Management plan for the Savannah Sparrow, princeps subspecies, in Canada [proposed] 2006

Table of Contents
Species Information
Introduction
Species’ background
Management
References Cited
Contact List
Appendix: Global Range of Ipswich Sparrow

About the Species at Risk Act Management Plan Series

What is the Species at Risk Act (SARA)?

SARA is the Act developed by the federal government as a key contribution to the common national effort to protect and conserve species at risk in Canada. SARA came into force in 2003, and one of its purposes is “to manage species of special concern to prevent them from becoming endangered or threatened.”

What is a species of special concern?

Under SARA, a species of special concern is a wildlife species that could become threatened or endangered because of a combination of biological characteristics and identified threats. Species of special concern are included in the SARA List of Wildlife Species at Risk.

What is a management plan?

Under SARA, a management plan is an action-oriented planning document that identifies the conservation activities and land use measures needed to ensure, at a minimum, that a species of special concern does not become threatened or endangered. For many species, the ultimate aim of the management plan will be to alleviate human threats and remove the species from the List of Wildlife Species at Risk. The plan sets goals and objectives, identifies threats, and indicates the main areas of activities to be undertaken to address those threats.

Management plan development is mandated under Sections 65–72 of SARA (http://www.registrelep-sararegistry.gc.ca/approach/act/default_e.cfm).

A management plan has to be developed within three years after the species is added to the List of Wildlife Species at Risk. Five years is allowed for those species that were initially listed when SARA came into force.

What’s next?

Directions set in the management plan will enable jurisdictions, communities, land users, and conservationists to implement conservation activities that will have preventative or restorative benefits. Cost-effective measures to prevent the species from becoming further at risk should not be postponed for lack of full scientific certainty and may, in fact, result in significant cost savings in the future.

The series

This series presents the management plans prepared or adopted by the federal government under SARA. New documents will be added regularly as species get listed and as plans are updated.

To learn more

To learn more about the Species at Risk Act and conservation initiatives, please consult the SARA Public Registry (http://www.sararegistry.gc.ca/)and the web site of the Recovery Secretariat (http://www.sararegistry.gc.ca/sar/recovery/default_e.cfm).

Recommended citation:

Environment Canada. 2006. Management plan for the Savannah Sparrow, princeps subspecies (Passerculus sandwichensis princeps), in Canada [Proposed]. Species at Risk Act Management Plan Series. Environment Canada, Ottawa. iv + 19 pp.

Additional copies:

Additional copies can be downloaded from the SARA Public Registry (http://www.sararegistry.gc.ca/).

Également disponible en français sous le titre

« Plan de gestion du Bruant des prés de la sous-espèce princeps (Passerculus sandwichensis princeps) au Canada [Proposition] »

ISBN To come

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

Declaration

Environment Canada has developed its management plan for the Savannah Sparrow, princeps subspecies, as required by the Species at Risk Act. This proposed management plan has been prepared in cooperation with jurisdictions responsible for the species, as described in the Preface.

Success in the conservation 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 plan and will not be achieved by Environment Canada or any other jurisdiction alone. In the spirit of the Accord for the Protection of Species at Risk, the Minister of the Environment invites all Canadians to join Environment Canada in supporting and implementing this plan for the benefit of the Savannah Sparrow, princeps subspeciesand Canadian society as a whole. Environment Canada will endeavour to support implementation, given available resources and varying species at risk conservation priorities. The Minister will report on progress within five years.

Responsible Jurisdictions

Environment Canada

Government of Nova Scotia

Author

Andrew G. Horn

Department of Biology

Dalhousie University

Halifax, Nova Scotia

B3H 4J1

Acknowledgments

The author especially thanks Andrew Boyne of the Canadian Wildlife Service for the opportunity to prepare this report and for guidance throughout its preparation. Andrew Boyne, Ian McLaren, Phil Taylor, Wayne Stobo, Julie McKnight, and Doug Bliss provided helpful comments on previous drafts. The Environmental Assessment Section of Environment Canada – Atlantic Region provided wording for sections related to environmental assessment. Invaluable unpublished information was provided by Marty Leonard, Zoe Lucas, Ian McLaren, Steve Mockford, Dave Patriquin, Jim Rising, and Bob Zink. Gerry Forbes, Zoe Lucas, and Ian McLaren deserve particular thanks for their tireless support of efforts to understand this bird and the island on which it breeds. Thanks also to Canadian Wildlife Service, Habitat Conservation Section for their advice and Canadian Wildlife Service, Recovery Section for their advice and efforts in preparing this document for posting.

Strategic Environmental Assessment

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

Management planning is intended to benefit species at risk and biodiversity in general. However, it is recognized that management plans 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 on non-target species or habitats. The results of the SEA are incorporated directly in the management plan itself, but are also summarized below.

This management plan will clearly benefit the environment by promoting the conservation of the Ipswich Sparrows. The potential for the plan to inadvertently lead to adverse effects on other species was considered. The SEA concluded that this plan will clearly benefit the environment and will not entail any significant adverse effects. Refer to the following sections of the document in particular: Species’ background (section 2); and Recommended approach/scale for managing the species (section 3.3).

Preface

The Savannah Sparrow, princeps subspecies (“Ipswich Sparrow”), is a migratory bird covered under the Migratory Birds Convention Act, 1994 and is under the management jurisdiction of the federal government. The Species at Risk Act (SARA, Section 65) requires the competent minister to prepare management plans for listed species of special concern. The Ipswich Sparrow was listed as a species of special concern under SARA in June 2003. The Canadian Wildlife Service – Atlantic Region, Environment Canada, led the development of this management plan. Nova Scotia, the only responsible jurisdiction, reviewed and approved the plan. The proposed plan meets SARA requirements in terms of content and process (Sections 65–66). It was developed in cooperation or consultation with:

the provincial jurisdiction in which the species occurs -- Nova Scotia;
Aboriginal groups -- the Nova Scotia Native Council and the Confederacy of Mainland Mi'kmaq;
environmental non-government groups -- the Sable Island Preservation Trust and the Nova Scotia Bird Society;
industry stakeholders -- Canada–Nova Scotia Offshore Petroleum Board; and
landowners -- Department of Fisheries and Oceans.

This will be the first management plan posted on the SARA Public Registry.

Executive Summary

The Savannah Sparrow, princeps subspecies (Passerculus sandwichensis princeps), also known as the Ipswich Sparrow, is listed as a Species of Special Concern in Canada. A morphologically and behaviourally distinct population of the widespread Savannah Sparrow, it nests almost exclusively on Sable Island, 150 km southeast of mainland Nova Scotia, and winters in coastal dunes from Nova Scotia to Florida. Censuses on the breeding grounds since 1967 have estimated an adult population varying between 1250 and 3400 individuals, although different census methods yielded 5962 individuals in 1998. The bird’s reproductive rate is very high; breeding starts in the second year, adult survival rates are fairly high for a migratory passerine (28–42%), fledging success is very high (72–84%), and pairs raise two to three clutches per season. The population is not currently under any known threat, but its restricted distribution would make it vulnerable to localized threats that may arise. In particular, a temporary population crash of about 50% appears to have occurred in the late 1970s, probably because of harsh weather during migration and wintering. Such crashes may introduce new factors as significant threats, including predation, human activity, habitat loss, chance demographic effects, and loss of genetic information.

This population probably should never be down-listed, because of its limited distribution. The specific goal of this management plan is to maintain the breeding population of Ipswich Sparrows at the current level. The objectives of this plan are to:

i. Maintain the breeding population at the current level, allowing that the population may decline below the target minimum following particularly harsh winters;

ii. Maintain the current amount and composition of breeding habitat;

iii. Remove or reduce threats to Ipswich Sparrows and their breeding and wintering habitat.

Actions to be undertaken to achieve these objectives include 1) monitoring the breeding population; 2) monitoring the breeding habitat; 3) examining the conservation status of Sable Island; 4) ensuring regulatory compliance on Sable Island; 5) ensuring a precautionary approach to projects with potential impacts on Ipswich Sparrows; 6) conserving wintering Ipswich Sparrows and their habitat; and 7) implementing education and communication programs.

Species Information

Common name: Sparrow princeps subspecies, Savannah

Scientific name: Passerculus sandwichensis princeps

Assessment summary

COSEWIC status:Special Concern

Reason for designation: This subspecies, endemic to Sable Island off Nova Scotia, has maintained a relatively stable population over several decades, varying between 2000 and 3000 individuals. This is roughly the number the island is able to support. There are currently no clear threats to the subspecies or its habitat. Despite this, the fact that the entire population is concentrated on a single small island is cause for concern.

Canadian occurrence: Nova Scotia

COSEWIC status history:Designated Special Concern in April 1979. Status reexamined and confirmed in May 2000. Last assessment based on an update status report.

Introduction

Status: The Savannah Sparrow, princeps subspecies, hereafter referred to as the Ipswich Sparrow, was first listed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as Threatened in 1979 (McLaren 1979) and was reclassified as Special Concern (formerly “Vulnerable”) in 1999 (Horn 1999) when assessment criteria were redefined. It is currently considered to be a subspecies of the Savannah Sparrow, with which it occasionally hybridizes (Horn 1999), but from which it is morphologically and behaviourally distinct (Stobo and McLaren 1975; Rising 2001). The DNA that is currently most useful in species taxonomy, mitochondrial DNA, shows no clear genetic difference between the Ipswich Sparrow and the subspecies of Savannah Sparrow that occupies most of North America (Zink et al. 2005).

Reason for status:The breeding population is restricted to one 40-km island. This necessitates designation as a Species of Special Concern, while the sparrow’s moderately large and stable population size does not justify a higher designation.

Occurrence:Sable Island, Nova Scotia, with a few individuals, perhaps fewer than 10 per year, breeding on the Nova Scotian mainland.

Information contained in the latest status report for this species is summarized only briefly here. This allows more space for information relevant to management that has become available since then, especially new population size estimates and new genetic information.

Species’ background

2.1 Biology, habitat, and distribution

The reproductive rate of Ipswich Sparrows is very high; they mature in a year, have high annual adult survival rates (28–42%) and high fledging success (72–84%), and raise two to three broods per breeding season (Stobo and McLaren 1975).

Ipswich Sparrows are the only passerines nesting in any numbers on Sable Island. They eat a variety of seeds and insects, especially marram seeds and, in winter, sea oat seeds. Predators include nest predators such as gulls, crows, European Starlings (Sturnus vulgaris), and blackbirds (family Icteridae), and adults are also taken by raptors, probably especially in migration and on the wintering grounds. If it is assumed that no areas of particular abundance have been missed, Ipswich Sparrows are too sparse in the wintering grounds to be ecologically important. On Sable Island, however, they are the dominant landbird, although their importance in ecosystem processes (e.g. whether they are a “keystone” species) is unknown.

The Ipswich Sparrow nests almost exclusively on Sable Island and likely evolved there in isolation from “typical” Savannah Sparrows (Passerculus sandwichensis sandwichensis) on the mainland. No other breeding location is known or suspected, although occasional breeders in mainland Nova Scotia pair with the “typical” Savannah Sparrow. The vegetated terrain on Sable Island constitutes this bird’s breeding habitat. All available breeding habitat on Sable Island appears to be used, albeit at varying density, depending on plant community and year. Introduction to other locales is inadvisable because of the sparrow’s specialization to its habitat and its potential to interbreed with “typical” mainland Savannah Sparrows.

Ipswich Sparrows winter along the Atlantic seaboard from Nova Scotia to Florida, with highest concentrations in the mid-Atlantic states (see map in Appendix). This distribution has not changed, at least in historic times. Winter habitat needs are poorly understood. The sparrow winters in beach grass on outer dunes, with a possible preference for sites with more access to fresh water, more relief, and a thicker and more extensive cover of beach grass (Stobo and McLaren 1971). Highest concentrations occur between New Jersey and Virginia, but the relative importance of this and the rest of the over 3000 km of coastline where the bird winters is unknown. Most of the population might winter on islands off Virginia, but these have not been surveyed for the bird.

2.2 Threats to population

The main intrinsic limiting factors for Ipswich Sparrows are their restricted breeding range and migratory dispersal across a broad winter range (McLaren 1979; Horn 1999). The population is not currently under any known threat. However, its localized distribution makes it particularly vulnerable to potential threats such as chance events, predation, human activity, and habitat loss. Studies of other grassland sparrows suggest that, in theory, the population could also be threatened by chance demographic effects and loss of genetic variation (Walters et al. 2000). Available evidence suggests that, aside from chance events, none of these factors currently threatens this particular population.

2.2.1 Breeding habitat loss

Erosion of vegetated terrain is the primary management concern in most dune habitats and would obviously be damaging to the Ipswich Sparrow population. Evidence that vegetated terrain has been reduced on Sable Island, however, is equivocal; it may have declined (Gray 1992), shifted distribution (McCann and Byrne 1994), or stayed unchanged (Freedman 1996). Detailed analysis of newly available georeferenced air photos (Desjardins 2002) may settle the issue.

Grazing and trampling by horses may contribute to loss of vegetation (e.g. DeStoppelaire et al. 2001). Grazing can also maintain floral diversity, however, by arresting succession (van Dijk 1992). In the case of Ipswich Sparrows, grazing may preserve habitat by arresting succession of herbs by woody shrubs (Horn 1999). Grazing may be beneficial for several species of grassland sparrows, although its effects vary among sites (Walk and Warner 2000). Thus, whether horses are detrimental or beneficial for sparrow habitat will require more research.

2.2.2 Human activity

Any project proposed on Sable Island has the potential to impact the Ipswich Sparrow or its habitat. The most likely type of project that would affect sparrow populations is construction of any structures on the island, such as new buildings, towers, stacks, or wind turbines. Given the sedentary habits of these birds and their resultant familiarity with objects on their territories, collisions with such structures do not pose a significant threat. However, while any given construction footprint will displace only a few sparrow territories, multiple construction projects will, of course, destroy habitat cumulatively. Also, even small-scale excavations can cause widespread erosion, with devastating effects on habitat.

Sable Island’s isolation provides some protection from landings, but its isolation will decrease as better and cheaper navigational aids make trips to the island easier. Most visits, whether project-related (e.g. maintenance of facilities, research) or more informal, are unlikely to affect the sparrow population. Nonetheless, they do carry a low risk of serious inadvertent or intentional damage to sparrow habitat -- for example, through fire, introduction of mammalian predators, or introduction of non-native plants. The latter two threats in particular have characterized the history of Sable Island’s biota.

Offshore petroleum development, which was accelerating when the updated status report was written (Horn 1999), has had no known effect on the sparrow or its habitat; the industry has avoided landing on the island and has adhered to visitor guidelines, including staying off vegetation, when there (Z. Lucas, pers. commun.). However, if offshore development continues, efforts to control its impact will have to be sustained.

A public review of the Sable Offshore Energy Project raised concerns that Ipswich Sparrows approaching or leaving Sable Island might be attracted to, collide with, or be disoriented by offshore gas platforms constructed by the project (Fournier et al. 1997).

Chemical toxins such as diesel or aviation fuel, motor oil, or other liquid fuels may cause sickness or be lethal if ingested or absorbed by Ipswich Sparrows.

2.2.3 Chance events

Harsh winter weather is known to be a threat, as it severely reduced overwinter survival and, in turn, the breeding population in 1977–1978 (McLaren 1979). In theory, harsh weather and disease during the breeding season seem to be the next most likely chance events that could affect the whole population, because of its limited distribution. Population reproductive rate, even within a season, is very high, however, so presumably recovery would be rapid (McLaren 1979; Horn 1999).

2.2.4 Chance demographic effects

Populations fluctuate in size by chance, so as a population becomes smaller relative to these fluctuations, it runs the risk of chance extinction. Data summarized in previous status reports suggested large yearly fluctuations (McLaren 1979; Horn 1999), probably linked to harsh weather during migration and wintering (see section 2.2.3 above). The population’s high reproductive rate probably buffers it against these fluctuations; to confirm this, the size of the fluctuations must be determined more precisely (Smith et al. 2003).

2.2.5 Predation

Possible avian predators of Ipswich Sparrow eggs and nestlings include gulls, crows, starlings, and blackbirds. According to both the original and updated status reports, predation may have caused high nest losses in some years, but not to the extent that would threaten the population (McLaren 1979; Horn 1999). Nest success data from 2001 and 2002 showed virtually no predation in either dense or sparse habitats (Taylor et al. 2001; Horn et al. 2003a).

Introduction of a mammalian predator to Sable Island might be catastrophic, as for other island populations of birds, although historically the population survived the long-term presence of mammalian predators, specifically cats and foxes (Elliot 1968).

2.2.6 Loss of genetic information

The updated status report suggested two potential genetic threats to Ipswich Sparrows: intergradation with mainland Savannah Sparrows and inbreeding within the Sable Island population (Horn 1999); both threats have been shown in many animal populations since then (Frankham et al. 2002). Preliminary results of studies since the updated status report, however, suggest that neither hybridization (Mockford et al. 2003; Zink et al. 2005) nor low genetically effective population size (Temple 2000; Horn et al. 2003a) is currently a pressing threat.

2.3 Monitoring history

From 1967 to 1979, estimates of the breeding population in early June (i.e. after adults arrived but before first eggs hatched) varied from 2100 to 3300 individuals, except for dips to 1700 individuals in 1977 and to 1250 in 1978, probably due to harsh winters that caused low overwinter survival (McLaren 1979). By 1979, the population had recovered to 2000 individuals; the next census was not until 1995, when the population was 3400 individuals (Horn 1999). A 1998 census using different methods yielded 5962 individuals (i.e. almost twice the maximum of the 1967–1979 censuses). This latest figure suggests either that there has been a large population increase or that one or both census methods are flawed.

Wintering populations are surveyed only through Christmas Bird Counts (CBCs). Totals suggest high variability in the amount and/or timing of winter mortality but are so low for any given count area that they may be unreliable (Horn 1999).

2.4 Knowledge gaps

The study of Stobo and McLaren (1975) remains one of the classic studies of any North American bird and provides comprehensive information on the ecology of the Ipswich Sparrow. However, knowledge is still poor in several key areas, listed below.

2.4.1 Breeding habitat use and trends

The importance of sparrow access to varied habitats in buffering population loss in years with high predation is not known, but such knowledge will be required to guide any future mitigative habitat management.

The dynamics of dune ecosystems elsewhere have been well studied but differ widely between sites (Doody 2001) and may be particularly distinct on Sable Island because of its unique location and biota. The factors that maintain long-term stability of the sparrow habitat on Sable Island are not well understood, nor is the role that horses play in the marram–beach pea assemblages. Research is required to clarify processes that create and maintain specific sparrow habitats -- for example, succession and nutrient cycling within dense marram, beach pea, and heath communities.

2.4.2 Winter habitat use and trends

Detailed information on wintering habitat and, more precisely, its use is lacking for this species. Mortality during migration and wintering, apparently the most important limit on the population, is very poorly understood. Limiting factors on the wintering grounds, such as habitat availability, food, and predation, need to be further identified.

Once wintering habitat has been better identified, trends in sparrow wintering habitat require review.

2.4.3 Genetic threats

The extent and stability of the hybrid zone, the success of hybrid pairs, and dispersal patterns on and off the island remain unstudied.

Management

3.1 Goals and objectives

The management goals and objectives, and the strategies for achieving them, are derived from the updated COSEWIC status report (Horn 1999), draft monitoring plans of the Sable Island Preservation Trust (Horn et al. 2003b), the Sable Island conservation strategy (Beson 1998), work done on the Ipswich Sparrow since the updated status report (Horn et al. 2003a; Smith et al. 2003), and recent work on other grassland sparrow populations.

3.1.1 Goal

The specific goal of this management plan is to maintain the breeding population of Ipswich Sparrows at the current level

This population’s restricted distribution means that it probably should never be down-listed from its status of Special Concern. Its breeding range cannot be increased; as far as is known, the bird has always bred almost exclusively on Sable Island. Instead, management can be directed only towards preventing any need for up-listing. Up-listing to Threatened for this species would occur if the population declined to fewer than 1000 mature individuals (COSEWIC 2003).

As mentioned previously, there is some debate over the current size of the population, so it is not possible to set an actual population goal. One of the management actions outlined in this plan is to establish an accurate and precise census method for the species. Intensive studies of the Ipswich Sparrow from 1967 to 1979 suggested that its population fluctuated widely but over the long term was stable at approximately 2000–3000 breeding birds (Stobo and McLaren 1975; McLaren 1979; Horn 1999). The most recent (1998) census, however (Smith et al. 2003), using more sophisticated statistical techniques, estimated the population at about double the size previously estimated (about 6000 birds). The lowest population estimates for this species occurred following two winters of unusually harsh weather (McLaren 1979); the population did not dip below the 1000 individual mark and showed signs of rapid recovery (Ross and McLaren 1981).

3.1.2 Objectives

The objectives of this management plan are to:

i. Maintain the breeding population at the current level, allowing that the population may decline below the target minimum following particularly harsh winters;

ii. Maintain the current amount and composition of breeding habitat;

iii. Remove or reduce threats to Ipswich Sparrows and their breeding and wintering habitat.

3.2 Management actions

Management of a population that appears stable over the long term and is not currently under threat requires approaches that maintain the status quo. Significant gaps in knowledge, most notably of true population size and winter habitat needs, however, require attention, as does coordination of management efforts at the Canadian breeding grounds and the American wintering grounds.

Along with limited distribution, one of the main reasons the Ipswich Sparrow is of Special Concern is its small, and likely variable, population size (Horn 1999). Small size in itself is a risk to a population, because chance fluctuations in size can lower the population below its minimum viable level (Lande 2002). Thus, any small population’s size and variability must be monitored closely.

Dune habitats, including those on Sable Island (Byrne and McCann 1995), are dynamic, and Sable Island is the sparrow’s only breeding site (apart from a few hybrid pairs on the mainland). Therefore, changes in habitat availability must be monitored and their causes understood. Concern over erosion of dunes worldwide has led to considerable experience with manipulations of dune habitat -- for example, through construction of barriers to wind-blown sand, revegetation, and exclusion or removal of grazing animals. There now is general recognition, however, that these efforts can backfire unless the dynamics of the particular site are well understood (Doody 2001). Thus, large-scale manipulation of habitat should be discouraged until habitat trends are better understood and their cause can be attributed to anthropogenic factors (see section 2.4, “Knowledge gaps”).

The protective status of the wintering range is complex and needs a thorough review that specifically focuses on Ipswich Sparrow habitat (for a general review, see Bernd-Cohen and Gordon 1998). Portions are protected under a variety of local, provincial, state, and federal designations -- for example, state or provincial parks, national wildlife refuges, national parks, and national seashores. Much of the range is under private ownership, however, where protection ranges from private refuges to a wide variety of state, provincial, and municipal regulations that affect dune habitat, especially dune erosion (Bernd-Cohen and Gordon 1998).

3.2.1 Monitor breeding population

Census the breeding population at appropriate intervals. As of the updated status report (Horn 1999), the number of Ipswich Sparrows nesting on Sable Island was thought to be, based on censuses conducted from 1967 to 1979 and in 1995, between 2100 and 3400, excepting dips to 1700 and 1250 birds in 1977 and 1978, respectively. A 1998 census, however, used more statistically rigorous methods to estimate a population of 5962 individuals (Smith et al. 2003). The large disparity between the estimates clearly throws doubt on our ability to accurately estimate the size and variability of the population.

An accurate and precise census method must be developed and then applied as needed until the population’s size and stability are confirmed. Censuses from 1967 to 1995 were done by flushing all birds within transects of varying size that contained representative habitat. Transects were chosen so that they could be easily recognized and be returned to from year to year, to allow even sampling of all habitats and precise estimation of yearly trends. Since sampling was not random, however, estimates may have been biased, and their variability could not be estimated (Smith et al. 2003). The 1998 census overcame this problem by randomly selecting count transects, but likely at the expense of representative, repeatable sampling.

Experience gained in these attempts and in successful grassland censuses elsewhere (e.g. Wiens 1985; Walters et al. 2000) should be applied to developing an improved census method for long-term modelling. Requisite features include 1) low year-to-year variance attributable to sampling error, 2) randomization that allows estimates of sampling error, and 3) estimation of observer error. Observer error can be measured by noting birds’ distance to transects during counts (Buckland et al. 1998), by repeatedly sampling some transects, and by censusing in areas where the true number of birds is known from territory mapping and banding studies (Walters et al. 2000).

These recommendations assume that transect flush counts will be used. Other methods should not be ruled out, but each has its drawbacks for this population. Specifically, point counts during singing season are the preferred method at some other study sites for surveying grassland sparrows (e.g. Curnutt et al. 1998), including Savannah Sparrows (e.g. Rotella et al. 1999). On Sable Island, however, the singing season is short (Reid and Weatherhead 1990), singing males are hard to hear in the windy conditions (pers. obs.), and the density of singing males may vary only weakly with population size (Reid and Weatherhead 1988). Mark–recapture banding programs can be highly accurate and yield valuable demographic information (Sillett and Holmes 2002), but they would require intensive effort across this sparrow’s particularly long breeding season.

Once a census method is developed, power analyses should be done to determine how often censuses must be performed if declines in the population are to be detected. Data on year-to-year variability in population size are needed to do this, as well as to estimate the risk of extinction through a chance downswing in numbers. Although the 1967–1979 censuses provide such data, recent indications that those data are unreliable (Smith et al. 2003) suggest that power analysis must await either a new series of yearly censuses or vindication of the earlier censuses. Population viability analysis (PVA) might then be applied to formally estimate the risk of extinction from variability alone, although infrequent catastrophes, such as storms, usually make PVA models overly optimistic for localized populations, even large ones (Pimm and Bass 2002).

3.2.2 Monitor breeding habitat

Estimate breeding habitat area and distribution. On the breeding ground, the area and distribution of vegetation across the island should be measured on a regular basis to detect changes across years. Aerial photography seems to be the most thorough and efficient way to do this (Freedman 1996; Desjardins 2002), although the use of satellite imagery to discern both vegetation (e.g. Mayer et al., no date) and topography (DeStoppelaire et al. 2001) should be explored. Certain habitats on Sable Island are difficult to discern from aerial photos (Z. Lucas, pers. commun.), so at first these surveys should be ground truthed. If the final design of the sparrow censuses (see section 3.2.1 above) requires or at least allows collection of data on vegetation distribution, such data might be used for ground truthing.

Surveys should be conducted often enough to detect not only changes in the total area of vegetated terrain, but also changes in the preponderance and continuity of low- and high-quality habitats for the sparrows -- marram- and heath-dominated terrain, respectively. A survey interval of 5–10 years, as recommended in the Sable Island conservation strategy (Beson 1998), seems realistic, given the high cost of surveys. It may also be adequate, because large-scale changes in habitat will presumably be slow. This interval should be reevaluated, however, as new data become available.

The Sable Island Preservation Trust is working with the Centre of Geographic Sciences (Nova Scotia Community College, Annapolis Valley Campus) to produce a digitized, georeferenced map that will greatly facilitate future censuses and vegetation surveys. A pilot comparison of aerial photos taken by this project in 2002 with provincial photos from 1996 and earlier data did not occur because of a funding shortfall; however, this project should be pursued (Desjardins 2002).

3.2.3 Examine conservation status of SableIsland

Strengthen legal protection of habitat.Sable Island is legally protected through the Sable Island Regulations of the Canada Shipping Act and the Migratory Bird Sanctuary Regulations of the Migratory Birds Convention Act, 1994. The former controls access to the island and regulates activities on it, while the latter prohibits disturbance of migratory birds and their nests. Neither protects habitat per se.

Critical habitat for Roseate Tern (Sterna dougallii) has been identified on Sable Island and will be protected under the Species at Risk Act. However, that critical habitat is centred on tern colonies and may only marginally overlap with Ipswich Sparrow habitat. Further steps should be taken to provide adequate protection.

3.2.4 Ensure regulatory compliance on SableIsland

Promote and ensure compliance with regulations on Sable Island. Sable Island’s isolation provides some protection, but its isolation will decrease as better and cheaper navigational aids make trips to the island easier. Most visits, whether project-related (e.g. maintenance of facilities, research) or more informal, are unlikely to affect the sparrow population. Nonetheless, they do carry a low risk of serious inadvertent or intentional damage to sparrow habitat -- for example, through fire, introduction of mammalian predators, or introduction of non-native plants. The latter two threats in particular have characterized the history of Sable Island’s biota.

Eliminating these threats requires close monitoring of all human activities on the island. Currently, visits to the island are very closely monitored. Except for persons in distress, permission to visit the island must be granted by the Canadian Coast Guard, to whom this authority was delegated by the Minister of Fisheries and Oceans Canada, pursuant to the Canada Shipping Act. All visitors are briefed on environmental protocol upon arrival and monitored throughout their visit by year-round resident staff.

3.2.5 Ensure precautionary approach to projects with potential impacts on Ipswich Sparrows

Critically examine projects for potential effects on Ipswich Sparrows and their habitat. Review of project proposals should always consider the potential for interactions with the Ipswich Sparrow and its habitat. Through application of environmental assessment processes, project alternatives should be identified, potential impacts avoided or minimized, uncertainties investigated, impact predictions verified, and mitigation effectiveness tested, taking into account the goals, objectives, and actions set out in the management plan. Throughout the breeding, migration, and wintering range of the Ipswich Sparrow, attention should be given to any project or activity that could result in 1) the loss or alteration of habitat, 2) the introduction of predators to Sable Island, or 3) direct mortality (e.g. collision with vertical structures, spills). A focus should be placed on assessing risk to habitat on Sable Island and ensuring that the management objective of maintaining available breeding habitat is respected.

Multiple projects and activities may have cumulative effects that are undetectable in the short term. Therefore, it is important that decisions on proposed projects that could interact with the Ipswich Sparrow and its habitats be informed by application of the precautionary principle, a consideration of potential contributions to cumulative effects, and a consideration of mitigation measures that could be taken to avoid or minimize adverse effects, including alternative means of carrying out the project. After a consideration of such factors, any approval that may be granted so as to allow a project to proceed should be accompanied by the requirement for an effects monitoring or follow-up program that is undertaken by personnel experienced with the Ipswich Sparrow and is sensitive enough to detect subtle cumulative effects.

3.2.6 Conserve wintering IpswichSparrows and their habitat

Collaborate with U.S. authorities to identify Ipswich Sparrow as a priority species. The North American Bird Conservation Initiative (NABCI) is a coalition of government, academia, private organizations, and industry in Canada, the United States, and Mexico. The objective of NABCI is to advance bird conservation through evaluation, planning, and implementation. NABCI divides North America into Bird Conservation Regions (BCR) and assesses the conservation priority of species in each region.

The Ipswich Sparrow is listed as a “highest priority” landbird species in BCR 14 (Dettmers 2003), the region in which it breeds as well as winters in small numbers. Wintering Ipswich Sparrows are not currently addressed in either BCR 27 or BCR 30, regions that cover the vast majority of their wintering range. To identify and promote actions that will benefit wintering Ipswich Sparrows, discussions with planning personnel from BCR 27 and BCR 30 should occur.

The size of this bird’s breeding range is dwarfed by its wintering range, suggesting that the wintering population is spread thinly across the eastern seaboard. Within that range, however, the bird appears to have specific habitat requirements that have not been adequately assessed. Also, islands off Virginia may host the bulk of the wintering population, but have never been formally searched (Stobo and McLaren 1971). Interest in counting Ipswich Sparrows in winter has stayed low since the bird’s relegation to subspecies status (McLaren 1979); CBC totals remain low and hence unreliable (Horn 1999).

Repeat winter survey. The survey of Stobo and McLaren (1971) should be repeated, with the improvements they suggest -- namely, more objective assessment of habitat associations and formal surveys of the islands off Virginia. A study of the behaviour and ecology of the bird on its wintering grounds would be invaluable for understanding its habitat needs and thus choosing appropriate management options. Both tasks would of course be easier with the participation of university or government researchers from the mid-Atlantic states.

Changes in wintering habitat should also be monitored, but this will first require better identification of that habitat than we currently have. As a preliminary step, a literature search of data on dune habitat trends along the east coast of North America would be an invaluable tool for deciding whether protection of winter habitat should be a management priority.

3.2.7 Implement education and communication programs

Engage public and media. Public support for protection of Sable Island and especially wintering habitat will aid management efforts. The Ipswich Sparrow, as one of Canada’s only endemic songbirds, adds to the appeal of Sable Island as a special place for Canada. Publicizing this fact will be beneficial for public and, in turn, political and financial support of conservation of Sable Island and the sparrow. Interest in this particular bird may translate directly into better estimates of winter population trends and distribution, as more birders seek them out during CBCs. Interest and awareness can be increased via public talks, web postings, pamphlets, and feature articles, both in Canada and along the Atlantic seaboard. The Canadian Wildlife Service and researchers at Dalhousie University have conducted periodic radio and TV interviews and public lectures on Ipswich Sparrows, although no formal campaign has been launched.

3.3 Recommended approach/scale for managing the species

Ipswich Sparrows use a variety of habitats on Sable Island, so their conservation is consistent with conservation of the island as a whole but not coincident with management of any single habitat. Also, their combined need for the island for breeding and the entire Atlantic U.S. coastline for wintering is unique and requires an approach that targets the population, rather than the habitat or species associated with it.

3.4 Evaluation

Management will be successful over the long term if the breeding population and both breeding and wintering habitats remain stable. Evaluation of management success will be through long-term monitoring programs that assess trends in breeding habitat and breeding population size. Any indication that breeding habitat, especially heath habitat, is declining should trigger immediate reassessment of the management needs of the sparrow and the island. Ipswich Sparrow management should be part of an integrated management plan for the island.

3.5 Summary table: management strategies

Priority¹	Objective	Section	Management action	Specific steps	Outcomes or deliverables
High	i	3.2.1	Monitor breeding population	Census the breeding population at appropriate intervals	Determine population trends and detect changes
Moderate	ii	3.2.2	Monitor breeding habitat	Estimate breeding habitat area and distribution	Detect breeding habitat changes
Moderate	ii/iii	3.2.3	Examine conservation status of Sable Island	Strengthen legal protection of habitat	Protect breeding habitat
High	All	3.2.4	Ensure regulatory compliance on Sable Island	Promote and ensure compliance with regulations on Sable Island	Minimize disturbance to breeding birds and breeding habitat
High	All	3.2.5	Ensure precautionary approach to projects with potential impacts on Ipswich Sparrows	Critically examine projects for potential effects on Ipswich Sparrows and their habitat	Minimize disturbance to birds and habitat Protect birds and habitat
Low	ii/iii	3.2.6	Conserve wintering Ipswich Sparrows and their habitat	Collaborate with U.S. authorities to identify Ipswich Sparrow as a priority species Repeat winter survey	Determine necessary winter habitat Protect winter habitat
Low	All	3.2.7	Implement education and communication programs	Engage public and media	Increase awareness

¹Priorities are defined as follows: High = top priority action, without which population may decline irreversibly; Moderate = required to evaluate and guide recovery actions; Low = all other actions necessary to provide for survival.

3.6 Implementation schedule

Shaded boxes indicate the proposed year(s) of implementation.

Specific steps	Section	Lead¹	Other¹	2005
Census the breeding population at appropriate intervals	3.2.1	CWS	University	Specifically, develop census method, which will dictate timing of future surveys
Estimate breeding habitat area and distribution	3.2.2	CWS	COGS SIPT
Strengthen legal protection of habitat	3.2.3	CWS
Promote and ensure compliance with regulations on Sable Island	3.2.4	CWS MSC DFO		Ongoing
Critically examine projects for potential effects on Ipswich Sparrows and their habitat	3.2.5	CWS EPB		Ongoing
Collaborate with U.S. authorities to identify Ipswich Sparrow as a priority species	3.2.6	CWS	U.S. agencies NABCI
Repeat winter survey	3.2.6	U.S. agencies NABCI	CWS	To be determined
Engage public and media	3.2.7	Various

¹ Acronyms are as follows:

COGS: Centre of Geographic Sciences, Nova Scotia Community College, Annapolis Valley Campus

CWS: Canadian Wildlife Service, Environmental Conservation Branch, Environment Canada

DFO: Department of Fisheries and Oceans

EPB: Environmental Protection Branch, Environment Canada

MSC: Meteorological Service of Canada, Environment Canada

NABCI: North American Bird Conservation Initiative

SIPT: Sable Island Preservation Trust

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