Canadian Wildlife Service Research Articles

Increasing Mallards, Decreasing American Black Ducks: Coincidence or Cause and Effect?

We used Canadian Wildlife Service (CWS) survey data (1971-87) to define 7 wetland categories regarding historical changes in mallard (Arras platyrhynchos) and black duck (A. rubripes) distributions in southern Ontario to examine the hypothesis that mallards first invaded and then replaced black ducks on fertile wetlands. Wetlands were defined as: Mallards 1970's―wetlands where mallards invaded in the 1970's but were never recorded as being used by black ducks; Mallards 1980's-wetlands where mallards invaded in the 1980's but were never recorded as being used by black ducks; Black Ducks Replaced 1970's-wetlands where mallards replaced black ducks in the 1970's; Black Ducks Replaced 1980's-wetlands where mallards replaced black ducks in the 1980's; Mallards/Black Ducks--wetlands that mallards and black ducks coinhabited; Black Ducks Only-wetlands used only by black ducks; and Unused

Systematics and conservation of the swift fox, Vulpes velox, in North America

Two subspecies of swift fox have been described for North America, Vulpes velox velox and Vulpes velox hebes, but the latter northern subspecies is no longer recognised as endangered due to controversy over systematic status. We analyse morphological variation in these North American foxes, and conclude that subspecific status for northern populations is probably not justified, even though there is significant geographic variation. Because geographic variation may reflect genetic variation, we feel it should be the object of conservation effort. Although taxa may receive variable conservation attention due to the existence of arbitrary subspecies classifications, such preservation efforts may be desirable. The Canadian Wildlife Service has initiated a swift fox rehabilitation project in Alberta, Saskatchewan, and Manitoba, where foxes are re-introduced from Colorado stock. We urge extreme caution in such programmes because of risk of interbreeding with rare swift foxes known to exist in northern Great Plains states and potential loss of genetic adaption to the rigours of northern environments.

Beating a Dead Horse: Reply to Levy's Comments

American AnthropologistVolume 87, Issue 1 p. 123-125 Free Access Beating a Dead Horse: Reply to Levy's Comments Alan J. Osborn, Alan J. Osborn Department of Anthropology University of NebraskaSearch for more papers by this author Alan J. Osborn, Alan J. Osborn Department of Anthropology University of NebraskaSearch for more papers by this author First published: March 1985 https://doi.org/10.1525/aa.1985.87.1.02a00120AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. REFERENCES CITED Berger J. 1983 Ecology and Catastrophic Mortality in Wild Horses: Implications for Interpreting Fossil Assemblages. Science, 202, 1403– 1404. Chalfant, S. A. 1974 Aboriginal Territory of the Nez Perce Indians. In Nez Perce Indians. S. A. Chalfant and V. F. Ray, eds. Pp. 1– 164. New York: Garland. Ewers, J. C. 1955 The Horse in Blackfoot Indian Culture: With Comparative Material from Other Western Tribes. Bureau of American Ethnology Bulletin No. 159. Harris, M. 1979 Cultural Materialism: The Struggle for a Science of Culture. New York: Random House. Kelsall, J. P., and W. Prescott 1971 Moose and Deer Behavior in Snow. Canadian Wildlife Service Report Series 15. Krebs, C.J. 1978 Ecology: The Experimental Analysis of Distribution and Abundance. New York: Harper & Row. Levy, J. E. 1961 Ecology of the Southern Plains: The Ecohistory of the Iowa, Comanche, Cheyenne, and Arapaho, 1830–1870. In Symposium: Patterns of Land Utilization and Other Papers. Proceedings of the American Ethnological Society. Viola E. Garfield, ed. Pp. 18– 25. Seattle: University of Washington Press. Mattfeld, G.J. 1974 The Energetics of Winter Foraging by Whitetailed Deer: A Perspective on Winter Concentration. Ph.D. thesis, Syracuse State University, Syracuse, New York. Mierau, G. W., and J. L. Schmidt 1981 The Mule Deer of Mesa Verde National Park. Mesa Verde Research Series, Paper No. 2. Moen, A. N. 1966 Factors Affecting the Energy Exchange of White-tailed Deer, Western Minnesota. Ph.D. thesis, University of Minnesota, St. Paul, Minnesota. Moen, A. N. 1968 Energy Exchange of White-tailed Deer, Western Minnesota. Ecology, 49, 676– 682. Moen, A. N. 1976 Energy Conservation by White-tailed Deer in the Winter. Ecology, 57, 192– 198. Morrison, F. B. 1957 Feeds and Feeding: A Handbook for the Student and Stockman. Ithaca, NY: Morrison Publishing. Murdock, G. P. 1967 Ethnographic Atlas. Pittsburgh: University of Pittsburgh Press. Osborn, Alan J. 1983 Ecological Aspects of Equestrian Adaptations in Aboriginal North America. American Anthropologist, 85, 563– 591. Pruitt, W. O. 1959 Snow as a Factor in the Winter Ecology of Barrenground Caribou. Arctic, 12, 158– 179. Roe, F. G. 1955 The Indian and the Horse. Norman: University of Oklahoma Press. United States Senate 1936 The Western Range: Letter from the Secretary of Agriculture. 74th Congress, 2nd Session, Senate Document No. 199. Washington, DC: U.S. Government Printing Office. van Dyne, G. M., N. R. Brockington, Z. Szocs, J. Duek, and C. A. Ribic 1980 Large Herbivore Subsystem. In Grasslands, Systems Analysis and Man. A. I. Breymeyer and G. M. , eds. Pp. 269– 537. Cambridge: Cambridge University Press. Vibe, C. 1967 Arctic Animals in Relation to Climatic Fluctuations. Meddelelser om Gronland, 179(5): 1– 227. Wilkinson, P. F. 1974 Behavior and Domestication of the Musk Ox. In The Behavior of Ungulates and Its Relation to Management, Vol 2. V. Geist and F. Walther, eds. Pp. 909– 920. Morjes, Switzerland: International Union for Conservation of Nature and Natural Resources. Volume87, Issue1March 1985Pages 123-125 ReferencesRelatedInformation

Canadian Wildlife Service Reductions: Response of Minister

Canadian Wildlife Service Reductions: Response of Minister

The Importance of Wildlife to Canadians: Highlights of the 1981 National Survey. Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, Canada. 1983. 40p

The Importance of Wildlife to Canadians: Highlights of the 1981 National Survey. Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, Canada. 1983. 40p

Relationship of Weight to Chest Girth in the Grizzly Bear

J. A. NAGY, Alberta Environmental Centre, Bag 4000, Vegreville, Alberta TOB 4LO0, Canada; M. C. KINGSLEY, Department of Fisheries and Oceans, 501 University Crescent, Winnipeg, Manitoba R3T 2N6, Canada; R. H. RUSSELL, Canadian Wildlife Service, Room 1000, 9942 108 Street, Edmonton, Alberta T5K 2J5, Canada; A. M. PEARSON, 209B Main Street, Whitehorse, Yukon V1A 2B2, Canada; and B. C. GOSKI, Alberta Environmental Centre, Bag 4000, Vegreville, Alberta TOB 4L0, Canada.

Tooth Wear Rate in Northern Bison

Wood Buffalo National Park is a boreal preserve that spans the border between Alberta and the Northwest Territories. In its 44,668-km2 area there are about 6,000 free-roaming bison (Bison bison) (Anions, 1982, pers comm.; Anions and Lukiwski, 1980). From 1977 until 1981, the Canadian Wildlife Service and Parks Canada performed field studies of the interactions between wolf (Canis lupus) and bison in the Park, allowing thorough documentation of a number of bison deaths due to predation (Oosenbrug et al., 1980a, 1980b). Carcasses were examined after wolves completed feeding and teeth were collected for the purpose of determining age. I collected additional lower jaws from skeletons that I encountered during ground surveys for bison bones (Haynes, 1983). Attributes of tooth eruption and wear as they reflect age in bison have been discussed by Fuller (1959), Armstrong (1965), Frison and Reher (1970), and Reher and Frison (1980). The latter two studies are the most detailed, but involve archeological samples of B. bison from prehistoric sites on the northern Great Plains. Although the subspecific status of bison in Wood Buffalo National Park is still unsettled (Geist and Karsten, 1977; Peden and Kraay, 1979), the animals clearly are conspecific with the northern Plains population. Additionally, bison in the two populations possess nearly identical dentition, and the sequence and timing of tooth eruption are the same for both (Frison and Reher, 1970; Haynes, unpubl. data). Therefore, it seems valid to compare wear rates of teeth in the northern and southern bison. The first mandibular molar was selected for age determination because it is a large tooth that usually persists even in weathered jaws and because it is fully erupted and in function at about 12 months of age (Frison and Reher, 1970). The thin layers of cementum that are laid down annually on the roots of the first molar will thus record all years of life (Armstrong, 1965). The enamel height on the metaconid was measured for each first molar from 20 dentaries. This measurement was taken with a sliding caliper, and records the height of the crown from occlusal surface to the boundary of the enamel with the cementum-covered root, measured parallel to the long axis of the cusp (Table 1). Next, the first molars from these 20 dentaries were examined microscopically to determine age, in some cases by use of both optical and scanning electron microscopes (SEM). Before examination, the molars were removed from dentaries by sawing out the alveolar bone around roots, using a 0.25 horsepower hand-held rotary saw, which polished as it cut. The root segment was sagittally sectioned, to expose the thickest part of the layered cementum at the interradicular zone between the two roots (Fig. 1). Hand-held magnifying lenses or stereo dissecting microscopes were used to make three separate and blind counts of the visible annular cementum layers on the sections. These microscopic paired light colored and dark bands are assumed to represent a full year of cementum deposition (Armstrong, 1965). Layers that appear very light-colored (nearly white) are in fact opaque and are richer in cementocyte cells than the darker layers, which are translucent when seen in thin section. Each 1 cm thick specimen section was soaked 15-30 min in a 5% solution of formic acid and dried for 12 h. The acid bath dissolves proportionately more of the lighter colored layers, and hence etches the cementum by causing alternating layers to collapse through partial dissolution. The resulting appearance of the cementum is of valleys (the collapsed layers that were originally white) between raised ridges (the less dissolved layers that were originally dark colored) (Armstrong, 1965). After three blind counts were made, 11 tooth segments were selected as a sample of age categories best represented by the dentaries. These specimens were sputter-coated with gold: palladium (40:60) and then micrographed in a Cambridge Mark IIA Stereoscan scanning electron microscope (SEM) operated at 20 kV. Using the micrographic prints, counts were made of paired ridges and valleys in the cementum layers (Fig. 1B). Cementum band counts from the optical and SEM examinations are presented in Table 1. The counts are thought to reflect to within ?2 years the actual ages of the sample animals. The plus/minus factor results from the fact that the first one or two paired light colored and dark layers of cementum are usually August 1984 487

MULTIVARIATE ANALYSIS OF PARAMETERS RELATED TO LAKE ACIDIFICATION IN QUEBEC1

ABSTRACT Physico‐chemical data from 234 lakes were collected during the spring and summer of 1980 by the Quebec Ministry of the Environment, the Quebec Ministry of Recreation, Hunting and Fishing and the Canadian Wildlife Service. A statistical method, based on the joint use of factorial correspondence analysis and cluster analysis, was applied to these data to obtain a general picture of the spatial variability of a number of physico‐chemical parameters related to the sensitivity or acidification of lakewaters. This method was first applied to the entire Quebec territory, and showed that the part of Quebec lying on the Canadian shield is especially vulnerable to acidification. The method also showed that the southwestern portion of this area of Quebec was more substantially affected by acid fallout. A detailed study of spatial variability over the shield area revealed the existence of greater spatial heterogeneity. More precisely, it was possible to pinpoint zones which are highly vulnerable to acid precipitation and zones whose lakes show clear signs of acidification resulting from such precipitation. These two statistical analyses led to a first general diagnosis on lake acidification in Quebec. They contributed to the rationalization of data acquisition in Quebec by delimitating zones where network density needs to be increased.

Artificial Nests for Ferruginous and Swainson's Hawks

JOSEF K. SCHMUTZ,' Department of Zoology, University of Alberta, Edmonton, Alberta T6G 2E9, Canada; RICHARD W. FYFE, Environment Canada, Canadian Wildlife Service, Room 1000, 9942-108th Street, Edmonton, Alberta T5K 2J5, Canada; DAVID A. MOORE, Alberta Energy and Natural Resources, Fish and Wildlife Division, Brooks Wildlife Centre, P.O. Bag 1540, Brooks, Alberta TOJ OJO, Canada; and ALAN R. SMITH, Environment Canada, Canadian Wildlife Service, Prairie Migratory Bird Research Centre, 115 Perimeter Road, Saskatoon, Saskatchewan S7N OX4, Canada.

Food intake and weight increments of Common Guillemot chicks Uria aalge: a comment

IbisVolume 126, Issue 3 p. 421-422 Food intake and weight increments of Common Guillemot chicks Uria aalge: a comment T. K. Birkhead, T. K. Birkhead Zoology Department, The Uniresity, Sheffield S10 2TNSearch for more papers by this authorD. N. Nettleship, D. N. Nettleship Canadian Wildlife Service, Bedford Institute of Oceanography, P.O. Ros 1006. Dartmouth, Nova Scotia, CanadaSearch for more papers by this author T. K. Birkhead, T. K. Birkhead Zoology Department, The Uniresity, Sheffield S10 2TNSearch for more papers by this authorD. N. Nettleship, D. N. Nettleship Canadian Wildlife Service, Bedford Institute of Oceanography, P.O. Ros 1006. Dartmouth, Nova Scotia, CanadaSearch for more papers by this author First published: July 1984 https://doi.org/10.1111/j.1474-919X.1984.tb00266.xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article.Citing Literature Volume126, Issue3July 1984Pages 421-422 RelatedInformation

A Group Threat Display Given by Walruses to a Polar Bear

Journal Article A Group Threat Display Given by Walruses to a Polar Bear Get access Ian Stirling Ian Stirling Canadian Wildlife Service, 5320-122nd Street, Edmonton, Alberta, Canada T6H 3S5 Search for other works by this author on: Oxford Academic Google Scholar Journal of Mammalogy, Volume 65, Issue 2, 31 May 1984, Pages 352–353, https://doi.org/10.2307/1381182 Published: 31 May 1984 Article history Received: 18 May 1983 Accepted: 22 September 1983 Published: 31 May 1984

Reindeer herding as private enterprise in Canada

AbstractAfter unsuccessful introductions of reindeer into Canada during the early decades of this century, a herd brought from Alaska in 1935 was maintained successfully under government management (latterly under the Canadian Wildlife Service) for almost 40 years in the Mackenzie Delta region, Northwest Territories. Sold in 1974 into private ownership, the herd has since increased substantially in size; new management techniques have been developed to herd, handle and slaughter the animals. Meat, antlers in velvet and skins are the main products of a small but profitable local industry under native ownership. Currently numbering some 16 000 animals, the herd now justifies new management decisions affecting its future size and the scope of the enterprise.

Conservation of Colonial Waterbirds in the Caribbean Basin: Summary of a Panel Discussion

The Caribbean region, including northern South America, is an important wintering area and migratory pathway for migrating birds. During the past 30 years especially, a great deal of habitat alteration has occurred because of human population growth. Of most significance to waterbirds has been the drainage of many wetlands in the region. A panel discussion on the issue of waterbird conservation was held at the seventh annual meeting of the Colonial Waterbird Group (CWG) in San Juan, Puerto Rico. The discussion was aimed at 1) describing what local, national, and international programs are currently underway pertaining to waterbirds, 2) reviewing major threats to species and their habitat in certain areas, and 3) identifying specific types of actions that could be taken through cooperation with such organizations as the World Wildlife Fund (WWF), International Council for Bird Preservation (ICBP), and the International Waterfowl Research Bureau (IRWB). Although some discussion of South American countries occurs in the following text, we focused mainly on the Caribbean region. Summaries of the presentations and discussion follow: Canadian Wildlife Service (I. M. Price). -A new Canadian Wildlife Service initiative is the Latin American Program (LAP) whose scope includes all of the Caribbean region, Central and South America. Its primary objective is to promote the conservation of birds that spend part of the year in Canada and winter in Latin America. After several months of consulting people with first-hand ecological experience in Latin America, CWS concluded that Latin American problems are similar to those of North America but that the scales differ. Habitat destruction, the use and abuse of agricultural chemicals, and industrial pollution were the gravest problems identified. The next step was to visit some Latin American countries to introduce the CWS and the LAP. We found Latin American wildlife agencies willing to work with us to promote the conservation of shared birds. We plan to meet our primary objective by sponsoring projects relating to surveys, shorebirds, waterbirds, toxic chemicals, wetland evaluation, and habitat loss. All projects should be jointly planned, carried out, and funded by us and one or more Latin American wildlife agencies or their designates. This latter point is important as joint funding increases the level of commitment by all parties. We also fund projects relating to training and professional development of Latin American biologists and technicians and are particularly interested in seeing measurable results at the end of a project. The first major project, headed by R. I. G. Morrison, was a survey of the northern and eastern coastline of South America to identify shorebird concentration areas and to obtain a preliminary assessment of the distribution and characteristics

Development of an evaluation system for wetlands in Southern Ontario

Wetland loss in Ontario is proceeding at an unprecedented rate. Beginning in 1980 a quantitative system of wetland evaluation was developed by the Ontario Ministry of Natural Resources and the Canadian Wildlife Service working under a Canada/Ontario Steering Committee. Field testing of the working draft took place in 1982 and the First Edition was used in 1983. Improvements to the methodology resulted in a Second Edition which was released in the spring of 1984. (The evaluation system groups wetland values according to biological, social, hydrological and special features components. Based on score totals from the four components, all wetlands assessed are ranked in Classes from I (highest) to VII (lowest). Wetlands receiving Class I or II ranking are considered provincially significant; those scoring as Class III are regionally significant. These rankings are presently being used to support wetland guidelines with the long-range goal of wetland protection for significant wetlands.)

Estimating Bias Due to Nonresponse In Mail Surveys. F. L. Filion. Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, Canada K1A 0E7. 1976. 11p

Estimating Bias Due to Nonresponse In Mail Surveys. F. L. Filion. Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, Canada K1A 0E7. 1976. 11p

Importance of Question Wording and Response Burden in Hunter Surveys. Fern L. Filion. Canadian Wildlife Service, Department of the Environment, Ottawa, Ontario, Canada K1A 0E7. 1981. 10p

Importance of Question Wording and Response Burden in Hunter Surveys. Fern L. Filion. Canadian Wildlife Service, Department of the Environment, Ottawa, Ontario, Canada K1A 0E7. 1981. 10p

Human Surveys In Wildlife Management. Fern L. Filion. Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, Canada K1A 0E7. 1980. 13p plus references

Human Surveys In Wildlife Management. Fern L. Filion. Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, Canada K1A 0E7. 1980. 13p plus references

Browse Production and Its Use by Moose and Snowshoe Hares at the Kenai Moose Research Center, Alaska

A 4-year study conducted at the Moose Research Center (MRC) on the Kenai National Wildlife Refuge, Alaska evaluated the effect of different densities of moose (Alces alces) on paper birch (Betula papyrifera) production and use. Production and use of quaking aspen (Populus tremuloides) and willow (Salix spp.) were also estimated and the impact of snowshoe hares (Lepus americanus) on paper birch was evaluated. The study was conducted in 4 2.6-km2 enclosures at the MRC where moose densities ranged from 1,237 to 5,851 moose-days/pen/winter period. Paper birch produced an average of 102 kg/ha in the 4 enclosures whereas willow and aspen together produced only 3.7 kg/ha. During the 1st 3 years there was a significant difference in per-plant production among 5 important vegetative types. Use by moose at higher densities affected mean plant production the 3rd and 4th years. Birch use ranged from 31.8 to 83.3% of current annual production. During the 4 years, snowshoe hares browsed a greater percentage of tagged plants than did moose. Sixty-five percent of the birch plants browsed by hares were less than 1.5 m tall and 62% of those browsed by moose were taller than 1.5 m. Birch plants browsed in a given year were shorter on the average the following growing season. Seventy percent of the willow and 58.7% of the aspen plants were browsed during winter. J. WILDL. MANAGE. 47(2):486-496 I evaluated the effects of forage use by moose at the Moose Research Center (MRC) on the Kenai National Wildlife Refuge (KNWR), Alaska from October 1971 through May 1975. The primary objective was to evaluate the effect of different moose densities on production and use of paper birch. Although quaking aspen and willow occur at the MRC, paper birch was the most abundant forage species and LeResche and Davis (1973) found that it composed the bulk of the moose's year-round diet. Snowshoe hares were near a cycle high when the study began and were having an obvious effect on the vegetation. Secondary objectives were to estimate production of aspen and willow and their use by herbivores, and to evaluate the impact of snowshoe hares on paper birch. P. D. Arneson, A. W. Franzmann, and R. E. LeResche of the Alaska Department of Fish and Game; J. B. Hakala, J. B. Monnie, and R. K. Seemel of the Kenai National Wildlife Refuge; and R. B. Finley, Denver Wildlife Research Center, provided logistic support and guidance for the study. I thank S. Blackhall, T. Corr, R. Pietron, D. Porter, and T. Spraker for field assistance. The manuscript was reviewed by C. P. Stone, National Park Service; A. W. Franzmann, Alaska Department of Fish and Game; T. Bailey and E. Bangs, Kenai National Wildlife Refuge; E. S. Telfe , Canadian Wildlife Service; J. 0. Wolff, University of Virginia; and W. L. Regelin, Denver Wildlife Research Center. The Moose Research Center is a cooperative research project between the Alaska Department of Fish and Game and the U.S. Fish and Wildlife Service.

Winter Distribution and Affinities of Canada Geese Marked on Hudson and James Bays

Management plans for redistribution of the Mississippi Valley Population of Canada geese (Branta canadensis) in the United States prompted our investigation of the fall and winter distribution, migration chronology, and population affiliation of Canada geese marked on nesting areas in Manitoba and Ontario. During 1976-77, 804 geese were neckbanded. Encounters in 1976 and 1977 (N = 1,418) demonstrated a strong association of geese from the coast of Hudson Bay and the western coast of James Bay with the Mississippi Valley Population. About 50-60% of the marked samples bypassed east central Wisconsin refuges in migrating to wintering areas. Marked individuals from both years were observed at all major goose refuges in east central Wisconsin and southern Illinois. The 8 October mean arrival date in Wisconsin in 1976 was 8 days earlier than that for geese marked in previous years at Horicon. Departure from Wisconsin in 1977 was earlier than in 1976 and was associated with abnormal heavy snowfall and the Horicon goose dispersal program. Age ratios in trapped samples (7.7 immatures/adult female) suggested the inclusion of gang broods. Geese from the same nesting area did not remain together during fall and winter. Although some family groups were identified on migration and winter refuges, the observed mean number of marked immatures per adult female (1.7) was lower than the mean recorded on the nesting areas. J. WILDL. MANAGE. 47(2):307-319 The Mississippi Valley Population (MVP) of Canada geese numerically increased during the past 3 decades, with most of the increased numbers of geese wintering on refuges in Wisconsin, Illinois, and Kentucky (Hankla and Rudolph 1967, Reeves et al. 1968). Large concentrations of geese may have impacts on hunting quality and agricultural operations (K. Klepinger and J. W. Ellis, unpubl. rep., U.S. Dep. Inter., Fish and Wildl. Serv., Minneapolis, Minn., 1975). Because of these impacts and a continuing desire for more geese in southern states, management agencies would like to redistribute some of the MVP from northern wintering areas to smaller, widely scattered southern refuges. If the MVP consists of aggregations of geese with discrete and consistent patterns of migration and refuge use, as suggested by Raveling (1969a) and Kennedy and Arthur (1974) and documented for giant Canada geese (B. c. maxima) by Raveling (1979), selective management could be applied. Development of a management plan for redistribution of the MVP requires data on the migration and distribution of MVP geese. These needs prompted this study. Our objectives were to (1) ascertain the degree of association of geese from sections of the nesting range of the MVP; (2) investigate variation in migration chronology of geese from nesting areas in Manitoba and Ontario, and (3) determine whether samples of geese from the breeding grounds have discrete migration patterns and winter distributions. We thank F. D. Caswell, M. Gillespie, and D. Soprovich of the Manitoba Department of Renewable Resources and K. Brace of the Canadian Wildlife Service for arrangement, support, and assistance in banding operations in 1976. We thank H. G. Lumsden and J. P. Prevett of the Ontario Ministry of Natural Resources for organizing and conducting the banding effort in 1977. J. P. Prevett, D. G. Raveling, and H. C. Hanson critically reviewed the manuscript. J. Wildl. Manage. 47(2):1983 307 This content downloaded from 207.46.13.128 on Fri, 29 Jul 2016 05:17:53 UTC All use subject to http://about.jstor.org/terms 308 MISSISSIPPI VALLEY POPULATION OF CANADA GEESE * Craven and Rusch

Double-crested Cormorants of the Great Lakes: egg-laying parameters, reproductive failure, and contaminant residues in eggs, Lake Huron 1972–1973

During the 1960s Double-crested Cormorants breeding on Lake Huron experienced a decline in numbers and an elevation in body and egg contaminant burdens. In 1972 and 1973 the Canadian Wildlife Service visited their colonies to collect demographic data and eggs for residue analysis. In 1972, colonies were small. They suffered high egg breakage and loss (95%) and nearly total reproductive failure (0.06–0.11 young per nest). Eggshells were 23.9% thinner than normal. Clutch size (2.0 ± 1.2 eggs) was low but egg production (4.1 ± 1.9 eggs) appeared normal. Subsequent clutches appeared in 45% of the nests. Levels of DDE (14.5 ± 5.6 ppm, wet weight) and PCBs (23.8 ± 9.6 ppm) in the eggs were higher than in other cormorant populations in Canada. Levels of DDT, DDD, dieldrin, heptachlor epoxide, hexachlorobenzene, and mercury were less than 1 ppm. Organochlorine levels in eggs from Georgian Bay were similar to those from the North Channel, but mercury levels were higher. Colony size continued to decline in 1973, although reproductive success improved (0.3 young per nest). These data may be used to assess subsequent changes in the status of Lake Huron cormorants which unpublished observations indicate are now recovering rapidly.