Dr. Gregory J. Robertson
Research Scientist, Canadian Wildlife Service, Adjunct Professor, Biology Department
Memorial Univ. of Newfoundland, 6 Bruce Street , Mount Pearl NF A1N 4T3 Canada
greg.robertson@ec.gc.caVoice: (709) 772-2778 FAX: (709) 772-5097
Greg Rob
Greg Robertson
Population demography of the endangered eastern Harlequin Duck
Wintering ecology of sea ducks in Belcher Islands, Nunavut
http://www.mun.ca/acwern/robertson.html
Publications
Peer reviewed journals
* Adams, P. A., G. J. Robertson, and I. L. Jones. in press. Time-activity budgets of Harlequin Ducks molting in the Gannet Islands, Labrador. Condor
* Gilchrist, H. G., and G. J. Robertson. in press. Observations of marine birds and mammals wintering at polynyas and ice edges in the Belcher Islands, Nunavut, Canada. Arctic 53.
* Robertson, G. J., F. Cooke, R. I. Goudie and W. S. Boyd. in press. Spacing patterns, mating system, and winter philopatry in Harlequin Ducks. Auk
* Wiebe, M. O., J. E. Hines, and G. J. Robertson. accepted. Collar retention of Canada Geese and Greater White-fronted Geese from the Western Canadian Arctic. Journal of Field Ornithology
* Cooke, F., G. J. Robertson, C. M. Smith, R. I. Goudie and W. S. Boyd. 2000. Survival, emigration, and winter population structure of Harlequin Ducks. Condor 102: 137-144.
* Smith, C. M., F. Cooke, G. J. Robertson, R. I. Goudie and W. S. Boyd. 2000. Long-term pair bonds in Harlequin Ducks. Condor 102: 201-205.
* Cullen, S. A., and G. J. Robertson. 1999. Temporal changes in the anti-predator flocking behavior of wintering shorebirds. Waterbirds 22: 156-159.
* Gilchrist, H. G., and G. J. Robertson. 1999. Population trends of gulls and Arctic Terns nesting in the Belcher Islands, Nunavut. Arctic 52: 325-331.
* Robertson, G. J., and F. Cooke. 1999. Winter philopatry in migratory waterfowl. Auk 116: 20-34.
* Robertson, G. J. 1998. Egg adoption can explain joint egg-laying in common eiders. Behavioral Ecology and Sociobiology 43: 289-296.
* Robertson, G. J., and H. G. Gilchrist. 1998. Evidence for population declines among Common Eiders breeding in the Belcher Islands, Northwest Territories. Arctic 51: 378-385.
* Robertson, G. J., F. Cooke, R. I. Goudie and W. S. Boyd. 1998. Moult speed predicts pairing success in male Harlequin Ducks. Animal Behaviour 55: 1677-1684.
* Robertson, G. J., F. Cooke, R. I. Goudie and W. S. Boyd. 1998. The timing of pair formation in Harlequin Ducks. Condor 100: 551-555.
* Wright, K. G., G. J. Robertson and R. I. Goudie. 1998. Evidence of spring staging and migration route of an individual breeding Harlequin Duck Histrionicus histrionicus in southern British Columbia. Canadian-Field Naturalist 112: 518-519.
* Cooke, F., G. J. Robertson, R. I. Goudie, and W. S. Boyd. 1997. Molt and the basic plumage of male Harlequin Ducks. Condor 99: 83-90.
* Gowans, B., G. J. Robertson, and F. Cooke. 1997. Behaviour and chronology of pair formation by Harlequin Ducks Histrionicus histrionicus. Wildfowl 48: 135-146.
* Robertson, G. J., F. Cooke, R. I. Goudie and W. S. Boyd. 1997. Estimating temporary emigration rates with supplementary information: an example with Harlequin Ducks. The Ring 19:169-178.
* Robertson, G. J. F. Cooke, R. I. Goudie and W. S. Boyd. 1997. The timing of arrival and moult chronology of Harlequin Ducks Histrionicus histrionicus. Wildfowl 48: 147-155.
* Robertson, G. J. 1995. Factors affecting nest site selection and nesting success in the Eider Somateria mollissima. Ibis 137: 109-115.
* Robertson, G. J. 1995. Annual variation in common eider egg size: effects of temperature, clutch size, laying date and laying sequence. Canadian Journal of Zoology 73: 1579-1587.
* Robertson, G. J., M. A. Owen, and R. F. Rockwell. 1995. Responses of lesser snow geese to artificially induced hatching asynchrony and increased clutch size. Auk 112: 790-794.
* Robertson, G. J., E. G. Cooch, D. B. Lank, R. F. Rockwell, and F. Cooke. 1994. Female age and egg size in the Lesser Snow Goose. Journal of Avian Biology 25: 149-155.
* Robertson, G. J. 1993. Interspecific killing in the Pacific Loon. Wilson Bulletin 105: 534-535.
* Robertson, G. J., and F. Cooke. 1993. Intraclutch egg-size variation and hatching success in the common eider. Canadian Journal of Zoology 71: 544-549.
* Watson, M. D., G. J. Robertson, and F. Cooke. 1993. Egg-laying time and laying interval in the Common Eider. Condor 95: 869-878.
* Robertson, G. J., M. D. Watson and F. Cooke. 1992. Frequency, timing and costs of intraspecific nest parasitism in the Common Eider. Condor 94: 871-879.
Peer reviewed conference proceedings
* Robertson, G. J., F. Cooke, R. I. Goudie, and W. S. Boyd. 1999. Within year fidelity of Harlequin Ducks to a moulting and wintering area. Pages 45-51 in Behaviour and ecology of sea ducks. (R. I. Goudie, M. R. Petersen and G. J. Robertson, eds.). Canadian Wildlife Service, Occasional Paper Series No. 100, Ottawa.
Peer reviewed species accounts
* Robertson, G. J. and R. I. Goudie. 1999. Harlequin Duck (Histrionicus histrionicus). In: The Birds of North America, No. 466. (A. Poole and F. Gill, eds.). Birds of North America, Inc., Philadelphia, PA.
Proceedings edited
* Goudie, R. I., M. R. Petersen and G. J. Robertson. (eds.). 1999. Behaviour and ecology of sea ducks. Canadian Wildlife Service Occasional Papers Series No. 100, Ottawa.
Current work
* Goudie, R. I., G. J. Robertson and A. Reed. Common Eider (Somateria mollissima). In The Birds of North America. (A. Poole and F. Gill, eds.). Birds of North America, Inc., Philadelphia, PA.
* Massaro, M., J.W. Chardine, I.L. Jones and G.J. Robertson. submitted. Delayed capelin (Mallotus villosus) availability influences large gull predatory behaviour on black-legged kittiwakes (Rissa tridactyla), causing a reduction in breeding success. Canadian Journal of Zoology
* Robertson, G. J., A. Reed and H. G. Gilchrist. submitted. Clutch, egg and body size variation among populations of common eiders breeding in Hudson Bay, Canada. Ecography
* Stenhouse, I. J., G. J. Robertson and W. A. Montevecchi. submitted. Herring Gull Larus argentatus predation on Leachâs Storm-Petrels Oceanodroma leucorhoa breeding on Great Island, Newfoundland. Atlantic Seabirds
* Torres, R., F. Cooke, G. J. Robertson and W. S. Boyd. submitted. Pairing decisions in the Harlequin Duck: costs and benefits. Auk
Invited contributions
* Chapdelaine, G., A. W. Diamond, R. D. Elliot and G. J. Robertson. 1999. Population status and current trends of Razorbills in Canada. Bird Trends 7: 18-22.
* Gilchrist, H. G. and G. J. Robertson. 1999. Population trends of gulls and Arctic Terns nesting in the Belcher Islands, Northwest Territories. Bird Trends 7: 28-30.
* Robertson, G. J. 1999. Estimating movement with Capture-Mark-Recapture models. Pp. 67-72 in Investigation of Animal Movement: Workshop Proceedings. (F. Huettmann and J. Bowman, eds.). Sir James Dunn Wildlife Research Centre, University of New Brunswick, Fredericton, Canada.
Plenary presentation
* Robertson, G. J. Sea ducks and the annual cycle. Symposium Plenary Paper. 23rd Waterbird Society Annual Meeting, Grado, Italy. 9 November 1999 (oral presentation).
Published abstracts
* Adams, P.A., G.J. Robertson and I.L. Jones. Time-activity budgets of Harlequin Ducks moulting in the Gannet Islands, Labrador. 23rd Waterbird Society Annual Meeting, Grado, Italy. 9 November 1999 (poster).
* Gilchrist, H.G., G.J. Robertson and K.A. Hobson. Diet and habitat constraints of sea ducks wintering in the Belcher Islands polynyas, Nunavut, Canada. 23rd Waterbird Society Annual Meeting, Grado, Italy. 9 November 1999 (oral presentation).
* Gilchrist, H.G., and G.J. Robertson. Evidence of breeding declines among common eider ducks breeding in the Belcher Islands, Nunavut, Canada. 23rd Waterbird Society Annual Meeting, Grado, Italy. 9 November 1999 (poster).
* Elliot, R.D., and G. J. Robertson. Razorbill population trends in the Gannet Islands, Labrador, and the effects of Arctic Fox presence on breeding numbers. Atlantic Society of Fish and Wildlife Biologists: annual meeting. 29 September 1999 and ACWERN annual meeting, Brier Island, NS. 16 October 1999 (oral presentation by R.D. Elliot).
* Torres, R., F. Cooke, G. Robertson, and S. Boyd. Costs and benefits of early pairing in the Harlequin Duck. Animal Behaviour Society, Annual Meeting, Lewisburg, PA. 27 June 1999 and Seventh congress of the European Society for Evolutionary Biology, Barcelona, Spain. 26 August 1999 (poster).
* Robertson, G.J., G. Chapdelaine, A. W. Diamond, F. Huetmann, and R. D. Elliot. Population status and trends of Razorbills in Canada. Eightieth meeting of the Wilson Ornithological Society, Waterville, ME. 11 June 1999 and 23rd Waterbird Society Annual Meeting, Grado, Italy. 9 November 1999 (poster).
* Smith, C.M., F. Cooke, G.J. Robertson, R.I. Goudie, and W.S. Boyd. Population dynamics of Harlequin Ducks in British Columbia and Alberta. Biology and Management of Species and Habitats at Risk Conference, University College of the Cariboo, Kamloops, BC. 16 February 1999 (oral presentation by C.M. Smith).
* Robertson, G. J. Estimating animal movement using Capture-Mark-Recapture models. Investigation of animal movements: analytical techniques across the animal kingdom. Symposium held at the ACWERN annual meeting, St. Johnâs, NF. 1 November 1998 (oral presentation).
* Robertson, G. J., R. D. Elliot and I. L. Jones. Razorbill surveys in the Gannet Islands, 1983-1998. ACWERN annual meeting, St. Johnâs, NF. 30 October 1998 (oral presentation).
* Moore, D. J. and G. J. Robertson. Sources of intraclutch egg size variation in the Common Tern. Society of Canadian Ornithologists, Annual Meeting, Vancouver, BC. 4 August 1998 (oral presentation by D. Moore).
* Robertson, G. J. Molt speed predicts pairing success in male Harlequin Ducks. North American Ornithological Conference, St. Louis, Missouri. 8 April 1998 (oral presentation: Best Student Paper Award, Colonial Waterbird Society).
* Robertson, G. J. and H. G. Gilchrist. Evidence for population declines among Common Eiders breeding in the Belcher Islands, Northwest Territories. North American Ornithological Conference, St. Louis, Missouri. 9 April 1998 (poster).
* Cooke, F. and G. J. Robertson. Survival estimates for Harlequin Ducks from wintering ground studies. Harlequin Duck Working Group, 4th Biennial Symposium, Newport, Oregon. 2 March 1998. (oral presentation by F. Cooke).
* Cooke, F. and G. J. Robertson. Moulting studies of Harlequin Ducks. Harlequin Duck Working Group, 4th Biennial Symposium, Newport, Oregon. 2 March 1998. (oral presentation by F. Cooke).
* Smith, C. M., F. Cooke, G. J. Robertson, R. I. Goudie and W. S. Boyd. Evidence of long-term pair bonds in Harlequin Ducks, (Histrionicus histrionicus). Harlequin Duck Working Group, 4th Biennial Symposium, Newport, Oregon. 2 March 1998 and Society of Canadian Ornithologists, Annual Meeting, Vancouver, BC. 4 August 1998 (oral presentations by C. M. Smith).
* Gilchrist, H. G. and G. J. Robertson. Evidence for population declines among Common Eiders breeding in the Belcher Islands, Northwest Territories. Pacific Seabird Group, Monterrey, CA. January 1998 (poster).
* Robertson, G. J., F. Cooke, R. I. Goudie, W. S. Boyd. Winter philopatry in Harlequin Ducks: implications for their conservation in the Strait of Georgia, BC. Society for Conservation Biology, Annual Meeting 1997, Victoria, BC. 7 June 1997 (oral presentation).
* Robertson, G. J., F. Cooke, R. I. Goudie, and W. S. Boyd. Movements and temporary emigration of moulting and wintering Harlequin Ducks. EURING 97, University of East Anglia, Norwich, UK. 8 April 1997 (poster).
* Robertson, G. J., F. Cooke, R. I. Goudie, and W. S. Boyd. Movements and survival of molting and wintering Harlequin Ducks. First North American Duck Symposium and Workshop, Baton Rouge, LA. 13 February 1997 (oral presentation).
* Robertson, G. J. Modeling the population demography of Harlequin Ducks. First North American Duck Symposium and Workshop, Baton Rouge, LA. 13 February 1997 and Pacific Ecology Conference, Bamfield, BC. 22 February 1997 (poster).
* Robertson, G. J., B. Gowans, and F. Cooke. Timing of pairing and molt chronology of Harlequin Ducks. First North American Duck Symposium and Workshop, Baton Rouge, LA. 13 February 1997 (poster).
* Robertson, G. J. Pre-hatch brood amalgamation in Common Eiders: why do eiders adopt eggs? 114th meeting of the AOU, Boise, ID. 15 August 1996 (poster).
* Robertson, G. J. Sex-biased winter philopatry in Harlequin Ducks: are waterfowl an exception to the rule? 114th meeting of the AOU, Boise, ID. 14 August 1996 (oral presentation).
* Robertson, G. J., F. Cooke, R. I. Goudie, and W. S. Boyd. Moulting and wintering site philopatry in Harlequin Ducks. Northwest Section of the Wildlife Society Conference, Banff, Alta. 30 March 1996 and 3rd Harlequin Duck Working Group meeting, Delta, BC. 11 March 1996 (oral presentations).
* Gowans, B., G. J. Robertson and F. Cooke. Behaviour and chronology of pair formation in Harlequin Ducks at White Rock, British Columbia. 3rd Harlequin Duck Working Group meeting, Delta, BC. 11 March 1996 (oral presentation by B. Gowans).
* Cooke, F., G. J. Robertson, R. I. Goudie, W. S. Boyd. Moult and the basic plumage of male Harlequin Ducks. 3rd Harlequin Duck Working Group meeting, Delta, BC. 11 March 1996 (oral presentation by F. Cooke).
* Robertson, G. J., F. Cooke, R. I. Goudie and W. S. Boyd. Moult chronology and the timing of pairing in Harlequin Ducks. Pacific Ecology Conference, Friday Harbour Laboratories, Wash. 5 February 1996 (oral presentation).
* Robertson, G. J. F. Cooke, and R. I. Goudie. Within-season moulting and wintering philopatry in Harlequin ducks. Pacific Seabird Group/Colonial Waterbird Society Joint Conference, Victoria, BC. 9 November 1995 (oral presentation).
* Robertson, G. J. Within-season moulting and wintering philopatry in Harlequin ducks. IWWR student/staff Symposium, Oak Hammock, Manitoba. 24 August 1995 (oral presentation).
* Robertson, G. J. Sources of egg size variation in eiders. Pacific Ecology Conference, Oregon Institute of Marine Biology, Coos Bay, OR. 26 February 1995 (oral presentation).
* Robertson, G. J. Joint egg-laying in eider ducks: nest parasitism or egg-adoption? Pacific Ecology Conference, Bamfield Marine Biology Station, BC. 5 March 1994 (oral presentation).
Philopatry in nesting adult female spectacled eiders at Kigigak Island, Yukon Delta National Wildlife Refuge, Alaska.
Moran, Tina L. Institute of Arctic Biology, Department of Biology and Wildlife,
University of Alaska, Fairbanks, Alaska 99775
In response to the dramatic decline of the species (early 1970's to 1990's) on the
Yukon-Kuskokwim Delta, I conducted a nesting ecology study on spectacled eiders
(Somateria fischeri) at Kigigak Island from 1992-1996. The Kigigak Island population
has had relatively high nest success between 1992-1996 (92%, 63%, 70%, 64%, and
82%, respectively). More than 50% of the nesting females have been marked (n=161).
Preliminary results show that 70% of the marked females have returned to nest at least
once following their banding year and that 52% returned at least two consecutive years.
The spectacled eider estimate on Kigigak is relatively high compared with return rates
reported for other duck species, including buffleheads (Bucephala albeola)( 44-50%)
and mallards (Anas platyrhynchos) (40-46%). Preliminary results also show that
returning females move an average of 200 m from previously used nest sites. I am
currently examining relationships between partial predation, clutch size, nesting
chronology and distances moved between individual female's nest sites.
Winter Philopatry In Harlequin Ducks: Implications For Their Conservation In The Strait Of Georgia, BC.
ROBERTSON, G.J., F. COOKE, Department of Biological Sciences, Simon Fraser
University, Burnaby BC and R. I. GOUDIE, and BOYD, W.S.Pacific Wildlife
Research Centre, Canadian Wildlife Service, Delta, BC, Canada
Habitat use and requirements for wintering birds has only recently received attention compared to breeding habitat use and requirements. For waterfowl, quality wintering habitat is important for not only surviving the winter period, but for courtship and pair bond formation as well. Harlequin Ducks are a small sea duck that nest on mountain streams and winter on coastal rocky shores. We have been marking a portion of the Harlequin Duck population in the Strait of Georgia with small tarsal leg bands annual ly
since 1993. One of our main objectives is to estimate the rate at which individuals utilize the same wintering sites between years. A focal population at White Rock, BC consisting of about 100 individuals has been intensively studied to achieve this ob jective. Over half and up to 3/4 of the individuals marked in one year returned to the site in a later year. If
both members of a pair return to the same wintering grounds they will re-unite. Limited data for younger age classes suggest that they have low er return rates. This tendency for individuals to return to the same site year after year has significant conservation implications for these birds. One, is that local populations may be genetically isolated reducing the effective population size. Second ly, major local habitat degredation may result in the loss of local populations with no subsequent recolonization even if the
habitat is restored. Thirdly, chronic disturbances and minor habitat degredation may cause birds to lose body condition which may result in poor productivity in the following breeding effort. Harlequin Ducks are currently listed as endangered on the east coast of North America, as such, they are known to be a very sensitive species. Threats to this species and its' habitat should be considered very real conservation concerns.
Winter Philopatry In Migratory Waterfowl.
Gregory J. Robertson, and Fred Cooke Auk Vol116 No.1 January 1999
ABSTRACT.--Philopatry in migratory species can apply to any location used during the annual cycle. The degree of philopatry influences the genetic structure of populations, but only at the stage of the annual cycle when pair formation and gene exchange occur. Because pair formation in birds typically occurs during the breeding season, most studies have focused on breeding-site philopatry. Waterfowl (Anseriformes) are an important exception to this pattern because pair formation often occurs during the winter months. Yet, surprisingly few studies have examined winter philopatry in waterfowl. To serve as an impetus for future research, we summarize published information on winter philopatry in waterfowl and examine these patterns in light of current hypotheses proposed to explain philopatric behavior. Our analyses indicate that geese, swans, and sea ducks show high levels of winter philopatry, with homing rates varying between 49 and 98% in small study areas. In contrast, return rates (0 to 20%) and homing rates (35 to 85%) to large study areas probably are comparatively lower for dabbling ducks and pochards. Unfortunately, detailed comparisons among groups are hindered by variation in the scale at which philopatric behavior is evaluated (ranging from 2 to 105 km2), and by confounding of return rates with homing rates. Future studies of winter philopatry would benefit by the adoption of a more standardized methodology. Many of the hypotheses proposed to explain breeding philopatry apply equally well to winter philopatry. In particular, both genetic and ecological mechanisms may play a role in the evolution of philopatry to the wintering ground. Additional field studies are needed to test these hypotheses, and we suggest future directions for a more detailed examination of this neglected area of research. Received 9 September 1996, accepted 28 April 1998.
Associate Editor: John M. Eadie
Sex-biased winter philopatry in Harlequin Ducks: are waterfowl really an exception to the rule?
GREGORY J. ROBERTSON, Dept. of Biol. Sci., Simon
Fraser Univ., Burnaby, BC.
Many birds species exhibit a resource based mating system where males defend breeding territories. This mating system is thought to have lead to male-biased philopatry as male birds are better able to defend familiar territories. In contrast, female waterfowl are more likely than males to return to their breeding grounds. Waterfowl are the exception because males cannot economically defend breeding territories and a mate-defense system has evolved. However, waterfowl pair in the winter. If male waterfowl can
defend winter territories a resource defense mating system may evolve and, consequently, male-biased philopatry to the wintering grounds. Since August 1994 I have studied a small population of wintering Harlequin Ducks (Histrionicus histrionicus) in coastal southwestern British Columbia. Locally, a total of 122 individuals have been caught during the wing molt and marked with individually identifiable tarsal leg bands. Weekly surveys were conducted to assess population size, sex ratio, age structure and as
many bands as possible were read. The local population size and sex ratio fluctuated considerably over the two winter seasons. An influx of young males and unpaired males occurred in April of each year, before departure to the breeding grounds. Males moved around the study site more than females. Unpaired males moved around the study site more than paired males. Return rates from one season to the next were high (males: 72%, females: 66%) and did not differ between the sexes. Pairing occurred early in the winter
(November) and pair re- formation occurred in 4 pairs where both members returned to the study area. Harlequin Ducks appear to have a mate-defense mating system and male-biased winter philopatry would not be expected.
Habitat Selection And Moult Characteristics Of Male Barrow's Goldeneye In Northern Yukon.
Debbie E. van de Wetering & Tony D. Williams.
Philopatry in Harlequin Ducks moulting in southern British Columbia by Andre M. Breault and Jean-Pierre L. Savard
Within-year fidelity of Harlequin Ducks to a moulting and wintering area by Gregory J. Robertson, Fred Cooke, R. Ian Goudie and W. Sean Boyd
Foraging strategies and habitat use of sea ducks breeding in northeast Russia by Alexander V. Kondratyev