Recovery Strategy for the Northern Goshawk laingi subspecies (Accipiter gentilis laingi) in Canada

Northern Goshawk, laingi subspecies
This photograph of an adult female Northern Goshawk was taken on Vancouver Island, British Columbia. The bird was in her nest high up on a tree.

Recommended citation:

Parks Canada Agency. 2017. Recovery Strategy for the Northern Goshawk laingi subspecies (Accipiter gentilis laingi) in Canada [Proposed]. Species at Risk Act Recovery Strategy Series. Parks Canada Agency, Ottawa. 2 parts, 31 pp. + Appendices + 56 pp.

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 RegistryFootnote 1.

Cover illustration: Ross Vennesland (adult female Northern Goshawk, Accipiter gentilis laingi, on Vancouver Island, British Columbia).

Également disponible en français sous le titre
«Programme de rétablissement de l’Autour des palombes de la sous-espèce laingi (Accipiter gentilis laingi) au Canada»

© Her Majesty the Queen in Right of Canada, represented by the Minister of Environment and Climate Change, 2017. All rights reserved.
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Content (excluding the illustrations) may be used without permission, with appropriate credit to the source.

Recovery Strategy for the Northern Goshawk laingi subspecies (Accipiter gentilis laingi) in Canada

2017

Under the Accord for the Protection of Species at Risk (1996), the federal, provincial, and territorial government signatories agreed to work together on legislation, programs, and policies to protect wildlife species at risk throughout Canada.

In the spirit of cooperation of the Accord, the Government of British Columbia has given permission to the Government of Canada to adopt the Recovery Strategy for the Northern Goshawk, laingi subspecies (Accipiter gentilis laingi) in British Columbia (Part 2) under Section 44 of the Species at Risk Act (SARA). Parks Canada Agency has included a federal addition (Part 1) which completes the SARA requirements for this recovery strategy.

The federal recovery strategy for the Northern Goshawk, laingi subspecies in Canada consists of two parts:

Part 1 – Federal Addition to the Recovery Strategy for the Northern Goshawk laingi subspecies (Accipiter gentilis laingi) in British Columbia, prepared by the Parks Canada Agency.

Part 2 – Recovery Strategy for the Northern Goshawk, laingi subspecies (Accipiter gentilis laingi) in British Columbia, prepared by the Northern Goshawk Accipiter gentilis laingi Recovery Team for the British Columbia Ministry of Environment

Table of contents

Part 1 – Federal addition to the recovery strategy for the Northern Goshawk laingi subspecies (Accipiter gentilis laingi) in British Columbia, prepared by the Parks Canada Agency

Preface

The federal, provincial, and territorial government signatories under the Accord for the Protection of Species at Risk (1996)Footnote 2 agreed to establish complementary legislation and programs that provide for effective protection of species at risk throughout Canada. Under the Species at Risk Act (Statutes of Canada (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 after the publication of the final document on the Species at Risk (SAR) Public Registry.

The Minister responsible for the Parks Canada Agency and the Minister of Environment and Climate Change are the competent ministers for the recovery of the Northern Goshawk, laingi subspecies and have prepared the federal component of this recovery strategy (Part 1), as per section 37 of SARA. To the extent possible, it has been prepared in cooperation with the Province of British Columbia, First Nations, environmental non-governmental organizations, academic experts, and other stakeholders including representatives of industrial and small-scale forestry operators, as per section 39(1) of SARA. SARA section 44 allows the Minister to adopt all or part of an existing plan for the species if it meets the requirements under SARA for content (sub-sections 41(1) or (2)). The Province of British Columbia provided the attached recovery strategy for the Northern Goshawk, laingi subspecies (Part 2) as science advice to the jurisdictions responsible for managing the species in British Columbia. It was prepared in cooperation with Environment and Climate Change Canada.

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 and will not be achieved by Environment and Climate Change 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 Northern Goshawk, laingi subspecies 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 and Climate Change Canada and 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.

The recovery strategy sets the strategic direction to arrest or reverse the decline of the species, including identification of critical habitat to the extent possible. It provides all Canadians with information to help take action on species conservation. When critical habitat is identified, either in a recovery strategy or an action plan, SARA requires that critical habitat then be protected.

In the case of critical habitat identified for terrestrial species including migratory birds SARA requires that critical habitat identified in a federally protected areaFootnote 3be described in the Canada Gazette within 90days after the recovery strategy or action plan that identified the critical habitat is included in the public registry. A prohibition against destruction of critical habitat under ss. 58(1) will apply 90days after the description of the critical habitat is published in the Canada Gazette.

For critical habitat located on other federal lands, the competent minister must either make a statement on existing legal protection or make an order so that the prohibition against destruction of critical habitat applies.

If the critical habitat for a migratory bird is not within a federal protected area and is not on federal land, within the exclusive economic zone or on the continental shelf of Canada, the prohibition against destruction can only apply to those portions of the critical habitat that are habitat to which the Migratory Birds Convention Act, 1994 applies as per SARA ss. 58(5.1) and ss. 58(5.2).

For any part of critical habitat located on non-federal lands, if the competent minister forms the opinion that any portion of critical habitat is not protected by provisions in or measures under SARA or other Acts of Parliament, or the laws of the province or territory, SARA requires that the Minister recommend that the Governor in Council make an order to prohibit destruction of critical habitat. The discretion to protect critical habitat on non-federal lands that is not otherwise protected rests with the Governor in Council.

Acknowledgments

This federal addition to the Province of British Columbia’s Recovery Strategy for the Northern Goshawk, laingi subspecies (A. gentilis laingi) in British Columbia was produced by the Parks Canada Agency, with input from the Northern Goshawk Accipiter gentilis laingi Recovery Team and Habitat Recovery Implementation Group (RIG). In particular, Parks Canada would like to acknowledge the crucial science support provided for the critical habitat identification by the following members of the recovery team and/or Habitat RIG: John Deal, David Donald, Frank Doyle, Todd Mahon, Erica McClaren, Louise Waterhouse and Berry Wijdeven. Input was also received from Vanessa Craig, Manon Dubé, Wendy Dunford, Megan Harrison, Paul Johanson, Dave Lindsay, Ian Parnell, Kella Sadler and Warren Warttig. Several forestry organizations provided technical input during consultations, including but not limited to B.C. Timber Sales, Coast Forest Products Association, Interfor, Island Timberlands, TimberWest and Western Forest Products. Critical habitat mapping for breeding areas was conducted by Todd Mahon, Todd Manning, Peter Berst and Paul Chytyck. Appendix A was compiled by Todd Mahon. This federal recovery strategy would not be possible without the many years of effort that the Northern Goshawk Accipiter gentilis laingi Recovery Team and Habitat RIG spent developing the provincial recovery strategy (NGRT 2008; Part 2) that forms the backbone to this federal addition.

Additions and modifications to the adopted document

The following sections have been included to address specific requirements of the federal Species at Risk Act (SARA) that are not addressed in the Recovery Strategy for the Northern Goshawk, laingi subspecies (Accipiter gentilis laingi) in British Columbia (NGRT 2008; Part 2 of this document, referred to henceforth as “the provincial recovery strategy”) and/or to provide updated or additional information.

Under SARA, there are specific requirements and processes set out regarding the protection of critical habitat.Therefore, statements in the provincial recovery strategy referring to protection of survival/recovery habitat may not directly correspond to federal requirements.Recovery measures dealing with the protection of habitat are adopted; however, whether these measures will result in protection of critical habitat under SARA will be assessed following publication of the final federal recovery strategy.

1. COSEWIC Species Assessment Information

This updated COSEWIC species assessment (COSEWIC 2013) replaces the COSEWIC species assessment information provided in the provincial recovery strategy.

Assessment Summary – May2013

Common Name

Northern Goshawk

Scientific Name

Accipiter gentilis laingi

Status:

Threatened

Reason for Designation

Over half of the global range of this subspecies occurs in coastal British Columbia, where it favours mature coniferous forest. This non-migratory bird needs a relatively large home range that contains a good food supply. Despite some recent habitat protection efforts, continuing habitat loss is predicted, in part because of anticipated short rotation times in forest harvest. On Haida Gwaii, populations are very low and face an added risk from declines of prey species due to forest understory losses associated with high levels of browsing from an introduced population of deer.

Occurrence

British Columbia

Status History

Designated Special Concern in April1995. Status re-examined and designated Threatened in November2000 and May2013.

2. Population and distribution objectives

This section replaces the recovery goal section in the provincial recovery strategy.

The provincial recovery strategy defined four conservation regions for the laingi subspecies in coastal B.C.: 1) South Coast, 2) Haida Gwaii, 3) North Coast, and 4) Vancouver Island. As per COSEWIC (2013), this federal recovery strategy modifies the conservation regions considered by the provincial recovery strategy by including both the wet and dry variants of the Coastal Western Hemlock (CWH) Biogeoclimatic Zone (MacKinnon et al. 1992). The provincial recovery strategy only included the wetter variants of the Coastal Western Hemlock (CWH) zone, not the drier variants that were defined as a “transition zone” to the continental atricapilus subspecies and thus not consider as the laingi subspecies.

In the provincial recovery strategy, the recovery goal was: “to ensure viable populations ... persist in each conservation region in coastal B.C.”. The term ‘viable’ was not defined in the provincial recovery strategy either quantitatively or qualitatively, and as such this goal was difficult to translate into an amount of critical habitat required to support the survival or recovery of the species. In addition, analyses performed subsequent to provincial recovery strategy suggest that the Northern Goshawk, laingi subspecies (hereafter Northern Goshawk) exists in B.C. in a quasi-metapopulation structure with partially isolated subpopulations (Talbot 2011, Sonsthagen et al. 2012). Northern Goshawks in Canada are not a single, isolated population but are in fact part of a larger population that extends into Alaska and Washington. Therefore, the concept of viability cannot easily be applied at the scale of conservation region or even at a national scale.

At this stage there is insufficient information to determine how many goshawks would be required in Canada, or in each conservation region or in each quasi-metapopulation, to recover the species in Canada. The provincial recovery strategy includes steps to support obtaining the necessary information to determine long-term population and distribution objectives.

In general, the Northern Goshawk will be considered recovered when the main threats (habitat loss and over-browsing by introduced species) have been addressed, when the Canadian portion of the population has achieved a degree of resilience, when habitat for multiple sub-populations is available and protected (redundancy), and when Northern Goshawk home ranges throughout the Canadian range are occupied (representation).

Note that Northern Goshawk was assessed as Threatened in part because of a threat of habitat loss due to relatively short rotation times currently used by the forest harvest industry (COSEWIC 2013). This threat can therefore theoretically be addressed by extending rotation times or alternatively by protecting an adequate amount of habitat to meet the population and distribution objectives.

In addition to addressing the threats, the Northern Goshawk will be considered recovered, as mentioned above, when the Canadian portion of the population has achieved resilience, redundancy, and representation.

Resilience refers to the ability of a population to recover from a perturbation. Resilience is influenced by population size, level of genetic diversity, as well as characteristics of the species and its habitat. In order for a species to be resilient the abundance would have to be large enough to have a high probability of persistence.As one of five primary criteria for assessing the risk of extinction or extirpation of species, COSEWIC assesses species as Threatened if they have a 90% probability of persistence over 100 years or less, so in order for a listed species to recover to the point of having resilience a higher probability (and lower level of risk) would be required. Probability of persistence can be estimated using population viability analysis (PVA).

There are only a few published reports that have attempted to estimate the viability of Northern Goshawk populations but many were not able to reach a conclusion because of a lack of data or because of high variability in the limited data that were available (Maguire and Call 1993, Broberg 1997, Ingraldi 2001). Hayward et al. (1996) and Kennedy (2003) noted that assurances of viable populations will always be difficult to obtain because of a lack of understanding of habitat requirements and the costs associated with conducting population surveys and monitoring.

Steventon (2012) successfully conducted a Population Viability Analysis (PVA) for the laingi subspecies on coastal British Columbia with input and peer review from members of the Province of B.C.’s Northern Goshawk Accipiter gentilis laingi Recovery Team. This PVA suggested that 346 home rangesFootnote4 would be required in B.C. for a 90% probability of persistence over 100 years. As one of five primary criteria for assessing the risk of extinction or extirpation of species, COSEWIC assesses species as Threatened if they have a 90% probability of persistence over 100 years or less. This threshold (90% over 100 years) essentially reflects the threshold for what would be required to remove the laingi subspecies from its assessment as Threatened.

To provide a buffer for the above threshold, 54 home ranges across the Canadian range were added to improve the probability of persistence for the species. Distributing these 400 home ranges among the four conservation regions in Canada based on their relative proportions of the Canadian population (as per COSEWIC 2013), sufficient habitat would need to be maintained for 110 home ranges on the South Coast (27.5%), 145 home ranges on Vancouver Island (36%), 128 home ranges on the North Coast (31.9%), and 18 home ranges on Haida Gwaii (4.5%). However, given the isolation of Haida Gwaii and limited exchange of genes with the rest of the population (Talbot et al. 2011, Sonsthagen et al. 2012), 18 home ranges is likely too small to prevent inbreeding. Conservation biology theory suggests that a minimum of 50 breeding individuals is required to reduce the risk of extinction due to the negative effects of inbreeding depression on demography (Franklin 1980, Soulé 1980, Jamieson and Allendorf 2012). Given an estimated home range occupancy rate of 43% (COSEWIC 2013), and assuming that all occupied home ranges result in breeding, 58 home ranges would be required to support 50 breeding adults on Haida Gwaii.

To provide an opportunity for further work to develop long-term recovery objectives, the following short-term population and distribution objectives for the Northern Goshawk in Canada are to:

  1. Maintain sufficient habitat to support at least 441 Northern Goshawk home ranges in Canada.
  2. Ensure that sufficient habitat is available amongst the four conservation regions of the Northern Goshawk in Canada as follows: South Coast – 110 home ranges, Vancouver Island – 145 home ranges, North Coast – 128 home ranges, and Haida Gwaii – 58 home ranges.

3. Broad strategies and general approaches recommended to meet the population and distribution objectives

The majority of the approaches recommended to meet the population and distribution objectives are contained in the recovery planning table of the provincial recovery strategy (Part 2; Table 3. Broad strategies that will be used to address threats and to achieve recovery of habitat and populations for A. gentilis laingi). Additional recommended approaches are included here (see Table 1) to meet the federal population and distribution objectives and to lay the groundwork for future recovery planning.

Table 1: Additional Recommended Approaches.
Approach / StrategyDescription of Management and Research ApproachesOutcome / DeliverablesPriority
Discover and/or protect additional home ranges to meet population and distribution objectives
  • Option 1 – discover additional home ranges through the use of surveys and protect habitat appropriately
  • Option 2 – Protect sufficient suitable habitat at a landscape level to ensure long term viability of sufficient home ranges
A sufficient number of home ranges are protected to meet population and distribution objectivesUrgent
Account for transition zone in population and distribution objectives
  • The population and distribution objectives require adjustment due to the inclusion of the transition zone in the federal recovery strategy
Revised population and distribution objectives that account for inclusion of the transition zoneNecessary
Genetic analysis
  • Conduct additional genetic analyses to confirm the range of the laingi subspecies
Revised range boundaries for laingi subspeciesNecessary
Develop approaches to mitigate human induced mortality
  • Mitigate human induced mortality (e.g., shooting birds that are attacking chickens) by assisting landowners in implementing non-lethal measures
Reduced human induced mortalityUrgent
Define a long term population and distribution objective
  • Additional work is required to determine a long term population objectiveand the appropriate distribution of the population target across the conservation regions
A long term population and distribution objectiveNecessary

4. Critical habitat

This section replaces the Critical Habitat section in the provincial recovery strategy.

4.1 Identification of critical habitat

The Species at Risk Act 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 a recovery strategy or action plan for the species.”

Critical habitat in this recovery strategy is identified for 89 Northern Goshawk breeding home ranges across the four conservation regions: 18 in the Haida Gwaii Conservation Region, 18 in the North Coast Conservation Region, 32 in the Vancouver Island Conservation Region and 21 in the South Coast Conservation Region (Appendix B).

Critical habitat is identified based on Northern Goshawk data available to the Government of Canada from the B.C. Conservation Data Centre (CDC). Although COSEWIC (2013) estimated the current Canadian population at about 723 home ranges, only 109 home ranges were available from the B.C. CDC for this critical habitat identification (B.C. CDC 2014).

This critical habitat identification is considered to be a partial identification of critical habitat because:

  • Some critical habitat has not been identified due to insufficient available information (the Habitat Suitability Index model output is currently not available for the transition zone – from coastal to interior habitat types – and for private lands on Vancouver Island);
  • Some critical habitat has not been identified due to ongoing cooperation and consultation. The Government of Canada will continue to work cooperatively with applicable organizations to complete the identification of critical habitat;
  • Critical habitat is only identified for home ranges at the scale of the breeding season because habitat requirements for the non-breeding season are not well understood (McClaren et al. 2015); and
  • Additional surveys (or a different approach to the critical habitat identification) will be required to identify additional suitable and/or occupied habitat to meet the population and distribution objectives (see Table 1).

A schedule of studies (Table 3) has been developed to provide the information necessary to complete the identification of critical habitat that will be sufficient to meet the population and distribution objectives.

The identification of critical habitat in this recovery strategy is based on the scale of a breeding home range for Northern Goshawk. A Northern Goshawk breeding home range (Figure 1) consists of a hierarchical arrangement of components that includes a cluster of nests that are used by a pair of Northern Goshawks over time (from one to 12 nests on the coast of B.C.; Mahon et al. 2013), Post Fledging Areas (PFAs; see provincial recovery strategy in Part 2) around each nest, a breeding area that includes all PFAs, and a larger foraging area (reviewed by Squires and Kennedy 2006, NGRT 2008, Mahon et al. 2013, McClaren et al. 2015). The breeding area is the core use area of Northern Goshawks during the breeding season, and is where juveniles spend the majority of their time prior to leaving their natal home range (Kennedy et al. 1994, McClaren et al. 2005; reviewed by Squires and Reynolds 1997, Squires and Kennedy 2006, McClaren et al. 2015). It typically includes multiple nest sites, each having an associated PFA (Kennedy et al. 1994, McClaren et al. 2005; reviewed by Manning 2012, Mahon et al. 2013, McClaren et al. 2015). The larger foraging area makes up the majority of the breeding home range and is where the adults hunt (Iverson et al. 1996, Bloxton 2002; reviewed by Squires and Reynolds 1997, NGRT 2008, McClaren et al. 2015). Foraging areas, and consequently home ranges, vary in size, reflecting differences in the availability of prey, hunting efficiency of individuals, and food requirements (Iverson et al. 1996, Bloxton 2002, Mahon et al. 2013; reviewed by Squires and Kennedy 2006; NGRT 2008, McClaren et al. 2015).

Both breeding areas and foraging areas are considered critical to ensure successful breeding and survival of Northern Goshawks (reviewed by Squires and Reynolds 1997, Daust et al. 2010, NGRT 2008, McClaren et al. 2015). Therefore, this recovery strategy includes an identification of critical habitat for breeding areas (based on known nests) and critical habitat for foraging areas around known nests. These are key concepts in the critical habitat identification because they delineate the areas within which critical habitat is identified. While breeding and foraging areas are distinct from one another, any given breeding area is overlapped by its associated and larger foraging area. This means that habitat managed for a breeding area can also contribute to habitat requirements for the associated foraging area. The biophysical attributes and amounts of critical habitat required are different for these two home range components, as described below.

diagram, long description below
Figure 1. Conceptual illustration of the components of a Northern Goshawk breeding home range (modified from Mahon et al. 2013).

Long Description for Figure 1

This diagram shows the breeding home range of the Northern Goshawk consists of a hierarchical arrangement of components that includes a cluster of nests that are used by a pair of goshawks over time, Post Fledging Areas around each nest, a breeding area that includes all PFAs, and a larger foraging area.

 

Critical habitat is identified in terms of its location(s), its biophysical attributes, and the amount required:

  • Location describes where critical habitat is found geographically.
  • Biophysical attributes describe the biological and physical characteristics of the suitable habitat.
  • Amount describes the quantity and extent of suitable habitat required at each location and/or across the species’ distribution.

This recovery strategy outlines and applies a methodology to identify the location, biophysical attributes, and amount of critical habitat required in a breeding home range. The configuration and location of suitable habitat within a home range may change over time. If more suitable habitat is available than required within a given home range, different areas of critical habitat can be identified and published in an amended recovery strategy and/or action plan. However, at any point in time, the critical habitat must meet the criteria for location, biophysical attributes and amount described herein.

4.1.1. Location of critical habitat

The location of critical habitat is based on the locations of known nests of the Northern Goshawk within coastal British Columbia for which data were available to the Government of Canada as of June2014. Data on nest locations for 109 Northern Goshawk breeding home ranges were obtained from the B.C. Conservation Data Centre (CDC).All records of Northern Goshawk nests were included in the identification, irrespective of age of observation or recent occupancy (B.C. CDC 2014). Breeding home ranges without evidence of recent occupancy were included because Northern Goshawks are difficult to detect and annual monitoring is limited over much of the species range (prior to 2014, intensive annual monitoring only occurred on parts of Vancouver IslandFootnote5 and Haida GwaiiFootnote 6), because they exhibit strong site fidelity to a breeding home range (McClaren 2005, Stuart-Smith et al. 2012), and because they have been known to re-occupy a particular area even after many years of apparent absence (Tommeraas 1994, Kenward 2006). Consequently, areas where Northern Goshawks have previously been detected are likely to continue to be used by Northern Goshawks, even if they are not detected over several surveys (McClaren 2005). In addition, given the relatively small number of birds known to occur in each conservation region, inclusion of unoccupied nests and/or breeding home ranges is considered necessary, as a precautionary measure, to ensure sufficient nesting locations and breeding home ranges are available to contribute towards providing a reasonable probability of long term persistence (Steventon 2012; see Section 2 Population and Distribution Objectives). If through field surveys, critical habitat is confirmed to be unsuitable for Northern Goshawk nesting or foraging, critical habitat can be refined and published in an amended recovery strategy and/or action plan.

4.1.2. Biophysical attributes of suitable habitat

Mahon et al. (2008, 2015) developed Habitat Suitability Index (HSI) models for Northern Goshawk breeding areas and foraging areas based on Northern Goshawk habitat usage and using equations that describe the combination of habitat attributes that are thought to be required by Northern Goshawks. The models are used to analyze forest cover data and to score forest stands (on a scale of 0-1) according to how suitable they are predicted to be for Northern Goshawks (with 0.5 to 1 defined as suitable).

The biophysical attributes of suitable habitat differ slightly between breeding areas and foraging areas, with breeding habitat being a subset of foraging habitat. In general, mature to old growth forests most often possess the characteristics required by Northern Goshawks. However, because the model is based on multiple variables, there is some flexibility in the attributes of forests that are rated as suitable. For example, as long as minimum height and age criteria are met, younger forest stands might still qualify as suitable habitat if they have high ratings for all other variables and as long as minimum height and age criteria are met.

The Mahon et al. (2008, 2015) Habitat Suitability Index (HSI) models are the only information sources that have objectively defined the attributes of Northern Goshawk habitat on the coast of B.C. They are based on the largest data set of nest locations and Northern Goshawk telemetry data that is available for coastal B.C., so represent the most comprehensive descriptions of suitable habitat for breeding and foraging. Because the models represent a description of typical habitat use, there will be cases when the models do not fully represent a particular local situation (e.g., highly managed forest lands in a productive landscape). In situations such as these, further planning may allow the models to be tailored to specific landscapes or different scales (e.g., through a home range plan based on a management unit or conservation region, see Section 3.2 Schedule of Studies) and in cases such as this, the critical habitat identification may be refined for the landscape being considered in an amended recovery strategy and/or an action plan.

Although not yet published, the Mahon et al. (2008, 2015) HSI models are the best tools available to quantify Northern Goshawk habitat. The models were developed using data on breeding areas (e.g., McClaren 2005, Mahon et al. 2013) and foraging habitat usage including telemetry data (McClaren 2005). The models were ground tested for accuracy in each of the four conservation regions, with strong results, and were subjected to sensitivity analyses (Mahon et al. 2015). In addition, the models have been reviewed by the Northern Goshawk Accipiter gentilis laingi Recovery Team and other species experts. The models were iteratively improved as a result of these processes and as more recent data have become available (Mahon et al. 2015).

At this time, there are no other options available for a multi-parameter quantitative description of suitable habitat. An alternative approach to the use of Mahon et al.’s (2015) models would be to use a single parameter such as tree age or tree height. However, this option would not provide a precise description of suitable habitat (e.g., old trees at high elevation will not be suitable, old trees of certain species will not be suitable, tall trees in some cases will not have the required branching structure to effectively hold nests). The Mahon et al. (2015) models take into account the variance in suitability based on the primary factors affecting habitat use for which standard forest cover data are available for mapping. As such, the models provide the most precise description of suitable habitat, based on the largest amount of data on habitat use by Northern Goshawks.

Spatial mapping output of the Mahon et al. (2015) HSI models has been produced using land cover data current to between 2005 and 2012 (Mahon et al. 2015). However, as of 2017 this mapped model output was not available for large areas of private lands owned by the forest industry on Vancouver Island (because forest cover data for these lands has not been made available to the Province of B.C. or the Government of Canada to allow spatial mapping of the models), and for the eastern margin of the Canadian range of the laingi subspecies. The eastern margin of the range was not mapped because the provincial recovery team considered this area (specifically, the drier variants of the Coastal Western Hemlock Biogeoclimatic Zone; MacKinnon et al. 1992) to be an area of transition between the coastal laingi subspecies and the continental atricapilus subspecies (NGRT 2008). The transition zone is included as part of the Canadian range of laingi subspecies federally as per COSEWIC (2013).

Although the HSI models met the ground testing accuracy requirements set by the provincial recovery team (Mahon et al. 2015), there remains error associated with the model output (related primarily to the accuracy of underlying forest cover data).

See Section 3.2 Schedule of Studies for activities including production of HSI model outputs for the transitional zone (from coastal to interior habitat types) and for private lands on Vancouver Island, and field verifications of current model outputs to refine the identification of critical habitat.

Critical habitat for breeding: biophysical attributes

Biophysical attributes of suitable habitat for breeding typically include mature or old forest with large trees suitable for holding large stick nests, a relatively closed canopy ( 50%), an open understory and abundant under canopy flyways (Iverson et al. 1996, Patla 1997, Daw and DeStephano 2001, Finn et al. 2002, McGrath et al. 2003, Desimone and DeStefano 2005, Doyle 2005, McClaren 2005, Boal et al. 2006, Harrower et al. 2010, Stuart-Smith et al. 2012, Mahon et al. 2013; reviewed by Squires and Reynolds 1997, Ministry of Water, Land and Air Protection (MWLAP) 2004, Squires and Kennedy 2006, United States Fish and Wildlife Service (USFWS) 2007, NGRT 2008, Mahon et al. 2015).

Using the following equation from the HSI model for breeding habitat (Mahon et al. 2014), suitable habitat for breeding must have a HSI rating of 0.5 or more, where

HSIn = mean (Ager, Heightr) *Edger * Inventory Type Group (ITG)r *Elevr*Sloper*BECvarr,

and where r=rating, from 0-1, based on estimates of how that particular variable affects habitat suitability for Northern Goshawk breeding (see Mahon et al. 2015).

The mean tree stand age (Ager) and height (Heightr) are included in the model because Northern Goshawks generally prefer older and taller trees. Estimates of breeding habitat suitability increase linearly from 0 below 40 years and 14m height up to 1 at 90 years of age and 32m height. Northern Goshawks also tend to avoid anthropogenic and natural edges (Edger), so that breeding sites farther away from edges are more suitable and receive a higher rating. Inventory Type Group variable (ITGr) relates certain structural requirements such as canopy to particular forest types. Structural attributes important to Northern Goshawk breeding appear to be most common in hemlock, fir and spruce dominated stands. As such, these forest types typically receive a rating of 1, whereas other forest types have lower ratings. The elevation of an area (Elevr) is included in the model because data suggest that Northern Goshawks prefer lower elevation sites. Lower elevation areas (400m on Haida Gwaii, 600m on the North Coast and 800m in the southern regions receive a rating of 1; with downgrades to a low of 0.5 at 1,300m. Slope (Sloper) is included because the vast majority of known nests occur on slopes 60%. Areas with a slope between 0-60% receive a rating of 1; areas with slopes 60% receive a reduced rating. The final variable in the model is the Biogeoclimatic Ecosystem Classification (BEC) variant (BECvarr), which represents the classification of the area based on the B.C. Biogeoclimatic Ecosystem Classification System (MacKinnon et al. 1992). Each class was assigned a rating, based on estimated habitat suitability for breeding. For example, tundra and alpine parkland classes have the lowest ratings at 0.4. See Appendix A for more details on the variables included in the model.

In addition to the attributes described in the model, an important biophysical attribute of critical habitat for breeding is habitat that is free from loud auditory disturbances during breeding season from courtship to fledging (15February – 31July) (Iverson et al. 1996; reviewed by Cooper and Stevens 2000). Activities that create loud noise within or adjacent to an active breeding area can cause disturbances of nesting birds and have negative consequences for production of young and mortality of young or adults (e.g., Boal and Mannan 1994, Toyne 1997, Bijslma 1999 in Rutz et al. 2006, Penteriani and Faivre 2001, Doyle in Stuart-Smith et al. 2012). For information on mitigation, see Section 2.3 Activities Likely to Result in the Destruction of Critical Habitat.

Critical habitat for foraging: biophysical attributes

There is strong evidence that Northern Goshawks prefer to forage in mature to old forests: nine of 10 telemetry studies conducted in North America found that they forage in forests with mature/old structural characteristics disproportionately more often than the availability of these forests on the landscape (Austin 1993, Bright-Smith and Mannan 1994, Beier and Drennan 1997, Bloxton 2002, Hasselblad 2004, Hargis et al. 1994, Iverson et al. 1996, Good 1998, Boal et al. 2006, Mahon 2009). The biophysical attributes of typical foraging habitat include relatively large trees, open understories and closed canopies; though a variety of other habitat types are used (Bloxton 2002, Iverson et al. 1996, Boal et al. 2006; reviewed by USFWS 2007, NGRT 2008, Stuart-Smith et al. 2012, COSEWIC 2013, Mahon et al. 2015).

Using the following equation from the HSI model for foraging areas (Mahon et al. 2015), suitable habitat for foraging must have a HSI rating of 0.5 or more, where

HSIf = mean(Ager, Heightr) * ITGr * BECvarr or Non-Forest rating, whichever is greater,

and where Non-Forest rating is any area that is not classified as a forest type under the B.C. Biogeoclimatic Ecosystem Classification Program. See above (Critical habitat for breeding areas: biophysical attributes) for explanations of the relevant model variables and Appendix A for more details on the variables included in the model.

4.1.3. Amount of Suitable Habitat Required for Critical Habitat

The biophysical attributes above describe biological and physical characteristics of suitable habitat, but not all suitable habitat is necessarily critical habitat.

Critical habitat for breeding: amount of suitable habitat

The amount of suitable breeding habitat required for critical habitat around each nest is 75.5 ha. This is based on empirical data: an analysis of the use of habitat by fledglings using telemetry for 12 laingi nests in B.C. found that 90% of the nests had a Post Fledging Areas (PFA) size of up to 75.5 ha (McClaren et al. 2005, Mahon et al. 2013, McClaren et al. 2015). Use of the 90th percentile should ensure that there will be sufficient critical habitat for breeding around each nest for most situations, which is important for species at risk, especially given that breeding areas represent the core use area of a breeding home range (Kennedy et al. 1994, Iverson et al. 1996, Moser 2009, McClaren et al. 2015).

Critical habitat for breeding should provide a buffer for nests from hard edgesFootnote 7 such as harvested areas (McClaren 2005, Iverson et al. 1996, Mahon et al. 2013, McClaren et al. 2015). Several studies have found that Northern Goshawks relocated their nests in response to timber harvesting near their nest locations (Penteriani and Faivre 2001, Mahon 2009, Moser and Garton 2009, Stuart-Smith et al. 2012). In a recent analysis of 283 nests on Vancouver Island and Haida Gwaii, Mahon et al. (2013) found that 90% of nests were at least 252m from cut-blocks that were present at the time the nest was first discovered. Additionally, McClaren et al. (2005) and McClaren (2005) found that radio-tagged Northern Goshawk fledglings were never confirmed using open areas such as harvested areas (E. McClaren, pers. comm. 2014).

Although beneficial (McClaren et al. 2015), it is not required that the critical habitat for breeding around each nest be connected to that of adjacent nests in the breeding home range because most studies have shown that limited harvesting within a breeding area is typically not detrimental to occupancy (e.g., Stuart-Smith et al. 2012). However, many nests are close enough (e.g., Mahon et al. 2013) that the critical habitat of adjacent nests will normally be connected (Appendix B).

Beyond ensuring sufficient suitable breeding habitat around known nests, additional critical habitat is required in some breeding home ranges to allow for the establishment of new nests. The number of nests within 63 breeding areas of the laingi subspecies in coastal B.C. ranged from one to 12 nests, with a 90th percentile of about six nests (Mahon et al. 2013). Therefore, using a precautionary approach, the critical habitat in each breeding area should provide sufficient suitable breeding habitat for supporting PFAs for at least six nests. Given that the median distance between nests is 275m and the 90thpercentile of intra-nest distances is 840m (Parks Canada, unpubl. data, n=294 intra-nest distances from 111 breeding home ranges), each supplementary PFA area, where necessary, should be centered at a location not less than 275m and not more than 840m from a known nest or other supplementary PFA locations.

Based on the above, critical habitat for breeding requires:

  • 75.5 ha of suitable breeding habitat around each known nest. The critical habitat must encompass the nest tree, and the critical habitat must be located within 840m of each nest. In addition, there must be at least 252m of contiguous suitable breeding habitat around each nest. Any suitable habitat within 840m of more than one nest can count towards the critical habitat necessary for each of those nests. If there is currently insufficient suitable habitat around a known nest to meet the 75.5 ha target, critical habitat will include all currently available suitable habitat within the 840m radius of the nest and the area should be managed to achieve the 75.5 ha through appropriate management actions outlined in an amended recovery strategy or action plan.
  • For breeding home ranges with fewer than six known nests, additional critical habitat for breeding (75.5 ha, as above) will be required in order to allow for the establishment of new nests. The additional critical habitat for breeding areas should be centered at a location not less than 275m and not more than 840m from known nests or supplementary nest locations, so that a total of six known or supplementary nest locations are contained within the critical habitat for breeding areas for each breeding home range. Where insufficient suitable habitat exists, the area should be managed to achieve this over time through appropriate management actions outlined in an amended recovery strategy, home range plan or action plan.

The areas containing critical habitat for breeding for the Northern Goshawk are presented in Appendix B, Figures B-1 to B-5. Within the areas identified as containing critical habitat for Northern Goshawk, critical habitat is identified where the biophysical attributes are found (section 3.1.2). Detailed methods and decision-making processes relating to critical habitat identification are archived in a supporting document.

Critical habitat for foraging: amount of suitable habitat required

As mentioned earlier, there is strong evidence that Northern Goshawks disproportionately select foraging habitat with mature/old forest characteristics over habitats with other characteristics. In addition, three studies have shown a positive relationship between the amount of mature and old forest within home ranges and home range occupancy (Ward et al. 1992 as cited in Greenwald et al. 1995, Patla 2005, Finn et al. 2002). However, as with breeding areas, there is limited unequivocal information about how big the foraging area needs to be, and how much suitable foraging habitat is required within it (reviewed by NGRT 2008, Stuart-Smith et al. 2012). Foraging areas vary in size, in part according to ecological conditions such as weather and prey availability (Kennedy et al. 1994, Iverson et al. 1996, Bloxton 2002). Both the size and quality of breeding home ranges likely vary across the four conservation regions (Doyle 2005, Doyle 2006, NGRT 2008, Deal and Mogensen 2013, Mahon et al. 2013).

To determine the amount of suitable habitat required for critical habitat for foraging, two steps were followed: 1) estimate mean breeding home range size, and 2) determine how much suitable habitat within this foraging area is required to be critical habitat. To ensure a regionally-appropriate critical habitat identification, these values are determined separately for each conservation region (and in some cases, the regions have been further subdivided to reflect variation where data were available; Appendix B). The results are summarized in Table 2.

First, regional estimates of mean breeding home range size (based on the spacing of breeding home ranges on the landscape) were used to determine the size of foraging areas used by Northern Goshawks (Deal and Mogensen 2013, Mahon et al. 2013, McClaren et al. 2015). In general, breeding home ranges for the laingi subspecies tend to be larger in the north of B.C. compared to the south (Doyle 2006, NGRT 2008, Mahon et al. 2013, McClaren et al. 2015). The size of breeding home ranges for the laingi subspecies has been estimated to be 8,495 ha on Haida Gwaii (sensu McClaren et al. 2015, Mahon et al. 2013), 3,739 ha on much of Vancouver Island (sensu McClaren et al. 2015, Mahon et al. 2013), and 1,963 ha in central-north Vancouver Island (sensu Deal and Mogensen 2013).

These estimates of breeding home range sizes likely over-estimate the required breeding home range size because Northern Goshawks tend to use a relatively small area within their observed breeding home range each year (e.g., 32% as per Kennedy et al. 1994; see also Bloxton 2002, Moser 2009). Therefore, the mean of the observed breeding home range sizes should provide a reasonable and precautionary conservation target.

Mean breeding home range size estimates are available for the Vancouver Island and Haida Gwaii conservation regions (sensu Deal and Mogensen 2013, Mahon et al. 2013, McClaren et al. 2015). The Vancouver Island conservation region has been divided into two sub-regions (see Table 2) because detailed information has been collected in Central-North Vancouver Island that indicates the area has a relatively dense population of Northern Goshawks, likely due to its high habitat quality (Deal and Mogensen 2013). Therefore, smaller breeding home range sizes are reasonable for this conservation sub-region. Additionally, the North Coast conservation region has been split into two sub-regions, based on the fact that the region spans a large latitudinal, and thus ecological, range. South of 51˚ latitude, mean breeding home range size is not available, but is assumed to be similar to Vancouver Island due to similar habitat qualities. North of 51˚ latitude, breeding home range size likely falls between those of Vancouver Island and Haida Gwaii because, while the sub-region is more ecologically similar to Haida Gwaii, it does not share the threat of invasive species that occurs on Haida Gwaii (Doyle 2005; reviewed by NGRT 2008). For this sub-region, the breeding home range size is estimated to be the mid-point between Haida Gwaii and Vancouver Island. In the future, as more information becomes available, these values can be refined in an amended recovery strategy and/or action plan.

Second, the amount of suitable habitat required within the foraging area of each breeding home range was determined based on the amount of suitable habitat (as predicted by the Mahon et al. 2015 models) that was present in consistently occupied breeding home ranges observed in a recent empirical study (McClaren et al. 2014). The 50th percentile (median) was selected because the amounts of suitable habitat across consistently occupied breeding home ranges were not symmetrically distributed; therefore, the median provides a better representation of the general tendency of the data.

Data were available for Vancouver Island, where the 50th percentile of the consistently occupied breeding home ranges had approximately 45% suitable foraging habitat (McLaren et al. 2014), and for Haida Gwaii, where the 50th percentile of the consistently occupied breeding home ranges had approximately 61% suitable foraging habitat (McLaren et al. 2014).

It was assumed that values for Vancouver Island could be applied to the South Coast due to similar latitude and ecologies (NGRT 2008; Part 2). The North Coast conservation region was split into two sub-regions. South of 51˚, the value was based on the mid-point between Haida Gwaii and Vancouver Island. It is acknowledged that there is significant uncertainty in the analyses used for setting foraging habitat targets. These values can be refined in an amended recovery strategy and/or action plan as more information becomes available.

The total amount of suitable habitat needed for critical habitat foraging in breeding home ranges is summarized in Table 2. To ensure that critical habitat is available to foraging Northern Goshawks, all critical habitat should be identified within the breeding home range radius listed in Table 2. The breeding home range radius should be measured from the centroid location of all known nests and supplementary nest locations.

Because foraging occurs throughout the breeding home range, including the breeding areas, within any given breeding home range, critical habitat for breeding will also contribute to the required amount of critical habitat for foraging (critical habitat for breeding always overlaps with critical habitat for foraging).

Table 2. The maximum radius requirement (based on breeding home range size estimates) for critical habitat for foraging, and the percentage and total amount of suitable habitat that is required for each breeding home range, for each of the four conservation regions of the Northern Goshawk in coastal B.C. (as critical habitat for foraging).
Conservation Region or Sub-regionBreeding home range Radius Estimate% suitable habitat requiredAmount suitable habitat required for critical habitat for foraging
South Coast3,450mTable 2 notea45%1,683 ha
Haida Gwaii5,200mTable 2 noteb61%5,182 ha
North Coast – south of 51˚ latitude3,450mTable 2 notec45%1,683 ha
North Coast – north of 51˚ latitude4,413mTable 2 noted53%2,521 ha
Vancouver Island3,450mTable 2 notee45%1,683 ha
Central-North Vancouver Island2,500mTable 2 notef45%883 ha

Table 2 notes

Table 2 note a

based on mean breeding home range spacing of 6.9km from Vancouver Island (Mahon et al. 2013, McClaren et al. 2015) and ecological and latitudinal similarity with Vancouver Island

 

Table 2 note b

based on a mean breeding home range spacing estimate of 10.4km (Mahon et al. 2013, McClaren et al. 2015)

 

Table 2 note c

based on a mean breeding home range spacing estimate of 6.9km (Mahon et al. 2013, McClaren et al. 2015)

 

Table 2 note d

based on the mid-point mean breeding home range spacing estimate of 6.9km and 10.4km (Mahon et al. 2013, McClaren et al. 2015)

 

Table 2 note e

based on mean breeding home range spacing estimate of 6.9km (Mahon et al. 2013, McClaren et al. 2015)

 

Table 2 note f

based on a sub-regional mean breeding home range spacing estimate of 5km (Deal and Mogensen 2013)

 

Therefore, in the South Coast region for example, the target for critical habitat for foraging is 1683 ha of suitable habitat within a 3,450m radius of the nest centroid (the centroid of all known nests and supplementary nest locations) for the breeding home range.

If the amount of suitable habitat available within the breeding home range radius estimate is currently less than the amount of suitable habitat required and critical habitat includes all currently available suitable habitat within the polygon, the regionally appropriate threshold should be achieved over time through appropriate management actions outlined in an amended recovery strategy, home range plan or action plan. Of the 89 home ranges for which critical habitat has been identified, the amount of suitable habitat required for foraging critical habitat is currently below the estimated targets for 74 home ranges (see Table B-1 in Appendix). The remaining 15 home ranges had an amount of suitable habitat above the estimated targets. In such cases, the breeding home range radius was reduced until the amount suitable habitat for foraging critical habitat was reached.

The areas containing critical habitat for foraging for the Northern Goshawk are presented in Appendix B, Figures B-1 to B-5. Within the areas identified as containing critical habitat for Northern Goshawk, critical habitat is identified where the biophysical attributes are found (section 3.1.2). Detailed methods and decision-making processes relating to critical habitat identification are archived in a supporting document.

4.2Schedule of studies to identify critical habitat

A list of studies and activities recommended to achieve a more complete identification of critical habitat for Northern Goshawk is provided in Table 3. Further studies and activities are required to 1) identify additional critical habitat that is required for the survival of the species, and 2) possibly refine critical habitat identification to maximize its implementation effectiveness (e.g.., verify whether critical habitat identification is most effective at a breeding home range, a management unit, or a regional scale).

Table 3. Studies and activities required for a full identification of critical habitat for Northern Goshawk to meet the short term population and distribution objectives for the species in this federal recovery strategy.
Description of activityOutcome/rationaleTimeline
Some critical habitat has not been identified due to ongoing cooperation and consultation. The Government of Canada will continue to work cooperatively with applicable organizations to increase the amount of critical habitat identified.
  • Increased amount of critical habitat identified.
On-going, pending progress respecting consultations
Produce HSI model output for transitional zone - coastal to interior habitat types – (NGRT 2008; Part 2) and for private lands on Vancouver Island within the species range.
  • To increase the number of breeding home ranges for which HSI data are available, allowing more critical habitat to be identified.
2017-2020
Conduct research to determine required availability of breeding and foraging habitat at breeding home range or landscape scale.
  • Results will provide a better understanding of the availability of breeding and foraging habitat thresholds required to sustain the overall Northern Goshawk population on the coast of B.C., and can be applied to re-assess the approach to identify critical habitat for foraging.
  • Additional empirical evidence will help to assess current thresholds and approaches to identifying foraging habitat.
  • Determine the extent to which areas with HSI ratings 0.5 can occur within a breeding area without having an effect on long-term occupancy.
2017-2022
Continue to research critical habitat knowledge gaps (patterns of home range use in breeding and non-breeding seasons, prey abundance, availability and diversity).
  • Understanding of patterns of home range use will inform the management of critical habitat (i.e., how much is required).
  • Information on winter habitat associations may influence the habitat included in critical habitat.
  • Knowledge of relationships between prey abundance, availability and diversity and foraging habitat characteristics will allow the refinement of specific foraging habitat targets for different habitat types.
  • Additional data to allow verification of habitat suitability and other models.
  • Assessment of potential alternatives to current habitat models.
  • Assessment of and approaches to deal with introduced deer on Haida Gwaii.
  • Knowledge of the relationship between rotation times of harvested forest and Northern Goshawk occupancy can be used to better manage critical habitat.
2017-2022
Verification of the HSI model outputs at stand-level scale.
  • Improve accuracy/precision of critical habitat boundaries.
2017-2027
4.3Activities likely to result in the destruction of critical habitat

Understanding what constitutes destruction of critical habitat is necessary for the protection and management of critical habitat. Examples of activities likely to destroy critical habitat are provided below (Tables 4 and 5); however, destructive activities are not limited to those listed. 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 single or multiple activities at one point in time or from cumulative effects over time.

Destruction of Northern Goshawk critical habitat includes, but is not limited to, the alteration or removal of forest suitable for breeding or foraging. In addition, loud noises occurring between the beginning of courtship (approximately mid-February) until fledging (approximately beginning of August) can disturb Northern Goshawks and potentially reduce the quality of the habitat in which they reside. Disturbance stimuli can cause the abandonment of nests, which can result in the mortality of eggs or young in the nest (Craig 2002, Environment Canada 2014).

Table 4. Examples of activities within or near to critical habitat for breeding and foraging that are likely to result in the destruction of critical habitat at all times of the year.
Activity categoriesExamples of potential effects on habitatExamples of potential effects on Northern Goshawk
  • Removal of critical habitat (e.g., through forest harvesting such as clear cutting).
  • Industrial development that removes or alters critical habitat (e.g., oil and gas, mines, construction of buildings or other infrastructure, hydro dams, and linear developments, etc.)
  • Reduces quality and or quantity of critical habitat for breeding and critical habitat for foraging
  • Negatively affects prey populations
  • Insufficient critical habitat remains to maintain a breeding pair of Northern Goshawks
  • Reduced availability of prey
  • Increased rate of predation of adults with increased edge
  • Increased rate of breeding abandonment from human disturbance
  • Greater competition with edge or open habitat-adapted species
Table 5. Examples of activities likely to destroy critical habitat for breeding during the breeding season only, and proposed setback distances that will make the activity unlikely to destroy critical habitat. Proposed setbacks were determined using the results of previous studies and considerations of the potential of a stimulus to cause a disturbance (i.e., potentially intense stimuli deserve more precautious setbacks; Environment Canada 2014). Mitigations should be in effect from courtship to the end of the nestling phase (15February – 31July; Iverson 1996, reviewed by Cooper and Stevens 2000).
Disturbance stimuliBuffer distance from active nest (m)
Hauling with truckTable 5 noteg100
Road constructionTable 5 note h500
Tree FellingTable 5 note i500
AircraftTable 5 note j
- repeated overflights or any overflights of heavy lift aircraft
1,000Table 5 note k
BlastingTable 5 note l1,000

Table 5 notes

Table 5 note g

McLaughlin (2002), Grubb et al. (2012), Deal (2013), E. McClaren pers. comm.

Table 5 note h

Vernier and Brunnell (2002), Stuart-Smith et al. (2012), E. McClaren pers. comm.

Table 5 note i

Boal and Mannan 1994, Penteriani and Faivre 2001, McLaughlin (2002), Stuart-Smith et al. (2012), E. McClaren pers. comm.

Table 5 note j

Stuart-Smith et al. (2012), E. McClaren pers. comm.

Table 5 note k

McLaughlin (2002), Stuart-Smith et al. (2012), E. McClaren pers. comm.

Table 5 note l

Aircraft buffer distance applied horizontally and vertically.

It should be noted that loud disturbance stimuli such as described here may only temporarily destroy critical habitat for breeding. The effects of noise disturbance may be very short (e.g., an adult temporary leaves the nest), occur for one season (e.g., the adults abandon the nest for the season but return the next year) or longer if the nest is abandoned for one or more years. But it is likely that if the physical habitat attributes remain suitable, the site should continue to be viable once the disturbance stimuli have ceased.

4.4 Summary of current provincial measures to manage activities within Northern Goshawk habitat

Substantial work has already been completed or is underway to manage activities within habitat for Northern Goshawk in B.C. For example, 1.6million ha of suitable breeding and foraging habitat occurs in provincial forestry reserves and parks (Ministry of Forests, Lands, and Natural Resource Operations (MoFLNRO) and Ministry of Environment (MoE) 2013). In addition, provincial ‘fine filter’ regulations constrain forest harvesting activities on the managed land base within 28 known breeding areas using Wildlife Habitat Areas, or WHAs, under the Forest and Range Practices Act, FRPA, or Reserves under the Land Act. These WHAs and Reserves total to 4,300 ha of core breeding habitat (i.e., suitable breeding and post-fledging habitats) and over 14,000 ha of suitable foraging habitat (MoFLNRO and MoE 2013).

Specific activities in some breeding and foraging habitat on provincial Crown land are constrained within:

  • Parks and protected areas (e.g.,B.C. Park Act);
  • Ungulate Winter Ranges through the Forest and Range Practices Act (FRPA);
  • Old Growth Management Areas through the B.C. Land Act;
  • Conservancies, Biodiversity, Mining and Tourism Areas and Strategic Level Reserve Design polygons within the Ecosystem-based Management planning area on the North and Central Coast (e.g., Horn et al. 2009); and
  • Strategic Land Use Agreements (SLUAs) with protection under Land Use Objectives Orders under the B.C. Land Act (e.g., on Haida Gwaii).

In addition to the habitats under the designations described above, timber harvesting in British Columbia is regulated through an “allowable annual cut” that is based on modelling of timber supply. Over the long term, it is projected that a steady state of forest age-classes (both structure and distribution) will be achieved so that the amount of old and mature age classes will become relatively constant over the long term (MoFLNRO and MoE 2013).

5. Measuring progress

Performance measures for Population and Distribution Objective 1:

  • There are at least 441 home rangesFootnote 8 with sufficient suitable habitat to support successful breeding in Canada.

Performance measures for Population and Distribution Objective 2:

  • There are breeding home rangesFootnote8 with sufficient suitable habitat to support successful breeding located across all four conservation regions, with at least 58 breeding home ranges on Haida Gwaii, 128 on the North Coast, 110 on the South Coast, and 145 on Vancouver Island.

6. Socio-economic considerations

The section in the provincial recovery strategy entitled Socioeconomic Considerations is not considered part of the federal SARA recovery strategy for this species.

A socio-economic analysis is not required in a recovery strategy under Section 41(1) of SARA. A formal evaluation of the socio-economic costs and benefits of implementing the action plan(s) will be included in one or more action plan(s) as required by SARA (section 49(e)).

7. Action plan

This section modifies information in the provincial recovery strategy.

One or more actions plans for Northern Goshawk will be completed and posted on the Species at Risk Public Registry five years following the final posting of this federal recovery strategy.

It is expected that home range plans will be developed to outline how breeding home ranges will be managed to maintain or attain a sufficient amount of critical habitat over time. Home range plans may be stand-alone documents or components of other planning documents, including action plans. The main purpose of a home range plan would be to outline how activities within the breeding home range will be managed over space and time to ensure critical habitat is protected from destruction. As such, each home range plan should outline the measures and steps that will be taken to manage the interaction between human disturbance, natural disturbance, and the need to maintain or establish sufficient breeding or foraging habitat to satisfy the requirements described in this recovery strategy.

8. 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 ProposalsFootnote 9. The purpose of a Strategic Environmental Assessment (SEA) is to incorporate environmental considerations into the development of public policies, plans, and program proposals to support environmentally sound decision-making and to evaluate whether the outcomes of a recovery planning document could affect any component of the environment or any of the Federal Sustainable Development Strategy’sFootnote 10 (Federal Sustainable Development Strategy (FSDS)) goals and targets.

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.

This recovery strategy will clearly benefit the environment by promoting the recovery of the Northern Goshawk, laingi subspecies through addressing knowledge gaps associated with population size, intra- and interspecific competition, amount and distribution of critical habitat, and winter habitat / diet associations; and reduction / mitigation of threats and maintenance of sufficient habitat on the landscape (long term).

The SEA concluded that this recovery strategy would have several positive effects and not cause any important negative effects. Other wildlife with similar habitat requirements and experiencing similar threats would stand to benefit from this recovery strategy. Further project-specific environmental assessments of actions identified as a result of research conducted in this recovery strategy, may be required.

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Mahon, T., E. McClaren, and F. Doyle. (2013). Recent analyses produced in support of development of Best Management Practices guidelines. Submitted for Parks Canada's October2013 Northern Goshawk workshop. Unpublished and not peer reviewed.

Mahon, T., E. McClaren, and F. Doyle. (2015). Northern Goshawk (Accipiter gentilis laingi) Habitat Models for Coastal British Columbia. Nesting and Foraging Habitat Suitability Models and Territory Analysis Model. Produced for the Northern Goshawk Recovery Team and Habitat RIG. Draft. Unpublished report. 52 pp.

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MoFLNRO and MoE (Ministry of Forests, Lands, and Natural Resource Operations and Ministry of Environment). (2013). Management plan for the Northern Goshawk, laingi subspecies (Accipiter gentilis laingi) in British Columbia.B.C. Ministry of Forests, Lands, and Natural Resource Operations and B.C. Ministry of Environment, Victoria, BC. 30 pp. Available from: http://www.env.gov.bc.ca/wld/recoveryplans/rcvry1.htm

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Appendix A: Northern Goshawk habitat suitability index models

Mahon et al. (2008, 2015) created Habitat Suitability Index (HSI) models for Northern Goshawk to aid in the identification of suitable habitat for Northern Goshawk. The model applications and output were described in Smith and Sutherland (2008). Habitat was rated by the models as highly suitable (HSI 0.75), moderately suitable (HSI = 0.75-0.5), of low suitability (HSI 0.5, or not suitable (HSI = 0).

This section provides an overview of the suitability models as per Mahon et al. (2015). The models are being used to describe the biophysical attributes of critical habitat identification in this recovery strategy.

For critical habitat for breeding areas, model parameters included:

  1. Stand age and height, where suitability increased linearly from lowest suitability (HSI = 0) below 40 years old and 14m tall to highest suitability (HSI = 1) above 90 years old and/or 32m tall. These estimates were based on habitat data collected around known nest areas on Haida Gwaii, the North Coast, and Vancouver Island. The model used an average of the ratings of these two variables because stand age and height are typically highly correlated.
  2. Edge habitat, where the presence of a ‘hard’ edge within 200m of the nest area makes the habitat less suitable. A ‘hard’ forest edge was considered to occur where mature forest was adjacent to non-forested habitat or younger forest, and where the height difference between the two habitat types was 15m. The impact of the edge habitat varied with distance from the nest area ( 100m or 100-200m), and the type of edge habitat: anthropogenic (primarily forest harvesting) or natural (e.g. along lakes or marshes). The impact of edge habitat was considered more severe when it was closer to the nest area, and occurred through anthropogenic influence.
  3. Forest composition, where stands dominated by Western Hemlock (Tsuga heterophylla), Sitka Spruce (Picea sitchensis), Douglas-fir (Pseudotsuga menziesii), Subalpine Fir (Abies lasiocarpa), Amabilis Fir (Abiesamabilis), or mixed forest were considered most suitable; stands dominated by Western Redcedar (Thuja plicata), deciduous forest, or Lodgepole Pine (Pinus contorta), or with Lodgepole Pine or Yellow Cedar (Chamaecyparis nootkatensis) as a secondary species were considered moderately suitable; and pure stands of Western Redcedar, or stands dominated by Yellow Cedar were rated low suitability.
  4. Elevation, where habitat at all elevations was considered potential breeding habitat if other suitable conditions existed. Overall habitat suitability declined slowly in a linear fashion from HSI = 1 below 400m on Haida Gwaii, 600m on the North Coast, and 800m on the South Coast and Vancouver Island to a minimum of HSI = 0.5 at 1,300m.
  5. Slope, where habitat at all elevations was considered potential breeding habitat if other suitable conditions existed. Slopes 30o were considered most suitable (HSI = 1), with a non-linear decrease in suitability to HSI = 0.5 at 90o.
  6. Biogeoclimatic Ecosystem Classification (BEC) zone variant, where most BEC zone variants were considered to provide potential breeding habitat if other suitable conditions existed. The most suitable habitat was in the Coastal Douglas-Fir (CDF) and Coastal Western Hemlock (CWH) zones. Slightly lower ranked, but still of high suitability were the remaining Coastal Western Hemlock (CWH) zone variants and the Mountain Hemlock (MH) zone. Engelmann Spruce – Subalpine Fir (ESSF) was of moderate suitability, and alpine tundra, alpine parkland, and ESSF parkland were all of low suitability.

The parameters were used in a habitat model that used a limiting factor, non-compensatory structure, where deficiencies in one parameter could not be compensated for by another parameter (Mahon et al. 2015).

For critical habitat for foraging areas, model parameters included:

  1. Stand age and height, where the lowest score for foraging habitats was HSI = 0.3, acknowledging that younger forests can provide some suitability for foraging (e.g., Bloxton 2002). Suitability increased linearly from lowest suitability (HSI = 0.3) below 40 years old and 14m tall to highest suitability (HSI = 1) above 90 years old and/or 32m tall. The model used an average of the ratings of these two variables because stand age and height are typically highly correlated.
  2. Forest composition, where all forest types have potential value as foraging habitat (lowest HSI = 0.6) if stand age and height were suitable. Stands where spruce is the dominant or secondary species, where Douglas-fir or Amabilis Fir is dominant (except where Yellow Cedar or Lodgepole Pine are secondary species) were considered most suitable. Stands dominated by Western Redcedar ( 80%) or Lodgepole Pine, or stands where Yellow Cedar was the dominant or secondary species were considered of moderate suitability.
  3. BEC variant, where most BEC variants were considered to have the potential to provide foraging habitat (Lowest HSI = 0.4) if other suitable conditions existed. The most suitable habitat was in the Coastal Douglas-Fir (CDF) and for some variants in Coastal Western Hemlock (CWH). The remaining Coastal Western Hemlock (CWH) variants, Mountain Hemlock (MH) and some variants of ESSF were ranked as moderate suitability, and alpine tundra was ranked as low suitability.
  4. Non-productive and non-forested habitats, where habitats such as wetlands and bogs, non-productive brush, and alpine potentially provide foraging habitat for Northern Goshawks. All vegetated polygons with a non-productive or non-forested descriptor (e.g. alpine, alpine forest, swamp, non-productive brush, clearing, meadow, open range, non-productive burn, or non-commercial brush) were assigned a low suitability rating (HSI = 0.3). Non-vegetated polygons with a non-productive or non-forested descriptor (e.g. rock, gravel, sand, clay bank, lake, gravel bar, river, or human development) were assigned a nil suitability rating (HSI = 0).

The foraging habitat model, like the breeding habitat model, used a limiting factor, non-compensatory structure, where deficiencies in one parameter could not be compensated for by another parameter (Mahon et al. 2015).

Appendix B: Location of critical habitat

Included in this appendix are maps showing the location of critical habitat for Northern Goshawk, laingi subspecies (Figures B-1 to B-5), and a table (Table B-1) that lists the home ranges within which critical habitat is identified for Northern Goshawk, the conservation region in which the home range occurs, and the amount of area within which critical habitat is found for the breeding and foraging.

For access to detailed mapping (e.g., Geographic Information System (GIS) shape files) and supporting documents, please see the contact information listed for Northern Goshawk, laingi subspecies on the Species at Risk Public Registry.

Figure B-1. Critical habitat for Northern Goshawk, laingi subspecies in the Haida Gwaii Conservation Region. This diagram shows the location of critical habitat for Northern Goshawk, laingi subspecies in the Haida Gwaii Conservation Region. Long description in table B1 below.

Figure B-2. Critical habitat for Northern Goshawk, laingi subspecies in the North Coast Conservation Region. This diagram shows the location of critical habitat for Northern Goshawk, laingi subspecies in the North Coast Conservation Region. Long description in table B1 below.

Figure B-3. Critical habitat for Northern Goshawk, laingi subspecies in the South Coast and Vancouver Island Conservation Regions. This diagram shows the location of critical habitat for Northern Goshawk, laingi subspecies in the South Coast and Vancouver Island Conservation Regions. Long description in table B1 below.

Figure B-4. Critical habitat for Northern Goshawk, laingi subspecies in the Vancouver Island and South Coast Conservation Regions. This diagram shows the location of critical habitat for Northern Goshawk, laingi subspecies in the South Coast and Vancouver Island Conservation Regions. Long description in table B1 below.

Figure B-5. Critical habitat for Northern Goshawk, laingi subspecies in the Vancouver Island and South Coast Conservation Regions. This diagram shows the location of critical habitat for Northern Goshawk, laingi subspecies in the South Coast and Vancouver Island Conservation Regions. Long description in table B1 below.

Table B-1. Location and amount of area within which critical habitat for breeding and foraging is found in each home range.
Home RangeConservation Region or Sub-regionFigure No.Nest CentroidTable B-1 notem
X Coordinate
Nest CentroidTable B-1 notem
Y Coordinate
Amount of area within which critical habitat for breeding is found (ha)Amount of area within which critical habitat for foraging is found (ha)
AinTable B-1 note*Haida GwaiiFigure B-1579719.8969993378.44991743942
Black BearHaida GwaiiFigure B-1594981.7197962828.01092564771
BonanzaHaida GwaiiFigure B-1572769.3218958805.98232003855
CreaseHaida GwaiiFigure B-1563268.7205994962.43862014333
DatlamenHaida GwaiiFigure B-1568791.1792967757.48132404118
DelkatlaTable B-1 note*Haida GwaiiFigure B-1603100.30571018036.73132181799
DemonHaida GwaiiFigure B-1579574.5056950723.14201683752
Florence CreekHaida GwaiiFigure B-1587318.8681970138.7639583892
IanHaida GwaiiFigure B-1556785.6519984715.28921293120
Ian 990Haida GwaiiFigure B-1574972.75041004244.63321374166
Lignite CreekHaida GwaiiFigure B-1568743.31141003845.7744343692
Sandy CreekHaida GwaiiFigure B-1623284.7293869704.1455303226
SkowkonaHaida GwaiiFigure B-1596290.3259940449.64421925179
SurveyHaida GwaiiFigure B-1597709.4307950365.74032235179
Three MileHaida GwaiiFigure B-1591203.7414951475.44172424397
Upper HancockHaida GwaiiFigure B-1583478.4479996422.8382884531
Windy BayHaida GwaiiFigure B-1629501.0558867975.54732504408
Yakoun LakeHaida GwaiiFigure B-1579828.6504941730.36712024991
Alder CreekNorth Coast - North of 51 lat.Figure B-2 (Inset)780010.38791027138.09972291832
Nusatsum EastNorth Coast - North of 51 lat.Figure B-2971881.2708813567.63961592521
Nusatsum NorthNorth Coast - North of 51 lat.Figure B-2972346.6560810585.90151822489
Nusatsum South UK & Nusatsum SouthNorth Coast - North of 51 lat.Figure B-2976538.8181807313.4263261919
Princess Royal Is.North Coast - North of 51 lat.Figure B-2826765.3134864309.05611601328
Saloompt CentralNorth Coast - North of 51 lat.Figure B-2962467.5543831660.82682252519
Saloompt Central 2North Coast - North of 51 lat.Figure B-2962026.0616834446.43492242519
Saloompt fireblockNorth Coast - North of 51 lat.Figure B-2964962.8623825598.29001122521
Saloompt South UKNorth Coast - North of 51 lat.Figure B-2963651.3121828087.49562452520
Snootli CreekNorth Coast - North of 51 lat.Figure B-2958391.9576818639.79021342520
TalchakoTable B-1 note*North Coast - North of 51 lat.Figure B-2991507.5056818124.89211521872
Brooks BayTable B-1 note*North Coast - South of 51 lat.Figure B-41034804.3224606943.6762691207
East ThurlowNorth Coast - South of 51 lat.Figure B-41035696.5886595745.92211081056
Forward HarbourNorth Coast - South of 51 lat.Figure B-41019053.3336610362.56472201410
Hardwicke Island 1North Coast - South of 51 lat.Figure B-41009660.1727601173.42692391319
Hardwicke Island 2North Coast - South of 51 lat.Figure B-41013691.8286604384.17891681431
Kwatzi BayNorth Coast - South of 51 lat.Figure B-4983029.2162649360.32081151573
West CracroftNorth Coast - South of 51 lat.Figure B-4969937.9639615444.61771731653
Bear CreekSouth CoastFigure B-3 (Inset)1309685.7723504829.22551061599
Brew CreekTable B-1 note*South CoastFigure B-31204820.4341564067.81974040
Chehalis WoodlotTable B-1 note*South CoastFigure B-3 (Inset)1298797.1887488336.94291571608
Chilliwack River (Nesaqauatch)Table B-1 note*South CoastFigure B-3 (Inset)1327127.8577463834.8952941683
Dorr LakeTable B-1 note*South CoastFigure B-31057443.2592590124.78652621138
Furry CreekSouth CoastFigure B-3 & B-51204044.1164513293.45971341682
Goat IslandSouth CoastFigure B-31114527.4825559967.34622331299
Harrison LakeSouth CoastFigure B-3 (Inset)1306629.5217494669.74751831148
HomathcoTable B-1 note*South CoastFigure B-31073869.6384674429.67694040
Lillooett RiverTable B-1 note*South CoastFigure B-31227647.6666599915.26142020
McNab CreekSouth CoastFigure B-3 & B-51186799.4532512130.172920927
PD 203South CoastFigure B-31114996.7024588024.751496818
Red Tusk CreekSouth CoastFigure B-31187752.6331533140.75981551528
Saltery Bay ST048South CoastFigure B-31129506.8923533172.56062161344
Skyline TrailTable B-1 note*South CoastFigure B-3 (Inset)1363724.9571459869.83282525
Stewart IslandTable B-1 note*South CoastFigure B-31062241.3557597705.679951381
Upper Elaho 1Table B-1 note*South CoastFigure B-31173620.8009601067.65712020
Upper Elaho 2Table B-1 note*South CoastFigure B-31176749.2162614111.14762020
Vancouver RiverSouth CoastFigure B-31166242.5239549840.42242061652
West Hope SlideTable B-1 note*South CoastFigure B-3 (Inset)1344855.8261488676.33992828
West RhodondaTable B-1 note*South CoastFigure B-31076790.2281583756.985801101
Anderson LakeTable B-1 note*Vancouver Island 1103524.7071407389.5990TBDTBD
Cervus CreekVancouver IslandFigure B-41015970.4105537155.91721911681
China CreekTable B-1 note*Vancouver IslandFigure B-51102099.3472458981.382401
Clayoquot SoundVancouver IslandFigure B-51016040.1622471704.81011631193
Colony LakesVancouver IslandFigure B-4887100.5553617041.7518164856
Consort CreekVancouver IslandFigure B-4996040.6297561333.91181331083
Cook CreekTable B-1 note*Vancouver IslandFigure B-51087884.5642489409.76361201255
Corrigan CreekTable B-1 note*Vancouver Island 1095816.9584448222.0686TBDTBD
DerbyVancouver IslandFigure B-4959597.1158602765.56321891586
Dove CreekTable B-1 note*Vancouver IslandFigure B-3 &
B-5
1061902.4989520820.088020117
Garbage CreekTable B-1 note*Vancouver Island 1140076.2676398006.0272TBDTBD
Gerald CreekVancouver IslandFigure B-4992174.8933568626.923258917
Great Central Lake BTable B-1 note*Vancouver Island 1063639.4443479021.1315TBDTBD
Green RiverTable B-1 note*Vancouver IslandFigure B-51118958.3650447840.55102020
Kelvin CreekTable B-1 note*Vancouver IslandFigure B-51166322.2959410595.2664129592
Lupin FallsTable B-1 note*Vancouver IslandFigure B-41029044.7493530181.955420771
MclaughlinTable B-1 note*Vancouver Island 1100126.6613461569.4505TBDTBD
Mt. EdinburghTable B-1 note*Vancouver Island 1115739.1474403760.6305TBDTBD
MuseumTable B-1 note*Vancouver Island 1096154.8869453041.9702TBDTBD
Nadira 700Table B-1 note*Vancouver Island 1101651.9915442404.9643TBDTBD
NahmintTable B-1 note*Vancouver Island 1074261.1158459163.0774TBDTBD
Norton PointVancouver IslandFigure B-4876578.1575622966.7631141720
Shushartie BayVancouver IslandFigure B-4869217.8035647221.2376211540
Thomas CreekTable B-1 note*Vancouver Island 1092216.8359452181.4872TBDTBD
Ucona RiverVancouver IslandFigure B-4996337.5994523154.40431961682
Claude ElliotTable B-1 note*Vancouver Island - Central NorthFigure B-4959229.1349586901.685288563
Conuma RiverVancouver Island - Central NorthFigure B-4974105.6303536592.1861125739
Elbow CreekVancouver Island - Central NorthFigure B-4997128.4559552448.1705251883
Frost LakeTable B-1 note*Vancouver Island - Central North 960057.0204572123.4096TBDTBD
Gold ParkVancouver Island - Central NorthFigure B-4993499.4977538730.901146590
Hoomak LakeTable B-1 note*Vancouver Island - Central North 962712.0718575944.2790TBDTBD
John RoadTable B-1 note*Vancouver Island - Central North 964493.2468566616.3805TBDTBD
Kaipit RoadTable B-1 note*Vancouver Island - Central North 945297.0429579613.7835TBDTBD
KlaklakamaTable B-1 note*Vancouver Island - Central North 966117.0030572162.1581TBDTBD
Loon LakeTable B-1 note*Vancouver Island - Central North 938457.2223581169.7360TBDTBD
Lower StellaVancouver Island - Central NorthFigure B-41032259.3585587667.0608205656
LukwaTable B-1 note*Vancouver Island - Central NorthFigure B-4963400.5490582515.8690028
Lukwa South (CT060)Table B-1 note*Vancouver Island - Central North 960320.7264578835.7103TBDTBD
Muchalat LakeVancouver Island - Central NorthFigure B-4989772.4974540176.7431109528
OktwanchVancouver Island - Central NorthFigure B-4987969.1223544435.6589237681
Paterson LakeVancouver Island - Central NorthFigure B-41024965.4565562773.3080118835
Pye LakeVancouver Island - Central NorthFigure B-41027736.9567586671.314020128
Roberts LakeVancouver Island - Central NorthFigure B-41027583.8842580547.1916191679
Rona LoopTable B-1 note*Vancouver Island - Central North 956858.4213576098.5124TBDTBD
Surprise LakeVancouver Island - Central NorthFigure B-41031117.7888569998.6295114691
TlatlosVancouver Island - Central NorthFigure B-4972586.5139589770.3571101466
Toad RoadTable B-1 note*Vancouver Island - Central North 950164.9709579225.5568TBDTBD
TsitikaVancouver Island - Central NorthFigure B-4967344.7598592241.6515236677
Tsitika WestVancouver Island - Central NorthFigure B-4961876.3810591137.0466217759
Twaddle LakeVancouver Island - Central NorthFigure B-4989901.0254553172.984977503
Upper StellaVancouver Island - Central NorthFigure B-41034864.6394584283.7026188697
Vernon RidgeTable B-1 note*Vancouver Island - Central North 968732.6489561105.8301TBDTBD

Table B-1 notes

Table B-1 note *

Some critical habitat has not been identified due to insufficient available information or ongoing cooperation and consultation (see schedule of studies in Table 3).

 

Table B-1 note m

Nest centroid is the centroid of all known nest and supplementary nest locations for a breeding home range.

 

Footnotes

Footnote 1

http://sararegistry.gc.ca/default.asp?lang=En&n=24F7211B-1

Return to footnote 1 referrer

Footnote 2

http://registrelep-sararegistry.gc.ca/default.asp?lang=En&n=6B319869-1%20

Return to footnote 2 referrer

Footnote 3

These federally protected areas are: a national park of Canada named and described in Schedule 1 to the Canada National Parks Act, The Rouge National Park established by the Rouge National Urban Park Act, a marine protected area under the Oceans Act, a migratory bird sanctuary under the Migratory Bird Convention Act, 1994 or a national wildlife area under the Canada Wildlife Act see ss. 58(2) of SARA.

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Footnote 4

Northern Goshawks are distributed in adult pairs that occupy a home range (sometimes referred to as a territory; COSEWIC 2013). The number of home ranges (rather than the number of birds) is used for the purposes of setting population and distribution objectives.

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Footnote 5

For example, Manning and Chytyk (2008).

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Footnote 6

For example, Doyle (2005).

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Footnote 7

A hard edge is defined as an abrupt change in the forest canopy, typically where mature or old forest is adjacent to non-forested habitat or younger forest, and where the height difference between the two habitat types is at least 15m (e.g., clearcut edge, lake shore, alpine area).

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Footnote 8

Breeding home ranges are based on BC Conservation Centre records and do not require recent evidence of occupancy because of the difficulty in detecting Northern Goshawks, a lack of widespread annual monitoring, and because they have been known to re-occupy a particular area even after many years of apparent absence (see details in Section 3.1.1).

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Footnote 9

http://www.ceaa.gc.ca/default.asp?lang=En&n=B3186435-1

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Footnote 10

http://www.ec.gc.ca/dd-sd/default.asp?lang=En&n=CD30F295-1

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Part 2 - Recovery Strategy for the Northern Goshawk, laingi subspecies (Accipiter gentilis laingi) in British Columbia, prepared by the Northern Goshawk Accipiter gentilis laingi Recovery Team for the British Columbia Ministry of Environment