Recovery strategy for the Acadian Flycatcher

About the Ontario recovery strategy series

This series presents the collection of recovery strategies that are prepared or adopted as advice to the Province of Ontario on the recommended approach to recover species at risk. The Province ensures the preparation of recovery strategies to meet its commitments to recover species at risk under the Endangered Species Act, 2007(ESA) and the Accord for the Protection of Species at Risk in Canada.

What is recovery?

Recovery of species at risk is the process by which the decline of an endangered, threatened, or extirpated species is arrested or reversed, and threats are removed or reduced to improve the likelihood of a species’ persistence in the wild.

What is a recovery strategy?

Under the ESA a recovery strategy provides the best available scientific knowledge on what is required to achieve recovery of a species. A recovery strategy outlines the habitat needs and the threats to the survival and recovery of the species. It also makes recommendations on the objectives for protection and recovery, the approaches to achieve those objectives, and the area that should be considered in the development of a habitat regulation. Sections 11 to 15 of the ESA outline the required content and timelines for developing recovery strategies published in this series.

Recovery strategies are required to be prepared for endangered and threatened species within one or two years respectively of the species being added to the Species at Risk in Ontario list. Recovery strategies are required to be prepared for extirpated species only if reintroduction is considered feasible.

What’s next?

Nine months after the completion of a recovery strategy a government response statement will be published which summarizes the actions that the Government of Ontario intends to take in response to the strategy. The implementation of recovery strategies depends on the continued cooperation and actions of government agencies, individuals, communities, land users, and conservationists.

For more information

To learn more about species at risk recovery in Ontario, please visit the Ministry of Natural Resources and Forestry Species at Risk webpage.

Recommended citation

Ontario Ministry of Natural Resources and Forestry. 2016. Recovery Strategy for the Acadian Flycatcher (Empidonax virescens) in Ontario. Ontario Recovery Strategy Series. Prepared by the Ontario Ministry of Natural Resources and Forestry, Peterborough, Ontario. v + 5 pp. + Appendix.

ISBN 978-1-4606-8986-8 (HTML)

ISBN 978-1-4606-8990-5 (PDF)

Content (excluding the cover illustration and images in the appended federal recovery strategy) may be used without permission, with appropriate credit to the source.

Acknowledgments

We thank Jody Allair and Audrey Heagy of Bird Studies Canada, and Chris Risley and Sarah McGuire of Ontario Ministry of Natural Resources and Forestry, for providing information that assisted in the development of this recovery strategy addendum.

Declaration

The recovery strategy for the Acadian Flycatcher (Empidonax virescens) was developed in accordance with the requirements of the Endangered Species Act, 2007 (ESA). This recovery strategy has been prepared as advice to the Government of Ontario, other responsible jurisdictions and the many different constituencies that may be involved in recovering the species.

The recovery strategy does not necessarily represent the views of all of the individuals who provided advice or contributed to its preparation, or the official positions of the organizations with which the individuals are associated.

The goals, objectives and recovery approaches identified in the strategy are based on the best available knowledge and are subject to revision as new information becomes available. Implementation of this strategy is subject to appropriations, priorities and budgetary constraints of the participating jurisdictions and organizations.

Success in the recovery of this species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the directions set out in this strategy.

Responsible jurisdictions

Ontario Ministry of Natural Resources and Forestry

Environment and Climate Change Canada – Canadian Wildlife Service, Ontario

Parks Canada Agency

Executive summary

Executive summary of Ontario’s recovery strategy

The Endangered Species Act, 2007(ESA) requires the Minister of Natural Resources and Forestry to ensure recovery strategies are prepared for all species listed as endangered or threatened on the Species at Risk in Ontario (SARO) List. Under the ESA, a recovery strategy may incorporate all or part of an existing plan that relates to the species.

The Acadian Flycatcher (Empidonax virescens) is listed as endangered on the SARO List. The species is also listed as endangered under the federal Species at Risk Act (SARA). Environment Canada prepared the Recovery Strategy for the Acadian Flycatcher (Empidonax virescens) and the Hooded Warbler (Wilsonia citrina) in Canada in 2012 to meet its requirements under the SARA. The portions of the recovery strategy relevant to the Acadian Flycatcher are hereby adopted under the ESA. With the additions indicated below, the enclosed strategy meets all of the content requirements outlined in the ESA.

The Critical Habitat section of the federal recovery strategy provides an identification of critical habitat (as defined under the SARA). Identification of critical habitat is not a component of a recovery strategy prepared under the ESA. However, it is recommended that the approach used to identify critical habitat for the Acadian Flycatcher in the federal recovery strategy be considered when developing a habitat regulation under the ESA.

Since the publication of the federal recovery strategy in 2012, many observations of Acadian Flycatcher have been reported at new locations in southern Ontario not contained in Ontario’s Natural Heritage Information Centre database or identified as critical habitat. Ontario’s Natural Heritage Information Centre has not yet processed these records, but there is a high probability they will become element occurrences in the near future, pending verification. The new locations for Acadian Flycatcher, in addition to those that are currently proposed as critical habitat for the Acadian Flycatcher in the federal recovery strategy for the Acadian Flycatcher in Canada (Environment Canada 2012), should also be considered in developing a habitat regulation for this species.

Executive summary of Canada’s recovery strategy

In Canada, the breeding range of the Acadian Flycatcher (Empidonax virescens) and the Hooded Warbler (Wilsonia citrina) is limited to southern Ontario. The Acadian Flycatcher is listed as Endangered federally and appears on Schedule 1 of the Species at Risk Act. It also is listed as Endangered provincially and is protected under Ontario’s Endangered Species Act, 2007 (ESA). The Hooded Warbler is listed as Threatened nationally under the Species at Risk Act and Special Concern provincially under Ontario’s Endangered Species Act, 2007 (ESA).

In Canada, the Acadian Flycatcher is confined almost entirely to the Carolinian forest region, where its numerical status, between 35 and 50 pairs in any given year, has been relatively stable since 1997 (when targeted surveys first began). Its continental population experienced an average, annual downward trend of 0.10% from 1966 to 2007, and an annual downward trend of 0.43% since 1980.

In recent years, Hooded Warbler numbers have increased dramatically in Ontario, from 88 territorial males (some of which were not paired) in 1997, to an estimated 436 territorial males (some of which were not paired) in 2007. In that time, the species has expanded its range, occupying other forests within the Carolinian forest region as well as areas to the north and east of this region. The Hooded Warbler has shown an increasing trend continentally at an average annual rate of 0.84% from 1966 to 2007, and showed an increase at an average annual rate of 0.87% since 1980. In Ontario, both species reach their highest densities in large, mature forests set in landscapes with at least 30% regional forest cover.

Both the Acadian Flycatcher and the Hooded Warbler have been regarded as area-sensitive species with a predilection for extensive tracts of deciduous forests. However, most of the original Carolinian deciduous forest cover has been removed, and many of the remaining forests are too small and isolated to accommodate Acadian Flycatchers, Hooded Warblers, and other species that depend on the specialized habitats found in large, mature forests. Specific threats include diameter-limit tree harvest, development for housing and/or agricultural uses, changes to hydrological regimes, invasive species, climate change and a number of threats to the species and their habitat outside of Canada. A single recovery strategy for these two species has been developed due to the similarity in occurrences, threats, and recovery actions. It was determined that recovery activities for both species could be effectively represented within one document.

There are unknowns regarding the feasibility of recovery of the Acadian Flycatcher and the Hooded Warbler. Nevertheless, in keeping with the precautionary principle, this recovery strategy has been prepared as per section 41(1) of SARA as would be done when recovery is determined to be feasible. This recovery strategy addresses the unknowns surrounding the feasibility of recovery.

The population and distribution objective for the Acadian Flycatcher is to maintain the current population of between 35 and 50 pairs distributed within the species’ current Ontario range. The population and distribution objective for the Hooded Warbler is to increase the number of Hooded Warbler breeding pairs to 500 distributed within the species’ current Ontario range.

Critical habitat for both the Acadian Flycatcher and the Hooded Warbler is identified within this recovery strategy. Broad strategies to be taken to address the threats to the survival and recovery of these species are presented in the section on Strategic Direction for Recovery.

One or more action plans will be posted on the Species at Risk Public Registry for the Acadian Flycatcher and the Hooded Warbler by December 2017.

Adoption of federal recovery strategy

The Endangered Species Act, 2007(ESA) requires the Minister of Natural Resources and Forestry to ensure recovery strategies are prepared for all species listed as endangered or threatened on the Species at Risk in Ontario (SARO) List. Under the ESA, a recovery strategy may incorporate all or part of an existing plan that relates to the species.

The Acadian Flycatcher (Empidonax virescens) is listed as endangered on the SARO List. The species is also listed as endangered under the federal Species at Risk Act (SARA). Environment Canada prepared the Recovery Strategy for the Acadian Flycatcher (Empidonax virescens) and the Hooded Warbler (Wilsonia citrina) in Canada in 2012 to meet its requirements under the SARA. The portions of this recovery strategy relevant to the Acadian Flycatcher are hereby adopted under the ESA. With the additions indicated below, the enclosed strategy meets all of the content requirements outlined in the ESA.

Species assessment and classification

Table 1. Species assessment and classification

 of the Acadian Flycatcher (Empidonax virescens). The glossary provides definitions for the abbreviations within, and for other technical terms in this document.

The federal recovery strategy includes information on the Hooded Warbler. The Hooded Warbler is not a species at risk in Ontario.

Distribution, abundance and population trends

Sections 3.2 and 7.2 of the federal recovery strategy for the Acadian Flycatcher and Hooded Warbler (Appendix 1) provide a description of the populations, distribution and critical habitat of Acadian Flycatcher in Ontario. Since the publication of the federal recovery strategy in 2012, many observations of Acadian Flycatcher have been reported at locations in southern Ontario not identified as critical habitat (Heagy 2013, Allair et al. 2015, and Natural Heritage Information Centre unpublished observations). Ontario’s Natural Heritage Information Centre (NHIC) has not yet processed these records, but there is a high probability some of them will become element occurrences. The locations on the following list may be outside the designated critical habitat shown in Appendix 2 of the federal recovery strategy for the Acadian Flycatcher and the Hooded Warbler (Appendix 1) and should be considered in developing a habitat regulation for this species.

New locations of Acadian Flycatcher that have been reported to the NHIC since the federal recovery strategy was published are listed below. The following are recent observations in their known distribution that may become new element occurrences:

• Durham Regional Municipality – one location
• Elgin County – three locations
• Essex County – one location
• Grey County – one location
• Halton Regional Municipality – one location
• Lambton County – three locations
• Middlesex Regional Municipality – one location
• Norfolk County – six locations
• York Regional Municipality – two locations

These new locations should be considered when the Ontario Ministry of Natural Resources and Forestry proposes a habitat regulation.

Area for consideration in developing a habitat regulation

Under the ESA, a recovery strategy must include a recommendation to the Minister of Natural Resources and Forestry on the area that should be considered in developing a habitat regulation. A habitat regulation is a legal instrument that prescribes an area that will be protected as the habitat of the species. The recommendation provided below will be one of many sources considered by the Minister, including information that may become newly available following completion of the recovery strategy, when developing the habitat regulation for this species.

The Critical Habitat section of the federal recovery strategy provides an identification of critical habitat (as defined under the SARA). Identification of critical habitat is not a component of a recovery strategy prepared under the ESA. However, it is recommended that the approach used to identify critical habitat for the Acadian Flycatcher in the federal recovery strategy be considered when developing a habitat regulation under the ESA. Pending verification, the locations of Acadian Flycatcher noted above, beyond what are currently proposed as critical habitat in the federal recovery strategy for the Acadian Flycatcher in Canada (Environment Canada 2012), should also be considered in developing a habitat regulation for this species.

Glossary

Committee on the Status of Endangered Wildlife in Canada (COSEWIC): The committee established under section 14 of the Species at Risk Act that is responsible for assessing and classifying species at risk in Canada.

Committee on the Status of Species at Risk in Ontario (COSSARO): The committee established under section 3 of the Endangered Species Act, 2007 (ESA) that is responsible for assessing and classifying species at risk in Ontario.

Conservation status rank: A rank assigned to a species or ecological community that primarily conveys the degree of rarity of the species or community at the global (G), national (N) or subnational (S) level. These ranks, termed G-rank, N-rank and S-rank, are not legal designations. Ranks are determined by NatureServe and, in the case of Ontario’s S-rank, by Ontario’s Natural Heritage Information Centre. The conservation status of a species or ecosystem is designated by a number from 1 to 5, preceded by the letter G, N or S reflecting the appropriate geographic scale of the assessment. The numbers mean the following:

• 1 = critically imperilled
• 2 = imperilled
• 3 = vulnerable
• 4 = apparently secure
• 5 = secure
• NR = not yet ranked

Element Occurrence: The basic unit of record for documenting and delimiting the presence and extent of a species on the landscape. It is an area of land and/or water where a species is, or was, present, and which has practical conservation value.

Endangered Species Act, 2007 (ESA): The provincial legislation that provides protection to species at risk in Ontario.

Species at Risk Act (SARA): The federal legislation that provides protection to species at risk in Canada. This act establishes Schedule 1 as the legal list of wildlife species at risk. Schedules 2 and 3 contain lists of species that at the time the Act came into force needed to be reassessed. After species on Schedule 2 and 3 are reassessed and found to be at risk, they undergo the SARA listing process to be included in Schedule 1.

Species at Risk in Ontario (SARO) List: The regulation made under section 7 of the Endangered Species Act, 2007 (ESA) that provides the official status classification of species at risk in Ontario. This list was first published in 2004 as a policy and became a regulation in 2008.

References

Allair, J., B. Stewart, M. Falconer, S. Dobney, and D. Tozer. 2015. Forest Birds at Risk in the Carolinian Forest of Southwestern Ontario 2014 Report including 4-year Summary. Unpublished report, Bird Studies Canada. 24 pp.

Environment Canada. 2012. Recovery Strategy for the Acadian Flycatcher (Empidonax virescens) and the Hooded Warbler (Wilsonia citrina) in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. viii + 32 pp.

Heagy, A. 2013. Ontario Forest Birds and Risk: 2012 Acadian Flycatcher Surveys. Unpublished report, Bird Studies Canada. 11 pp.

Appendix 1. Recovery strategy for the Acadian Flycatcher (Empidonax virescens) and the Hooded Warbler (Wilsonia citrina) in Canada

Federal cover illustrations: Acadian Flycatcher (top): Michael Patrikeev; Hooded Warbler (bottom): U.S. Fish and Wildlife Service.

Document information

Recommended citation

Environment Canada. 2012. Recovery strategy for the Acadian Flycatcher (Empidonax virescens) and the Hooded Warbler (Wilsonia citrina) in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa, Ontario. viii + 32 pp.

Additional copies

For copies of the recovery strategy, or for additional information on species at risk, including COSEWIC Status Reports, residence descriptions, action plans, and other related recovery documents, please visit the Species at Risk (SAR) Public Registry (www.sararegistry.gc.ca).

© Her Majesty the Queen in Right of Canada, represented by the Minister of the Environment, 2012. All rights reserved.

ISBN 978-1-100-18539-2

Catalogue no. En3-4/103-2012E-PDF

Content (excluding the illustrations) may be used without permission, with appropriate credit to the source.

Preface

The federal, provincial, and territorial government signatories under the Accord for the Protection of Species at Risk (1996) agreed to establish complementary legislation and programs that provide for effective protection of species at risk throughout Canada. Under the Species at Risk Act (S.C. 2002, c.29) (SARA), the federal competent ministers are responsible for the preparation of recovery strategies for listed Extirpated, Endangered, and Threatened species and are required to report on progress within five years.

The Minister of the Environment and the Minister responsible for the Parks Canada Agency are the competent ministers for the recovery of the Acadian Flycatcher and Hooded Warbler and have prepared this strategy, as per section 37 of SARA. It has been prepared in cooperation with the Province of Ontario (Ministry of Natural Resources) and Long Point Region Conservation Authority as per section 39 (1) of SARA.

Success in the recovery of these species depends on the commitment and cooperation of many different constituencies that will be involved in implementing the directions set out in this strategy and will not be achieved by Environment Canada, the Parks Canada Agency, or any other jurisdiction alone. All Canadians are invited to join in supporting and implementing this strategy for the benefit of the Acadian Flycatcher and Hooded Warbler and Canadian society as a whole.

This recovery strategy will be followed by one or more action plans that will provide information on recovery measures to be taken by Environment Canada, the Parks Canada Agency and other jurisdictions and/or organizations involved in the conservation of the species. Implementation of this strategy is subject to appropriations, priorities, and budgetary constraints of the participating jurisdictions and organizations.

Acknowledgments

The recovery strategy was developed by members of the Acadian Flycatcher and Hooded Warbler Recovery Team: Lyle Friesen, Debbie Badzinski, Christine Vance, Jon McCracken, Dave Martin, Audrey Heagy, and Angela McConnell. The recovery strategy benefited from input and suggestions from the following individuals and organizations: Bird Studies Canada; Conservation Halton; Toronto and Region Conservation; Stephanie Melles, Corina Brdar, Andre Dupont, Chris Risley, Don Sutherland, Joe Nocera, Kristine Blakey and Bree Walpole – Ontario Ministry of Natural Resources; Clint Jacobs and Jared Macbeth - Walpole Island Heritage Centre; Krista Holmes, Angela Darwin, Marie-Claude Archambault, Madeline Austen, Lesley Dunn, Burke Korol, Lucie Metras, Marie-José Ribeyron and Kari Van Allen – Environment Canada. Thanks are extended to Michael Patrikeev and the U.S. Fish and Wildlife Service for the cover photos.

Executive summary

In Canada, the breeding range of the Acadian Flycatcher (Empidonax virescens) and the Hooded Warbler (Wilsonia citrina) is limited to southern Ontario. The Acadian Flycatcher is listed as Endangered federally and appears on Schedule 1 of the Species at Risk Act. It also is listed as Endangered provincially and is protected under Ontario’s Endangered Species Act, 2007 (ESA). The Hooded Warbler is listed as Threatened nationally under the Species at Risk Act and Special Concern provincially under Ontario’s Endangered Species Act, 2007 (ESA).

In Canada, the Acadian Flycatcher is confined almost entirely to the Carolinian forest region, where its numerical status, between 35 and 50 pairs in any given year, has been relatively stable since 1997 (when targeted surveys first began). Its continental population experienced an average, annual downward trend of 0.10% from 1966 to 2007, and an annual downward trend of 0.43% since 1980.

In recent years, Hooded Warbler numbers have increased dramatically in Ontario, from 88 territorial males (some of which were not paired) in 1997, to an estimated 436 territorial males (some of which were not paired) in 2007. In that time, the species has expanded its range, occupying other forests within the Carolinian forest region as well as areas to the north and east of this region. The Hooded Warbler has shown an increasing trend continentally at an average annual rate of 0.84% from 1966 to 2007, and showed an increase at an average annual rate of 0.87% since 1980. In Ontario, both species reach their highest densities in large, mature forests set in landscapes with at least 30% regional forest cover.

Both the Acadian Flycatcher and the Hooded Warbler have been regarded as area-sensitive species with a predilection for extensive tracts of deciduous forests. However, most of the original Carolinian deciduous forest cover has been removed, and many of the remaining forests are too small and isolated to accommodate Acadian Flycatchers, Hooded Warblers, and other species that depend on the specialized habitats found in large, mature forests. Specific threats include diameter-limit tree harvest, development for housing and/or agricultural uses, changes to hydrological regimes, invasive species, climate change and a number of threats to the species and their habitat outside of Canada. A single recovery strategy for these two species has been developed due to the similarity in occurrences, threats, and recovery actions. It was determined that recovery activities for both species could be effectively represented within one document.

There are unknowns regarding the feasibility of recovery of the Acadian Flycatcher and the Hooded Warbler. Nevertheless, in keeping with the precautionary principle, this recovery strategy has been prepared as per section 41(1) of SARA as would be done when recovery is determined to be feasible. This recovery strategy addresses the unknowns surrounding the feasibility of recovery.

The population and distribution objective for the Acadian Flycatcher is to maintain the current population of between 35 and 50 pairs distributed within the species’ current Ontario range. The population and distribution objective for the Hooded Warbler is to increase the number of Hooded Warbler breeding pairs to 500 distributed within the species’ current Ontario range.

Critical habitat for both the Acadian Flycatcher and the Hooded Warbler is identified within this recovery strategy. Broad strategies to be taken to address the threats to the survival and recovery of these species are presented in the section on Strategic Direction for Recovery.

One or more action plans will be posted on the Species at Risk Public Registry for the Acadian Flycatcher and the Hooded Warbler by December 2017.

Recovery feasibility summary

Based on the following four criteria outlined by the Government of Canada (2009), there are unknowns regarding the feasibility of recovery of the Acadian Flycatcher and Hooded Warbler. In keeping with the precautionary principle, a recovery strategy has been prepared as per section 41(1) of SARA, as would be done when recovery is determined to be feasible. This recovery strategy addresses the unknowns surrounding the feasibility of recovery.

Acadian Flycatcher

1. Individuals of the wildlife species that are capable of reproduction are available now or in the foreseeable future to sustain the population or improve its abundance.
   Yes. Individuals capable of reproduction are present in Ontario and in nearby New York, Pennsylvania, Ohio, and Michigan to sustain the population or improve its abundance.
2. Sufficient suitable habitat is available to support the species or could be made available through habitat management or restoration.
   Yes. Sufficient habitat is available to sustain the current estimated population. Additional habitat could be made available to support the species through habitat management techniques or restoration efforts to support an increase in species’ abundance.
3. The primary threats to the species or its habitat (including threats outside Canada) can be avoided or mitigated.
   Unknown. Many of the threats on the breeding grounds in Canada can be avoided or mitigated through targeted recovery actions. However, the extent and feasibility of mitigating threats on United States breeding grounds and/or wintering grounds are unknown at this time. Further, it is currently unknown if some threats, such as invasive species, can be effectively mitigated. These threats will greatly affect the recovery of the species in Canada but without further research it can not be determined whether it is possible to successfully mitigate them. Recovery on a global scale is critical for the recovery of the species in Canada.
4. Recovery techniques exist to achieve the population and distribution objectives or can be expected to be developed within a reasonable timeframe.
   Unknown. Some of the necessary recovery techniques are available (e.g., protection of existing mature forests and management of woodlands for older growth). However, it is unknown whether using these recovery techniques will be effective in meeting the population and distribution objectives.

As the small Canadian population of Acadian Flycatchers occurs at the northern part of its continental range, and the vast majority of its continental distribution and population occurs further south in the United States, it is important to note that population changes at the continental level may have a significant effect on recovery feasibility in Canada. As the continental population of the Acadian Flycatcher is experiencing an ongoing downward population trend, its range may contract away from the current periphery, with individuals remaining closer to the centre of the range. In such a case, despite best efforts described in this strategy to ensure that sufficient suitable habitat is available and key threats are mitigated, the numbers of Acadian Flycatcher in Canada may continue to decline.

Hooded Warbler

1. Individuals of the wildlife species that are capable of reproduction are available now or in the foreseeable future to sustain the population or improve its abundance.

Yes. Individuals capable of reproduction are currently available in Ontario and are known to be contributing to the current population increase and range expansion.

1. Sufficient suitable habitat is available to support the species or could be made available through habitat management or restoration.

Yes. Given that the Hooded Warbler has expanded its Ontario range, sufficient habitat is available to support the present estimated population. Additional habitat could be made available through management techniques or restoration efforts to support an increase in species’ abundance.

1. The primary threats to the species or its habitat (including threats outside Canada) can be avoided or mitigated.

Unknown. Many of the threats on the breeding grounds in Canada can be avoided or mitigated through targeted recovery actions. However, the extent and feasibility of mitigating threats to the United States breeding grounds and/or winter grounds are unknown at this time. Further, it is currently unknown if some threats, such as invasive species, can be effectively mitigated. These threats will greatly affect the recovery of the species in Canada but without further research it can not be determined whether it is possible to successfully mitigate them. Recovery on a global scale is critical for the recovery of the species in Canada.

1. Recovery techniques exist to achieve the population and distribution objectives or can be expected to be developed within a reasonable timeframe.

Unknown. The necessary recovery techniques are available and effective (e.g., protection of existing mature forests, management of woodlands for older growth, and the use of sound forestry practices). However, it is unknown whether using these restoration techniques will be effective in meeting the population and distribution objectives.

As the small Canadian population of Hooded Warbler occurs at the northern part of its continental range, and the vast majority of its continental distribution and population occurs further south in the United States, it is important to note that population changes at the continental level may have a significant effect on recovery feasibility in Canada. As the continental population of the Hooded Warbler is experiencing an ongoing increasing population trend, its range may expand outward from the current periphery, and individuals may emigrate out from the centre of the range. In such a case, in response to the provision of sufficient suitable habitat and mitigation of key threats, the rate of recovery of the Canadian population of Hooded Warblers and rate of achievement of population and distribution objectives may exceed those anticipated here.

1. COSEWIC species assessment information

Acadian Flycatcher

Date of assessment: April 2010

Common name (population): Acadian Flycatcher

Scientific name:Empidonax virescens

COSEWIC status: Endangered

Reason for designation: In Canada, this species is restricted to certain types of mature forest in southern Ontario. Only small numbers breed in Canada. Although the population appears to have been relatively stable over the past 10-20 years, this is most likely due to immigration from U.S. populations. The species is threatened by forestry practices, particularly those that target removal of large trees. Serious conservation concerns, both in Canada and the adjacent U.S. also stem from increasingly widespread losses of a variety of favoured nest tree species owing to the spread of an array of invasive forest insects and pathogens. Collectively, these threats to habitat greatly reduce potential for rescue from adjacent U.S. populations.

Canadian occurrence: Ontario

COSEWIC status history: Designated Endangered in April 1994. Status re-examined and confirmed Endangered in November 2000 and April 2010. Last assessment based on an update status report.

Hooded Warbler

Date of assessment: November 2000

Common name (population): Hooded Warbler

Scientific name:Wilsonia citrina

COSEWIC status: Threatened

Reason for designation: This population is small and the quantity and quality of habitat will likely decline in the future. The likelihood of a rescue effect from U.S. populations is limited by availability of suitable habitat in Canada.

Canadian occurrence: Ontario

COSEWIC status history: Designated Threatened in April 1994. Status re-examined and confirmed in November 2000. Last assessment based on an update status report.

2. Species status information

Acadian Flycatcher

The Acadian Flycatcher is listed as Endangered both nationally under the Species at Risk Act and provincially under Ontario’s Endangered Species Act, 2007 (ESA). It is considered globally secure (G5) (NatureServe 2009). In the United States, the species is nationally secure (N5B) (NatureServe 2009) and occurs in 33 states with varying subnational ranks (Table 1). In Canada, the species is considered imperiled nationally (N2B) and subnationally imperiled to vulnerable (S2BS3B) (NatureServe 2009). It is estimated that less than 1% of the Acadian Flycatcher’s global population occurs in Canada (Martin 2007; BirdLife International 2010a).

Table 1. Subnational conservation ranks (S-rank) for the Acadian Flycatcher (NatureServe 2009).

S1 – critically imperilled; S2 – imperilled; S2S3 – imperilled to vulnerable; S3 – vulnerable; S3S4 – vulnerable to apparently secure; S4 – apparently secure; S4S5 – apparently secure to secure; S5 – secure; SH – possibly extirpated; SNR – unranked; B – breeding population; N – non-breeding population.

Hooded Warbler

The species is listed as Threatened nationally under the Species at Risk Act and Special Concern under Ontario’s Endangered Species Act, 2007. It is considered globally secure (G5) (NatureServe 2009). In the U.S., the Hooded Warbler is considered nationally secure (N5B) but within the 36 states where the species occurs, the subnational ranks vary from critically imperiled to secure (Table 2). In Canada, the species is considered vulnerable nationally (N3B) and subnationally (S3B) (NatureServe 2009). It is estimated that less than 1% of the Hooded Warbler’s global population occurs in Canada (Badzinski 2007; BirdLife International 2010b).

Table 2. Subnational conservation ranks (S-rank) for the Hooded Warbler (NatureServe 2009)

S1 – critically imperilled; S2 – imperilled; S2S3 – imperilled to vulnerable; S3 – vulnerable; S3S4 – vulnerable to apparently secure; S4 – apparently secure; S4S5 – apparently secure to secure; S5 – secure; SNA – conservation status not applicable because the species is not a suitable target for conservation activities; SNR – unranked; B – breeding population; N – non-breeding population; M – migrant/transient population.

3. Species information

3.1 Species description

Acadian Flycatcher

The Acadian Flycatcher is a small, sparrow-sized flycatcher that measures approximately 14cm to 16.5 cm in length. Adults are olive-green above and white below, with yellowish sides. They have a light eye ring and two white wing bars. Juveniles resemble adults but have buffy wing bars and buff-edged body feathers. This flycatcher is most often found by following the male’s loud “PEET-sa” or “TEE-chup” song. Nesting females make frequent “chiff” calls.

Hooded Warbler

The male Hooded Warbler is strikingly coloured; its greenish back and satiny black hood contrast with a bright yellow face and underparts; it is about 12.5cm to 14.5cm in length. Flashing white patches in the tail also help to confirm its identity. Females are similar in appearance to males, except that they have varying amounts of black on their crown and throat. Although males have several song types, one of the most common and recognizable songs has been likened to “weeta-weeta-weetee-o”. Nesting females make frequent metallic “chip” calls.

3.2 Population and distribution

To document the status, distribution and trends of Acadian Flycatcher and Hooded Warbler populations in Canada, extensive surveys of known and potential habitat were carried out in 1997 (Heagy et al. 1997), 1998 (McCracken et al. 1998), 2002 (Carson et al. 2003) and 2007 (Heagy and Badzinski 2008). The purpose of these surveys was to: determine which of the known historic breeding sites in Ontario are still occupied; check a selection of other potential sites to determine if they were occupied; produce an updated and reliable estimate of the population size of Acadian Flycatchers and Hooded Warblers in Ontario; and assess and monitor the status of these two species in the province (Heagy and Badzinski 2008). Additional surveys have also been conducted in the last ten years by Bird Studies Canada and the Ontario Ministry of Natural Resources.

Acadian Flycatcher

The Acadian Flycatcher breeds throughout much of the eastern United States and northward into southern Ontario, where it reaches the northern limit of its breeding range (Figure 1). Its winter range extends along both the Caribbean and Pacific slopes of Central America from Nicaragua south to northwestern South America (Sauer et al. 2005).

Globally, the Acadian Flycatcher has an estimated population of about 2 350 000 pairs (Rich et al. 2004). It has been described as a common bird in many large forests in the core part of its U.S. breeding range (Whitehead and Taylor 2002). In Canada, the Acadian Flycatcher population is estimated to be approximately 35 to 50 pairs in any given year (Martin 2007; Heagy 2010; Lyle Friesen pers. comm.). Its continental population experienced an average, annual downward trend of 0.10% from 1966 to 2007, and an annual downward trend of 0.43% between 1980 and 2007 (Sauer et al. 2008).

In Canada the Acadian Flycatcher occurs only in Ontario. The species breeds primarily in the Carolinian forest region of Ontario, especially in Elgin and Norfolk counties. During the first Ontario Breeding Bird Atlas (1981–1985), Acadian Flycatchers were found in 29 (10km X 10km) squares in eight regions (Cadman et. al 2007). During the second atlas (2001‑2005), the flycatcher was found in 50 squares in 11 regions (Martin 2007) (Figure 2). Much of the Ontario increase may be attributable to directed searches for the species since 1997, rather than an actual increase in numbers (Martin 2007). It also appears that some core sites are intermittently occupied and breeding activity at other sites is sporadic (Heagy 2008). However, the number of sites occupied annually is relatively stable, with sites that are not re-inhabited offset by newly inhabited sites.

Map produced by Andrew Couturier, Bird Studies Canada. Source: Cadman et al., 2007.

Hooded Warbler

During the breeding season the Hooded Warbler is widely distributed in woodlands throughout the eastern and mid-western United States and sparingly in southern Ontario, where it reaches the northern limit of its breeding range (Figure 3). Its primary wintering grounds are along the Caribbean coast between central Mexico and southern Costa Rica, with lower, but still significant, densities in the Greater Antilles (Evans, Ogden and Stutchbury 1994).

Globally, the Hooded Warbler has an estimated population of about 2 000 000 pairs (Rich et al. 2004).

The North American Hooded Warbler population trend has shown an increase at an average annual rate of 0.84% from 1966 to 2007 and by 0.87% since 1980 (Sauer et al. 2008). Since the last COSEWIC report (James 2000), considerably more data have been obtained on the abundance and distribution of the species in Ontario. This data indicates that there has been a significant population expansion in the province.

In Canada, the Hooded Warbler occurs only in Ontario. Historically, the majority of the Canadian population was found at only a few breeding sites, with most occurring in Norfolk County (Badzinski 2007). In the last twenty years, the species has expanded its range to the north, west and east. Although still most commonly found in the Carolinian forest region, Hooded Warblers are now also known to occur in the Lake Simcoe-Rideau and Southern Shield Regions.

During the first Ontario Breeding Bird Atlas, the species was recorded in 21 atlas squares in six regions within the Carolinian forest region (Sutherland and Gartshore 1987). During the second atlas, the species was reported from 77 squares in 14 regions, with almost 21% of the squares outside the Carolinian forest region (Badzinski 2007) (Figure 4). Surveys in recent years have shown a marked population increase — from an estimated 88 territorial males (some of which were not paired) found in 1997 to 436 territorial males (some of which were not paired) in 2007. Surveys conducted since 1997 suggest that the bulk of Ontario’s Hooded Warbler population is concentrated within eight forest complexes [i].

Map produced by Andrew Couturier, Bird Studies Canada. Source: Cadman et al., 2007.

3.3 Needs of the Acadian Flycatcher and Hooded Warbler

Both Acadian Flycatchers and Hooded Warblers return to Ontario from wintering areas in early to mid-May, with females typically arriving a few days later than males. Nest construction begins in May or early June, and the nest site is used for approximately five weeks. Double-brooding in both species is a common occurrence in Ontario, which extends the active breeding season to the end of August. Triple-brooding in Hooded Warblers has also been documented in Ontario (Bird Studies Canada 2003).

Returning males of both species often occupy the same territory in subsequent years. Adults and juveniles of both species depend on a wide variety of insects, insect larvae, and other arthropods (Evans Ogden and Stutchbury 1994; Whitehead and Taylor 2002).

Both the Acadian Flycatcher and the Hooded Warbler prefer large, mature woodlands in areas with high (>30%) regional forest cover (Environment Canada 2004). Although the species have slightly different habitat preferences, larger blocks of mature forest with structural diversity are likely to accommodate the habitat requirements of both species. More details of specific habitat elements for each species are outlined below.

Acadian Flycatcher

Forest size and regional forest cover

The Acadian Flycatcher is an area-sensitive species throughout most of its breeding range, choosing large forests over small ones (Whitehead and Taylor 2002). In Ohio, for example, the species preferentially selects deciduous forests exceeding 40 ha, although it is regularly found in smaller forest blocks that are located near extensive forests (Peterjohn and Rice 1991). In Ontario, 92% of the patches supporting breeding Acadian Flycatchers are larger than 25 ha, and 56% of the patches are larger than 100 ha (B. Woolfenden and B. Stutchbury, unpubl. data). Of the 14 most productive breeding forests in Ontario, 11 are located in areas with more than 30% forest cover within 1 km of the nest (B. Woolfenden and B. Stutchbury, unpubl. data).

Forest type

The Acadian Flycatcher occupies a broad spectrum of deciduous and mixed woodlands across its breeding range (Whitehead and Taylor 2002). In Ontario, the species is found in uplands, swamps, and well-wooded ravines (D. Martin, unpubl. data 2004). It inhabits a range of forest types, including maple–beech, oak–maple, and beech–hemlock. Nests have been found in at least 20 tree species in Ontario, with the majority in American Beech (Fagus grandifolia) and Eastern Hemlock (Tsuga canadensis) (D. Martin, unpubl. data; B. Woolfenden and B. Stutchbury, unpubl. data).

Forest structure

Acadian Flycatchers occupy mature woodlands and prefer forests with a closed canopy, a relatively open understorey, and sparse ground layer. The species prefers woodlands with permanent or ephemeral ponds and steep-sided, wooded ravines with streams. The presence of water may help to maintain the structure of woodlands preferred by the flycatcher (e.g., vernal pools prevent the establishment of a dense shrub layer). Territories are established in areas where there are few shrubs or branches within 2 to 3 m of the ground (Walkinshaw and Brewer 1991). Although the flycatcher sometimes builds nests in relatively dry woods (Peterjohn and Rice 1991), it often suspends nests over water (D. Martin, unpubl. data), or other open areas (Whitehead and Taylor 2002).

Post-fledging/pre-migration habitat

There is little information on the habitat used by Acadian Flycatchers after the young have left the nest, or the habitat that is used by adults and young prior to migration. Post-fledging habitat likely contains elements essential to juvenile survival such as vegetation for cover and food.

Habitat on wintering grounds

Acadian Flycatchers winter in dry, humid and wet mature forests (Whitehead and Taylor 2002). They are found in primary (>100 years) and secondary forests (50 to 80 years) at elevations ranging from lowland (50 m) to premontane (2700 m), and they tend to avoid patchy or open areas (Whitehead and Taylor 2002).

Hooded Warbler

Forest size and regional forest cover

The Hooded Warbler is an area-sensitive species over most of its breeding range and prefers larger tracts of mature forest to smaller ones (Evans Ogden and Stutchbury 1994). The minimum threshold forest size for the species was 30 ha in Maryland (Robbins 1979) and 15 ha in New York and Ohio (Eaton 1988; Peterjohn and Rice 1991). In northwestern Pennsylvania, where regional forest cover is much higher than in southern Ontario, Hooded Warblers often nest in extremely small (3–5 ha) forest fragments (Norris and Stutchbury 2001). In Ontario, the majority of occurrences of Hooded Warbler have been in forests larger than 100 ha (Flaxman 2003). However, the species has nested successfully in woodlots as small as 8 ha when the woodlot was located near larger forests (Melles 2004). These variations in area sensitivity likely reflect differences in the amount of regional forest cover (Freemark and Collins 1992). At three forest complexes in Ontario where Hooded Warblers and Acadian Flycatchers both occur, regional forest cover ranged from 61% to 77% within 1 km of the nest sites (B. Woolfenden and B. Stutchbury, unpubl. data).

Forest type

Hooded Warblers prefer woodlands where trees are large enough (i.e. Diameter at Breast Height >38cm) to create tree-fall gaps with a median size of 40 to 200 m² (Evans Ogden and Stutchbury 1994; Whittam et al. 2002). Maple, beech, and oak usually dominate occupied deciduous forests throughout the breeding range of the Hooded Warbler (Evans Ogden and Stutchbury 1994). In Ontario, well-drained sandy sites dominated by Red Maple (Acer rubrum), White Oak (Quercus alba), Sugar Maple (Acer saccharum), American beech, and Eastern White Pine (Pinus strobus) are preferred breeding areas (Gartshore 1988). Shrub layer plants include Maple-leaf Viburnum (Viburnum acerifolium), Wild Red Raspberry (Rubus idaeus), Black Raspberry (Rubus occidentalis), White Ash (Fraxinus americana) and Chokecherry (Prunus virginiana) (Gartshore 1988). Red Elderberry (Sambucus racemosa ssp.pubens) is a fairly common shrub layer plant in forest complexes with large concentrations of Hooded Warblers in Canada (Heagy and Badzinski 2006).

Forest structure

Hooded Warblers generally breed in mature woodlands with canopy gaps where there is a proliferation of shrubs, saplings, vines, brambles, and other herbaceous growth (Evans Ogden and Stutchbury 1994). Territories are located around the gaps, with nests being typically located within the gaps, or at their edges. The size of the gaps can vary considerably, although it is not clear how this affects nesting success and productivity (Whittam et al. 2002; D. Burke, unpubl. data). Suitable habitat can persist for periods of approximately 10 to 15 years from the time the ground vegetation is established until the canopy closes (Whittam et al. 2002).

Hooded Warbler territory size is variable and is likely influenced by population density, habitat quality and breeding status. In the St.William’s Conservation Reserve, mean territory size ranged from 2.3 to 3.5 ha in the three years that it was studied (BSC, unpub. data). It is also well known that male and female Hooded Warblers will travel within the forest – well beyond their territorial boundaries (e.g., for extra-pair copulations; Stuchbury et al. 2005).

Post-breeding/pre-migration habitat

There is limited information on what habitat adults or fledglings use in Ontario after nesting is finished and before migration begins. During the first week post-fledging, young are incapable of flight and move only short distances from the nest site. Post-fledging habitat selection is a critical period because mortality rates can be very high in the 1 to 2 weeks post-fledging before flight ability is obtained (Rush and Stuchbury 2008). In southern Ontario, Hooded Warbler pairs attend their young into early September, at which time the fledglings have undergone a pre-basic moult, attaining adult-like plumage. As young mature, they move progressively further from the nest site, possibly in search of future breeding territories.

In late August and September, this species joins mixed flocks before migrating (A. Heagy, unpubl. data). During this period, the species uses forest edge and scrub habitat (B. Stutchbury, unpubl. data). When breeding season movements, post-fledging and pre-migratory movements are considered, Hooded Warblers will use most of the forested area within a site.

Habitat on wintering grounds

Winter habitat for Hooded Warbler ranges from brushy fields and late successional shrubs to dry deciduous and semi-evergreen forest, second-growth forest, and mature forest. Both males and females establish winter territories, although in different habitats, with males occupying more mature habitats than females (Evans Ogden and Stutchbury 1994).

[i] Woodlots 10 hectares in size or larger that are in close proximity to each other.

1. Threats

1.1 Threat assessment

Table 3. Threat assessment table for Acadian Flycatcher and Hooded Warbler.

Habitat loss or degradation.

Exotic, invasive, or introduced species/genomes.

Climate and natural disasters.

Level of Concern: signifies that managing the threat is of (high, medium or low) concern for the recovery of the species, consistent with the population and distribution objectives. This criterion considers the assessment of all the information in the table.

Severity: reflects the population-level effect (High: very large population-level effect, Moderate, Low, Unknown).

Causal certainty: reflects the degree of evidence that is known for the threat (High: available evidence strongly links the threat to stresses on population viability; Medium: there is a correlation between the threat and population viability e.g., expert opinion; Low: the threat is assumed or plausible).

1.2 Description of threats

In general, the Acadian Flycatcher, with its more exacting requirements for undisturbed forests, is more vulnerable to threats that impact the age, structure, and function of woodlands than the Hooded Warbler. All threats described below pertain to the species’ habitats versus individuals of the species directly, and are listed in order of importance.

Diameter-limit tree harvest [i]

Diameter-limit harvesting is widely practiced in southern Ontario woodlands (OMNR 2000) but is incompatible with the needs of the Acadian Flycatcher and the Hooded Warbler. This silvicultural treatment removes all or most of the oldest and largest trees, thereby eliminating the closed canopy condition required by Acadian Flycatchers. Forests harvested in this manner may lack suitable Acadian Flycatcher habitat for up to 40 years (K. Elliott, unpubl. data). Hooded Warblers readily occupy sites that have been selectively logged [ii] provided that many large-diameter trees have been retained (Evans Ogden and Stutchbury 1994; Whittam et al. 2002). Conversely, diameter-limit logging removes too many large-diameter trees and reduces nest success for Hooded Warblers by increasing brood parasitism and predation rates (Friesen and Stabb 2001).

Housing development/development for agricultural uses

i) In woodlands containing Acadian Flycatcher or Hooded Warbler habitat

The Carolinian forest is one of Canada’s most threatened habitats. Agricultural and development pressures have been intense in the Carolinian forest region, where existing forest cover ranges from 3% to 22% (Riley and Mohr 1994). The remaining woodlots are generally too small and isolated to support area-sensitive species such as Acadian Flycatchers and Hooded Warblers. There appears to be a strong relationship between the amount of forest cover on a landscape and bird occurrence — where regional forest cover is low, the likelihood of either species occurring is also low. The loss of forests for residential housing (or any other type of development) would intensify negative pressures on these species.

ii) Development adjacent to woodlands

The expansion of rural estate housing and other development activities adjacent to woodlands could negatively affect both species at the local level. Certain portions of the bird community ─ neotropical migrants in particular ─ decline or disappear when forests are surrounded or fragmented by residential housing (Friesen et al. 1995; Kluza et al. 2000). The reasons for these changes are unknown but may be related to elevated predation (by both wild and feral animals) and brood parasitism rates, changes in vegetation and food supply, or an avoidance to anthropogenic activity (Manke and Gavin 2000; Chase and Walsh 2006). The construction and expansion of urban and rural estate housing are currently not widespread at or adjacent to sites where Acadian Flycatchers and Hooded Warblers are concentrated, but are known to occur in several locations (L. Friesen, pers. comm.) Fragmentation of forests, like direct habitat loss, exacerbates existing negative pressures on these species.

The preceding threats may also contribute to increased brood parasitism rates. In some years, the brood parasitism rates on Hooded Warblers have been low (18% in 2001, 15% in 2004) and in other years, they have been much higher (52% in 1999). Hooded Warblers are small-sized birds and productivity is significantly reduced if their nests contain cowbird young. Sound forestry practices (e.g., selective logging) and prevention of forest fragmentation are effective ways to reduce cowbird parasitism rates.

Activities that change water and moisture regimes in woodlands

Acadian Flycatchers may be impacted by management activities that alter water tables and moisture regimes in forests because standing water in woodlands helps maintain the open understorey conditions necessary for this species. If water conditions are altered so that the understorey is dry for long periods, woody vegetation may flourish and modify habitat structure. Agricultural tiling, drainage, and irrigation projects are examples of activities that can lower water tables in forests. It is not known how a change in water and moisture regime may impact Hooded Warblers.

Loss of overwintering or United States breeding habitat

Threats on the wintering grounds may represent a significant challenge to Acadian Flycatchers and Hooded Warblers. The continued deforestation of mature forests in the tropics will almost certainly have negative impacts on both species (Evans Ogden and Stutchbury 1994; Whitehead and Taylor 2002; Stutchbury 2007). In addition, threats similar to those in Canada may impact on the United States breeding grounds, leading to a decline in Acadian Flycatcher and/or Hooded Warbler populations and reducing the likelihood of population rescue effect occurring into Ontario. More information is required on the threats to these species in both the wintering grounds and the United States breeding grounds before it can be determined to what level these will impact the Canadian population.

Recreational vehicles

Use of motorized vehicles, including snowmobiles and all-terrain vehicles, can degrade existing habitats by damaging the native understorey, thereby decreasing habitat quality for Hooded Warblers. Additionally, recreational vehicle use has been linked to soil erosion, soil compaction and the establishment of invasive species. Such effects can dramatically alter the composition and structure of woodlands, with uncertain results for Acadian Flycatchers and Hooded Warblers.

Invasive plants

Invasive plants can significantly alter the open understorey and sparsely vegetated ground cover preferred by Acadian Flycatchers. Acadian Flycatchers are absent at some apparently suitable ravine locations along Lake Erie where the entire ground layer is composed of Garlic Mustard (Alliaria petiolata) (D. Martin, unpubl. data). In other unoccupied ravines, Multiflora Rose (Rosa multiflora) dominates the ground layer and understorey. Finally, in some deeply shaded woodlands in Middlesex County, Common Buckthorn (Rhamnus cathartica) forms dense tangles in the shrub layer and understorey and renders the sites unsuitable for Acadian Flycatchers (D. Martin, unpubl. data). Effects of invasive plants on Hooded Warbler site occupancy are currently unknown.

Insects and diseases

Ontario’s woodlands could be fundamentally altered by invasive forest insects such as the Emerald Ash Borer (Agrilus planipennis) and Hemlock Wooly Adelgid (Adelges tsugae). Tree diseases such as Beech Bark (Neonectria faginata), Dogwood Anthracnose (Discula sp.) and Ash Yellows (caused by mycoplasma-like organisms) also have the potential to kill large numbers of trees. This could benefit Hooded Warblers up to a point (by creating or enhancing breeding habitat through the creation of a thick shrub layer for nesting) but would be detrimental if too many large trees were eliminated. Extensive removal of the canopy layer would have severe consequences for Acadian Flycatchers. The Wooly Adelgid causes extreme damage to hemlocks which often are an important component of Acadian Flycatcher breeding habitat in ravines and riparian settings in southern Ontario.

Changes in weather/climate

The potential impacts of projected climate change on the habitat and nesting success of the Hooded Warbler and the Acadian Flycatcher in Ontario are unknown. Climate change could affect forests in southern Ontario by modifying precipitation patterns and increasing the frequency and intensity of ice and wind storms. Individually or in combination, these changes could dramatically alter the composition and structure of woodlands across landscapes to the detriment of Acadian Flycatchers and Hooded Warblers. Alternatively, climate change could have a positive impact on one or both species in Ontario by creating favourable climatic conditions for northern range expansion (Matthews et al. 2004).

2. Population and distribution objectives

Acadian Flycatcher

The population and distribution objective for the Acadian Flycatcher is to maintain the current population of between 35 and 50 pairs distributed within the species’ current Ontario range. This will maintain the current population, which has been essentially unchanged in size for the last decade and has remained stable over the past few decades (COSEWIC 2010).

An earlier recovery goal of 250 pairs identified in the 2000 recovery plan (Friesen et al. 2000) was partially based on the belief, widely held at the time that a sustainable population had to comprise several hundred pairs of breeding individuals (Salwasser et al. 1984). Recent research suggests that the recruitment of only one immigrating breeding pair every two years may be sufficient to prevent the extirpation of the current population of Acadian Flycatchers in Ontario (Tischendorf 2003).

As the small Canadian population of Acadian Flycatchers occurs at the northern part of its continental range, and the vast majority of its continental distribution and population occur further south in the United States, it is important to note that population changes at the continental level may have a significant effect on the recovery feasibility in Canada. As the continental population of the Acadian Flycatcher is experiencing an ongoing downward population trend, its range may contract away from the current periphery, and individuals may immigrate towards the centre of the range. In such a case, despite best efforts described in this strategy to ensure that sufficient suitable habitat is available and key threats are mitigated, the numbers of Acadian Flycatcher in Canada may decline.

Hooded Warbler

The population and distribution objective is to increase the number of Hooded Warbler breeding pairs to 500 distributed within the species’ current Ontario range.

Both the continental population and the Canadian population of Hooded Warbler are experiencing an increase in numbers. There has been a sizeable expansion in the Canadian population and range since the last COSEWIC status report update in 2000. Since the Canadian Hooded Warbler population comprises less than 1% of the global population, it is important to note that population changes at a continental level may have a significant effect on the recovery feasibility in Canada. It is currently not known why the population of Hooded Warblers is increasing and expanding its range to the north. More research is required to determine the causes of such significant increases.

3. Broad strategies and general approaches to meet objectives

3.1 Strategic direction for recovery [iii]

Table 4. Recovery planning table for Acadian Flycatcher and Hooded Warbler.

4. Critical habitat

[i] Diameter-limit tree harvesting involves the removal of all trees greater than a pre-determined diameter-limit. The diameter-limit in eastern deciduous forests traditionally has been 30.5 cm.

[ii] Selective logging is the removal of a proportion of standing trees based on specified limits of minimum tree size and/or minimum large trees that must remain. Selective logging allows forest regeneration following and between selective harvests and results in a forest structure similar to a natural mix of tree ages. The ecological impact and long term sustainability of the forest depends upon the application and adherence to specifications applicable to the forest type and the history of logging and other uses of the forest area.

[iii] Although the Broad Strategies to Recovery are applicable to both species, specific management activities will need to consider any and all Species at Risk in a given location, particularly those of greater conservation concern.

1.1 Acadian Flycatcher critical habitat

1.1.1 Identification of the species’ critical habitat

SARA defines critical habitat as “…the habitat that is necessary for the survival or recovery of a listed wildlife species and that is identified as the species’ critical habitat in the recovery strategy or in an action plan for the species.”

Critical habitat is identified in this recovery strategy for the Acadian Flycatcher based on the best available data (up to and including 2009). Additional critical habitat may be identified across the range as new information becomes available for the Acadian Flycatcher in Ontario.

The identification of critical habitat for the Acadian Flycatcher is based on two criteria: habitat suitability and multi-year occupancy by Acadian Flycatchers.

1.1.1.1 Suitable habitat

Habitat suitability is characterized as the areas where individuals of the species carry out essential aspects of their breeding cycle (i.e., courtship, territory defense, feeding, nesting and post-fledgling) in Canada. The Acadian Flycatcher is an area sensitive species throughout most of its breeding range (Whitehead and Taylor 2002) with a predilection for extensive tracts of deciduous forests (Freemark and Collins 1992). For the Acadian Flycatcher, suitable habitat includes large blocks of relatively undisturbed, mature, deciduous or mixed forests, as well as steep-sided, forested ravines. As a result, suitable habitat for the Acadian Flycatcher has been identified in the following two manners:

Forest

In forests, suitable habitat consists of large contiguous [i] blocks of relatively undisturbed, mature, deciduous or mixed forests. It contains a closed canopy structure, a relatively open understory and sparse ground cover layer and is typically dominated by combinations of tree species including maple-beech, oak-maple, and beech-hemlock. Swamps or sites with permanent or ephemeral ponds or streams are also typical in suitable habitat, although they may be difficult to detect in some years due to drought or low water tables.

Suitable habitat is the contiguous forest. A forest is considered contiguous where it is a connected area. Patches separated by anthropogenic features, including municipal gravel roads, unmaintained roadways and utility lines, will not be considered contiguous.

Riparian

In riparian sites, that is, sites with a linear spatial distribution associated with watercourses, Acadian Flycatchers have been shown to have a linear arrangement of territories following the watercourses. In Pennsylvania, telemetry studies conducted on Acadian Flycatchers in riparian habitats have documented that males travel an average distance of 910 m away from their territorial nests in search of other females to copulate with (extra-pair fertilization) and, consequently, utilize a large amount of suitable riparian habitat (Wolfenden et. al. 2005).

For these reasons, suitable habitat is the connected forest within the ravine (i.e. from the watercourse to the top of bank) to a distance of up to 1 km upstream and downstream (including tributaries) of the observation or to the end of contiguous habitat, whichever comes first.

1.1.1.2 Suitable habitat occupancy

Suitable habitat occupancy criterion:

Suitable habitat that has confirmed, probable, or possible breeding evidence of Acadian Flycatchers during the breeding season for at least two separate years from 1995 to 2009 and where at least one of these records was categorized as confirmed or probable evidence of breeding in any single year from 1995 to 2009.

The Suitable Habitat Occupancy Criterion identifies areas of suitable habitat that have evidence of both within-season territoriality (evidence of probable or confirmed breeding in at least one year) and between-season fidelity (i.e., where Acadian Flycatchers have returned to the same area of suitable habitat in multiple years). Acadian Flycatchers may occasionally occupy habitat in a specific area for only one year and never return. Evidence of breeding in suitable habitat for at least two years, however, indicates that the site is sufficiently suitable to warrant critical habitat identification.

The definition of confirmed, probable, or possible breeding follows standard Breeding Bird Atlas codes in Canada (Table 5). Observations of a single Acadian Flycatcher without attributes of breeding (e.g., singing males, incidental observations, etc.) are not considered probable breeders as they could be prospecting for territories, or be transient birds occupying suitable habitat. Confirmed, probable and possible breeding evidence must be obtained on the site from reliable sources [ii] for the site to be considered as critical habitat.

A 15 year window (1995 to 2009) has been identified as an appropriate time frame for including Acadian Flycatcher breeding records to assess population trends in species and be representative of the current nesting habitat use. This time frame best corresponds to the 12 year longevity record for an individual Acadian Flycatcher (Twedt 2008), a species that exhibits site fidelity to its breeding site (Whitehead and Taylor 2002) and is the most appropriate time interval to assess the population trends based on the current Acadian Flycatcher monitoring programs in Ontario.

Table 5. Standard Ontario Breeding Bird Atlas codes (Cadman et al. 2007).

1.1.1.3 Critical habitat identification for the Acadian Flycatcher

Critical habitat is identified in this recovery strategy as the area of suitable habitat (see Section 7.1.1.1) currently known to be occupied by the Acadian Flycatcher according to the Suitable Habitat Occupancy Criterion in Section 7.1.1.2. Open areas, including fields, and existing anthropogenic features such as roads or houses are excluded from critical habitat. Critical habitat excludes any human-made structures.

Using available data (up to and including 2009) 28 sites are identified as critical habitat, with an estimated total area for critical habitat of 4,546 ha (Appendix 2); all of these sites are on non-federal lands (provincial parks, conservation authority lands and private lands). It is anticipated that the identified critical habitat will provide sufficient habitat to meet the population and distribution objectives of maintaining the current population of approximately 35 to 50 pairs within the species’ current Ontario range. As additional information becomes available, critical habitat sites may be added or refined where they meet the critical habitat criteria at sites across the range of the Canadian Acadian Flycatcher population.

1.1.2 Activities likely to result in the destruction of critical habitat

Destruction is determined on a case by case basis. Destruction would result if part of the critical habitat was degraded, either permanently or temporarily, such that it would not serve its function when needed by the species. Destruction may result from a single activity or multiple activities at one point in time or from the cumulative effects of one or more activities over time (Government of Canada, 2009).

Activities that are likely to result in the destruction of Acadian Flycatcher critical habitat include, but may not be limited to:

• Diameter-limit tree harvesting, development for housing or agricultural purposes, and other activities that are detrimental to the retention of mature trees and/or canopy cover in critical habitat locations. These activities destroy critical habitat because they eliminate the closed canopy condition required by Acadian Flycatchers.
• Activities that cause radical or lasting alterations to hydrological regimes, such as the drainage of wetland, the construction of dams and infilling of swampy lowlands. These activites can destroy critical habitat by altering the open understorey conditions preferred by Acadian Flycatchers in riparian areas.
• Activities that create habitat fragmentation such as the construction of infrastructure and the development of roads, trails and footpaths. These activities can result in the destruction of critical habitat because they reduce the area of contiguous and relatively undisturbed forest required by the species.
• Upgrades and / or maintenance of existing infrastructure (e.g., buildings and roads) either within or adjacent to critical habitat, as Acadian Flycatchers appear to avoid areas of anthropogenic activity.

1.2 Hooded Warbler critical habitat

1.2.1 Identification of the species’ critical habitat

SARA defines critical habitat as “…the habitat that is necessary for the survival or recovery of a listed wildlife species and that is identified as the species’ critical habitat in the recovery strategy or in an action plan for the species.”

Critical habitat is identified in this recovery strategy for Hooded Warbler based on the best available data (up to and including 2009). Additional critical habitat may be identified across the range as more information becomes available on Hooded Warbler in Ontario.

The identification of critical habitat for the Hooded Warbler is based on two criteria: habitat suitability and multi-year occupancy by Hooded Warblers.

1.2.1.1 Suitable habitat

Habitat suitability is characterized as the areas where individuals of the species carry out essential aspects of their breeding cycle (i.e., courtship, territory defense, feeding, nesting, and post-fledgling) in Canada. Suitable habitat includes mature deciduous or mixed forests that are contiguous and have canopy gaps that have been created through tree-fall or by selective logging. Dense ground vegetation (i.e. shrub layer within 1 m of the ground) and large mature trees (Diameter Breast Height >38cm) have also been shown to be components of suitable habitat (Whittam et al. 2002).

Suitable habitat is the contiguous forest. A forest is considered contiguous where it is a connected area. Patches separated by anthropogenic features, including municipal gravel roads, unmaintained roadways and utility lines, will not be considered contiguous.

1.2.1.2 Suitable habitat occupancy

Suitable habitat occupancy criterion:

Suitable habitat that has confirmed or probable breeding evidence of Hooded Warblers during the breeding season for at least two separate years from 2000 to 2009.

The Suitable Habitat Occupancy Criterion identifies areas of suitable habitat that have evidence of breeding within a breeding season (evidence of probable or confirmed breeding in a given year) and between-season fidelity (i.e., suitable habitat where Hooded Warblers have returned to breed in multiple years). Hooded Warblers may occasionally occupy habitat in a specific area for only one year and never return. Evidence of breeding in suitable habitat for at least two years, however, indicates that the site is sufficiently suitable to warrant critical habitat identification.

The definition of probable or confirmed breeders follows standard Breeding Bird Atlas codes in Canada (Table 5). Observations of Hooded Warblers without attributes of breeding (e.g., singing males, incidental observations etc.) are not considered probable breeders as they could be prospecting for territories, or be transient birds occupying suitable habitat. Confirmed and probable breeding evidence must be obtained on the site from reliable sources [iii] for the site to be considered as critical habitat.

A 10 year window (2000 to 2009) has been identified as an appropriate time frame for including Hooded Warbler breeding records because habitat is ephemeral, with forest gaps becoming suitable about 3 years after the creation of a forest gap and remaining suitable for about 10 years. Whittam et al. (2002) found that gap age at Hooded Warbler nest sites ranged from 1 to 14 years with an average gap age of 6.2 and 7.6 years in 1999 and 2000 respectively. Any record outside of ten years would need to be validated to determine the continued presence of suitable habitat and use of the site by Hooded Warblers.

1.2.1.3 Critical habitat identification for the Hooded Warbler

Critical habitat is identified in this recovery strategy as the area of suitable habitat (see Section 7.2.1.1) currently known to be occupied by Hooded Warbler according to the Suitable Habitat Occupancy Criterion in Section 7.2.1.2. Open areas, including fields, and existing anthropogenic features such as roads or houses are excluded from critical habitat. Critical habitat excludes any human-made structures.

Using available data (up to and including 2009), 58 sites are identified as critical habitat, with an estimated total area for critical habitat of 9,740 ha (Appendix 3); all of these sites are on non‑federal lands (provincial parks, conservation authority lands and private lands). It is anticipated that the identified critical habitat will provide sufficient habitat to meet the population and distribution objective of 500 pairs. As additional information becomes available, critical habitat sites may be added or refined where they meet the critical habitat criteria across the range of the Canadian Hooded Warbler population.

1.2.2 Activities likely to result in the destruction of critical habitat

Destruction is determined on a case by case basis. Destruction would result if part of the critical habitat were degraded, either permanently or temporarily, such that it would not serve its function when needed by the species. Destruction may result from a single or multiple activities at one point in time or from the cumulative effects of one or more activities over time.

Activities that are likely to result in the destruction of Hooded Warbler critical habitat include, but may not be limited to:

• Diameter-limit tree harvesting, development for housing or agricultural purposes, and other activities that are detrimental to the retention of mature trees and canopy openings in critical habitat locations. These activities destroy Hooded Warbler critical habitat which consists of mature trees, contiguous forest and small canopy gaps. Additionally, such practices can increase brood parasitism and nest predation rates.
• Activities that cause habitat fragmentation, such as the construction of infrastructure, the development of roads, trails and footpaths. These activities destroy critical habitat by reducing the area of contiguous and relatively undisturbed forest required by Hooded Warbler and also lead to increases in brood parasitism and nest predation.
• Upgrades and/or maintenance of existing infrastructure (e.g., buildings and roads) either within or adjacent to critical habitat, which can damage or reduce the dense, shrubby vegetation used during Hooded Warbler nesting and post-fledging periods.
• Activities that cause soil erosion and compaction, such as the use of motorized vehicles (e.g., snowmobiles, all-terrain vehicles), which can result in the destruction of critical habitat by introducing invasive species and destroying the native understorey required by the species.

2. Measuring progress

The performance indicators presented below provide a way to define and measure progress toward achieving the population and distribution objectives. Specific progress towards implementing the recovery strategy will be measured against indicators outlined in subsequent action plans.

Acadian Flycatcher

To measure progress, every five years, success of recovery strategy implementation will be measured against the following performance indicators:

• Having maintained the continued persistence of between 35 and 50 pairs of the Acadian Flycatcher in Canada;
• Having maintained the current distribution of Acadian Flycatchers in Canada.

Hooded Warbler

To measure progress, every five years, success of recovery strategy implementation will be measured against the following performance indicators:

• Having increased the breeding population to 500 pairs in Canada;
• Having maintained the current distribution of Hooded Warblers in Canada.

3. Statement on action plans

One or more action plans will be posted on the Species at Risk Public Registry for the Acadian Flycatcher and the Hooded Warbler by December 2017.

4. References

Badzinski, D. 2007. Pages 524-525 in: Atlas of the Breeding Birds of Ontario, 2001-2005. (M.D. Cadman, D.A. Sutherland, G.G. Beck, D. Lepage, and A.R. Couturier (eds)). Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources, and Ontario Nature, Toronto, ON.

Bird Studies Canada. August 2003. News archive.

BirdLife International. 2010a. Species factsheet: Empidonax virescens. Downloaded on 7/9/2010.

BirdLife International. 2010b. Species factsheet: Wilsonia citrina. Downloaded on 7/9/2010.

Blake, J.G. and J.R. Karr, Breeding birds of isolated woodlots: area and habitat relationships, Ecology 68 (1987), pp. 1724–1734.

Burke, D. 2007. Comparison of habitat features at nest sites and post-fledgling use of sites for Acadian Flycatcher and Hooded Warbler. Draft manuscript. 11 pp.

Burke, D. Unpublished. Effects of forest management on Hooded Warblers and Acadian Flycatchers in Ontario. Unpublished report prepared for Canadian Wildlife Service – Ontario. Environment Canada, 22 pp.

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, ON.

Carson, J., D. Badzinski, D. Graham, and J. McCracken. 2003. The 2002 southern Ontario Hooded Warbler/Acadian Flycatcher survey. Report for Environment Canada’s Habitat Stewardship Program. Bird Studies Canada, Port Rowan, ON. 15pp. plus appendices.

Chase, J.F. and J.J. Walsh. 2006. Urban effects on native avifauna: a review. Landscape and Urban Planning 74:46–69

COSEWIC. 2010. COSEWIC Assessment and Status Report on the Acadian Flycatcher Empidonax virescens in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. X + 38 pp.

Eaton, S.W. 1988. Hooded warbler. Page 418 in: The Atlas of the Breeding Birds in New York State (R.F. Andrle and J.R. Carroll, eds.). Cornell University Press, Ithaca, N.Y.

Environment Canada. 2004. How Much Habitat is Enough?: A Framework for Guiding Habitat Rehabilitation in Great Lakes Areas of Concern, Second Edition. Environment Canada, Canadian Wildlife Service, Ottawa, ON. 80pp.

Evans Ogden, L.J. and B.J. Stutchbury. 1994. Hooded Warbler (Wilsonia citrina). In: The Birds of North America, No. 110 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, Pennsylvania; and The American Ornithologists’ Union, Washington, D.C.

Flaxman, M. 2003. Habitat Identification and Mapping for the Acadian Flycatcher, Hooded Warbler and Prothonotary Warbler in Southern Ontario. Interdepartmental Recovery Fund Project No. 31, FY 2002–03. National Wildlife Research Centre, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario.

Freemark, K. and B. Collins. 1992. Landscape ecology of birds breeding in temperate forest fragments. Pages 443–454 in: Ecology and Conservation of Neotropical Migrant Landbirds (J. Hagan and D. Johnston, eds.). Smithsonian Institution Press, Washington, D.C.

Freemark, Kathryn. 1999. Area sensitivity and thresholds for birds in fragmented hardwood forests. Canadian Wildlife Service, Hull Quebec.

Friesen, L.E., P.F.J. Eagles, and R.J. MacKay. 1995. Effects of residential development on forest-dwelling neotropical migrant songbirds. Conservation Biology 9: 1408–1414.

Friesen, L., M. Cadman, P. Carson, K. Elliott, M. Gartshore, D. Martin, J. McCracken, J. Oliver, P. Prevett, B.J.M. Stutchbury, D. Sutherland, and A. Woodliffe. 2000. National Recovery Plan for Acadian Flycatcher (Empidonax virescens) and Hooded Warbler (Wilsonia citrina). National Recovery Plan No. 20. Recovery of Nationally Endangered Wildlife (RENEW), Ottawa, Ontario. 33 pp.

Friesen, L. and M. Stabb. 2001. Conserve Ontario’s Carolinian Forests: Preserve Endangered Songbirds: Acadian Flycatchers and Hooded Warblers. Prepared by Bird Studies Canada, the Hooded Warbler and Acadian Flycatcher Recovery Team and Environment Canada-Canadian Wildlife Service. 8pp.

Gartshore, M.E. 1988. A summary of the breeding status of Hooded Warblers in Ontario. Ontario Birds 6:84–99.

Government of Canada. 2009. Species at Risk Act Policies, Overarching Framework [Draft]. Species at Risk Act Policy and Guideline Series. Environment Canada. Ottawa. 38 pp.

Heagy, A. 2008. Update COSEWIC status report on Acadian Flycatcher. Prepared for Committee on the Status of Endangered Wildlife in Canada.

Heagy, A. and D. Badzinski. 2008. 2007 Surveys of Acadian Flycatcher & Hooded Warbler Habitat in Southern Ontario. Unpublished report prepared for the Acadian Flycatcher & Hooded Warbler Recovery Team in April 2008. 16pp.

Heagy, A. and D. Badzinski. 2006. Productivity, Population Size and Demographics of Hooded Warbler in St. Williams Forest, Ontario. Unpublished report prepared for the Canadian Wildlife Service – Ontario, Environment Canada.

Heagy, A., D. Martin, and J. McCracken. 1997. Acadian Flycatcher and Hooded Warbler Recovery Activities: 1997 Field Surveys in Southwestern Ontario. Unpublished report to the Endangered Species Recovery Fund, World Wildlife Fund Canada and Canadian Wildlife Service. Long Point Bird Observatory, Port Rowan, ON. 19pp. plus appendices.

James, R.D. 2000. Update COSEWIC Status Report on the Hooded Warbler Wilsonia citrina in Canada. Unpublished report prepared for the Committee on the Status of Endangered Wildlife in Canada, Ottawa, Ontario. 9 pp.

Kluza, D.A., C.R. Griffin, and R.M. DeGraaf. 2000. Housing developments in rural New England: effects on forest birds. Animal Conservation 3: 15–26.

Manke, R.G. and T.A. Gavin. 2000. Breeding bird density in woodlots: effects of depth and buildings at the edges. Ecological Applications 10: 598-611.

Martin, D. 2007. Acadian Flycatcher. Pages 344-345 in: Atlas of the Breeding Birds of Ontario, 2001-2005. (M.D. Cadman, D.A. Sutherland, G.G. Beck, D. Lepage, and A.R. Couturier (eds)). Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources, and Ontario Nature, Toronto, ON.

Martin, D. Unpublished. ACFL Survey Activities in 2005. Unpublished report presented to the Acadian Flycatcher/Hooded Warbler Recovery Team. 3 pp.

Martin, D. Unpublished. ACFL Surveys and Stewardship Activities in 2004. Unpublished report presented to the Acadian Flycatcher/Hooded Warbler Recovery Team. 4 pp.

Martin, D. Unpublished. 2003 ACFL Summary and Highlights. Unpublished report presented to the Acadian Flycatcher/Hooded Warbler Recovery Team. 4 pp.

Martin, D. Unpublished. ACFLs in Elgin, Middlesex and Chatham-Kent: 2001 Summary Report presented to Lyle Friesen, Canadian Wildlife Service. 3 pp.

Matthews, S.N., R.J. O’Connor, L.R. Iverson, and A.M. Prasad. 2004. Atlas of Climate Change Effects in 150 Bird Species of the Eastern U.S. General Technical Report NE-318. Forest Service, U.S. Department of Agriculture. 46 pp.

McCracken, J., D. Martin, I. Bisson, M. Gartshore, and R. Knapton. 1998. 1998 Surveys of Acadian Flycatchers and Hooded Warblers in Ontario. Unpublished report to Canadian Wildlife Service, Ontario Region, and Environment Canada Action 21 Program. Bird Studies Canada, Port Rowan, ON. 19pp. plus appendices.

Melles, S. 2004. Hooded Warbler Landscape Connectivity and Small Forested Patch Usage Study. Unpublished report prepared for the Canadian Wildlife Service – Ontario, Environment Canada.

NatureServe. 2009. NatureServe Explorer: An online encyclopedia of life [web application]. Version 4.7. NatureServe, Arlington, Virginia. [website accessed July 17, 2009].

Norris, D.R. and B.J.M. Stutchbury. 2001. Extraterritorial movements of a forest songbird in a fragmented landscape. Conservation Biology 15: 729–736.

OMNR (Ontario Ministry of Natural Resources). 2000. A Silviculture Guide to Managing Southern Ontario Forests, Version 1.1. Queen’s Printer for Ontario, Toronto, Ontario. 648 pp.

Peterjohn, B.G. and D.L. Rice. 1991. The Ohio Breeding Bird Atlas. Division of Natural Areas and Preserves, Ohio Department of Natural Resources, Columbus, Ohio. 416 pp.

Rich, T.D., C.J. Beardmore, H. Berlanga, P.J. Blancher, M.S.W. Bradstreet, G.S. Butcher, D.W. Demarest, E.H. Dunn, W.C. Hunter, E.E. Iñigo-Elias, J.A. Kennedy, A.M. Martell, A.O. Panjabi, D.N. Pashley, K.V. Rosenberg, C.M. Rustay, J.S. Wendt, and T.C. Will. 2004. Partners in Flight North American Landbird Conservation Plan. Cornell Laboratory of Ornithology, Ithaca, New York.

Riley, J.L. and P. Mohr. 1994. The Natural Heritage of Southern Ontario’s Settled Landscapes. Science and Technology Transfer Technical Report TR-001. Ontario Ministry of Natural Resources, Queen’s Printer for Ontario, Toronto, Ontario.

Robbins, C.S. 1979. Effect of forest fragmentation on bird populations. Pages 198–212 in: Management of North Central and Northeastern Forests for Gamebirds (R.M. DeGraaf and K.E. Evans, eds.). General Technical Report NC-51. North Central Forest Experiment Station, Forest Service, U.S. Department of Agriculture, St. Paul, Minnesota.

Rush, S.A., and B.J.M. Stuchbury. 2008. Survival of fledgling Hooded Warblers (Wilsonia citrina) in small and large forest fragments. Auk 125: 183-191.

Salwasser, H., S.P. Mealy, and K. Johnson. 1984. Wildlife population viability: a question of risk. Transactions of the North American Wildlife and Natural Resources Conference 49: 421–439.

Sauer, J. R., J. E. Hines, and J. Fallon. 2008. The North American Breeding Bird Survey, Results and Analysis 1966 - 2007. Version 5.15.2008. USGS Patuxent Wildlife Research Center, Laurel, MD.

Sauer, J.R., J.E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, Results and Analysis 1966–2004. Version 2005.2. Patuxent Wildlife Research Center, U.S. Geological Survey, Laurel, Maryland.

Stutchbury, B. 2007. Silence of the Songbirds. HarperCollins, Toronto, ON.

Stutchbury, B. J. M., T. E. Pitcher, D. R Norris, E. M. Tuttle and R.A. Gonser. 2005. Does male extra-territory foray effort affect fertilization success in hooded warblers (Wilsonia citrina) Journal of Avian Biology 36: 471-477.

Sutherland, D.A. and M.E. Gartshore. 1987. Hooded Warbler, Wilsonia citrina. Page 418 in: Atlas of the Breeding Birds of Ontario (M.D. Cadman, P.F.J. Eagles, and F.M. Helleiner, eds.). University of Waterloo Press, Waterloo, Ontario. 619 pp.

Tischendorf, L. 2003. The Acadian Flycatcher: population viability and critical habitat in southern Ontario, Canada. Interdepartmental Recovery Fund project. National Wildlife Research Centre, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario.

Twedt, D.J. 2008. Longevity Records for Acadian Flycatcher and White-eyed Vireo following Prescribed Timber Harvest. North American Bird Bander Vol. 33, No. 2

Walkinshaw, L.H. and R. Brewer. 1991. Acadian Flycatcher. Pages 282–283 in: The Atlas of Breeding Birds of Michigan (R. Brewer, G.A. McPeek, and R.A. Adams, eds.). Michigan State University Press, East Lansing, Michigan.

Whitehead, D.R. and T. Taylor. 2002. Acadian Flycatcher (Empidonax virescens). In: The Birds of North America, No. 614 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, Pennsylvania.

Whittam, R.M., J.D. McCracken, C.M. Francis, and M.E. Gartshore. 2002. The effects of selective logging on nest-site selection and productivity of Hooded Warblers (Wilsonia citrina) in Canada. Canadian Journal of Zoology 80: 644–654.

Woolfenden, B.E., B.J.M. Stutchbury, and E.S. Morton. 2005. Male Acadian Flycatchers, Empidonax virescens, obtain extrapair fertilizations with distant females. Animal Behaviour. 69: 921-929.

Woolfenden, B. and B. Stutchbury. 2004. Acadian Flycatcher habitat selection in south-western Ontario. Interim Report for Recovery Team Meeting, 2 November 2004.

[i] A forest is considered contiguous where it is a connected area (i.e., there are few breaks in the forest canopy, and these breaks are a result of gap dynamics).

[ii] Reliable sources may include, but are not limited to: records held by the Ontario Natural Heritage Information Centre, records from the Ontario Breeding Bird Atlas, observations from acknowledged species experts, observations from recognized birders with photographic evidence, OMNR, CWS, or BSC survey reports.

[iii] Reliable sources may include but are not limited to: records within the Ontario Natural Heritage Information

Centre, records in the Ontario Breeding Bird Atlas, observations from acknowledged species experts, observations from recognized birders with photographic evidence, OMNR, CWS, or BSC survey reports, etc.

Appendix 1: Effects on the environment and other species

A strategic environmental assessment (SEA) is conducted on all SARA recovery planning documents, in accordance with the Cabinet Directive on the Environmental Assessment of Policy, Plan and Program Proposals. The purpose of a SEA is to incorporate environmental considerations into the development of public policies, plans, and program proposals to support environmentally sound decision-making.

Recovery planning is intended to benefit species at risk and biodiversity in general. However, it is recognized that strategies may also inadvertently lead to environmental effects beyond the intended benefits. The planning process based on national guidelines directly incorporates consideration of all environmental effects, with a particular focus on possible impacts upon non‑target species or habitats. The results of the SEA are incorporated directly into the strategy itself, but are also summarized below in this statement.

Recovery activities that protect large tracts of mature forest for the Acadian Flycatcher and the Hooded Warbler will positively affect a number of other species requiring similar habitats.

List of species that are expected to benefit from recovery activities directed at the Acadian Flycatcher and Hooded Warbler, based upon confirmed records of overlap of occurrence at known occupied sites.

Acadian Flycatcher and/or Hooded Warbler habitat is shared by many other species including other species at risk. While some of the proposed recovery activities will benefit the environment in general and are expected to positively affect other sympatric native species, there could be consequences to those species whose requirements differ from those of Acadian Flycatcher and/or Hooded Warbler. Consequently, it is important that habitat management activities for the Acadian Flycatcher and/or Hooded Warbler be considered from an ecosystem perspective through the development, with input from responsible jurisdictions, of multi-species plans, ecosystem-based recovery programs or area management plans that take into account the needs of multiple species, including other species at risk.

Many of the stewardship and habitat improvement activities to benefit the Acadian Flycatcher and Hooded Warbler will be implemented through existing ecosystem-based recovery programs that have already taken into account the needs of other species at risk.

Appendix 2: Sites identified as critical habitat for the Acadian Flycatcher in Canada

Appendix 2 table. Sites identified as critical habitat for the Acadian Flycatcher in Canada.

^a Geographic centroid of critical habitat sites. Some irregularly shaped sites may have a site centroid that falls outside the boundary of the site.

^b Site size is approximate.

Appendix 3: Sites identified as critical habitat for the Hooded Warbler in Canada

Appendix 3 table. Sites identified as critical habitat for the Hooded Warbler in Canada.

[a] Geographic centroid of critical habitat sites. Some irregularly shaped sites may have a site centroid that falls outside the boundary of the site.

[b] Site size is approximate.

Endnotes

[i] Woodlots 10 hectares in size or larger that are in close proximity to each other.

[ii] Diameter-limit tree harvesting involves the removal of all trees greater than a pre-determined diameter-limit. The diameter-limit in eastern deciduous forests traditionally has been 30.5 cm.

[iii] Selective logging is the removal of a proportion of standing trees based on specified limits of minimum tree size and/or minimum large trees that must remain. Selective logging allows forest regeneration following and between selective harvests and results in a forest structure similar to a natural mix of tree ages. The ecological impact and long term sustainability of the forest depends upon the application and adherence to specifications applicable to the forest type and the history of logging and other uses of the forest area.

[iv] Although the Broad Strategies to Recovery are applicable to both species, specific management activities will need to consider any and all Species at Risk in a given location, particularly those of greater conservation concern.

[v] A forest is considered contiguous where it is a connected area (i.e., there are few breaks in the forest canopy, and these breaks are a result of gap dynamics).

[vi] Reliable sources may include, but are not limited to: records held by the Ontario Natural Heritage Information Centre, records from the Ontario Breeding Bird Atlas, observations from acknowledged species experts, observations from recognized birders with photographic evidence, OMNR, CWS, or BSC survey reports.

[vii] Reliable sources may include but are not limited to: records within the Ontario Natural Heritage Information

Centre, records in the Ontario Breeding Bird Atlas, observations from acknowledged species experts, observations from recognized birders with photographic evidence, OMNR, CWS, or BSC survey reports, etc.