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Roseate Tern (Sterna Dougallii)

Schedule of studies to identify remaining critical habitat

Identify key characteristics that make potential nesting sites attractive to Roseate Terns

It is widely accepted that the key habitat feature for breeding Roseate Terns is the presence of breeding Common Terns (Gochfeld et al. 1998). Therefore, the health of colonies of Common Terns (and, in eastern Canada, Arctic Terns) is key to the recovery of Roseate Terns. Characteristics of colonies where Roseate Terns have bred in the past, particularly as they relate to the size and distribution of colonies of other species of terns, may help determine which sites could support Roseate Terns in the future. This would help identify potential sites for restoration and sites where Roseate Terns could relocate should existing Roseate Tern colonies be impacted by events such as predation or erosion. If the number of suitable sites is limited then they may warrant identification as critical habitat.

·       Studies to investigate the relationship between Roseate Tern nesting and the size and distribution of colonies of other species of terns will be completed before 2007.

Identify foraging habitat at secure colonies

At several colonies in the US, Roseate Terns forage at only a few sites. More than one colony may share a single foraging site; for example, 20-25 % of the US population forages at one shallow water site (Nisbet and Spendelow 1999). The foraging sites of Roseate Terns at Canadian colonies may also be localized and thus vulnerable, but their locations are unknown. Work on foraging habitat was initiated by the Canadian Wildlife Service and Dalhousie University in 2003 (A.W. Boyne pers. comm.). If consistent foraging areas are found, the features that distinguish them from similar, but unused, areas should be determined, to see whether foraging sites are limited and whether any management, especially protection, is possible or required.

·       Studies to investigate Roseate Tern foraging habitat were initiated in 2003. An evaluation of the need to identify foraging areas as critical habitat will be completed by 2009.

Identify transit and resting habitat beyond colonies

Other important aspects of habitat use away from colonies are still poorly understood, particularly the location of transit, roosting and foraging areas used by non-breeding birds. Due to the small Canadian population it is not currently feasible to implement directed studies on transit or resting habitats for Roseate Terns, however if additional information is collected the necessity of designating critical habitat at these sites will be evaluated. Sightings of Roseate Terns away from known colonies should be recorded in a single database that includes information such as the number, behaviour, and age of birds, together with time of year, time of day, and time of tide cycle. Teams can then revisit these sites to confirm the presence of the species and nature of the use of the habitat. If areas are located, the features that distinguish them from similar, but unused, areas should be determined, to see whether they are limited and whether management can or should be attempted.

·       Due to the small Canadian population, it is not currently feasible to implement directed studies on transit or resting habitats for Roseate Terns.

Protect habitat

Actions completed or underway

Since the last Recovery Plan was written, there have been rapid expansions in recreational and commercial use of coastal habitat. Thus, special efforts are needed to maintain the safety of existing colonies and to ensure that all necessary habitats, especially restored colonies, are undisturbed.

As per section 58(5) of SARA, within 180 days after posting the final version of this recovery strategy, the Minister of the Environment will make an order to protect critical habitat on Country Island, now administered by the Department of Fisheries and Oceans. The key colony on The Brothers Islands has been acquired by the Nova Scotia Department of Natural Resources and will be designated a Wildlife Management Area. As per section 58(2) of SARA, within 90 days after posting the final version of this recovery strategy, the Minister of the Environment will publish in the Canada Gazette a description of the critical habitat that is on Sable Islands, a Migratory Bird Sanctuary. Ninety days after that description is published, prohibitions on critical habitat destruction will apply to that critical habitat.

Several other nesting locations have or will soon have some form of designation, for example as Migratory Bird Sanctuaries (e.g., Machias Seal Island, NB), Wildlife Management Areas (e.g., Grassy Island, NS [candidate area] and Pearl Island, NS), or Important Bird Areas (e.g., The Brothers, NS).

The Roseate Tern is currently protected under the Migratory Birds Convention Act, 1994, the Nova Scotia Endangered Species Act (1996), and the federal Species at Risk Act (2002). The Québec Advisory Committee on Threatened or Endangered Species recommended in November 2002 that the Roseate Tern be designated as Threatened (equivalent to Endangered by COSEWIC) under the « Loi sur les espèces menacées ou vulnérables ». As a result the Roseate Tern should be officially designated in Québec in 2006.The Roseate Tern currently appears on the« Liste des espèces de la faune vertébrée susceptibles d’être désignées menacées ou vulnérables ».

Actions to be initiated

Designate and secure colony sites

Colony sites should, wherever possible, be acquired and designated appropriately as Migratory Bird Sanctuaries, National Wildlife Areas, Wildlife Management Areas (Nova Scotia) or Wildlife Habitat (Québec). The Important Bird Areas program can be used to formalize public recognition of the value of particular sites, although this first step must be followed up with designations that provide legal protection. Tern colonies may shift location from year to year, so designation should encompass several alternative nesting sites nearby where the terns may relocate (e.g., not just an individual island, but also its surrounding archipelago).
Develop local site-specific plans for protection from human disturbance

Terns can habituate to regularly repeated diurnal visits to colonies, as happens at colonies with ongoing research programs (Nisbet 2000). Well-managed, systematic visits by researchers and guardians may have a positive impact on Roseate Terns, as these visits may deter gulls from nesting in the colony and promote habituation to human presence, which could mitigate unforeseen disturbances and provide an environment conducive to research. However, uncontrolled, infrequent visits to colonies by humans or pets flush adult terns from their nests, which can cause nest failure because of cooling or predation of eggs and young. Such disturbance can also cause abandonment of the colony, especially early in the nesting period (Gochfeld et al. 1998). Activities may not be directed at the terns and may be inadvertent, but if prolonged could possibly be devastating. Legislation on interference with nesting birds (e.g., on Wildlife Management Areas and Migratory Bird Sanctuaries) does not necessarily offer adequate protection against such disturbance, unless there is adequate enforcement.

For all colonies, site-specific plans to discourage disturbance should be formalized in writing and reviewed annually, in consultation with landowners and local residents, whenever possible. All these plans must include provision for some form of on-site staff (these could be in the form of researchers or local stewards) and education (e.g., information boards, pamphlets). Signage and ‘symbolic’ fencing may be useful where it would not be resented or attract vandals. Policies should take into account that actions taken against traditional uses of particular islands (e.g., camping or picnicking) may be resented and counter-productive if they are not part of an integrated plan that includes landowner and community participation.

Although no formal protection is yet in place under the Species at Risk Act, the marine components of the critical habitats identified within this strategy are currently managed or subject to management practices which benefit the protection and recovery of Roseate Terns.  For instance, the oil and gas industry has established a moratorium on oil and gas exploration and development on or within one kilometre of Sable Island.  Traditional fishing practices undertaken in the vicinity of Country and the Brothers Islands have not been observed to affect Roseate Terns but plans for reviewing changes to these activities in terms of their impacts on Roseate Terns will need to be developed.


Site-specific plans for protection from human disturbance should be supported where possible by enforcement. Despite protective legislation, obtaining the information needed to enforce the legislation is difficult. Management agencies should provide the stewards of every colony with the information and actions that are needed to collect evidence required for successful prosecution of infringements of legislation protecting terns. Appropriate enforcement agencies near each colony should be prepared to act quickly in case of such infringements.

Identify limiting factors at managed colonies

Actions to be initiated

The factors that limit productivity at colonies free of predation are not clear, but must be understood if reproductive success is to be enhanced. Nisbet and Spendelow (1999) make the point that the integration of research and management actions should occur at the outset of a project because it takes time for research to provide the results that are necessary to implement an appropriate management program. Researchers also act as de facto stewards and guardians.  Factors to consider include parental quality, foraging opportunities, sex ratio, nest site availability, overcrowding, competition for nest sites or foraging areas with Common or Arctic Terns, and the effect of winter mortality on the return rates of adults (Gochfeld et al. 1998).

Monitor threats

Rapid natural and anthropogenic changes, especially in coastal regions, may place all recovery objectives at risk if they are not monitored. Potential threats include poaching in the wintering areas, displacement and predation by gulls, recreation activities, changes in food abundance, and currently unforeseen events.

Actions completed or underway

Monitor gull population and distribution

Gull numbers and distribution around Country Island were mapped in 1998-2000, and some gulls were marked to trace their movements (Smith et al. 2000). Gull surveys were conducted for Nova Scotia and the Magdalen Islands in 2002. This work should continue and similar projects should be started at other colonies, especially where gull discouragement programs are planned or underway.

Monitor recreational use of existing and potential colony sites

The Bluenose Atlantic Coastal Action Program is assembling these data for the islands in Mahone Bay (Boyne 1999); similar efforts should be undertaken elsewhere.

Monitor changes in food sources

Foraging watches at Country Island have assessed the diet of Arctic and Common Terns but the data for Roseate Terns are poor (e.g., Boyne et al. 2001a). More detailed observations occurred on Country Island in 2003 and will be continued (J. Rock, pers. comm.). Preliminary foraging observations started at The Brothers in 2001 (D'Eon 2001) should continue and be quantified if possible. No attempt has been made to integrate information on food distribution and abundance with habitat use or reproduction by Roseate Terns.

Determine risk of singular events and devise contingency plans

Risks to seabirds from shipping lanes and petroleum activities have been mapped (A.R. Lock pers. comm.) but need to be integrated with information on tern habitat use as it becomes available. Ring-billed (Larus delawarensis) and Laughing Gulls (L. atricilla) may be extending their breeding range into this region (Boyne et al. 2001b; Boyne and Hudson 2002; Taylor et al. 2002) and their spread should be watched carefully for its effect on tern colonies.

Mortality on wintering grounds

Canadian research and management efforts have, so far, been limited to Canadian breeding sites.

Actions to be initiated

Monitor gull population and distribution

The increase and spread in Herring (L. argentatus) and Great Black-backed Gull (L. marinus) populations throughout the northeastern North American Atlantic coast in the early 20th century have been attributed partly to increased refuse from fisheries and landfills (Kadlec and Drury 1968). Conversely, a significant decline in number and reproductive success of Herring Gulls, and a possible decline in Great Black-backed Gulls, late in the century may be attributable to a decline in fisheries and to improved landfill practices (Mawhinney et al. 1999; Boyne and Hudson 2002). If these declines are real, then recovery of tern populations may ensue, especially in areas where these changes in practices are proceeding particularly quickly.

However, concomitant with declines in larger gull species is an increase in smaller gulls. Ring-billed Gulls are expanding in the Gulf of St. Lawrence (Lock 1988; Boyne et al. 2001b; Boyne and Hudson 2002), and Laughing Gulls have nested at two sites in eastern Canada for the first time in over a half century (Taylor et al. 2002). In Maine, where the species has increased dramatically at several sites, Laughing Gulls are having a negative effect on tern colonies through both predation and displacement from breeding habitat (Kress and Hall 2004). If these populations continue to increase the impact could be significant. The expansion and associated predation on terns by Ring-billed Gulls and Laughing Gulls should be monitored.

On a broad scale, historic seabird census data should be compared to data on fish plant and landfill practices to see whether there is any correlation between changes in these practices and changes in gull and tern distribution. At selected field sites, especially those near key colonies, more data should be collected on resource use, home range size, and determinants of reproductive success of gulls, with the specific aim of identifying places where changes in land use practices would reduce the number of gulls at tern colonies. If actions are implemented that affect a local gull population, efforts should be made to determine the pathway through which the gulls are impacted, and whether they move and become a problem elsewhere.

Monitor recreational use of existing and potential colony sites

Recreational use of coastal habitats probably is increasing, but is poorly monitored and managed. Available data on recreational use of islands (e.g., from recreational groups, tourism bureaus, tour companies) should be assembled and compared to the distribution and tenure of colonies. Attitudes towards control of recreational use near colonies should be assessed and incorporated in local management plans.

Monitor changes in food sources

For Roseate Tern colonies that are free of heavy predation, reproductive success probably is limited by food abundance and availability. The foraging ecology of Roseate Terns in Canada is poorly understood and should be monitored wherever possible. Information on distribution of the small fish most likely taken by the terns should be included in analyses of tern foraging areas. Potential conflicts with fishing or commercial developments (e.g., aquaculture, pipelines) can then be better assessed. Note that effects of declines in adult fish, for example due to fishing, seals, or climate change, may originate in areas far removed from tern colonies, and may take a few years to trickle down to the younger cohorts of fish that terns prey upon (Amey 1998). Where possible, these more distant events should also be monitored, even though the precise spatial and temporal scales that are relevant to the terns are difficult to define in advance.

Determine risk of singular events and devise contingency plans

Sudden, unexpected threats to terns may include severe storms (Hatch et al. 1997; Spendelow et al. 2002; Lebreton et al. 2003), disease, spills of petroleum or other toxins, unanticipated declines in prey species, or range expansions of new predators. Little can be done to prevent some of these events, but the likelihood that they will occur in any given area can be mapped and then used in selecting sites for restoring colonies and in formulating contingency plans for each colony site. Use of the oceans in the Maritime Provinces is changing rapidly, so these risk assessments should be updated regularly.

Mortality on wintering grounds

Most annual adult mortality occurs on the wintering grounds, but distribution and ecology in wintering areas are poorly understood (Nisbet and Spendelow 1999). Adult mortality is a key threat, so efforts to reduce it contribute directly to recovery of the Canadian population. The Canadian Recovery Team should explore possibilities for international collaborations that will identify and eliminate threats to wintering terns.

Improve decision-making and planning

Actions completed or underway

Planning and decision-making which influences human activities in the coastal zone can have significant implications for the health and recovery of the Roseate Tern.  The review of project proposals should always consider the potential for interactions with the Roseate Tern, especially along the east coast of Nova Scotia, the Bay of Fundy and the Magdalen Islands. Examples of project types typically proposed and reviewed in these coastal regions are marinas, ports, docks, wharves, boat launches, small craft harbours, wastewater treatment plants and outfalls, trails, aquaculture, wind turbines, and oil and gas exploration and development.  Related activities include infilling, drilling, dredging, disposal at sea, vessel traffic, waste disposal, and human presence.

Particular attention is required in reviewing project proposals that include, or can lead to, any activities that directly or indirectly impact critical habitat. Review processes, which make provision for early attention to potential impacts on the Roseate Tern, can help secure and advance the recovery goal and objectives.  For example, through application of, and involvement in, federal or provincial environmental assessment processes, project alternatives can be identified, potential impacts avoided or minimized, uncertainties investigated, recovery initiatives supported, impact predictions verified and mitigation effectiveness tested.

Initiation of three major commercial projects near key colony sites in the last decade underscores the importance of strongly advocating precautionary approaches and sensitive monitoring programs.

  1. Concerns were raised during public review of the Sable Offshore Energy Project, an offshore gas extraction project, that laying pipeline 5 km from Country Island would negatively affect Roseate Terns nesting there (Joint Public Review Panel 1997). Assurances that pipe laying would not occur during the breeding season were not met, so a monitoring program was conducted that did not detect any ill effects (Paquet et al. 1999).
  2. The same project review was assured that support flights for offshore rigs near Sable Island would avoid disturbing terns and other wildlife on the island, and this assurance has been met (Horn and Shepherd 1998).
  3. The Recovery Team was unable to influence the placement of an aquaculture project 250 m from The Brothers. The project apparently did not attract gulls or otherwise disturb the terns, as some members of the public had expected (T.C. D’Eon pers. comm.). However, its effects may have been mitigated, both because a steward (T.C. D’Eon) was attending the colony and because the project was small in scale and was dismantled in 1999 after only a few years of operation. The rate at which aquaculture operations are being established in the Atlantic region is still a concern.

Actions to be initiated

Ensure a precautionary approach to commercial development near important habitat

Activities in the coastal zone, including development of marine resources, are intensifying in Atlantic Canada, and the effects on Roseate Terns may be difficult to foresee.  For example, aquaculture or pipeline trenching may pose significant threats, even if they do not affect local fish populations overall, but only reduce them in areas where the terns forage.  Also, 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 Roseate Terns and their 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 considering 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 Roseate Tern, and is sensitive enough to detect subtle cumulative effects.

Develop and maintain linkages

Actions completed or underway

The Canadian Roseate Tern Recovery Team should coordinate its efforts with those of the US recovery team and with the Gulf of Maine Seabird Working Group (GOMSWG). The Atlantic Canada Tern Working Group (ACTWoG) was reactivated after a hiatus of several years, and has met yearly since 1998. Its chair also attends meetings of the GOMSWG and coordinates the activities of the two groups. The Canadian Roseate Tern Recovery Team has met more irregularly; yearly meetings are essential. The team also met with the US Roseate Tern Recovery Team in 2001, and plans to continue to do so on a regular basis. A member of the Canadian Recovery Team spent three weeks working with Brazilian and American biologists on the wintering grounds in Brazil in 2003 (A. W. Boyne pers. comm.). Further coordination with conservation efforts on the wintering grounds should be explored, especially since this is where most mortality limiting the population probably occurs (Nisbet and Spendelow 1999). Regional efforts within Canada should be coordinated through yearly meetings of the Canadian recovery team and ACTWoG. In turn, both of these organizations should, where possible, coordinate their efforts with any coastal and marine conservation management plans and programs that are relevant to tern habitat (e.g., those listed under 1.4 Existing management opportunities, below), as well as with stakeholders from industry and other interest groups.

Address sociopolitical issues

Actions completed or underway

Public support for tern recovery, enforcement of habitat protection, and coordination of recovery partners are all critical to the success of the Recovery Strategy.

New funding for collaborative approaches to tern restoration is being used to support new tern research and/or management programs at several sites, for example, Sable Island (Atlantic Coastal Action Program (ACAP) Science Linkages), Mahone Bay (Bluenose ACAP), The Brothers (IBA) and Country Island (IBA, World Wildlife Fund Endangered Species Recovery Fund).

Interpretive signs have been set up near Paquet Island, Québec, The Brothers, NS, and near Westhaver Island, NS, a former colony site (Gregoire 2000; D’Eon 2001; F. Shaffer pers. comm.). The Canadian Wildlife Service and researchers at Dalhousie University have also conducted periodic radio interviews and public lectures, and the Canadian Wildlife Service produced a booklet and video ("Hinterland Who's Who") about Roseate Terns. On the Magdalen Islands, the non-government group Attention Fragîles has informed the public about terns through various means, including posters, post cards, mascots, and school programs.

Public education and consultation on lethal gull control at Sable Island were initiated by the Canadian Wildlife Service in 1993. The control program nevertheless met some public resistance and as a result was cancelled (Whittam 1999). This experience, and similar experiences in the US (Nisbet and Spendelow 1999), should be used in planning future gull control.

Actions to be initiated


Full advantage should be taken of these new opportunities for local conservation management (see 1.4 Existing management opportunities, below) by advertising and explaining these opportunities, by encouraging active participation, and by offering financial and logistic support.

Education and awareness

Public support for tern conservation should be enhanced, not only to encourage compliance with protective policies, but also to engage the public in stewardship. Public talks, web postings, pamphlets, and feature articles should be used to increase public pride and interest in Roseate Terns, encourage political and financial support of conservation efforts, advertise protective policies, and solicit information on tern sightings and potential threats to conservation. The fishing industry, particularly fishermen operating near Roseate Terns, would be a key target audience.


Existing management opportunities

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A handbook of tern management techniques was prepared by the National Audubon Society for USFWS, with Canadian input (Kress and Hall 2004), and terns are included in the North American Waterbird Conservation Plan (Kushlan et al. 2002) and Wings Over Water: Canada’s Waterbird Conservation Plan (Milko et al. 2003).

Many new organizations and funding sources have appeared in Atlantic Canada since the previous recovery plan was written. Full use should be made of these new opportunities, especially those that encourage collaborative efforts among private, public, and government stakeholders to conserve terns. Examples include federal funding that promotes habitat stewardship (Species at Risk Habitat Stewardship Program) and non-profit groups that acquire lands (e.g., Nova Scotia Nature Trust) or aid inventory and monitoring (e.g., Bird Studies Canada, Atlantic Canada Conservation Data Centre) for conservation.


Potential management impacts on other species

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Roseate Terns preferentially settle in large colonies of other species of terns, so any management options that increase the number and size of tern colonies in general are likely to be beneficial for all species of terns, and perhaps also for other co-habiting species such as Leach’s Storm-petrels (Oceanodroma leucorhoa), Least Sandpipers (Calidris minutilla), Common Eiders (Somateria mollissima), Black Guillemots (Cepphus grylle) and Atlantic Puffins (Fratercula arctica). Roseate Terns are far out numbered by Common Terns, however, enhancement of the denser nest sites that Roseate Terns prefer, if it is done where Common Terns normally nest, may reduce nesting area for Common Terns.

Discouragement of gulls in the vicinity of tern colonies may reduce their reproductive success locally, but, given their abundance and wide distribution, is unlikely to affect gull populations overall.


Development of Action Plans

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Roseate Terns currently nest in only two jurisdictions in Canada (Québec and Nova Scotia), with sporadic nesting records from New Brunswick. Over 95% of the Canadian population nests in one jurisdiction, Nova Scotia, and as a result the Recovery Team is small, with only six members. Therefore, it is felt that Recovery Implementation Groups (RIGs) are not needed, as the strategy will be implemented by the entire team. The Recovery Team currently foresees the need for an Action Plan which will specifically outline how the Recovery Strategy will be implemented, by whom, and when. This Action Plan will be completed within one year of posting the Recovery Strategy.

A second Action Plan will be prepared in conjunction with Environment Canada – Atlantic Region’s environmental assessment program detailing how proposed projects should be assessed in terms of predicting, mitigating and verifying effects on Roseate Terns taking into account the recovery goal and objectives.  A focus will be placed on project sectors and activities most likely to interact with the Roseate Tern and its habitat (e.g., oil and gas, small-craft harbours, dredging, wind energy, recreation). The guidance will be directed primarily at government departments and project proponents responsible for environmental assessments and reflect mandatory requirements to consider species at risk under the Canadian Environmental Assessment Act (CEAA) and the Species at Risk Act.  Guidance will also be premised on the need for recovery strategies and action plans to be respected (s. 2, CEAA) and the need for federal authorities “…to exercise their powers in a manner that protects the environment and human health and applies the precautionary principle” (s. 4 [2], CEAA).  The guidance will offer best management practices that have broad applicability to any project or activity that may interact with the Roseate Tern, but may not be subject to a formal environmental assessment or review process.  This Action Plan will be completed within two years of posting the Recovery Strategy.

As more research is conducted on foraging habitat and other non-breeding habitats, additional Action Plans to identify critical habitat may be required. Research on foraging habitat near Country Island will be completed in 2005-2006. It will not be clear whether or not there will be foraging habitat that is deemed “necessary for the survival or recovery of the species” until this research is completed. Due to the small Canadian population it is not currently feasible to implement directed studies on transit or resting habitats for Roseate Terns, however if additional information is collected the necessity of designating critical habitat at these sites will be evaluated at annual Recovery Team meetings.

The need for additional Action Plans will be evaluated at annual Recovery Team meetings.