CANADIAN MANAGEMENT PLAN
for the
IVORY GULL
(Pagophila eburnea)
Prepared by
Iain J. Stenhouse
Cognitive & Behavioural Ecology Programme
Memorial University of Newfoundland
St. John’s, NL, A1B 3X9
June 2004
Canadian Ivory Gull Management Plan
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Recommended Citation: Stenhouse, I.J. (2004) Canadian management plan for the Ivory Gull
(Pagophila eburnea). Canadian Wildlife Service, St. John’s, NL.
Canadian Ivory Gull Management Plan
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Contributors to this plan:Iain J. Stenhouse
Postdoctoral Fellow
Cognitive & Behavioural Ecology Programme
Memorial University of Newfoundland, St. John’s, NL, A1B 3X9
H. Grant Gilchrist
Research Scientist
Canadian Wildlife Service – Prairie & Northern Region
National Wildlife Research Centre
Carleton University, Ottawa, ON, K1A 0H3
Mark L. Mallory
Seabird Biologist
Canadian Wildlife Service – Prairie & Northern Region
P.O. Box 1714, Iqaluit, NU, X0A 0H0
Gregory J. Robertson
Research Scientist – Marine Birds
Canadian Wildlife Service – Atlantic Region
6 Bruce Street, St. John’s, NL, A1N 4T3
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Responsible Jurisdictions
Environment Canada:
Canadian Wildlife Service – Prairie & Northern Region
Rm 200, 4999-98 Avenue
Edmonton, AB T6B 2X3
Contact: Grant Gilchrist
Tel: (613) 998-7364, E-mail: grant.gilchrist@ec.gc.ca
or
Mark Mallory
Tel: (867) 975-4637, E-mail: mark.mallory@ec.gc.ca
Canadian Wildlife Service – Atlantic Region
6 Bruce Street
Mount Pearl, NL A1N 4T3
Contact: Greg Robertson
Tel: (709) 772-2778, E-mail: greg.robertson@ec.gc.ca
Service canadien de la faune – Québec Region
1141 Route de l’Église
C.P. 10100
Sainte-Foy, QC G1V 4H5
Contact: Jean-François Rail
Tel : (418) 648-4001, E-mail : jean-francois.rail@ec.gc.ca
New Brunswick:
Department of Natural Resources
Government of New Brunswick
P.O. Box 6000
Hugh John Flemming Forestry Complex
Fredericton, NB E3B 5H1
Contact: Maureen Toner
Tel: (506) 453-2440, E-mail: maureen.toner@gnb.ca
Newfoundland & Labrador:
Department of Environment and Conservation
Inland Fish and Wildlife Division
Government of Newfoundland and Labrador
P.O. Box 2007
Corner Brook, NL A2H 7S1
Contact: Isabelle Schmelzer
Tel: (709) 637-2051, E-mail: IsabelleSchmelzer@gov.nl.ca
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Northwest Territories:
Wildlife and Fisheries Division
Department of Resources, Wildlife and Economic Development
Government of the Northwest Territories
Scotia Centre, 5th Floor, 600-5120 50th Avenue
Yellowknife, NT, X1A 3S8
Contact: Suzanne Carrière
Tel: (867) 920-6327. E-mail: Suzanne_Carriere@gov.nt.ca
Nova Scotia:
Wildlife Division
Department of Natural Resources
Government of Nova Scotia
Provincial Building
136 Exhibition Street
Kentville, NS B4N 4E5
Contact: Sherman Boates
Tel: (902) 679-6146, E-mail: boatesjs@gov.ns.ca
Nunavut:
Department of Sustainable Development
Government of Nunavut
PO Box 120
Arviat, NU, X0C 0E0
Contact: Michael Setterington, Ecosystem Monitoring Biologist
Prince Edward Island:
Department of Environment and Energy
Government of Prince Edward Island
11 Kent Street
Charlottetown, PE C1A 7N8
Contact: Rosemary Curley
Tel: (902) 368-4807, E-mail frcurley@gov.pe.ca
Yukon:
Department of Environment, Fish and Wildlife Branch
Government of Yukon
P.O. Box 2703
Whitehorse, YT Y1A 2C6
Contact: Thomas Jung, Senior Biologist
Tel: (867) 667-5766 E-mail: tom.jung@gov.yk.ca
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Disclaimer
This management plan was written when the species was assessed as special
concern by COSEWIC. This document is considered by Environment Canada as
a technical document that would support the drafting of a recovery strategy
should the species be updated on the List of Wildlife Species at Risk by the
federal government. Consultations with Wildlife Management Boards have not
yet taken place.
This management plan does not necessarily represent either the official positions
of agencies or the views of individuals that were involved in its preparation. The
recovery goal and objectives are based on the best existing data and are subject
to modification resulting from new information. The working group recognizes
that the implementation of the plan, and recovery activities in general, will be
subject to the priorities and budgetary constraints of the participating jurisdictions
and organizations.
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Acknowledgements
This document is a reflection of the careful and considered opinions of the entire
Canadian Ivory Gull Working Group. We sincerely thank Kevin Davidson, Kim
Mawhinney and Neil Burgess, of the Canadian Wildlife Service – Atlantic Region,
for their valuable comments and advice. We also thank Suzanne Carrière, Gilles
Chapdelaine and Maureen Toner for their input and Myra Robertson for making
the maps. Hallvard Strøm and David Boertmann provided information on the
legislative status of Ivory Gulls in Norway and Greenland, respectively.
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Species Information
Common name: Ivory Gull
Scientific name: Pagophila eburnea
Current status: Special Concern
Date of assessment: November 2001
Reason for designation: Relatively rare species with few breeding colonies,
potential threats from human disturbance and oil spills.
Occurrence: YT, NT, NU, NL
Status history: Designated a species of Special Concern in 1979 (MacDonald
& Cooper 1979). Status re-examined and confirmed in April 1996, and again in
November 2001, based on an updated status report (Alvo & MacDonald 1995).
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Executive Summary
The Ivory Gull (Pagophila eburnea) is a medium-sized gull that breeds in the
High Arctic, and is the sole representative of its genus. It is pelagic for much of
the year, wintering in cold northern waters, and is associated with pack ice year
round. It is currently listed as a species of Special Concern under the federal
Species at Risk Act (SARA). However, recent breeding colony surveys suggest
that Ivory Gulls have declined by up to 85 % in Canada since the 1980s.
While little is known about the anthropogenic activities that may affect Ivory Gulls
in Canada, potential threats that may be contributing to mortality include hunting,
disturbance, habitat degradation, and oiling. However, identifying and addressing
potential threats is extremely difficult, due to the lack of information on the
species’ breeding biology, winter ecology, life history and behaviour, as well as a
lack of information on the extent of the threats themselves.
The management plan outlines specific measures that can be taken to increase
knowledge and promote the recovery of Ivory Gulls in Canada. The long-term
recovery goal is to restore “the Canadian breeding population to historic levels
and to expand the breeding range to historically occupied areas”. The objectives
aim to:
1) maintain Ivory gull colonies currently in existence and prevent further
loss,
2) identify and understand the threats to Ivory Gulls in Canada, with a
focus on anthropogenic activities,
3) acquire further knowledge to understand the life history characteristics
of the species,
4) identify and protect critical habitat,
5) educate stakeholders and the general public on ways to support
recovery, and
6) work collaboratively at an international level to further recovery.
A major challenge in the recovery of Ivory Gulls is the scarcity of information
regarding the species’ general ecology. As additional information is collected,
however, the goals and objectives of the plan will be adapted and improved, and
the potential to achieve the recovery of the species in Canada will be increasingly
enhanced.
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Table Of Contents
Executive Summary ............................................................................................. ix
I. BACKGROUND .................................................................................................1
1. Description ....................................................................................................1
Phylogeny ......................................................................................................1
Physical Description ......................................................................................1
Distribution.....................................................................................................1
Abundance.....................................................................................................2
Biologically limiting factors .............................................................................3
Socio-economic considerations .....................................................................3
Legal Protection.............................................................................................3
2. Threats ..........................................................................................................4
3. Critical Habitat ...............................................................................................4
II. RECOVERY......................................................................................................5
4. Recovery Feasibility ......................................................................................5
5. Recovery Goal, Objectives and Corresponding Activities .............................6
a) Recovery Goal...........................................................................................6
b) Recovery Objectives..................................................................................6
c) Broad Strategy to be Taken .......................................................................6
d) Research and Management Activities Needed to Meet Objectives ...........9
e) Effects on Non-Target Species................................................................14
f) Evaluation.................................................................................................14
6. Knowledge Gaps .........................................................................................14
7. Timeline for Action Plans.............................................................................15
9. References Cited.........................................................................................16
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I. BACKGROUND
1. Description
Phylogeny
The Ivory Gull (Pagophila eburnea) is considered phylogenetically distinct, and is the
only representative of its genus. Recent phylogenetic analysis based on mitochondrial
DNA, has provided strong evidence that the Ivory Gull is a sister taxa to the Sabine’s
Gull (Xema sabini: Crochet et al. 2000). These species are estimated to have diverged
early, some 2 million years ago, compared with most other gull groupings, which are
estimated to have diverged in the last million years (Crochet et al. 2000). Differentiation
between the Ivory Gull and Sabine’s Gull is thought to have taken place within the
Arctic, rather than these species independently colonizing the far north (Crochet et al.
2000).
Physical Description
The Ivory Gull is a medium-sized gull, approximately 10% larger and longerwinged than the Black-legged Kittiwake (Rissa tridactyla; (Cramp & Simmons
1983). It is distinctive at all ages, but is particularly striking in its pure white adult
plumage. Immature birds have a dusky face, and black spots on the breast and
flanks, tips of the primaries, and tail and outer wing coverts (Grant 1986),
although the extent of speckling is highly variable among individuals. The eye is
dark, giving the bird a gentle expression (Cramp & Simmons 1983). It exhibits a
short period of immaturity for a gull of its size, acquiring adult plumage in its
second winter. In adults, the bill is generally slate blue at the base, becoming
pale yellow and tipped with red, but is darker in juveniles. The Ivory Gull has
relatively short legs, which are black at all ages. Its round chest, short legs, and
rolling gait give it a pigeon-like appearance when on the ground. However,
although it is a stocky built bird, in the air it has a graceful and agile flight.
Overall, the sexes are similar in appearance, and, once they reach maturity,
there is little or no seasonal variation in characteristics.
Distribution
The Ivory Gull has a circumpolar but patchy breeding distribution across the High
Arctic, with small, scattered colonies in North America, Greenland, Spitzbergen,
and the northern islands and archipelagos of Russia (Fig. 1).
In Canada, it breeds exclusively in Nunavut, concentrated around the Jones and
Lancaster sounds, with colonies on southeastern Ellesmere Island, eastern
Devon Island, and the Brodeur Peninsula of northern Baffin Island. One outlying
colony exists further west on Seymour Island, off the northern coast of Bathurst
Island. This species winters among the pack ice of the Davis Strait, Labrador
Sea, Strait of Belle Isle, and northern Gulf of St. Lawrence. It is occasionally seen
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ashore along east coast of Newfoundland and Labrador, particularly the Northern
Peninsula of Newfoundland, and on the Lower North Shore of Québec.
The eastern Canadian Arctic represents 100 % of the North American breeding
range, and approximately 25 % of the global breeding range and unknown but
possibly a very high (up to 100%) proportion of the global wintering range (Orr
and Parsons 1982).
The North American distribution appears to have been shrinking since late 1800s
(Haney & MacDonald 1995). The Canadian breeding range has certainly
contracted since the 1980s. Only one active colony now exists north of Makinson
Inlet on Ellesmere Island. Considerably fewer colonies now exist on the western
side of the Brodeur Peninsula, Baffin Island, with none in the area of Jackson
Inlet, which supported three known colonies in the past (Gilchrist & Mallory
2004).
Abundance
The global population of Ivory Gulls has been estimated at around 14,000
breeding pairs (Volkov & de Korte 1996). However, this figure incorrectly
included 2,400 pairs estimated to be breeding in Canada in the 1980s, when the
original estimate was in fact 2,400 individuals (1,200 pairs; Thomas &
MacDonald 1987). This global estimate also admittedly included a likely overoptimistic estimate for the Russian population (~10,000 pairs; Volkov & de Korte
1996).
The global population trend is unknown. Long-term declines have been
suggested for various parts of the breeding range (Bateson & Plowright 1959,
Cramp & Simmons 1983, Glutz von Blotzheim & Bauer 1982, Haney 1993), but
only well documented in Spitzbergen (Bateson & Plowright 1959, Birkenmajer
1969).
The Canadian Arctic was thought to support 20-30% of the entire global breeding
population, and to represent colonies of continental and global importance
(Gaston 1991). However, aerial surveys carried out in 2002 and 2003 indicate
that the Canadian breeding population has declined by 80-85% since the early
1980s (Gilchrist & Mallory 2004), one of the greatest population declines
detected for a bird species in North America.
Ivory Gulls are also known to winter in Canadian waters, although the percentage
of the global population to do so is unknown. A single study in the late 1970s,
based on aerial transects in the Davis Strait and Labrador Sea in March 1978,
estimated approximately 35,000 individuals in that region (Orr & Parsons 1982).
If that estimate is accurate, it suggests that Canada is responsible for a large
proportion of the global population throughout the year.
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Biologically limiting factors
Ivory Gulls have a relatively low adult survival rate compared with other gulls
(0.86; Stenhouse et al. 2004), and are likely to experience high post-fledging
mortality (Haney & MacDonald 1995).
Like most seabird species, Ivory Gulls display a delayed maturity, and
presumably do not breed until they are 2-3 years old, although there is little to no
data available (Haney & MacDonald 1995). They also show a relatively low
productivity rate, with a clutch size of 1 or 2, compared with the more usual 3-egg
clutch seen in most other gulls. Mean clutch sizes are also known to be lower
during years when there is less pack ice near colonies (Dalgety 1932).
Breeding success is limited, due to the extreme and variable nature of their
breeding environment. In some years, Ivory Gull colonies fail to produce any
young, and in years when conditions are completely unsuitable they may be
forced to forego breeding altogether (MacDonald 1976).
Socio-economic considerations
The Ivory Gull was traditionally hunted for food in both breeding and wintering
areas. However, due to their relatively small numbers and unpredictable
presence, harvest of this species was probably always rather opportunistic in
nature and it is unlikely that they ever provided a major food source for
subsistence hunters.
The existence of the Ivory Gull in Canada has no monetary value, and its worth is
principally derived from an aesthetic standpoint and in its contribution to
biodiversity. The Inuit regard this species with great affection, and appear to
consider its decline in Canada as an ominous indicator of a greater systemic ill in
the northern environment.
Legal Protection
The Ivory Gull is a non-game species, and as such is protected in Canada under
the Migratory Birds Convention Act (1994) and Regulations.
It has been protected in West Greenland since 1977 under the Local government
order of 21st December on bird hunting in West Greenland (Landsraadsvedtaegt
af 21. december 1977 om jagt paa fugle i Vestgroeland). In 1988, hunting
regulations were revised and applied to all of Greenland, under the Greenland
Home Rule order of 5th May 1988 on protection of birds in Greenland
(Hjemmestyrets bekendtgoerelse af 5. maj 1988 om fredning af fugle i
Groenland; D. Boertmann, pers. comm.).
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The Ivory Gull is on the Norwegian Red List, in the category DM, which stands
for ‘declining, monitoring’ (Directorate for Nature Management 1999). In
Svalbard, it has been protected since 1978, under the Svalbard Environmental
Protection Act (H Strøm, pers. comm.).
In Russia, it is registered as a Category 3 (Rare) species in the Red Data Book of
the former USSR (Haney 1993).
The provincial government of Newfoundland and Labrador adopted the
COSEWIC designation of Vulnerable in August 2002, so Ivory Gulls are also
protected under their provincial Endangered Species Act. The territorial
government of Nunavut has listed the Ivory Gull as May Be At Risk (Department
of Sustainable Development 2001).
2. Threats
Currently, the hunting of birds on migration is negatively affecting survival and
possibly population viability (Stenhouse et al. 2004). Human disturbance at
breeding colonies may have a considerable effect. In addition to reducing
reproductive success, via disturbance, human activities in the vicinity of a colony
may play a significant role in habitat degradation. Resource extraction in the
extreme climate and topography of Ivory Gull breeding areas requires
considerable flying time and use of ATVs, which introduces noise and pollution.
The presence of semi-permanent drilling camps may attract predators to
otherwise remote areas.
However, there are several other possible factors influencing the potential for
recovery in Ivory Gulls, for which there is no current data, including: 1) ecological
perturbation, such as changes in the extent of ice cover causing degradation of
winter habitat, 2) exposure to toxic pollutants in the marine environment, and 3)
vulnerability to oiling.
3. Critical Habitat
Although there is no provision under the Species at Risk Act for the protection of
critical habitat for Species of Special Concern, the precipitous decrease in North
American Ivory Gull populations suggests that strong efforts should be made to
identify and protect habitat necessary for the conservation and recovery of this
species. At this time, there is a great need for information that will allow the
identification of critical habitat. Although it may be possible to assess habitat
characteristics remotely, via satellite imagery, confirmation of the details will
require preliminary mapping and on-the-ground survey work.
Ivory Gulls have been found to nest in only four well-defined regions of the
Canadian Arctic: 1) cliffs on south east Ellesmere Island, 2) cliffs on east Devon
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Island, 3) flat ground on Cornwallis Island and the Brodeur Peninsula of Baffin
Island and, 4) on Seymour Island, a small offshore island. The currently known
Canadian breeding colonies of Ivory Gulls are listed in Tables 1 and 2 and should
be designated critical habitat (see also Figure 1). Areas of similar geomorphology
that are proximate to open water should be searched for breeding Ivory Gulls and
possible inclusion as critical habitat (such as the eastern region of Somerset
Island, west Devon Island, the southeastern interior of Cornwallis Island which
have geologies similar to the Brodeur Peninsula and the nunataks between
Talbot Inlet and Alexander Fiord on Ellesmere Island which shows a similar
geology to the rest of southeastern Ellesmere Island).
The general wintering habitat used by Ivory Gulls along the ice edges of Davis
Strait and the Labrador Sea is broadly know, but specific habitat requirements
during the non-breeding season are not known. As such, more work on wintering
habitat requirements and selection would be needed before critical habitat
designation could be made for non-breeding habitat.
II. RECOVERY
4. Recovery Feasibility
As outlined throughout this document, detailed information on the Ivory Gull is
scarce. However, the recovery goals and objectives, and the strategies for
achieving them, laid out in the Canadian Ivory Gull Management Plan are based
on all information currently available. As such, this document takes advantage of
new information and provides an update to the 2001 COSEWIC Status Report for
the Ivory Gull.
The management plan sets goals and objectives that are expected to contribute
to the recovery of the Ivory Gull population in Canada and fulfills the legislative
requirements outlined in the Species at Risk Act (SARA) for the development of
Management Plans for Species of Special Concern (Sections 65-72). Currently,
however, there is too little information on population growth rates available to
know if this is achievable within the timeframe recommended, and this should be
considered a preliminary assessment to be reviewed and revised as necessary.
The main challenges to the recovery process are:
1) the current lack of information on demographic parameters and life-history
traits,
2) the expense of initiating research on these topics, and the time required to
gain this information,
3) conflict between industrial development (i.e. mining) and the need to protect
colonies from disturbance, particularly on the Brodeur Peninsula, and
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4) the ethical and public relations challenges of predator control, should that be
deemed necessary.
5. Recovery Goal, Objectives and Corresponding Activities
a) Recovery Goal
The primary objective of the Ivory Gull Management plan is the recovery of the
Canadian breeding population to historic levels, and to expand the breeding
range to historically occupied areas.
The specific goal of the plan is the recovery of the Canadian breeding population
to ~1,000 breeding pairs in at least 4 regional breeding areas distributed across
the known historic range in Canada (Ellesmere Island, Devon Island, Seymour
Island, and the Brodeur Peninsula on Baffin Island) by 2014.
b) Recovery Objectives
By 2009, the objectives are to:
4 Objective 1: Prevent further loss. Maintain Ivory Gull colonies and numbers
currently in existence in Canada.
4 Objective 2: Understand threats. Identify and understand anthropogenic
threats to Ivory Gulls in Canada.
4 Objective 3: Understand life history. Initiate research and monitoring aimed at
filling knowledge gaps concerning Ivory Gulls in Canada.
4 Objective 4: Protect habitat. Identify characteristics of critical habitat and
protect habitat from alteration and disturbance.
4 Objective 5: Initiate public outreach. Develop and implement activities that
support Ivory Gull recovery in Canada.
4 Objective 6: Encourage international cooperation. Develop and facilitate
international initiatives contributing to the recovery of Ivory Gulls.
c) Broad Strategy to be Taken
Objective 1: Prevent further loss. Maintain colonies and numbers currently in
existence.
Rationale: If the current decline in the Canadian Breeding population (85% since
the 1980s) is allowed to continue, the Ivory Gull may be extirpated in Canada
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before recovery can be achieved. The existing colonies, particularly Seymour
Island, must be maintained in order to provide recovery source.
Strategies:
a) minimize risk of further decline by providing legislative protection for main
breeding areas.
b) enforce legal protection in Canada and promote increased awareness in
Greenland to eliminate mortality due to hunting, particularly for birds passing
through northwest Greenland.
c) introduce predator control at Seymour Island, if deemed necessary.
d) monitor Canadian breeding population size, distribution and movements, by
continuing breeding colony surveys and initiating banding programme(s).
Objective 2: Understand threats. Identify and understand anthropogenic threats
to Ivory Gulls in Canada.
Rationale: currently little or no information exists on anthropogenic threats to
breeding sites, migration routes or wintering areas. This information is urgently
required to design and implement mitigative measures and population recovery.
Strategies:
a) identify potential threats and, based on any existing data, evaluate their
impacts on survival and recovery.
b) quantify threat posed to Canadian population by hunting, particularly in
northwest Greenland, through banding studies.
c) quantify threat(s) posed by pollution by measuring toxin loads in Canadian
breeding population.
d) quantify anthropogenic sources of disturbance at Canadian breeding colonies.
Objective 3: Understand life history. Initiate research and monitoring aimed at
filling knowledge gaps concerning Ivory Gulls in Canada.
Rationale: The current level of knowledge regarding the reproductive biology and
ecology of Ivory Gulls throughout their range is very poor, and limits effective
recovery efforts in Canada.
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Strategies:
a) synthesize existing information from previous research and monitoring
undertaken in Canada, and throughout the range of the Ivory Gull.
b) assess population status and reproductive success through demographic
studies at colonies in Canada, likely most feasible at Seymour Island and the
Brodeur peninsula.
c) build a population model, based on current life history information from the
Canadian breeding population.
d) clarify links between Canadian and Greenlandic populations and identify
management units through banding and population genetics study.
Objective 4: Protect habitat. Identify characteristics of critical habitat and protect
habitat from disturbance.
Rationale: At present, little information exists on the breeding and wintering
habitats of Ivory Gulls, and this lack of information limits the ability to protect
critical habitat.
Strategies:
a) undertake research to identify the characteristics of habitat(s) used by Ivory
Gulls during breeding and at-sea/wintering in Canada.
b) assess the extent of critical habitat in Canada.
Objective 5: Initiate public outreach. Develop and implement activities that
support Ivory Gull recovery in Canada.
Rationale: Education of general public and communication with stakeholders
could help to further recovery efforts, and may improve the health of the marine
environment in general.
Strategies:
a) document aboriginal and traditional ecological knowledge of Ivory Gulls in
Canada.
b) identify target groups and develop resources (e.g. pamphlets, posters, etc.) to
educate stakeholders about their role in Ivory Gull conservation.
c) engage Greenlandic government to develop similar resources.
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Objective 6: Encourage international cooperation. Develop and facilitate
international initiatives contributing to the recovery of Ivory Gulls.
Rationale: Canada has the opportunity to play a leading role in the conservation
of the Ivory Gull throughout its range. Canadian agencies should encourage
recovery and education activities in other countries, especially Greenland.
Strategies:
a) alert other nations to the decline in Ivory Gulls in Canada.
b) encourage international cooperation in the conservation of Ivory Gulls
throughout their range.
c) collaborate with researchers in other countries to obtain information on the
status and demography of Ivory Gulls in their jurisdictions.
d) Research and Management Activities Needed to Meet Objectives
Monitor Population Size, Distribution, and Movement
Ivory Gulls are notoriously difficult to census, as colonies are known to move
around from year to year, and birds may forego breeding in some years due to
extreme environmental conditions (Haney & MacDonald 1995). Until recently, no
population trend information existed for this species in Canada. Since 2002,
however, comprehensive aerial surveys have been carried out in and around
previously known breeding areas. The results suggest a drastic decline in the
Canadian breeding population of up to 85% since the early 1980s (Gilchrist &
Mallory 2004). However, annual aerial surveys of breeding colonies must be
continued, at least for the foreseeable future, in order to accurately assess the
Canadian breeding population and to evaluate the effect of recovery measures.
A standardized protocol for dedicated Ivory Gull aerial surveys should be
formalized, such that it can be distributed and used across the species global
range. Aerial surveys initiated in Canada in 2002, must be continued annually for
the foreseeable future to fully assess the extent of the population decline.
A banding programme should be initiated for the Canadian breeding population,
to band adults and young. This could only be carried out at the most accessible
colony sites, particularly Seymour Island and the Brodeur Peninsula on Baffin
Island. A number of birds were banded at these sites in the 1970s and early
1980s, and repeating this work could provide valuable information on long-term
changes in the population.
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In the past, wintering and migrating Ivory Gulls were also banded at community
refuse dumps in the Canadian High Arctic, but few birds are now seen at these
sites (Mallory et al. 2003, Stenhouse et al. 2004). However, wintering birds could
be surveyed and banded at the ice front between Canada and Greenland in
conjunction with other government agencies. For example, the Department of
Fisheries and Oceans carries out surveys of marine mammals (particularly seals)
in the same region of the northwest Atlantic in which a large proportion of the
global population of Ivory Gulls is thought to winter.
Demographic Parameters
There is an urgent need to quantify demographic parameters, without which it is
extremely difficult to assess the potential for recovery in this species. Long-term
colony studies must be carried out to quantify nest numbers, clutch sizes,
fledging success, and the extent of annual variation in these. In addition, it will be
important to estimate the extent of philopatry exhibited, age at first breeding,
intervals between breeding attempts, and lifetime reproductive success.
A recent capture-mark-recapture analysis, based on recoveries of birds banded
in Nunavut, mainly in the 1970s and early 1980s, provides an initial adult survival
rate (0.86; Stenhouse et al. 2004). However, it is recognized that this study is
based on a sparse data set, and as such provides only a preliminary estimate,
which should be increasingly refined as further information becomes available.
Illegal Hunting
Recent analysis of banding recoveries shows that Ivory Gulls are still at risk of
mortality due to hunting. Of over 1500 birds banded in Nunavut in the 1970s and
early 80s, 26 have been recovered (Stenhouse et al. 2004). Most of those
recovered were shot in northwest Greenland (n = 17) and a few were shot in
Canada (n = 5), despite being legally protected in both these countries
(Stenhouse et al. 2004). (Note that Inuit currently have the right to harvest these
birds in Nunavut pursuant to harvest rights guaranteed in the Nunavut Land
Claim Agreement, but these gulls are taken incidentally and not actively
pursued).
Given the small size of the Canadian breeding population of Ivory Gulls, and the
recently documented decline in that population (Gilchrist & Mallory 2004), it is
critical that both the Greenland and the Canadian governments take steps to
eliminate mortality due to hunting. If this proves to be significant, the Canadian
federal government and the Greenland government should take steps to target
appropriate hunting and law enforcement groups for stewardship and education.
Predation
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Arctic foxes (Alopex lagopus) are well-known nest predators, and can wipe out
entire Ivory Gull breeding colonies in some years (Zubakin 1984). Polar bears
(Ursus maritimus) will take eggs and young on occasion (Haney & MacDonald
1995). Therefore, quantifying predation and the extent of variation between years
is a research priority. If predation is shown to be extensive, careful predator
control may be deemed necessary at specific colony locations.
Feeding Ecology
Like most gulls, the Ivory Gull is an opportunistic feeder. At sea, it is a surfacefeeder, foraging primarily on small fish, such as lantern-fish (Myctophidae) and
juvenile Arctic cod (Boreogadus saida), and macro-zooplankton, such as
amphipods and euphausiids (Haney & MacDonald 1995). Pellets found near
nests and containing small bones and hair, suggest that, at least during breeding,
they catch small mammals (Bent 1921).
Ivory Gulls are also keen scavengers at times, especially of marine mammals
killed by large predators, and are strongly attracted to blood on the ice. They are
also reported to forage on marine mammal faeces and placentae (Haney &
MacDonald 1995), and, in doing so, are potentially subject to high toxin loading.
However, their interest in scavenging may be influenced by a temporary lack of
available open water in which to feed (Stishov et al. 1991).
Monitoring food provisioning rates and identifying prey items fed to chicks may
help to establish whether there has been a change in the availability or
abundance of prey during breeding, which may be associated with changes in ice
distribution.
Colony Disturbance
Remoteness and inaccessibility of breeding locations limits the number of direct
risks from human disturbance. However, there is evidence that Ivory Gull
colonies are easily disturbed, particularly by low flying aircraft, ground traffic, or
careless human activity in or near the colony (MacDonald & Cooper 1979).
Disturbances of this nature may cause abandonment of breeding in a given year
or even abandonment of the colony altogether (Haney & MacDonald 1995).
In recent years, much of the Canadian Arctic has become more and more
accessible and the potential for disturbance at colonies has no doubt increased.
Thus, it is extremely important to identify potential sources of disturbance at
colonies, and to quantify their effects on breeding success. This is particularly
relevant on the Brodeur Peninsula, where mining exploration has increased
dramatically.
Habitat Mapping
Canadian Ivory Gull Management Plan
11
Like other seabirds breeding in the Arctic, Ivory Gulls have simple but critical
habitat requirements. Specifically, they require breeding sites that are safe from
terrestrial predators, but within close proximity to open water early in the
breeding season. These limitations restrict the possible range of breeders in the
Canadian Arctic, much more so than was perhaps originally thought (Gilchrist &
Stenhouse, in prep).
In order to protect nesting habitat, both current and potential nesting habitat must
first be determined. Foraging habitat and wintering areas are only loosely known
and must also be clearly identified. This could employ aerial or satellite images
and ground-truthing at colony locations.
Habitat Protection
The cliff colonies of Ellesmere and Devon Islands probably remain fairly
protected due to their extreme inaccessibility; however, the Brodeur Peninsula on
Northern Baffin Island is under increasing pressure. This is due to an increase in
mineral exploration and mining activities in that region, but uncontrolled tourism
may also cause unintentional disturbance at some breeding locations.
At present, Seymour Island is the only colony with any legislative protection and
was designated as a Migratory Bird Sanctuary in 1975, based solely on the
existence of a large Ivory Gull colony (MacDonald & Cooper 1979). Habitat
protection should be explored for other areas under threat, particularly the
Brodeur Peninsula, where construction (including buildings, gravel pads, roads,
and airstrips) and related activities (including low level flying, and use of ATVs)
should not be permitted near Ivory Gull colonies (i.e. within 10 km). In order to
achieve such protection, all stakeholders must be identified, made aware of the
situation, and involved in the development of mitigative measures; relevant
mechanisms available through provincial/territorial legislations to protect these
areas should be explored.
Public Outreach
In order to reduce mortality and prevent colony abandonment, it is critical to raise
the public profile of this species and highlight the impacts of hunting and
disturbance. An education outreach programme should be initiated to improve
understanding of the situation among relevant stakeholders and the general
public.
The development of a pamphlet and poster aimed initially at Canadian and
Greenlandic hunters should be a priority. This would be specifically designed to
draw attention to the population decline and reiterate legislative regulations in
both countries. As a matter of course, this would require discussion and
consultation with the Greenland government.
Canadian Ivory Gull Management Plan
12
Education materials should be written in Inuktitut and Danish, as well as the
usual English and French, in the first instance. However, these materials could
be expanded to reach other regions through collaboration with members of the
CAFF Circumpolar Seabird Group. This has been done for education materials
on the Thick-billed Murre and Common Eider, where a basic poster design was
provided to each political unit, which then translated the text into the appropriate
language to reach the relevant audience(s) in their region.
Genetics
Ivory Gulls from the Canadian Arctic and Greenland, and perhaps much further
afield, are known to winter at the ice front in the Davis Strait and Labrador Sea
(Orr & Parsons 1982, Renaud & MacLaren 1982). Thus, a large percentage of
the global population may be wintering in Canadian waters, and a single
catastrophic event or ecological change in this region could seriously affect the
entire world population. Consequently, it is necessary to identify the breeding
colony source(s) of birds wintering in Canada.
Blood samples from birds caught and banded in Canadian colonies and
throughout their breeding range, along with tissue samples from museum skins,
whose precise capture locations are known, would allow the first genetic analysis
of population structure for this species and identification of management units.
Furthermore, the development of molecular markers for particular breeding
populations would also allow wintering birds to be ‘sourced’.
This will involve partnering with a genetics laboratory with experience in wildlife
population studies. There are several laboratories in Canada and worldwide that
already have considerable experience of working on the genetic relationships
within seabird families (see Friesen et al. 1996, Crochet et al. 2000) and in the
population structuring within specific seabird species (see Birt-Friesen et al.
1992).
Contaminants
The bioaccumulation of toxins is known to affect surface-feeding birds and other
Arctic species, particularly animals at the top of the food web, such as fish-eating
birds and marine mammals (Braune et al. 1999, Muir et al. 1999, Fisk et al. 2003,
Buckman et al. 2004). High levels of toxic compounds, such as PCBs, DDE,
dioxins, and mercury, can cause abnormal behaviour in adult birds, deformities
and reduced growth in young birds, and/or embryo toxicity in eggs (Hoffman et
al. 2003).
As yet, it is unclear if contaminants have played a part in the recent breeding
population decline in Canada. However, given the potential for bioaccumulation
in Ivory Gulls, it is necessary to determine the extent to which heavy metals and
organic compounds may be influencing the Canadian breeding population.
Canadian Ivory Gull Management Plan
13
Blood and feather samples could be easily collected whenever birds are handled
for banding. Eggs which fail to hatch should also be collected whenever possible.
The Canadian Wildlife Service's Wildlife Toxicology Division at the National
Wildlife Research Centre, Ottawa, is willing to carry out appropriate chemical
analyses and to archive tissue samples in their specimen bank.
e) Effects on Non-Target Species
There are likely few, if any, potential impacts of recovery on other species, as
Ivory Gulls do not strongly associate with any other species.
Should it be deemed necessary, some form of predator control, such as the
discouragement or removal of Arctic foxes early in the breeding season, may be
necessary to enhance reproductive success at some colony locations. However,
given their abundance and wide distribution, this is unlikely to affect Arctic fox
populations to any measurable degree.
f) Evaluation
Meaningful performance indicators are expected to develop with the acquisition
of critical information on Ivory Gull ecology and demography. However, it is
important to ‘build in’ performance indicators of recovery from the outset i.e. to
match each recovery objective with a specific performance indicator or indicators.
Initially, population surveys in breeding and wintering areas will be critical to the
assessment of recovery measures. Without an accurate picture of the number of
Ivory Gulls in Canada, and their population trend, the success or failure of
specific recovery measures will be completely unknown.
An important measure of overall performance is the publication of new
information in peer-reviewed scientific journals. Not only does this give the entire
species recovery process a scientific legitimacy, and provide evidence of the
advancement of knowledge, it also shows a willingness to share new information
with researchers around the world and fosters cooperation between individuals
and nations.
6. Knowledge Gaps
The current knowledge of Ivory Gull ecology in Canada, and worldwide, is sadly
lacking, and acutely insufficient to accurately define recovery objectives and
approaches. Information is required on almost all aspects of their breeding and
wintering ecology, especially details of breeding productivity, identification of
critical habitat and potential threats.
Canadian Ivory Gull Management Plan
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7. Timeline for Action Plans
An aerial survey of Ivory Gull colonies was initiated in Canada in 2002. This must
be continued annually, at least for the foreseeable future, to assess the full extent
and progress of the current population trend.
A study of local ecological knowledge, carried out in Nunavut, provided important
information on Ivory Gull populations (Mallory et al. 2003). A comparative study is
currently underway in Newfoundland and Labrador (P. Ryan, pers. comm.). A
similar study should be carried out along the Lower North Shore of Québec, to
assess potential changes in numbers across a broader area.
Consultations with other jurisdictions, particularly provincial and territorial
government agencies, but also international governments, on the subject of Ivory
Gulls were initiated in 2002 and 2003. This effort must be continued to establish
a strong collaborative approach to species recovery.
Collaborative decision-making and planning will be essential to an efficient and
successful recovery programme. Given the opportunities for collaborative efforts,
lines of communication with other governmental departments, particularly the
Department of Fisheries and Oceans, need to be kept open and the existing links
strengthened.
A dedicated and collaborative field research programme will provide critical
information on mortality, productivity, and movements, as well as the opportunity
to band birds and sample blood and feathers. This should be initiated at the
earliest possible date, which would be the breeding season (July-August) of
2004.
Canadian Ivory Gull Management Plan
15
9. References Cited
Alvo, R. & MacDonald, S.D. 1995. Updated Status Report on the Ivory Gull
(Pagophila eburnea) in Canada. Committee on the Status of Endangered
Wildlife in Canada, Ottawa, 8pp.
Bateson, P.P.G. & Plowright, R.C. 1959. The breeding biology of the Ivory Gull in
Spitsbergen. British Birds 52: 105-114
Bent, A.C. 1921. Life histories of North American gulls and terns. US National
Museum Bulletin 113: 29-35.
Birkenmajer, K. 1969. Observations on Ivory Gull (Pagophila eburnea) in south
Vestspitsbergen. Acta Ornitologica 11: 461-476.
Birt-Friesen, V.L., Montevecchi, W.A., Gaston, A.J. & Davidson, W.S. 1992.
Genetic structure of Thick-billed Murre (Uria lomvia) populations examined
using direct sequence analysis of amplified DNA. Evolution 46:267-272.
Braune, B., Muir, D., de March, B., Gamberg, M., Poole, K., Currie, R., Dodd, M.,
Duschenko, W., Eamer, J., Elkin, B., Evans, M., Grundy, S., Hebert, C.,
Marshall, K., Reimer, K., Sanderson, J. & Shutt, L. 1999. Spatial and temproal
trends of contaminants in Canadian Arctic freshwater and terrestrial
ecosystems: a review. Science of the Total Environment 230:145-207.
Buckman, A. H.; Norstrom, R. J.; Hobson, K. A.; Karnovsky, N. J.; Duffe, J. &
Fisk, A. T. 2004. Organochlorine contaminants in seven species of Arctic
seabirds from northern Baffin Bay. Environmental Pollution 128:327-338.
COSEWIC. 2001. Canadian Species at Risk, May 2001. Committee on the
Status of Endangered Wildlife in Canada, Ottawa.
Cramp, S. and Simmons, K.E.L. 1983 Handbook of the birds of Europe, the
Middle East and North Africa; the birds of the Western Palearctic. Vol. 3:
waders to gulls. Oxford University Press, Oxford.
Crochet, P.-A., F. Bonhomme and J.-D. Lebreton. 2000. Molecular phylogeny
and plumage evolution in gulls (Larini). Journal of Evolutionary Biology 13:
47-57.
Dalgety, C.T. 1932. The Ivory Gull in Spitsbergen. British Birds 26: 2-7.
Department of Sustainable Development. 2001. Nunavut Wild Species, 2000.
Government of Nunavut, Iqaluit. 33 pp.
Canadian Ivory Gull Management Plan
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Directorate for Nature Management. 1999. Norwegian Red List 1998. DN Report
3:1-161.
Fisk, A.T., Hobbs, K. & Muir, D.C.G. (eds.) 2003. Canadian Arctic Contaminants
Assessment Report II: Contaminant levels, trends and effects in the biological
environment. Indian & Northern Affairs Canada, Ottawa.
Friesen, V.L, Baker, A.J. & Piatt, J.F. 1996. Phylogenetic relationships within the
Alcidae (Charadriiformes: Aves) inferred from total molecular evidence.
Molecular Biology & Evolution 13: 359-367.
Gaston, A.J. 1991. Conservation issues and Canadian Wildlife Service priorities
for marine birds. Canadian Wildlife Service, unpublished report.
Gilchrist, H.G. & Mallory, M. 2004. Population declines and distribution of Ivory
Gulls breeding in Canada. Biological Conservation: in press.
Gilchrist, H.G. & Stenhouse, I.J. (in prep) Colony site selection in Ivory Gulls
breeding in Canada.
Glutz von Blotzheim, U.N. & Bauer, K.M. 1982. Handbuch der Vögel
Mitteleuropas: Charadriformes. Akademische Verlagsgesellschaft,
Wiesbaden.
Grant, P.J. 1986. Gulls: a guide to identification, 2nd edition. Academic Press,
San Diego.
Haney, J.C. 1993. Rare, local, little known and declining breeders. A closer look:
Ivory Gull. Birding 24: 330-338.
Haney, J.C. & MacDonald, S.D. 1995. Ivory Gull (Pagophila eburnea). In The
Birds of North America, No. 175 (Poole, A. & Gill. F., eds.). The Birds of North
America, Inc., Philadelphia.
Hoffman, D.J., Rattner, B.A., Burton, G.A. & Cairns, J. (eds.) 2003. Handbook of
ecotoxicology, 2nd edition. Lewis Publishing, Boca Raton.
MacDonald, S.D. 1976. Phantoms of the polar pack ice. Audubon 78: 2-19.
MacDonald, S.D. & Cooper, C. 1979. Status report on Ivory Gull (Pagophila
eburnea). Committee on the Status of Endangered Wildlife in Canada,
Ottawa, 22pp.
Mallory, M.L., Gilchrist, H.G., Fontaine, A.J. & Akearok, J.A. 2003. Local
ecological knowledge of Ivory Gull declines in Arctic Canada. Arctic 56:293298.
Canadian Ivory Gull Management Plan
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Mallory, M.L., Akearok, J. & Fontaine, A.J. 2001. Community knowledge on the
distribution and abundance of species at risk in southern Baffin Island,
Nunavut, Canada. Technical Report Series No. 363, Canadian Wildlife
Service, Prairie & Northern Region.
Muir, D., Braune, B., de March, B., Norstrom, R., Wagemann, R., Lockhart, L.,
Hargrave, B., Bright, D., Addison, R., Payne, J. & Reimer, K. 1999. Spatial
and temporal trends and effects of contaminants in the Canadian Arctic
marine ecosystem: a review. Science of the Total Environment 230:83-144.
Orr, C.D. & Parsons, J.L. 1982. Ivory Gulls (Pagophila eburnea) and ice edges in
Davis Strait and the Labrador Sea. Canadian Field-Naturalist 96: 323-328.
Stenhouse, I.J., Robertson, G.J. & Gilchrist, H.G. 2004. Recoveries and survival
rates of Ivory Gulls banded in Nunavut, Canada, 1971-1999. Waterbirds in
press.
Stishov, M.S., Pridatko, V.I. & Baranyuk, V.V. 1991. Birds of Wrangel Island.
Nauka, Siberian Division, Novosibirsk.
Thomas, V.G. & MacDonald S.D. 1987. The breeding distribution and current
population status of the Ivory Gull in Canada. Arctic 40: 211-218.
Volkov, A. & de Korte, J. 1996. Distribution and numbers of breeding Ivory Gulls
(Pagophila eburnea) on Zevernja Zemlja, Russian Arctic. Polar Research 15:
11-21.
Canadian Ivory Gull Management Plan
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Table 1. Number of Ivory Gulls present at historically known colonies (data from
Gilchrist and Mallory 2004).
General Location
ELLESMERE ISLAND
Sydkap Glacier
Mansen Ice Field
Mansen Ice Field
Smith Bay
Matkinson Inlet
Talbot Inlet north
Mansen Ice Field
Mansen Ice Field
Mansen Ice Field
Mansen Ice Field
Mansen Ice Field
Mansen Ice Field
Mansen Ice Field
Makinson Inlet and Smith Bay
BAFFIN ISLAND
Brodeur Peninsula, south of Cape York
DEVON ISLAND
Belcher Glacier
Raper Point
Bethune Inlet
Bethune Inlet
SEYMOUR ISLAND
Seymour Island
Latitude
Longitude
# colonies
considered
Year of
Historical
survey
Previous
# Birds
2002
# Birds
2003
# Birds
76º 23’
76º 56.135’
76º 55’
77º 9.5’
77º 27’
78º 50’
77º 1.463’
76º 48’
76º 51.79’
76º 46.117’
76º 47.5’
76º 48.223’
76º 42.57’
84º 58’
80º 31.002’
79º 58’
79º 20’
79º 14’
78º 11’
80º 34.482’
79º 55’
79º 44.837’
79º 53.242’
80º 25’
80º 15.645’
80º 7.75’
1
1
1
1
1
1
1
1
1
1
1
1
1
1982
1977
1977
1977
1977
1977
1990
1990
1990
1990
1990
1990
1990
275-300
60
15
50
50
30
24
28
20
28
70
90
70
0
0
0
0
0
0
0
0
5
0
0
6
10
0
0
.
5
0
0
0
0
0
0
0
0
0
Thomas and MacDonald 1987
Frisch and Morgan 1979
Frisch and Morgan 1979
Frisch and Morgan 1979
Frisch and Morgan 1979
Frisch and Morgan 1979
France and Sharp 1992
France and Sharp 1992
France and Sharp 1992
France and Sharp 1992
France and Sharp 1992
France and Sharp 1992
France and Sharp 1992
.
.
14
1981-83
730-830
.
.
Thomas and MacDonald 1987
.
.
10
1982-83
560-580
0
0
Thomas and MacDonald 1987
75º 28.120’
75º 20.447’
74º 57.185’
74º 46.300’
81º 22.103’
80º 44.663’
81º 0.043’
80º 42’
1
1
1
1
1981
1981
1981
1981
25
30
30
6
0
6
0
.
0
0
0
.
Frisch 1983
Frisch 1983
Frisch 1983
Frisch 1983
76º 48’
101 º16’
1
1974
340
0
200
Canadian Ivory Gull Management Plan
Historical data source
MacDonald 1976
19
Table 2. Number of Ivory Gulls present at colonies discovered in 2001-2003
(data from Gilchrist and Mallory 2004).
Location
Latitude
Longitude
# Birds 2001
# Birds 2002
# Birds 2003 Colony Type
(ºN)
(ºW)
Ellesmere Island
77º 11.052’
79º 35.459’
.
4
0
Eroded Cliff
Ellesmere Island
76º 49.677’
79º 50.855’
.
19
3
Sheer Spire
Ellesmere Island
76º 49.3’
79º 50.250’
.
20
0
Sheer Spire
Ellesmere Island
76º 46.117’
79º 53.242’
.
1
0
Sheer Spire
Ellesmere Island
76º 43.79’
79º 53.969’
.
2
1
Sheer Spire
Ellesmere Island
76º 42.836’
80º 0.167’
.
2
0
Sheer Spire
Ellesmere Island
76º 41.547’
80º 3.560’
.
11
0
Sheer Spire
Ellesmere Island
77º 7.112’
79º 53.500’
.
1
0
Sheer Spire
Ellesmere Island
77º 1.414’
80º 35.658’
.
1
0
Sheer Spire
Ellesmere Island
77º 3.460’
79º 56.650’
.
.
2
.
Brodeur Peninsula
73º 19.410’
87º 54.400’
.
.
50-60
Flat ground
Brodeur Peninsula
73º 25.000’
86º 21.200’
.
.
26
Flat ground
Brodeur Peninsula
73º 25.200’
87º 32.900’
.
.
7
Flat ground
Brodeur Peninsula
73º 30.865’
86º 54.399’
35
.
0
Flat ground
Brodeur Peninsula
73º 38.801’
87º 18.100’
20
.
0
Flat ground
Canadian Ivory Gull Management Plan
20
Fig. 1: The global breeding distribution of Ivory Gull (dots), and their wintering
range (stipples).
Canadian Ivory Gull Management Plan
21
Fig. 2: Ivory Gull breeding colonies in Canada. Locations of former Ivory Gull
colonies without birds (○) and with birds (●), new colonies with birds (▲) as found
during the July 2002 and 2003 surveys, and colonies with birds in 2001 but not
2002 and 2003 (∆).
Canadian Ivory Gull Management Plan
22