Northern Prairie Wildlife Research Center
Albers, P. H. 1980. Transfer of crude oil from contaminated water to bird eggs. Envir. Resour. 22:307-314. Alison, R. M. 1975. Breeding biology and behavior of the oldsquaw (Clangula hyemalis L.). Ornithol. Monogr. 18. Alliston, W. G. 1975. Web-tagging ducklings in pipped eggs. J. Wildl. Manage. 39:625-628. -----. 1979. The population ecology of an isolated nesting popula- tion of redheads (Aythya americana). Dissertation. Cornell Univ., Ithaca, New York, USA. Amat, J. A. 1983. Pursuit flights of mallard and gadwall under differ- ent environmental conditions. Wildfowl 34:14-19. Anderson, D. R., & K. P. Burnham. 1976. Population ecology of the mallard. VI. The effect of exploitation on survival. U.S. Fish Wildl. Serv. Resour. Publ. 128. Anderson, D. W., & J. J. Hickey. 1972. Eggshell changes in certain North American birds. Intern. Ornithol. Congr. 15:514-540. Anderson, D. W., D. G. Raveling, R. W. Risebrough, & A. M. Springer. 1984. Dynamics of low-level organochlorines in adult cackling geese over the annual cycle. J. Wildl. Manage. 48:1112-1127. Anderson, W. 1965. Waterfowl production in the vicinity of gull colo- nies. Calif. Fish Game J. 51:5-15. Anderson, W. L. 1978. Waterfowl collisions with power lines at a coal- fired power plant. Wildl. Soc. Bull. 6:77-83. Ankney, C. D. 1980. Egg weight, survival, and growth of lesser snow goose goslings. J. Wildl. Manage. 44:174-182. Ankney, C. D., & C. D. MacInnes. 1978. Nutrient reserves and repro- ductive performance of female lesser snow geese. Auk 95:459-471. Arnold, T. W., & E. K. Fritzell. 1987. Food habits of prairie mink dur- ing the waterfowl breeding season. Canadian J. Zool. 65:2322- 2324. Ashworth, W. 1979. The Carson factor. Hawthorn Books, New York, New York, USA. Bailey, R. 0., & R. E. Jones. 1976. Mallard mortality in Manitoba's extended spring muskrat-trapping season. Wildl. Soc. Bull. 4:26-28. Baker, J. L. 1970. Wood duck brood survival on the Noxubee National Wildlife Refuge. Proc. Southeastern Assoc. Game Fish Comm. 24:104-108. Ball, I. J. 1973. Ecology of duck broods in a forest region of north- central Minnesota. Dissertation. Univ. Minnesota, St. Paul, Minne- sota, USA. Ball, I. J., D. S. Gilmer, L. M. Cowardin, & J. H. Riechmann. 1975. Survival of wood duck and mallard broods in north-central Minne- sota. J. Wildl. Manage. 39:776-780. Balser, D. S., H. H. Dill, & H. K. Nelson. 1968. Effect of predator re- duction on waterfowl nesting success. J. Wildl. Manage. 32:669- 682. Banko, W. E. 1960. The trumpeter swan -- its history, habits, and pop- ulation in the United States. North Amer. Fauna 63. Barry, T. W. 1964. Brant, Ross' goose, and emperor goose. Pages 145- 154 in J. P. Linduska, ed. Waterfowl tomorrow. U.S. Govern. Printing Off., Washington, D.C., USA. -----. 1967. The geese of the Anderson River Delta, Northwest Ter- ritories. Dissertation. Univ. Alberta, Edmonton, Alberta, Canada. -----. 1968. Observations on natural mortality and native use of ei- der ducks along the Beaufort Sea Coast. Canadian Field-Nat. 82:140-144. Bartonek, J. C., & D. L. Trauger. 1975. Leech (Hirudinea) infestations among waterfowl near Yellowknife, Northwest Territories. Canadian Field-Nat. 89:234-243. Batt, B. D. J., & G. W. Cornwell. 1972. The effects of cold on mallard embryos. J. Wildl. Manage. 36:745-751. Beetz, J. 1916. Notes on the eider. Auk 33:286-291. Bellrose, F. C. 1980. Ducks, geese and swans of North America. Stack- pole Books, Harrisburg, Pennsylvania, USA. Bellrose, F. C., K. L. Johnson, & T. U. Meyers. 1964. Relative value of natural cavities and nesting houses for wood ducks. J. Wildl. Man- age. 28:661-676. Bennett, L. J. 1938. The blue-winged teal, its ecology and manage- ment. Collegiate Press, Ames, Iowa, USA. Bird, R. D. 1961. Ecology of the aspen parkland of western Canada in relation to land use. Canadian Dep. Agr. Publ. 1066. Bishop, R. A., & R. Barratt. 1970. Use of artificial nest baskets by mallards. J. Wildl. Manage. 34:734-738. Blohm, R. J., F. Van Dyke, & B. C. Livezey. 1980. Marsh hawks feed- ing on waterfowl. Wilson Bull. 92:251-252. Blohm, R. J., R. E. Reynolds, J. P. Bladen, J. D. Nichols, J. E. Hines, K. E. Pollock, & R. T. Eberhardt. 1987. Mallard mortality rates on key breeding and wintering areas. Trans. North Amer. Wildl. & Nat. Re- sour. Conf. 52:246-257. Blus, L. J., C. J. Henny, D. J. Lenhart, & E. Cromartie. 1979. Effects of heptachlor-treated cereal grains on Canada geese in the Columbia Basin. Pages 105-116 in R. L. Jarvis & J. C. Bartonek, eds. Manage- ment and biology of Pacific Flyway geese. Oregon State Univ. Book- stores, Inc., Corvallis, Oregon, USA. Bolen, E. G. 1967. Nesting boxes for black-bellied tree ducks. J. Wildl. Manage. 31:794-797. Bouffard, S. H., D. E. Sharp, & C. C. Evans. 1987. Overwater nesting by ducks: a review and management implications. Proc. Great Plains Wildl. Damage Control Workshop 8:153-157. Bousfield, M. A., & Ye. V. Syroechkovskiy. 1985. A review of Soviet research on the lesser snow goose on Wrangel Island, U.S.S.R. Wild- fowl 36:13-20. Boyd, H. 1961. Reported casualties to ringed ducks in the spring and summer. Wildfowl Trust Ann. Rep. 12:144-146. -----. 1977. Waterfowl hunting by native peoples in Canada: the case of James Bay and northern Quebec. Intern. Cong. Game Biol. 13:463-473. Brakhage, G. K. 1965. Biology and behavior of tub-nesting Canada geese. J. Wildl. Manage. 29:751-771. Brand, C. J. 1984. Avian cholera in the central and Mississippi flyways during 1979-80. J. Wildl. Manage. 48:399-406. Braun, B. M., P. A. Heinz, & G. H. Heinz. 1980. Herring gull preda- tion on red-breasted merganser ducklings. Wilson Bull. 92:403. Braun, C. E., K. W. Harmon, J. A. Jackson, & C. D. Littlefield. 1978. Management of National Wildlife Refuges in the United States: its impacts on birds. Wilson Bull. 90:309-321. Brown, B. W. 1972. The Big Lake wood duck: a two-year study of its pre-flight mortality, nesting population growth and migration, 1970-71. Proc. Southeastern Assoc. Game Fish Comm. 26:195-202. Brown, P. W, & M. A. Brown. 1981. Nesting biology of the white- winged scoter. J. Wildl. Manage. 45:38-45. Brown, P. W. & M. L. Hunter, Jr. 1984-85. Potential effects of insec- ticides on the survival of dabbling duck broods. J. Minnesota Acad. Sci. 50:41-45. Cain, B. 1972. Cold hardiness and development of homeothermy in young black-bellied tree ducks. Wilson Bull. 84:483-485. -----. 1973. Effect of temperature on energy requirements and northward distribution of the black-bellied tree duck. Wilson Bull. 85:308-317. Caldwell, P. J., & A. E. Snart. 1974. A photographic index for aging mallard embryos. J. Wildl. Manage. 38:298-301. Calverley, B. K., & D. A. Boag. 1977. Reproductive potential in park- land and arctic-nesting populations of mallards and pintails (Anatidae). Canadian J. Zool. 55:1242-1251. Canadian Wildlife Service & U.S. Fish & Wildlife Service. 1986. North American waterfowl management plan. Canadian Wildl. Serv., Ottawa, Canada, & U.S. Fish Wildl. Serv., Washington, D.C., USA. Canadian Wildlife Service & U.S. Fish & Wildlife Service. 1987. Draft report--stabilized duck hunting regulations evaluation. Canadian Wildl. Serv., Ottawa, Canada, & U.S. Dep. Int., Fish Wildl. Serv., Washington, D.C., USA. Choate, J. S. 1967. Factors influencing nesting success of eiders in Pe- nobscot Bay, Maine. J. Wildl. Manage. 31:769-777. Cooch, F. G. 1958. The breeding biology and management of the blue goose Cben caerulescens. Dissertation. Cornell Univ., Ithaca, New York, USA. -----. 1961. Ecological aspects of the blue-snow goose complex. Auk 78:72-89. -----. 1965. The breeding biology and management of the northern eider (Somateria mollissima borealis) in the Cape Dorset area, Northwest Territories. Canadian Wildl. Serv. Wildl. Manage. Bull., Series 2, No. 10. -----. 1986. The current status of goose populations in Canada. Trans. North Amer. Wildl. & Nat. Resour. Conf. 51:480-486. Cook, G. F. 1986. Alaska waterfowl management and the law. Trans. North Amer. Wildl. & Nat. Resour. Conf. 51:516-526. Cooke, A. S. 1973. Shell thinning in avian eggs by environmental pol- lutants. Environ. Poll. 4:85-152. Cooper, J. A. 1978. The history and breeding biology of the Canada geese of Marshy Point, Manitoba. Wildl. Monogr. 61. Cornely, J. E., S. P. Thompson, E. L. McLaury, & L. D. Napier. 1985a. A summary of trumpeter swan production at Malheur National Wildlife Refuge, Oregon. Murrelet 66:50-55. Cornely, J. E., B. H. Campbell, & R. L. Jarvis. 1985b. Productivity, mortality and population status of dusky Canada geese. Trans. North Amer. Wildl. & Nat. Resour. Conf. 50:540-548. Cornwell, G., & H. A. Hochbaum. 1971. Collisions with wires -- a source of anatid mortality. Wilson Bull. 83:305-306. Cott, H. B. 1953/1954. The exploitation of wild birds for their eggs. Ibis 95:409-449, 643-675; 96:129-149. Cowan, W. F. 1982. Waterfowl production on zero tillage farms. Wildl. Soc. Bull. 10:305-308. Cowardin, L. M., & D. H. Johnson. 1979. Mathematics and mallard management. J. Wildl. Manage. 43:18-35. Cowardin, L. M., D. H. Johnson, A. M. Frank, & A. T. Klett. 1983a. Simulating results of management actions on mallard production. Trans. North Amer. Wildl. & Nat. Resour. Conf. 48-.257-272. Cowardin, L. M., A. B. Sargeant, & H. E Duebbert. 1983b. Problems and potentials for prairie ducks. Naturalist 34(4):4-11. Cowardin, L. M., D. S. Gilmer, & C. W Shaiffer. 1985. Mallard re- cruitment in the agricultural environment of North Dakota. Wildl. Monogr. 92. Crabtree, R. L., & M. L. Wolfe. 1988. Effects of alternate prey on skunk predation on waterfowl nests. Wildl. Soc. Bull. 16:163-169. Crissey, W. F. 1969. Prairie potholes from a continental viewpoint. Pages 161-171 in Saskatoon Wetlands Seminar. Canadian Wildl. Serv. Rep. Series 6. Dane, C. W., & G. L. Pearson. 1971. Effect of a spring storm on wa- terfowl mortality and breeding activity. Pages 258-267 in A. 0. Hau- gen, ed. Proc., snow and ice in relation to wildlife and recreation symposium. Iowa State Univ., Ames, Iowa, USA. Davison, K. L., & J. L. Sell. 1974. DDT thins shells of eggs from mal- lard ducks maintained on ab libitum or controlled-feeding regimens. Arch. Environ. Contamination & Toxicol. 2:222-232. Dekker, D. 1987. Peregrine falcon predation on ducks in Alberta and British Columbia. J. Wildl. Manage. 51:156-159. Doty, H. A., F. B. Lee, & A. D. Kruse. 1975. Use of elevated nest bas- kets by ducks. Wildl. Soc. Bull. 3:68-73. Dow, J. S. 1943. A study of nesting Canada geese in Honey Lake Val- ley, California. California Fish Game 29:3-18. Duebbert, H. F. 1966. Island nesting of the gadwall in North Dakota. Wilson Bull. 78:12-25. -----. 1969. High nest density and hatching success of ducks on South Dakota CAP lands. Trans. North Amer. Wildl. & Nat. Resour. Conf. 34:218-228. -----. 1982. Nesting of waterfowl on islands in Lake Audubon, North Dakota. Wildl. Soc. Bull. 10:232-237. Duebbert, H. R, & H. A. Kantrud. 1974. Upland duck nesting related to land use and predator reduction. J. Wildl. Manage. 38:257-265. Duebbert, H. F. & H. A. Kantrud. 1987. Use of no-till winter wheat by nesting ducks in North Dakota. J. Soil & Water Consem 42:50- 53. Duebbert, H. F., & J. T. Lokemoen. 1976. Duck nesting in fields of undisturbed grass-legume cover. J. Wildl. Manage. 40:39-49. Duebbert, H. F., & J. T. Lokemoen. 1980. High duck nesting success in a predator-reduced environment. J. Wildl. Manage. 44:428-437. Duebbert, H. F., J. T. Lokemoen, & D. E. Sharp, 1983. Concentrated nesting of mallards and gadwalls on Miller Lake Island. J. Wildl. Manage. 47:729-740. Duebbert, H. F., J. T. Lokemoen, & D. E. Sharp. 1986. Nest sites of ducks in grazed mixed-grass prairie in North Dakota. Prairie Nat. 18:99-108. Duncan, D. C. 1986, Survival of dabbling duck broods on prairie im- poundments in southeastern Alberta. Canadian Field-Nat. 100:110- 113. Dwernychuk, L. W., & D. A. Boag. 1972. Ducks nesting in association with gulls -- an ecological trap? Canadian J. Zool. 50:559-563. Dzubin, A., & J. B. Gollop. 1972. Aspects of mallard breeding ecology in Canadian parkland and grassland. Pages 113-152 in Population ecology of migratory birds: a symposium. U.S. Fish Wildl. Serv. Wildl. Res. Rep. 2. Dzubin, A., H. W. Miller, & G. V. Schildman. 1964. White-fronts. Pages 135-143 in J. P. Linduska, ed. Waterfowl tomorrow. U.S. Gov- ern. Printing Off., Washington, D.C., USA. Eberhardt, L. E., & A. B. Sargeant. 1977. Mink predation on prairie marshes during the waterfowl breeding season. Pages 33-43 in R. L. Phillips & C. Jonkel, eds. Proc. 1975 predator symposium. Univ. Montana, Missoula, Montana, USA. Eberhardt, L. E., W. C. Hanson, J. L. Bengtson, R. A. Garrott, & E. E. Hanson. 1982. Arctic fox home range characteristics in an oil-devel- opment area. J. Wildl. Manage. 46:183-190. Eberhardt, L. E., R. A. Garrott, & W. C. Hanson. 1983. Den use by arctic foxes in northern Alaska. J. Mammal. 64:97-102. Eberhardt, R. T., & M. L. Sperry. 1986. Age related productivity in ring-necked ducks. Page 23 in B. J. Joselyn, compiler. Summaries of wildlife research project findings 1985. Unpubl. Rep. Minnesota Dep. Nat. Resour., 1 October. St. Paul, Minnesota, USA. Eisenhauer, D. I., & C. M. Kirkpatrick. 1977. Ecology of the emperor goose in Alaska. Wildl. Monogr. 57. Eisenhauer, J. H. 1977. Nesting ecology and behavior of Pacific brant in Alaska. Baccalaureate Thesis. Univ. Lethbridge, Alberta, Canada. Ely, C. R., & D. G. Raveling. 1984. Breeding biology of pacific white- fronted geese. J.Wildl. Manage. 48:823-837. Ely, C. R., D. A. Budean, & U. G. Swain. 1987. Aggressive encounters between tundra swans and greater white-fronted geese during brood rearing. Condor 89:420-422. Erskine, A. J. 1971. Buffleheads. Canadian Wildl. Serv. Monogr. Se- ries, No. 4. Evans, R. D., & C. W. Wolfe, Jr. 1967. Waterfowl production in the rainwater basin area of Nebraska. J. Wildl. Manage. 31:788-794. Ewaschuk, E., & D. A. Boag. 1972. Factors affecting hatching success of densely nesting Canada geese. J. Wildl. Manage. 36:1097-1106. Faanes, C. A. 1987. Bird behavior and mortality in relation to power- lines in prairie habitats. U.S. Fish Wildl. Serv. Tech. Rep. 7. Faber, R. A., & J. J. Hickey. 1973. Eggshell thinning, chlorinated hy- drocarbons, and mercury in inland aquatic bird eggs, 1969 and 1970. Pest. Monitor J. 7:27-36. Fimreite, N. 1974. Mercury contamination of aquatic birds in north- western Ontario. J. Wildl. Manage. 38:120-131. Fleskes, J. P. 1986. Evaluation of waterfowl recruitment at Union Slough National Wildlife Refuge. Thesis. Iowa State Univ., Ames, Iowa, USA. Friend, M. 1981. Waterfowl management and waterfowl disease: in- dependent or cause and effect relationships? Trans. North Amer. Wildl. & Nat. Resour. Conf. 46:94-103. Fyfe, R. W. 1957. Hail damage in the June 17 storm. Blue Jay 15:170- 171. Gates, J. M. 1965. Duck nesting and production on Wisconsin farm- lands. J. Wildl. Manage. 29:515-522. Geis, M. B. 1956. Productivity of Canada geese in the Flathead Valley, Montana. J. Wildl. Manage. 20:409-419. Gershman, M., J. E. Witter, H. E. Spencer, Jr., & A. Kalvaitis. 1964. Case report: epizootic of fowl cholera in the common eider duck. J. Wildl. Manage. 28:587-589. Glover, F. A., & J. D. Smith. 1963. Waterfowl status report, 1963. U.S. Fish Wildl. Serv. Spec. Sci. Rep. -- Wildl. 75. Glup, S. S., & L. L. McDaniel. 1988. Bullsnake predation on water- fowl nests on Valentine National Wildlife Refuge, Nebraska. Proc. Great Plains Wildl. Damage Control Workshop 8:149-152. Greenburg, R. R., R. W Risebrough, & D. W Anderson. 1979. P-P'- DDE-induced changes in the organic and inorganic structure of egg- shells of the mallard, Anas platyrbynchos. Toxicol. & Applied Pharmacol. 48:279-286. Greenwood, R. J. 1969. Mallard hatching from an egg cracked by freezing. Auk 86:752-754. -----. 1986. Influence of striped skunk removal on upland duck nest success in North Dakota. Wildl. Soc. Bull. 14:6-11. Grice, D., & J. P. Rogers. 1965. The wood duck in Massachusetts. Fi- nal Report, Federal Aid in Wildlife Restoration, Project Number W19-R, Massachusetts Div. Fisheries & Game. Gross, A. 0. 1944. The present status of the American eider on the Maine coast. Wilson Bull. 56:15-26. Grue, C. E., L. R. Deweese, P. Mineau, G. A. Swanson, J. R. Foster, P. M. Arnold, J. N. Huckins, P. J. Sheehan, W. K. Marshall, & A. P. Ludden. 1986. Potential impacts of agricultural chemicals on water- fowl and other wildlife inhabiting prairie wetlands: an evaluation of research needs and approaches. Trans. North Amer. Wildl. & Nat. Resour. Conf. 51:357-383. Grue, C. E., M. W. Tome, G. A. Swanson, S. M. Borthwick, & L. R. Deweese. 1988. Agricultural chemicals and the quality of prairie- pothole wetlands for adult and juvenile waterfowl -- what are the concerns? Pages 55-64 in P. J. Stuber, coordinator. Proc. National Symp. Protection of Wetlands from Agricul. Impacts. U.S. Fish Wildl. Serv. Biol. Rep. 88(16). Gudmundsson, F. 1979. The past status and exploitation of the My- vatn waterfowl populations. Oikos 32:232-249. Haines, T. A., & M. L. Hunter, Jr. 1981. Waterfowl and their habitat: threatened by acid rain? Intern. Waterfowl Symp. 4:177-188. Hall, E. R. 1981. The mammals of North America. Volume 2. John Wiley & Son, New York, New York, USA. Hammond, M. C., & W. R. Forward. 1956. Experiments on causes of duck nest predation. J. Wildl. Manage. 20:243-247. Hansen, H. A. 1961. Loss of waterfowl production to tide floods. J. Wildl. Manage. 25:242-248. Hansen, H. A., P. E. K. Shepherd, J. G. King, & W. A. Troyer. 1971. The trumpeter swan in Alaska. Wildl. Monogr. 26. Hanson, H. C. 1965. The giant Canada goose. Southern Illinois Univ. Press, Carbondale, Illinois, USA. Hanson, H. C., P. Queneau, & P. Scott. 1956. The geography, birds and mammals of the Perry River region. Arctic Inst. North Amer. Spec. Publ. 3. Hanson, W. C., & L. L. Eberhardt. 1971. A Columbia River Canada goose population 1950-1970. Wildl. Monogr. 28. Haramis, G. M., & D. S. Chu. 1986. Acid rain effects on waterfowl: use of black duck broods to assess food resources of experimentally acidified wetlands. Pages 173-181 in A. W. Diamond and F. L. Filion, eds., The value of birds. Intern. Council Bird Preserv. Tech. Publ. No. 6. Haramis, G. M., & D. Q. Thompson. 1984. Survival of juvenile wood ducks in a northern greentree impoundment. J. Wildl. Manage. 48:1364-1369. Harvey, J. M. 1971. Factors affecting blue goose nesting success. Ca- nadian J. Zool. 49:223-234. Haseltine, S. D., B. M. Mulhern, & C. Stafford. 1980. Organochlorine and heavy metal residues in black duck eggs from the Atlantic Fly- way, 1978. Pest. Monitor J. 14:53-57. Heath, R. G. 1969. Nationwide residues of organochlorine pesticides in wings of mallards and black ducks. Pest. Monitor J. 3:115-123. Heath, R. G., J. W. Spann, & J. F. Kreitzer. 1969. Marked DDE im- pairment of mallard reproduction in controlled studies. Nature 224:47-48. Heinz, G. 1975. Effects of methylmercury on approach and avoidance behavior of mallard ducklings. Bull. Environ. Contamination & Tox- icol. 13:554-564. Herman, C. M., J. H. Barrow, Jr., & I. B. Tarshis. 1975. Leucocytozoo- nosis in Canada geese at the Seney National Wildlife Refuge. J. Wildl. Diseases 11:404-411. Heusmann, H. W. 1984. The effects of weather on local wood duck production. J. Wildl. Manage. 48:573-577. Hickey, J. J., & D. W. Anderson. 1968. Chlorinated hydrocarbons and eggshell changes in raptorial and fish-eating birds. Science 162:271- 273. Higgins, K. F. 1977. Duck nesting in intensively farmed areas of North Dakota. J. Wildl. Manage. 41:232-242. Hik, D. S., & F. Cooke. 1988. A possible case of intraspecific killing in the lesser snow goose. Wilson Bull. 100:665-666. Hilden, O. 1964. Ecology of duck populations in the island group of Valassaaret, Gulf of Bothnia. Annales Zool. Fennici 1:153-279. Hill, D., R. Wright, & M. Street. 1987. Survival of mallard ducklings Anas platyrhynchos and competition with fish for invertebrates on a flooded gravel quarry in England. Ibis 129:159-167. Hines, J. E., & G. J. Mitchell. 1983. Breeding ecology of the gadwall at Waterhen Marsh, Saskatchewan. Canadian J. Zool. 61:1532-1539. Hunter, M. L., Jr., J. W. Witham, & H. Dow. 1984. Effects of a car- baryl-induced depression in invertebrate abundance on the growth and behavior of American black duck and mallard ducklings. Cana- dian J. Zool. 62:452-456. Jahn, L. R., & R. A. Hunt. 1964. Duck and coot ecology and manage- ment in Wisconsin. Wisconsin Conser. Dep. Tech. Bull. 33. Jarvis, R. L., & S. W. Harris. 1971. Land-use patterns and duck pro- duction at Malheur National Wildlife Refuge. J. Wildl. Manage. 35:767-773. Johnson, D. H. 1979. Estimating nest success: the Mayfield method and an alternative. Auk 96:651-661. Johnson, D. H., & A. T. Klett. 1985. Quick estimates of success rates of duck nests. Wildl. Soc. Bull. 13:51-53. Johnson, D. H., & A. B. Sargeant. 1977. Impact of red fox predation on the sex ratio of prairie mallards. U.S. Fish Wildl. Serv. & Wildl. Res. Rep. 6. Johnson, D. H., & T. L. Shaffer. 1987. Are mallards declining in North America? Wildl. Soc. Bull. 15:340-345. Johnson, M. A., T. C. Hinz, & T. L. Kuck. 1987. Duck nest success and predators in North Dakota, South Dakota, and Montana: the Central Flyway study. Proc. Great Plains Wildl. Damage Control Workshop 8:125-133. Jones, J. K., Jr., D. M. Armstrong, R. S. Hoffmann, & C. Jones. 1983. Mammals of the northern Great Plains. Univ. Nebraska Press, Lin- coln, Nebraska, USA. Kalmbach, E. R. 1937. Crow-waterfowl relationships in the prairie provinces. Trans. North Amer. Wildl. Conf. 2:380-392. -----. 1938. A comparative study of nesting waterfowl on the Lower Souris Refuge: 1936-1937. Trans. North Amer. Wildl. Conf. 3:610- 623. -----. 1939. Nesting success: its significance in waterfowl reproduc- tion. Trans. North Amer. Wildl. Conf. 4:591-604. Kear, J. 1965. The internal food reserves of hatching mallard duck- lings. J. Wildl. Manage. 29:523-528. Keith, L. B. 1961. A study of waterfowl ecology on small impound- ments in southeastern Alberta. Wildl. Monogr. 6. Kelso, D. D. 1982. Subsistence use of fish and game resources in Alaska: considerations in formulating effective management poli- cies. Trans. North Amer. Wildl. & Nat. Resour. Conf. 47:630-640. Kerbes, R. H. 1969. Biology and distribution of nesting blue geese on Koukdjuak Plain, Baffin Island, N.W.T. Thesis. Univ. Western On- tario, London, Ontario, Canada. Kiel, W. H., Jr., A. S. Hawkins, & N. G. Parret. 1972. Waterfowl hab- itat trends in the aspen parkland of Manitoba. Canadian Wildl. Serv. Rep. Series 18. King, J. G. 1965. Storm driven flood tides on the Clarence Rhode Na- tional Wildlife Range. U.S. Bur. Sport Fish. & Wildl. Files, Bethel, Alaska, USA. King, J. G., & D. V. Derksen. 1986. Alaska goose populations: past, present and future. Trans. North Amer. Wildl. & Nat. Resour. Conf. 51:464-479. Kirby, R. E., & L. M. Cowardin. 1986. Spring and summer survival of female mallards from northcentral Minnesota. J. Wildl. Manage. 50:38-43. Klein, D. R. 1966. Waterfowl in the economy of the Eskimos on the Yukon-Kuskokwim Delta, Alaska. Arctic 19:319-336. Klett, A. T., & D. H. Johnson. 1982. Variability in nest survival rates and implications to nesting studies. Auk 99:77-87. Klett, A. T., H. R. Duebbert, C. A. Faanes, & K. F. Higgins. 1986. Tech- niques for studying nest success of ducks in upland habitats in the prairie pothole region. U.S. Fish Wildl. Serv. Resour. Publ. 158. Klett, A. T., T. L. Shaffer, & D. H. Johnson. 1988. Duck nest success in the prairie pothole region. J. Wildl. Manage. 52:431-440. Knight, O. W. 1895. Breeding of Somateria dresseri near Isle au Haut, Maine. Auk 12:388. Korschgen, C. E. 1977. Breeding stress of female eiders in Maine. J. Wildl. Manage. 41:360-373. Korschgen, C. E., H. C. Gibbs, & H. L. Mendall. 1978. Avian cholera in eider ducks in Maine. J. Wildl. Disease 14:254-258. Koskimies, J. 1954. Juvenile mortality and population balance in the velvet scoter (Melanitta fusca) in maritime conditions. Proc. Intern. Ornithol. Congr. 11:476-479. Koskimies, J., & L. Lahti. 1964. Cold-hardiness of the newly hatched young in relation to ecology and distribution in ten species of Euro- pean ducks. Auk 81:281-307. Krapu, G. L. 1974. Avian mortality from collisions with overhead wires in North Dakota. Prairie Nat. 6:1-6. -----. 1977. Pintail reproduction hampered by snowfall and agricul- ture. Wilson Bull. 89:154-157. Krapu, G. L., G. A. Swanson, & H. K. Nelson. 1973. Mercury resi- dues in pintails breeding in North Dakota. J. Wildl. Manage. 37:395-399. Krohn, W. B., & E. G. Bizeau. 1980. The Rocky Mountain population of the western Canada goose: its distribution, habitats, and manage- ment. U.S. Fish Wildl. Serv. Spec. Sci. Rep. 229. Labisky, R. F. 1957. Relation of hay harvesting to duck nesting under a refuge-permittee system. J. Wildl. Manage. 21:194-200. Larson, S. 1960. On the influence of the arctic fox Alopex lagopus on the distribution of arctic birds. Oikos 11:276-305. Lehner, P. N., & A. Egbert. 1969. Dieldrin and eggshell thickness in ducks. Nature 224:1218-1219. Lemieux, L. 1959. The breeding biology of the greater snow goose on Bylot Island, Northwest Territories. Canadian Field-Nat. 73:117- 128. Lensink, C. J. 1973. Population structure and productivity of whis- tling swans on the Yukon Delta, Alaska. Wildfowl 24:21-25. Livezey, B. C. 1981. Duck nesting in retired croplands at Horicon Na- tional Wildlife Refuge, Wisconsin. J. Wildl. Manage. 45:27-37. Lokemoen, J. T. 1984. Examining economic efficiency of management practices that enhance waterfowl production. Trans. North Amer. Wildl. & Nat. Resour. Conf. 49:584-607. Lokemoen, J. T., H. A. Doty, D. E. Sharp, & J. E. Neaville. 1982. Elec- tric fences to reduce mammalian predation on waterfowl nests. Wildl. Soc. Bull. 10:318-323. Longcore, J. R., & F. B. Samson. 1973. Eggshell breakage by incubat- ing black ducks fed DDE. J. Wildl. Manage. 37:390-394. Longcore, J. R., & R. C. Stendell. 1982. Black ducks and DDE: review and status. Trans. Northeast Sect. Wildl. Soc. 39:68-75. Longcore, J. R., F. B. Samson, & T. W. Whittendale, Jr. 1971. DDE thins eggshells and lowers reproductive success of captive black ducks. Bull. Environ. Contamination & Toxicol. 6:485-490. Longcore, J. R., J. D. Heyland, A. Reed, & P. Laporte. 1983. Contam- inants in greater snow geese and their eggs. J. Wildl. Manage. 47:1105-1109. McAloney, R. K. 1973. Brood ecology of the common eider (Somate- ria mollissima dresseri) in the Liscombe area of Nova Scotia. Thesis. Acadia Univ., Wolfville, Nova Scotia, Canada. McAuley, D. G., & J. R. Longcore. 1988. Survival of juvenile ring- necked ducks on wetlands of different pH. J. Wildl. Manage. 52:169-176. McCorkle, C. 0., & J. E. Halver (committee co-chairmen). 1982. Im- pacts of agricultural trends on interior wetland habitats. Pages 221- 252 in Impacts of emerging agricultural trends on fish and wildlife habitat. National Acad. Press, Washington, D.C., USA. McGilvrey, F. B. 1969. Survival in wood duck broods. J. Wildl. Man- age. 33:73-76. MacInnes, C. D. 1962. Nesting of small Canada geese near Eskimo Point, Northwest Territories. J. Wildl. Manage. 26:247-256. MacInnes, C. D., & R. K. Misra. 1972. Predation on Canada goose nests at McConnell River, Northwest Territories. J. Wildl. Manage. 36:414-422. MacInnes, C. D., R. A. Davis, R. N. Jones, B. C. Lieff, & A. J. Paku- lak. 1974. Reproductive efficiency of McConnell River small Can- ada geese. J. Wildl. Manage. 38:686-707. McInvaille, W. B., Jr., & L. B. Keith. 1974. Predator-prey relations and breeding biology of the great horned owl and red-tailed hawk in cen- tral Alberta. Canadian Field-Nat. 88:1-20. McKinney, F., S. R. Derrickson, & P. Mineau. 1983. Forced copulation in waterfowl. Behaviour 86:250-294. McLandress, M. R. 1983. Temporal changes in habitat selection and nest spacing in a colony of Ross' and lesser snow geese. Auk 100:335-343. MacLennan, R. 1977. Reproductive ecology of ducks on an irrigated hay marsh. Saskatchewan Dep. Tourism & Renewable Resour. Tech. Bull. 4. Malcolm, J. M. 1982. Bird collisions with a power transmission line and their relation to botulism at a Montana wetland. Wildl. Soc. Bull. 10:297-304. Mann, G. H. 1974. The prairie pothole region: a zone of environmen- tal opportunity. Naturalist 25(4):2-7. Manning, T. H. 1942. Blue and lesser snow geese on Southampton and Baffin Islands. Auk 59:158-175. Marcstrom, V. 1966. Mallard ducklings (Anas platyrhynchos L.) dur- ing the first days after hatching. Viltrevy 4:343-370. Mayfield, H. 1961. Nesting success calculated from exposure. Wilson Bull. 73:255-261. -----. 1975. Suggestions for calculating nest success. Wilson Bull. 87:456-466. Meltofte, H. 1978. A breeding association between ciders and tethered huskies; in north-east Greenland. Wildfowl 29:45-54. Mendall, H. L. 1958. The ring-necked duck in the northeast. Univ. Maine Bull. 60(16). Mendenhall, V. M. 1979. Brooding of young ducklings by female ei- ders Somateria mollissima. Ornis Scand. 10:94-99. Mendenhall, V. M., & H. Milne. 1985. Factors affecting duckling sur- vival of ciders Somateria mollissima in northeast Scotland. Ibis 127:148-158. Mickelson, P. G. 1975. Breeding biology of cackling geese and associ- ated species on the Yukon-Kuskokwirn Delta, Alaska. Wildl. Monogr. 45. Miller, H. W. & D. H. Johnson. 1978. Interpreting the results of nest- ing studies. J. Wildl. Manage. 42:471-476. Milne, H. 1974. Breeding numbers and reproductive rate of ciders at the sands of Forvie National Nature Reserve, Scotland. Ibis 116:135-154. Milonski, M. 1958. The significance of farmland for waterfowl nest- ing and techniques for reducing losses due to agricultural practices. Trans. North Amer. Wildl. Conf. 23:215-228. Mitchell, D. C. 1986. Native subsistence hunting of migratory water- fowl in Alaska: a case study demonstrating why politics and wildlife management don't mix. Trans. North Amer. Wildl. & Nat. Resour. Conf. 51:527-534. Mora, M. A., D. W. Anderson, & M. E. Mount. 1987. Seasonal vari- ation of body condition and organochlorines in wild ducks from California and Mexico. J. Wildl. Manage. 51:132-141. Moyle, J. B., ed. 1964. Ducks and land use in Minnesota. Minnesota Dep. Conserv. Tech. Bull. 8. Munro, D. A. 1963. Ducks and the great plains wetlands. Canadian Audubon Magaz. September-October:2-8. Murie, 0. J. 1959. Fauna of the Aleutian Islands and Alaska penin- sula. North Amer. Fauna 61. Nelson, R. K. 1969. Hunters of the northern ice. Univ. Chicago Press, Chicago, Illinois, USA. Newton, I., & C. R. G. Campbell. 1975. Breeding of ducks at Loch Leven, Kinross. Wildfowl 26:83-102. Nichols, J. D., M. J. Conroy, D. R. Anderson, & K. P. Burnham. 1984. Compensatory mortality in waterfowl populations: a review of the evidence and implications for research and management. Trans. North Amer. Wildl. & Nat. Resour. Conf. 49:535-554. Nigus, T. A., & J. J. Dinsmore. 1980. Productivity of Canada geese in northwestern Iowa. Proc. Iowa Acad. Sci. 87:56-61. Oetting, R. B., & J. F. Cassell. 1971. Waterfowl nesting on interstate highway right-of-way in North Dakota. J. Wildl. Manage. 35:774- 781. Oetting, R. B., & C. C. Dixon. 1975. Waterfowl nest densities and suc- cess at Oak Hammock Marsh, Manitoba. Wildl. Soc. Bull. 3:166- 171. Ogilvie, M. A. 1967. Population changes and mortality of the mute swan in Britain. Wildfowl Trust Ann. Rep. 18:64-73. -----. 1978. Wild geese. Buteo Books, Vermillion, South Dakota, USA. Ohlendorf, H. M., & M. R. Miller. 1984. Organochlorine contami- nants in California waterfowl. J. Wildl. Manage. 48:867-877. Ohlendorf, H. M., R. L. Hothem, C. M. Bunck, T. W Aldrich, & J. E Moore. 1986. Relationships between selenium concentrations and avian reproduction. Trans. North Amer. Wildl. & Nat. Resour. Conf. 51:330-342. Orthmeyer, D. L. 1987. Survival of mallard broods on Benton Lake National Wildlife Refuge in north-central Montana. Thesis. Univ. Montana, Missoula, Montana, USA. Owen, M. 1980. Wild geese of the world. B. T. Batsford Limited, Lon- don, England. Page, R. D. 1974. The ecology of the trumpeter swan on Red Rock Lakes National Wildlife Refuge, Montana. U.S. Fish Wildl. Serv. Fi- nal Rep., Region 1. Pakulak, A. J. 1969. Nesting ecology of Canada geese of the Churchill area, northern Manitoba. Thesis. Colorado State Univ., Fort Collins, Colorado, USA. Palmer, R. S., ed. 1976. Handbook of North American birds. Volumes 2 and 3. Yale Univ. Press, New Haven, Connecticut, USA. Pamplin, W., L., Jr. 1986. Cooperative efforts to halt population de- clines of geese nesting on Alaska's Yukon-Kuskokwim Delta. Trans. North Amer. Wildl. & Nat. Resour. Conf. 51:487-506. Pehrsson, O. 1986. Duckling production of the oldsquaw in relation to spring weather and small rodent fluctuations. Canadian J. Zool. 64:1835-1841. Peterson, R. W., J. A. Busterud, & B. E. Willard. 1976. The seventh annual report of the council on environmental quality. U.S. Govern. Printing Off., Washington, D.C., USA. Piehl, J. L. 1979. Avian mortality from a severe hail storm. Prairie Nat. 11:75-77. Piest, L. A., & L. K. Scowls. 1985. Breeding duck use of a sewage marsh in Arizona. J. Wildl. Manage. 49:580-585. Polunin, N. 1960. Introduction to plant geography. McGraw-Hill Book Company, New York, New York, USA. Pospahala, R. S., D. R. Anderson, & C. J. Henny. 1974. Population ecology of the mallard. II. Breeding habitat conditions, size of the breeding populations, and production indices. U.S. Fish Wildl. Serv. Resour. Publ. 115. Ratcliffe, D. A. 1967. Decrease in eggshell weight in certain birds of prey. Nature 215:208-210. -----. 1970. Changes attributable to pesticides in egg breakage fre- quency and eggshell thickness in some British birds. J. Applied Ecol. 7:67-115. Raveling, D. G. 1977. Canada geese of the Churchill River basin in north-central Manitoba. J. Wildl. Manage. 41:35-47. -----. 1984. Geese and hunters of Alaska's Yukon Delta: manage- ment problems and political dilemmas. Trans. North Amer. Wildl. & Nat. Resour. Conf. 49:555-575. -----. 1989. Nest-predation rates in relation to colony size of black brant. J. Wildl. Manage. 53:87-90. Raveling, D. G., & H. G. Lumsden. 1977. Nesting ecology of Canada geese in the Hudson Bay lowlands of Ontario: evolution and popu- lation regulation. Ontario Min. Nat. Resour. Fish Wildl. Res. Rep. 98. Raveling, D. G., & D. S. Zezulak. 1988. Distribution, abundance, and survival of cackling Canada geese, 1982-1987. Unpubl. Prog. Rep., U.S. Fish Wildl. Serv., Univ. California, Davis, California, USA. Reed, A. 1975a. Reproductive output of black ducks in the St. Lawrence estuary. J. Wildl. Manage. 39:243-255. -----. 1975b. Migration, homing, and mortality of breeding female eiders Somateria mollissima dresseri of the St. Lawrence estuary, Quebec. Ornis Scand. 6:41-47. Reed, A., & J. G. Cousineau. 1967. Epidemics involving the common eider (Somateria mollissima) at Ile Blanche, Quebec. Nat. Canadian 94:327-334. Reese, J. G. 1980. Demography of European mute swans in Chesa- peake Bay. Auk 97:449-464. Reeves, H. M., F. G. Cooch, & R. E. Munro. 1976. Monitoring arctic habitat and goose production by satellite imagery. J. Wildl. Manage. 40:532-541. Ringelman, J. K., & J. R. Longcore. 1982. Survival of juvenile black ducks during brood rearing. J. Wildl. Manage. 46:622-628. Ringelman, J. K., & J. R. Longcore. 1983. Survival of female black ducks Anas rubripes, during the breeding season. Canadian Field- Nat. 97:62-65. Rockwell, R. E, C. S. Findlay, & F. Cooke. 1987. Is there an optimal clutch size in snow geese? Amer. Nat. 130:839-863. Ryder, J. P. 1967. The breeding biology of Ross' goose in the Perry River region, Northwest Territories. Canadian Wildl. Serv. Rep. Se- ries 3. -----. 1971. Distribution and breeding biology of the lesser snow goose in central Arctic Canada. Wildfowl 22:18-28. -----. 1972. Biology of nesting Ross' geese. Ardea 60:185-215. Sanderson, G. C., & E. C. Bellrose. 1986. A review of the problem of lead poisoning in waterfowl. Illinois Nat. Hist. Surv. Spec. Publ. No. 4. Sargeant, A. B. 1978. Red fox prey demands and implications to prai- rie duck production. J. Wildl. Manage. 42:520-527. -----. 1981. Road casualties of prairie nesting ducks. Wildl. Soc. Bull. 9:65-69. Sargeant, A. B., & P. M. Arnold. 1984. Predator management for ducks on waterfowl production areas in the northern plains. Proc. Vertebrate Pest Conf. 11:161-167. Sargeant, A. B., & L. E. Eberhardt. 1975. Death feigning by ducks in response to predation by red foxes (Vulpes fulva). Amer. Midl. Nat. 94:108-119. Sargeant, A. B., G. A. Swanson, & H. A. Doty. 1973. Selective preda- tion by mink, Mustela vison, on waterfowl. Amer. Midl. Nat. 89:208-214. Sargeant, A. B., S. H. Allen, & R. T. Eberhardt. 1984. Red fox preda- tion on breeding ducks in midcontinent North America. Wildl. Monogr. 89. Schamel, D. 1977. Breeding of the common eider (Somateria mollis- sima) on the Beaufort Sea coast in Alaska. Condor 79:478-485. Schmutz, J. K., S. M. Schmutz, & D. A. Boag. 1980. Coexistence of three species of hawks (Buteo spp.) in the prairie-parkland ecotone. Canadian J. Zool. 58:1075-1089. Schmutz, J. K., R. J. Robertson, & F. Cooke. 1983. Colonial nesting of the Hudson Bay eider duck. Canadian J. Zool. 61:2424-2433. Schranck, B. W. 1972. Waterfowl nest cover and some predation rela- tionships. J. Wildl. Manage. 36:182-186. Scott, P. 1972. The swans. Houghton Mifflin Co., Boston, Massachu- setts, USA. Sheehan, P. J., A. Baril, P. Mineau, D. K. Smith, A. Harfenist, & W. K. Marshall. 1987. The impact of pesticides on the ecology of prairie nesting ducks. Canadian Wildl. Serv. Headquarters Tech. Rep. Series No. 19. Sherbin, I. G. 1979. Mercury in the Canadian environment. Economic and Technical Review Report EPS 3-EC79-6. Environ. Protect. Serv., Ottawa, Canada. Sherwood, G. A. 1968. Factors limiting production and expansion of local populations of Canada geese. Pages 73-85 in R. L. Hine and C. Schoenfold, eds. Canada goose management: current continental problems and programs. Dembar Educ. Res. Serv., Madison, Wis- consin, USA. Siegfried, W. R. 1972. Ruddy ducks colliding with wires. Wilson Bull. 84:486-487. Smith, A. G. 1971. Ecological factors affecting waterfowl production in the Alberta parklands. U.S. Fish Wildl. Serv. Resour. Publ. 98. Smith, A. G., & H. R. Webster. 1955. Effects of hail storms on water- fowl populations in Alberta, Canada -- 1953. J. Wildl. Manage. 19:368-374. Smith, A. G., J. H. Stoudt, & J. B. Gollop. 1964. Prairie potholes and marshes. Pages 39-50 in J. P. Linduska, ed. Waterfowl tomorrow. U.S. Govern. Printing Off., Washington, D.C., USA. Sowls, L. K. 1955. Prairie ducks: a study of their behavior, ecology and management. Stackpole Co., Harrisburg, Pennsylvania, USA. Spencer, D. L., U. C. Nelson, & W. A. Elkins. 1951. America's greatest goose-brant nesting area. Trans. North Amer. Wildl. Conf. 16:290- 295. Springer, P. F., G. V. Byrd, & D. W. Woolington. 1978. Reestablishing Aleutian Canada geese. Pages 331-338 in S. A. Temple, ed. Endan- gered birds: management techniques for preserving threatened spe- cies. Univ. Wisconsin Press, Madison, Wisconsin, USA. Stehn, R. 1986. Nesting success of geese in the coastal tundra region of the Yukon-Kuskokwim Delta, 1985. Unpubl. U.S. Fish Wildl. Serv. Rep., Anchorage, Alaska, USA. Stendell, R. C., H. M. Ohlendorf, E. E. Klaas, & J. B. Elder. 1976. Mercury in eggs of aquatic birds, Lake St. Clair -- 1973. Pest. Mon- itor J. 10:7-9. Stoudt, J. H. 1971. Ecological factors affecting waterfowl production in the Saskatchewan parklands. U.S. Fish Wildl. Serv. Resour. Publ. 99. -----. 1982. Habitat use and productivity of canvasbacks in south- western Manitoba, 1961-72. U.S. Fish Wildl. Serv. Spec. Sci. Rep. -- Wildlife 248. Stout, I. J. 1967. The nature and pattern of nonhunting mortality in fledged North American waterfowl. Thesis. Virginia Polytech. Inst., Blacksburg, Virginia, USA. Stout, I. J., & G. W. Cornwell. 1976. Nonhunting mortality of fledged North American waterfowl. J. Wildl. Manage. 40:681-693. Street, M. 1977. The food of mallard ducklings in a wet gravel quarry, and its relation to duckling survival. Wildfowl 28:113-125. Sugden, L. C. 1978. Canvasback habitat use and production in Saskatchewan parklands. Canadian Wildl. Serv. Occasional Paper 34. Sugden, L. G., & G. W. Beyersbergen. 1984. Farming intensity on wa- terfowl breeding grounds in Saskatchewan parklands. Wildl. Soc. Bull. 12:22-26. Swanson, G. A. 1977. Diel food selection by anatinae on a waste-sta- bilization system. J. Wildl. Manage. 41:226-231. Syroechkovskiy, E. V. 1972. Some peculiarities of interrelationships between the snow-geese and the arctic foxes on the Wrangel Island. Zoologicheskii Zhurnal 51:1208-1213. Szaro, R. C., R. H. Albers, & N. C. Coon. 1978. Petroleum: effects on mallard egg hatchability. J. Wildl. Manage. 42:404-406. Szaro, R. C., G. Hensler, & G. H. Heinz. 1981. Effects of chronic in- gestion of No. 2 fuel oil on mallard ducklings. J. Toxicol. & Envir. Health 7:789-799. Talent, L. G., R. L. Jarvis, & G. L. Krapu. 1983. Survival of mallard broods in south-central North Dakota. Condor 85:74-78. Townsend, G. H. 1966. A study of waterfowl nesting on the Saskatch- ewan river delta. Canadian Field-Nat. 80:74-88. Trainer, C. E. 1959. The 1959 western Canada goose (Branta canaden- sis occidentalis) study on the Copper River Delta, Alaska. Pages 1-11 in H. A. Hansen, ed. Annual Waterfowl Report Alaska, 1959. Un- publ. U.S. Fish Wildl. Serv. Ann. Waterfowl Rep., Washington, D.C., USA. Trauger, D. L., & J. C. Bartonek. 1977. Leech parasitism of waterfowl in North America. Wildfowl 28:143-152. Trauger, D. L., & J. H. Stoudt. 1978. Trends in waterfowl populations and habitats on study areas in Canadian parklands. Trans. North Amer. Wildl. & Nat. Resour. Conf. 43:187-205. U.S. Fish & Wildlife Service & Canadian Wildlife Service. 1987. Status of waterfowl and fall flight forecast. Untitled Report. July 25. U.S. Fish Wildl. Serv., District Columbia, USA, & Canadian Wildl. Serv., Ottawa, Canada. Untergasser, G., & J. S. Hayward. 1972. Development of thermoreg- ulation in ducklings. Canadian J. Zool. 50:1243-1250. Vermeer, K. 1968. Ecological aspects of ducks nesting in high densities among larids. Wilson Bull. 80:70-83. -----. 1970a. Breeding biology of California and ring-billed gulls: a study of ecological adaptation to the inland habitat. Canadian Wildl. Serv. Rep. Series 12. -----. 1970b. Some aspects of the nesting of ducks on islands in Lake Newell, Alberta. J. Wildl. Manage. 34:126-129. Vermeer, K., & F. A. J. Armstrong. 1972. Mercury in Canadian prairie ducks. J. Wildl. Manage. 36:179-182. Vermeer, K., F. A. J. Armstrong, & D. R. M. Hatch. 1973. Mercury in aquatic birds at Clay Lake, western Ontario. J. Wildl. Manage. 37:58-61. Weller, M. W. 1956. A simple field candler for waterfowl eggs. J. Wildl. Manage. 20:111-113. -----. 1964. The reproductive cycle. Pages 35-79 in J. Delacour, ed. The waterfowl of the world. Volume 4. Country Life Limited, Lon- don, England. -----. 1980. The island waterfowl. Iowa State Univ. Press, Ames, Iowa, USA. Westerskov, K. 1950. Methods for determining the age of game bird eggs. J. Wildl. Manage. 14:56-67. White, D. H., & E. Cromartie. 1977. Residues of environmental pol- lutants and shell thinning in merganser eggs. Wilson Bull. 89:532- 542. White, D. H., & L. F. Stickel. 1975. Impacts of chemicals on water- fowl reproduction and survival. Intern. Waterfowl Symp. 1:132-142. Williams, C. S., & W. H. Marshall. 1938. Duck nesting studies, Bear River Migratory Bird Refuge, Utah, 1937. J. Wildl. Manage. 2:29- 48. Williams, M. J. 1974. Creching behaviour of the shelduck Tadorna tadorna L. Ornis Scand. 5:131-143. Wittenberger, J. F., & G. L. Hunt, Jr. 1985. The adaptive significance of coloniality in birds. Pages 1-78 in D. S. Farrier, J. R. King, & K. C. Parkes, eds. Avian biology. Volume 8. Acad. Press, Incorp., Orlando, Florida, USA. Wobeser, G. A. 1981. Diseases of wild waterfowl. Plenum Press, New York, New York, USA. Wobeser, G. [A.], A. Gajadhar, G. W. Beyersbergen, & L. G, Sugden. 1981. Myiasis by Wohlfahrtia opaca (Cog.): a cause of mortality of newly hatched wild ducklings. Canadian Field-Nat. 95:471-473. Wolf, K. 1955. Some effects of fluctuating and falling water levels on waterfowl production. J. Wildl. Manage. 19:13-23. Wright, B. S. 1954. High tide and an cast wind. Stackpole Co., Har- risburg, Pennsylvania, USA. Zicus, M. C. 1981. Canada goose brood behavior and survival esti- mates at Crex Meadows, Wisconsin. Wilson Bull. 93:207-217.