excavated by other species, mainly downy woodpeckers and chickadees. It favours small, shallow holes situated at low heights in dead or dying trees, in which it builds a nest lined with moss. Nests are typically situated over standing or slow-moving water. Artificial nest boxes are also readily accepted and perhaps even preferred. Males often build one or more incomplete “dummy” nests. Females usually select one of these to complete, but they may also build an entirely new nest on their own. In any case, several suitable cavities appear to be required in each territory to accommodate all of these nests. The key wintering habitat of the Prothonotary Warbler is the coastal mangrove forest that grows in the tidal zones of Central America and northern South America. The Prothonotary Warbler also winters in swamps and wet woodlands, mainly below 1300 m elevation.

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Biology

This small nocturnal migrant arrives in southern Ontario in early May and departs for its wintering habitat in September. Prothonotary Warblers, particularly after-second-year males, exhibit strong fidelity to breeding sites. These birds are highly territorial during the breeding season. In Canada, an average of just over one-third of all territorial males remain unmated over the course of the breeding season. An apparent shortage of females in the Canadian population limits reproductive potential. In Canada, the species typically produces only one brood per year. The interior of the nest, which is built by both parents, is lined with moss. From late May to early July, the female typically lays four to six eggs and she incubates them alone. Both parents feed the young, which remain in the nest for 9 to 11 days. Nestling survival is highly variable and depends largely on nest predation and parasitism rates, particularly parasitism by the brown-headed cowbird, which may lay its own eggs in the nest. The average brown-headed cowbird parasitism rate in Ontario is 27%, which seems exceptionally high for a cavity-nesting species. When the house wren is present in high densities, it is a serious competitor, destroying the eggs and young of the Prothonotary Warbler and usurping its nests. Losses of Prothonotary Warbler nestlings and eggs are also attributed to foxsnakes and to certain mammals, mainly raccoons and southern flying squirrels. The Prothonotary Warbler is an insectivore, feeding mostly on caterpillars, flies, midges and spiders. Like all small birds, it has a short average lifespan, about 2.5 years.

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Threats

The severity of threats imposed by invasive insects (especially Emerald Ash Borer) and invasive plants (especially European Common Reed) on the quality of habitat on the Canadian breeding grounds has increased dramatically since the last assessment. In addition, forest harvest has also been shown to negatively affect Prothonotary Warblers (e.g., Heltzel and Leberg 2010), and there has been an ongoing loss of wetlands in the US breeding range (e.g., Stedman and Dahl 2008). [Updated 2018-02-19]

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Protection

Federal Protection

The Prothonotary Warbler 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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Recovery Initiatives

Status of Recovery Planning

Recovery Strategies :

Name Recovery Strategy for the Prothonotary Warbler (Protonotaria citrea) in Canada
Status Final posting on SAR registry

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Recovery Team

Prothonotary Warbler Recovery Team

  • Jon McCracken - Chair/Contact - Conservation organization (NGO)
    Phone: 519-586-3531  Fax: 519-586-3532  Send Email
  • Jeff Robinson - Chair/Contact - Environment Canada
    Phone: 519-472-6695  Send Email

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Recovery Progress and Activities

Summary of Progress to Date The Prothonotary Warbler recovery team has been working under the guidance of a recovery plan since 2001. Wetland conservation and restoration initiatives have benefited Prothonotary Warblers as well as many other species at risk. However, forest swamp habitats continue to be eroded and conservation of Prothonotary Warbler breeding habitat remains as urgent as ever. Furthermore, pressure on wintering habitat in Central America is growing, and the recovery team is studying and promoting the bird’s conservation needs outside Canada. Summary of Research/Monitoring Activities Recovery initiatives for Prothonotary Warbler take an adaptive management approach; the effectiveness of techniques is closely monitored so that they can be refined and improved. For example, research indicates that nest boxes can successfully reduce cowbird parasitism and mammalian predation of Prothonotary Warbler nests, thereby increasing production of young. However, House Wrens also use nest boxes in some locations, increasing competition for nest sites. The recovery team continues to experiment with nest box modifications in an attempt to dissuade wren occupancy. Annual population monitoring showed a population increase in the initial years of the recovery program, followed by a recent decline. The decline has been attributed to a series of drought years in combination with a storm event at one site that resulted in a substantial loss in canopy cover. House Wren competition and “vandalism” also appears to have increased at some sites. A bird-banding program on Prothonotary Warbler breeding grounds suggests the population is heavily skewed towards older birds and that about 23% of the warblers are unmated males. This suggests that production and/or survival of young is low. Researchers will investigate why such a high proportion of the population is not mating. The banding program has also shown that, although the birds return to the same breeding site each year, there is genetic interchange between subpopulations; this finding indicates that isolation between subpopulations is not a threat at this point. Research has shown that the Canadian population depends on a low level of immigration of birds from the U.S. “source” population; therefore, the recovery team has begun to initiate a dialogue with colleagues in the U.S. states adjacent to the Great Lakes. In 2005, the recovery team will assess the level of threat that invasive plants (particularly Phragmites) and exotic insect pests (particularly Emerald Ash Borer) present to long-term recovery efforts in Canada. Then, appropriate management alternatives will be presented to land managers. Researchers are also banding and studying wintering populations in five Costa Rican mangrove forests. This research has shown that Prothonotaries typically return to the same winter site between years and prefer young mangrove forests, using - to a lesser extent - adjacent habitats (including dry coastal forest). The banded population in Costa Rica is heavily dominated by males, suggesting that the sexes are segregated (possibly according to habitat) on the wintering grounds and may face different threats. Summary of Recovery Activities Since 1997, nearly 300 nest boxes have been erected at important breeding sites, as well as several other sites that support suitable habitat. Nest boxes are monitored in order to track annual productivity. Since 2003, the recovery team has worked with the Ontario Wetland Habitat Fund to provide landowner workshops, tours and demonstrations on habitat restoration strategies that benefit the Prothonotary Warbler and other species at risk. Techniques have been developed and tested to restore floodplain forests and to restore and/or create wetlands by altering drainage ditches, excavating, installing water control devices (as appropriate), and planting native trees. Novel restoration tools have been applied in several habitat restoration projects. In addition, the recovery team provides outreach materials to landowners and land managers in both Canada and the U.S. through both a brochure and web page. Local conservation awareness programs are also part of the work being undertaken in Costa Rica.

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.

20 record(s) found.

Reports on the Progress of Recovery Document Implementation

COSEWIC Status Reports

  • COSEWIC assessment and update status report on the Prothonotary Warbler Protonotaria citrea in Canada (2007-08-29)

    The Prothonotary Warbler is one of North America’s most dazzling songbirds. Males and females look alike, but males are more brightly coloured. Both have golden yellow heads and breasts, olive-green backs, and blue-grey wings and tails. White tail spots are quite prominent. Prothonotary Warblers are small birds, weighing about 14 grams, and measuring about 14 cm long.
  • COSEWIC Status Appraisal Summary on the Prothonotary Warbler Protonotaria citrea in Canada (2017-10-24)

    In Canada, this species breeds only in deciduous forest swamps in the Carolinian region of southwestern Ontario. The population is small, fewer than 30 individuals, and at risk of decreasing further. This warbler is vulnerable to degradation of breeding habitat from wetland drainage, forest harvest, development, invasion of European Common Reed, and loss of tree canopy cover due to dieback caused by Emerald Ash Borer. Loss of mangrove wintering habitat to aquaculture and coastal development in Central and South America poses additional threats.

Response Statements

  • Response Statement - Prothonotary Warbler (2007-12-04)

    In Canada, this species breeds only in deciduous swamp forests in southwestern Ontario. It has shown an 80% decrease in abundance over the last 10 years and its current population is between 28 and 34 mature individuals only. Threats include loss and degradation of breeding habitat, loss of coastal mangrove forests in Central and South America where the species winters, and disturbances of habitat that result in increased nest site competition with House Wrens and increased nest parasitism by Brown-headed Cowbirds.
  • Response Statement - Prothonotary Warbler (2018-01-18)

    In Canada, this species breeds only in deciduous forest swamps in the Carolinian region of southwestern Ontario. The population is small, fewer than 30 individuals, and at risk of decreasing further. This warbler is vulnerable to degradation of breeding habitat from wetland drainage, forest harvest, development, invasion of European Common Reed, and loss of tree canopy cover due to dieback caused by Emerald Ash Borer. Loss of mangrove wintering habitat to aquaculture and coastal development in Central and South America poses additional threats.

Recovery Strategies

  • Recovery Strategy for the Prothonotary Warbler (Protonotaria citrea) in Canada (2011-03-01)

    The Minister of the Environment is the competent minister for the recovery of the Prothonotary Warbler and has prepared this strategy, as per section 37 of SARA. It has been prepared in cooperation with Parks Canada Agency and the Province of Ontario. This document is a revised version of the Recovery Strategy for the Prothonotary Warbler (Protonotaria citrea) in Canada [PROPOSED] originally posted on the Species at Risk Registry on July 23, 2007, for a 60-day comment period.

Action Plans

  • Multi-species Action Plan for Point Pelee National Park of Canada and Niagara National Historic Sites of Canada (2016-07-05)

    The Multi-species Action Plan for Point Pelee National Park of Canada and the Niagara National Historic Sites of Canada applies to lands and waters occurring within the boundaries of the two sites: Point Pelee National Park of Canada (PPNP) and the Niagara National Historic Sites of Canada (NNHS). The NNHS is being used as a term to collectively refer to two locations in the Niagara region that consist of three National Historic Sites: Fort George National Historic Site, Battlefield of Fort George National Historic Site, and Butler’s Barracks National Historic Sites of Canada. The plan meets the requirements for action plans set out in the Species At Risk Act (SARA s.47) for species requiring an action plan and that regularly occur in these sites. Measures described in this plan will also provide benefits for other species of conservation concern that regularly occur at PPNP and at NNHS.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2007 (2007-08-30)

    2007 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
  • COSEWIC Annual Report 2016 to 2017 (2017-10-24)

    Over the past year COSEWIC re-examined the status of 40 wildlife species; of these, the majority (78 %) were reassessed at the same or lower level of risk. Of a total of 73 species assessed 11 were assigned the status of Not at Risk (8 re-assessments and 3 new assessments). To date and with the submission of this report, COSEWIC’s assessments now include 735 wildlife species in various risk categories including 321 Endangered, 172 Threatened, 219 Special Concern and 23 Extirpated (i.e. - no longer found in the wild in Canada). In addition 16 species have been assessed as Extinct, 58 have been designated as Data Deficient and 186 were assessed and assigned Not at Risk status.

Permits and Related Agreements

Consultation Documents

  • Consultation on Amending the List of Species under the Species at Risk Act - Terrestrial Species (2008-03-10)

    As part of its strategy for protecting wildlife species at risk, the Government of Canada proclaimed the Species at Risk Act (SARA) on June 5, 2003. Attached to the Act is Schedule 1, the list of the species that receive protection under SARA, also called the List of Wildlife Species at Risk. Please submit your comments by March 25, 2008 for species undergoing normal consultations and by March 27, 2009 for species undergoing extended consultations.
  • Consultation on Amending the List of Species under the Species at Risk Act: Terrestrial Species January 2018 (2018-01-26)

    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 555 wildlife species at risk. In 2017, final listing decisions were made for 44 terrestrial species and 15 aquatic species. Of these 59 species, 35 were new additions, sixteen were reclassifications, three had a change made to how they are defined, two were removed from Schedule 1, one was referred back to COSEWIC for further evaluation and two were the object of ‘do not list’ decisions. In 2017, on the recommendation of the Minister of the Environment, the Governor in Council approved listing proposals for 45 wildlife species. It is proposed that 21 species be added to Schedule 1, 11 be reclassified, 12 would have a change made to how they are defined, and one would be referred back to COSEWIC for further evaluation. The listing proposals were published in Canada Gazette, part I for a 30-day public comment period and final listing decisions for all 45 species are expected by August of 2018. Please submit your comments by May 22, 2018, for terrestrial species undergoing normal consultations and by October 22, 2018, for terrestrial species undergoing extended consultations. For a description of the consultation paths these species will undergo, please visit the Species at Risk Public Registry (SAR) website.

Residence Description

  • Residence Description - Prothonotary Warbler (Protonotaria Citrea) in Canada (2007-01-02)

    As a migratory bird protected under the Migratory Birds Convention Act, the Prothonotary Warbler is under federal jurisdiction. This means the residence prohibition is in effect for all nest residences on all lands on which the species occurs immediately upon its addition to the legal list of species at risk. Preface updated on May 17, 2017.

Critical Habitat Descriptions in the Canada Gazette

  • Description of critical habitat of Least Bittern and Prothonotary Warbler in Point Pelee National Park of Canada (2016-09-10)

    The Least Bittern (Ixobrychus exilis) is a migratory bird protected under the Migratory Birds Convention Act, 1994 and listed on Schedule 1 of the Species at Risk Act as a threatened species. In Canada, the Least Bittern occurs south of the Canadian Shield in Manitoba, Ontario, Quebec, New Brunswick, and Nova Scotia. It breeds in freshwater and brackish marshes with tall emergent plants interspersed with open water.
  • Description of critical habitat of the Prothonotary Warbler in Big Creek National Wildlife Area (2011-05-28)

    The Prothonotary Warbler (Protonotaria citrea) is a migratory bird protected under the Migratory Birds Convention Act, 1994 and listed on Schedule 1 of the Species at Risk Act as an endangered species. In Canada, the Prothonotary Warbler breeds primarily along the shores of Lake Erie, nesting in cavities that were created naturally (e.g. by rot or decay) or excavated by primary cavity nesters such as Black-capped Chickadees (Poecile atricapilla) and Downy Woodpeckers (Picoides pubescens), or in suitably designed artificial nest boxes erected for the species. The Recovery Strategy for the Prothonotary Warbler in Canada identifies critical habitat for the species in a number of areas, including within the Hahn Marsh Unit of Big Creek National Wildlife Area, having central coordinates of East ing 538667 and Northing 4713889, Universal Transverse Mercator (UTM), Zone 17, and the Big Creek Unit of Big Creek National Wildlife Area, having central coordinates of Easting 543195 and Northing 4715682, Universal Transverse Mercator (UTM), Zone 17.
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