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NORTHERN SPOTTED OWL (Strix occidentalis caurina)
- Recovery Strategy for the Northern Spotted Owl
- Range Jurisdictions
- Executive Summary
- 1: Background
- 2. Distribution
- 3. Population Abundance
- 4. Biologically Limiting Factors
- 5. Threats to the Species
- 6. Habitat Identification
- 7. Ecological Role
- 8. Importance to People
- 9. Anticipated Conflicts or Challenges
- 10. Knowledge Gaps
- 11. Ecological and Technical Feasibility of Species Recovery
- 12. Recommended Approach / Scale for Recovery
- 13. Socio-economic Considerations
- 14. Recovery Goal
- 15. Recovery Objectives
- 16. Strategies to Meet Recovery Objectives
- 17. Potential Impacts of the Recovery Strategy on Other Species and Ecological Processes
- 18. Actions Already Completed Or Underway
- Literature Cited
- Appendix 1
- Appendix 2
- Appendix 3
- Appendix 4
- Appendix 5
- Appendix 6
- Addendum 1
- Addendum 2
16. Strategies to Meet Recovery Objectives
The SORT has identified the following strategies to effect recovery of the Spotted Owl in British Columbia. A summary of these strategies is presented in Table 2. It is recommended that some strategies be implemented immediately. Other recovery strategies require further analysis and consideration before identifying the best approach to achieve recovery objectives. Recovery action plans that provide recommendations on detailed strategies and actions for recovery should be completed within a year of release of the recovery strategy. Where appropriate, components of the recovery action plans should be implemented as soon as possible (before March 2005) to assist recovery and prevent extirpation. To assist the SORT, Recovery Implementation Groups may be established to refine and implement strategies, objectives, and recovery action plans.
16.1 Immediate Strategies
Strategies to stop the decline and prevent extirpation
Due to the critical nature of the Spotted Owl population in British Columbia, in January 2003, the SORT presented the provincial government with interim management recommendations to be implemented immediately to prevent extirpation and maintain options to recover the species (Appendix 1). New management recommendations to stop the decline and prevent extirpation will be part of recovery action plans that will include the identification of critical habitats and/or management actions to augment the population.
16.1.1 Immediately protect all Spotted Owls.
Due to the small population size, there is critical need to protect all Spotted Owls and their habitat in British Columbia as the highest priority recovery action. Such action is needed immediately to prevent extirpation. All remaining individuals are essential to provide the genetic diversity and act as a “seed” source to increase and recover the population. As well, any disturbance (natural or otherwise) that lowers the reproductive potential of the population will increase the rate of population decline.
220.127.116.11 Find all Spotted Owls.
To implement this strategy, a continuing inventory that locates all remaining individuals is needed in order to apply protection to the owls. This information will also provide essential baseline information on the number, distribution and reproductive status of owls throughout their range in British Columbia on which recovery actions will depend. For example, if more owls are found than expected (i.e., more than 33 potential breeding pairs) then recovery actions thought to be needed may be lessened. Conversely, if fewer pairs of owls exist than expected, then more stringent recovery actions may be warranted. A failure to obtain such information could delay actions that affect recovery as well as lead to poor management decisions and perpetuate economic uncertainty, all of which could increase the likelihood of extirpation.
16.1.2 Immediately identify and conserve survival habitat.
Survival habitat represents the minimum quantity, quality, and distribution of habitat needed to maintain the current population and prevent further population decline. Simply conserving habitats found only within currently occupied territories will not guarantee maintenance of the population. Factors such as the distribution of owls and the ability of individuals to find habitats and mates play significant roles in maintaining the population. As such, survival habitat must include those habitats found within occupied territories, as well as habitats that are needed to facilitate dispersal and new territory establishment. Further loss of survival habitat could result in further declines in the population and jeopardize the likelihood of naturally recovering the species.
16.2 Population Strategies
Strategies to support population growth
Large populations are more resilient to fluctuations in population size than small populations. Simply stabilizing the population at its current small size will result in a population that is still extremely vulnerable to extirpation. Therefore, the population size must be increased to higher and more resilient levels. These levels will then maintain the population’s capability to restore itself after natural declines in owl numbers. To increase the population requires the protection of unoccupied suitable habitats that are sufficient to maintain potential breeding pairs and that allow dispersing individuals to establish new territories.
16.2.1 Monitor the population trend.
Monitoring of the population is necessary to determine the success or failure of any management actions taken to effect recovery of the species. Monitoring will provide information to assess the health of the population and allow informed management decisions to be made. Given the apparent imminent threat of extirpation, it is recommended that a comprehensive monitoring program be immediately implemented on an annual basis. This monitoring program should continue until the population becomes stable and the risk of population decline is relatively low.
16.2.2 Determine the minimum population size required to attain a stable, self-sustaining population distributed across the species’ natural range.
The minimum population size needed for a stable, self-sustaining population in British Columbia is unknown. To down-list the species to Threatened status, one COSEWIC criterion is to maintain a minimum of 250 mature individuals (owls older than 2 years). However, simply distributing 250 mature owls across the species’ natural range could result in an unstable population because distances between these owls may be too great to allow pair formation and to sustain recruitment of owls into the population. In conjunction with habitat supply models, it is recommended that population models be used to determine the minimum number of mature owls needed and time frames required to achieve a stable, self-sustaining population throughout the species’ natural range. The models should assess the influence of various biological and limiting factors on population recovery. It is also recommended that these models consider a range of recovery actions (e.g., population augmentations, habitat protection, etc.) to determine the most effective methods of attaining a self-sustaining population over the shortest timeframe. Target date for completion of models is within a year of release of the recovery strategy.
16.2.3 Artificially increase owl recruitment through population augmentation.
The population decline in British Columbia over the last decade indicates that conditions were not favourable during this period to support population growth. Future conditions that will influence population growth are unknown. For the population to naturally increase requires that owls find mates and sufficient suitable habitat to support regular breeding. Because of the small, sparsely distributed population, as well as the low amount and fragmentation of habitats in the landscape, chances of owls naturally finding mates and suitable habitat is thought to be low. Natural population growth may therefore require many decades to increase to more resilient levels, during which time the population may become extirpated due to stochastic events.
Given the critical nature of the status of the Spotted Owl population in British Columbia, it is recommended that population augmentations be considered (i.e., assessed and evaluated for feasibility) immediately, and implemented--if deemed appropriate-- to prevent further declines and extirpation. Population augmentations are very risky and have the potential to cause more harm to the population if management actions are not well planned and closely monitored. Therefore, the Population Augmentation Action Plan should include an assessment of the risks, costs, and benefits associated with the capture and overwintering of juveniles, the translocation of single adult owls to other territories with single owls, importing owls from the United States, and the establishment of a captive breeding/release program. Furthermore, these actions should not be implemented without adequate conservation of habitats needed to support the population. Simply increasing owl numbers will not result in recovery if the habitat and environment cannot support a self-sustainable population.
18.104.22.168 Overwintering juveniles.
Juvenile Spotted Owls have low survival rates than adults. The primary causes of juvenile mortality are starvation and predation during dispersal. If juveniles are not being recruited into the population at a rate that replaces adults, then extirpation is certain. To increase the survival rate of juveniles during dispersal, juvenile owls could be captured before they disperse from their natal territory and held over the winter in an appropriate holding facility. The owls can then be released the next year during favourable conditions into areas with sufficient habitat, and possibly into a territory that contains a single owl of the opposite sex. The intent of this strategy removes the initial challenge facing juveniles of learning to forage efficiently and finding sufficient habitat during harsh winter conditions.
The very low and declining number of breeding pairs that exist, the even lower number that produce fledglings, and the low survival rate of juveniles suggests that overwintering of juveniles may be an effective direct recovery action that could be taken immediately. The capture and overwintering of one juvenile owl in 2002/2003 shows that capture and overwintering of Spotted Owls is feasible (Ian Blackburn pers comm.). The bird readily adapted to captivity, caught and fed on live rodents, and survived the winter in good health. However, the bird only survived one month in the wild after its release in the spring, although care was taken to select a suitable site for its release. Mortality was caused by starvation. The lessons learned from this attempt will be extremely valuable if it is tried again, although, of course, even more caution will need to be taken to obtain a successful outcome.
22.214.171.124 Translocating single owls.
The Spotted Owl population in British Columbia is very small and pockets of occupied territories are becoming more isolated from each other. The likelihood of a single owl dispersing and finding another single owl of the opposite sex is daunting, especially for established individuals that may be reluctant for various reasons to leave their territories. To facilitate pairing, single Spotted Owls could be captured and translocated into the home range of another owl of the opposite sex. Adequate pre-capture and pre-release monitoring to determine single status, as well as sexing, would be required before this management technique would be viable. This option would create a vacant territory and preclude a natural pairing in that territory if a dispersing juvenile of the correct sex found its way to the territory. However, this method offers the advantage of pairing between two adult birds, which may increase breeding opportunities rather than waiting a year or two for the juvenile owl to mature. This method should be considered only after any juveniles being overwintered have been assigned territories for release. As with other population augmentation activities, great caution must be taken to weigh the positive and negative consequences of non-action versus action. Potential negative consequences could include lack of compatibility of owls, as well as reduced carrying capacity if prey is limiting in the receiving site. Some risks may be reduced by translocating owls from the United States into habitats in British Columbia. However, this may create other risks to the population (e.g., incompatibility to local climates, disease).
126.96.36.199 Captive breeding.
It may be necessary to capture Spotted Owls with the intent of developing a captive breeding program. Candidate owls of opposite sex would be paired within a facility to produce viable offspring. The offspring would then be released into unoccupied habitats or paired with a single owl of the opposite sex within an adequate home range. Maintaining a pedigree program is essential in order to reduce the chances of inbreeding and the potential expression of deleterious traits. Due to the high risk of extirpation, it may be necessary to immediately consider captive breeding to allow any chance of recovery.
The costs and logistical requirements of a captive-breeding program are substantial and consideration must be given to the genetic requirements for a viable breeding program. It is recommended that this approach, if implemented, be tested on a trial basis before proceeding on a large scale. Priority should be given to using any existing non-releasable captive owls (e.g., from wildlife rehabilitation facilities) where possible.
16.2.4 Artificially increase owl survivorship and fecundity
188.8.131.52 Augment the abundance of prey at active owl territories.
The availability of prey during the breeding period may limit the number of owls attempting to breed, and may result in low fecundity if nesting attempts fail or do not occur during years with low prey abundances. Artificially increasing the abundance of prey at nesting areas may increase nesting attempts and fecundity, as well as potentially increasing adult survivorship as prey resources are sufficient to sustain all individuals. Concerns for such actions include habituating owls to a supplemental food program, increasing the presence of other competitors/predators that also feed on the same prey items, as well as the feasibility and associated cost and magnitude of such a program.
184.108.40.206 Track and feed juvenile owls through the winter.
Survival and recruitment of juvenile Spotted Owls is low. Attaching transmitters to juvenile owls before they fledge would enable tracking and feeding them throughout the critical winter period. If successful, increasing survivorship of first year birds may prove to be a comparatively cost-effective method of population augmentation. Direct hand feeding of the young owls would negate concern of increasing the presence of other competitors/predators that could result from actions suggested in 220.127.116.11, however, concerns for habituating the birds to supplemental food and to humans need to be considered and mitigated. A trial project was initiated in 2003.
18.104.22.168 Remove competitors and predators from active owl territories.
To artificially increase prey abundance within owl territories, the removal of major competitors and predators (e.g., Barred Owls and Great Horned Owls) from these areas may reduce competitive pressures on prey and prevent possible displacement/predation of Spotted Owls. This may be most applicable around nest sites during the breeding period to ensure an abundance of prey items to support the owl family.
Before applying such techniques, the effect of competition on limiting prey abundance for Spotted Owls during breeding must be assessed to confirm that such action seems reasonable. In addition, the effectiveness of removing competitors may be jeopardized by other individuals simply moving in to replace the removed birds. This might require increased fieldwork and funding for ongoing monitoring and removals that could affect the program’s feasibility. If implemented, it is recommended that these measures be tested on a trial basis first before expanding this program. Lastly, removal of competitors may incite displeasure from some organizations and some members of the general public opposed to that type of wildlife management.
16.3 Habitat Strategies
Strategies to address habitat conservation
It is still uncertain how much of what types of habitat needs to be conserved in what spatial distribution in British Columbia to allow survival and recovery of the Spotted Owl. The existing management plan (SOMIT 1997a) tried to address these issues. However, the plan does not include the entire range of the owl as it is known today and also does not protect new sites found within the plan area after 1995. As well, although the plan anticipated an immediate decline before a long-term increase/stabilization, the short-term decline rate is higher than anticipated, and the owl is now considered to be in imminent danger of extirpation from British Columbia How much of the decline is due to habitat factors versus other factors is unknown, but the habitat needs for recovery to meet RENEW criteria need to be assessed to enable future habitat management for the species.
16.3.1 Identify and conserve critical habitat.
Critical habitat is composed of survival and recovery habitats throughout the species’ natural range. These habitat types will be determined in the Habitat Action Plan. Until critical habitats are defined and formalized through appropriate government land-use decisions and federal registry, it is recommended to use existing surrogate definitions of habitat used in the Spotted Owl Management Plan (see section 6.2), and apply the recommendations in section 16.1 to protect habitat for the Spotted Owl.
The Habitat Action Plan will identify the quantitative and qualitative aspects of suitable habitat needed for nesting, roosting, foraging, and dispersal of Spotted Owls, and whether landscape-level conditions influence this suitability. It will review and assess the accuracy of the currently defined minimum age of suitable habitat as being more than 100 years old, as well as the landscape requirement to maintain at least 67% suitable habitat within active owl territories or Long-Term Activity Centres. When combined with temporal and spatial modeling, this should enable the more accurate definitions of survival and recovery habitat that are necessary to define the species’ critical habitat.
22.214.171.124 Determine the minimum amount and distribution of critical habitat needed to maintain a stable, self-sustaining population distributed throughout the species’ natural range.
In conjunction with population modeling, it is recommended that habitat supply models be used to assess the adequacy of the current distribution of habitat to recover the species. Such models can also predict future habitat supply and the timeframes required to create the habitat conditions (positive or negative) necessary for the owl’s survival. The model should assess various habitat conservation scenarios to determine the timeframe and likelihood of achieving a stable, self-sustaining population throughout the species’ natural range. This assessment should also evaluate the effectiveness of the current Spotted Owl Management Plan. Target date for model completion is within a year of release of the recovery strategy.
126.96.36.199 Develop management guidelines to conserve critical habitats.
Once survival and recovery habitats are established, guidelines are needed to identify management actions to conserve habitat within each jurisdiction (e.g., protected areas, federal lands, etc.). The guidelines should include management actions to create, enhance, and maintain habitat, as well as actions to reduce threats from natural disturbances such as fire and insects. The guidelines should consider and evaluate existing management strategies for these types of activities that are identified in the existing Spotted Owl Management Plan. Until new guidelines for conserving areas identified as critical habitat are in place, it is recommended that the Spotted Owl Management Plan’s strategies be used to conserve habitat within existing owl management areas.
16.4 Other Supporting Strategies
Government policy alone may not necessarily guarantee recovery. To best effect recovery, it is recommended that partnerships with stakeholders be established to promote the conservation of the Spotted Owl. Aside from conserving the owl, other apparent benefits may include shared resources, focused activities (e.g., research), ecocertification support, goal orientated resource management (e.g., habitat enhancement), and increased public awareness.
16.4.1 Promote habitat stewardship
Portions of the Spotted Owl’s natural range currently contain unfavourable habitat conditions for supporting owls. Restoration of habitat may accelerate the recruitment of these habitats and increase chances of recovery of the species. It is recommended that goal-oriented resource stewardship plans be established by stakeholders to address key habitat supply issues (e.g., dispersal habitat). For example, areas of unsuitable habitat within areas conserved for Spotted Owls should be prioritized for habitat enhancement. Furthermore, these plans may result in financial support to implement these actions (e.g., Federal Habitat Stewardship Fund, Provincial Forest Investment Account, and Spotted Owl Recovery Fund, if established; see section 16.4.3).
16.4.2 Promote owl population stewardship
Because of the small population size, close monitoring of the owl population is needed to implement recovery actions. Implementation of some population augmentation measures will require facilities for breeding and overwintering, as well as staff time to monitor the effectiveness of these actions. These types of actions will require substantial resources to fund and maintain. It is recommended that partnerships among stakeholders be established to share resources and assist in these recovery actions to stabilize and increase the owl population.
16.4.3 Promote financial support to assist recovery actions
To effect recovery will require substantial resources. A potential limiting factor that may prevent recovery and cause extirpation is a lack of sufficient funding to develop and implement recovery actions. The provincial government is the lead jurisdiction responsible for the protection and recovery of the Spotted Owl. As such, it is recommended that the provincial government establish and financially support a Spotted Owl Recovery Fund. It is also recommended that the government seek partnerships with other stakeholders (including the federal government), as well as seek other funding avenues and public donations to sustain the recovery fund over the long term until the species has recovered. These funds will be used to support recovery actions that could include research and inventory, habitat recovery, population recovery, and effectiveness monitoring. Use of these funds should follow the priorities of the SORT. A conceptual framework for this fund is presented in Appendix 3.
16.4.4 Promote adaptive management / research to address information gaps and improve the effectiveness of recovery actions
Although the Spotted Owl is one of the best studied birds in North America, some pertinent information that would improve recovery efforts in British Columbia is lacking (see section 10). In addition, as recovery actions are implemented, monitoring their effectiveness on the province’s Spotted Owl population is necessary to ensure that such actions are warranted and do not cause further harm to the species. Adaptive management is a process that can improve management actions incrementally by implementing actions in ways that maximize opportunities to learn from experience. It is recommended that research and monitoring activities be coordinated so that these activities are focused on high-priority projects needed to accomplish and monitor recovery actions. A preliminary list of priority projects is provided in Appendix 2.
16.4.5 Promote public awareness
An integral part of recovery is public awareness of the plight of, and actions taken to conserve, the species. Recovery of the Spotted Owl depends on public support. Unfortunately, most media attention focuses on the conflict of “Spotted Owls versus Forestry Jobs,” rather than focusing on the challenges and solutions to maintain both. The conservation of the Spotted Owl is not achieved just at the local level, but is also influenced at the provincial, national, and international levels. To effect recovery, it is recommended that a communication strategy be implemented to provide information on recovery efforts and plight of the owl that is accessible at the local, provincial, national, and international levels. Consideration should be given to establishing a Web site for the Spotted Owl.
16.4.6 Promote innovative solutions to address social and economic consequences
The recovery of the Spotted Owl has social and economic consequences that extend beyond just the forest industry and the jobs it provides. Our society includes those that want to harvest resources, those that want to save endangered species, and those that want both. To balance both will require innovative solutions to optimize recovery efforts while minimizing negative consequences. A comprehensive social and economic analysis, including an ecological economic component, should be completed for recovery options identified within recovery action plans. It is also recommended that innovative solutions be considered in these evaluations. A strategic overview of the scope of socio-economic issues is presented in section 13 of this report
Table 2. Summary of strategies needed to meet recovery objectives.*
|Section||Priority||Objective||Broad Strategy||Specific Steps||Anticipated Effect|
|16.1.1||Urgent||15.1||Protect population||Protect all occupied and managed territories||Prevent extirpation|
|188.8.131.52||Urgent||15.1, 15.2, 15.3||Inventory||Conduct comprehensive inventory||Improved management of habitat and augmentation|
|16.1.2||Urgent||15.1, 15.3||Protect habitat||Identify and conserve Survival Habitat||Prevent extirpation|
|16.2.1||Urgent||15.1, 15.2, 15.3||Monitor population status||Assess viability of current population||If population declines, then urgency for actions increases|
|16.2.2||Urgent||15.2, 15.3||Minimum viable population size||Develop population model to help determine minimum numbers of breeding owls needed for self-sustaining population||Establish population benchmark for recovery|
|184.108.40.206||Necessary||15.1, 15.2, 15.3||Augment population||Decision on capture and over wintering juvenile owls within a year of release of the recovery strategy||Potentially increases recruitment of juveniles|
|220.127.116.11||Necessary||15.1, 15.2, 15.3||Augment population||Decision on translocating single adult owls within a year of release of the recovery strategy||Potentially increases number of breeding individuals|
|18.104.22.168||Necessary||15.1, 15.2, 15.3||Augment population||Decision on captive breeding by within a year of release of the recovery strategy||Potentially increases recruitment|
|22.214.171.124||Beneficial||15.1, 15.2||Augment prey abundance||Supplemental feeding program at nesting area||Increases fecundity and owl survivorship|
|126.96.36.199||Beneficial||15.1, 15.2||Augment prey abundance||Radio-track and supplemental feed juveniles through winter||Increases juvenile owl survivorship/recruitment|
|188.8.131.52||Beneficial||15.1, 15.2||Augment prey abundance||Remove prey competitors and owl predators from owl territory||Increases fecundity and owl survivorship|
|16.3.1||Urgent||15.1, 15.2, 15.3||Protect habitat||Define critical habitat including survival and recovery habitat||Identify habitat requirements needed to effect recovery|
|184.108.40.206||Urgent||15.1, 15.2, 15.3||Habitat protection||Develop habitat supply model to help determine minimum habitat needs to maintain self-sustaining population||Establish habitat benchmark for recovery|
|220.127.116.11||Beneficial||15.1, 15.2, 15.3||Habitat enhancements||Develop silvicultural guidelines to create, enhance, maintain habitat||Increases recruitment rate of suitable habitat|
|16.4.1||Beneficial||15.1, 15.3, 15.4||Habitat stewardship||Promote habitat stewardship with forest companies||Improved forest management plans that benefit Spotted Owls and forest company|
|16.4.2||Beneficial||15.1, 15.2, 15.4||Population stewardship||Promote owl population stewardship with stakeholders||Improved population management and augmentation success|
|16.4.3||Urgent||15.1, 15.2, 15.3, 15.4||Financial support||Promote a funding strategy to sustain resources||Long-term funding resources available to effect recovery|
|16.4.4||Necessary||15.1, 15.2, 15.3, 15.4||Adaptive management and research||Promote research and adaptive management to address information gaps||Improved effectiveness of recovery actions|
|16.4.5||Beneficial||15.1, 15.2, 15.3, 15.4||Public awareness||Promote public awareness for greater support for recovery actions||Improved public support and understanding of challenges and actions|
|16.4.6||Necessary||15.2, 15.3, 15.4||Socioeconomic considerations||Promote innovative solutions to socioeconomic consequences||Reduced socioeconomic impacts of recovery|
* Note: Because of the level of endangerment of this species, the SORT feels that all these strategies are necessary and of high importance, but have ranked them here in accordance with their relative important to each other.
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