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1 Pacific Flyway Management Plan Dusky Canada Geese ; // : d ~,. / ~ I,. ~, ;/ f ~., ' I'- \.,,!.\V::::).... 'I:!J"".-...,..._ ' / ----x;;..- --f.. _-. ' c;:(' i.i,. I ;' \. I :~ / \ 1 ~ '... _... _ i l I,' 1 c ---L T-~ ~ 1 \, f { -') I ARLIS Alaska Resources Library & Information Services Anch\..)ra Alaska

2 This management plan is one of a series of cooperatively developed plans for managing various species of migratory birds of the Pacific Flyway. Inquiries about this plan may be directed to member states of the Pacific Flyway Council or to the Pacific Flyway Representative, U.S. Fish and Wildlife Service, 500 N.E. Multnomah St., Suite 1692, Portland, Oregon

3 PACIFIC FLYWAY ~~NAGEMENT FOR THE DUSKY CANADA GEESE PLAN Prepared f or the: Pacific Fl yway Council Canadian Wildlif e Service U. S. Fish and Wil dl ife Service July 1985

4 PACIFIC FLYWAY MANAGEMENT PLAN FOR THE PUSKY CANADA GEESE Prepared by the Subcommittee on dusky Canada geese of the Pacific Flyway Study Committee: Palmer Sekora, U.S. Fish anq Wildlife Service, Corvallis, OR, Subco~ittee Chairman Jim Bartonek, U.S. Fish and Wildlife Service, Portland, OR nick Bauer, U.S. Fish and Wildlife Service, Portland, OR Ken Durbin, Oregon Department of Fish and Wildlife, Portland, OR Gary Kaiser, Canadian Wildlife Service, Delta, BC Don Kraege, Washington Department of Game, Olympia, WA Bill Munro, British Columbia Fish and Wildlife Branch, Victoria, BC Dick Pospahala, U.S. Fish and Wildlife Service, Anchorage, AK Tcim Rothe, Alaska Department o.f Fish and Game, Anchorage, AK Approved by: July 28, 1985 ii

5 TABLE OF CONTENTS I. INTRODUCTION. II. GOALS AND OBJECTIVES. III. STATUS Taxonomy. Numbers and Distribution Nesting and Production Migration.... Wintering Grounds Public Use. Scientific Use Management IV. PROBLEMS., 6 Nesting Grou"Qds Wintering Grounds! V. RECOMMENDED MANAGEMENT PROCEDURES AND RESEARCH Habitat,..... Public Use..... Depredation Control Inventories... Research.... Annual Review of Plans.- '.' ' VI. LITERATURE CITED LIST OF TABLES LIST OF FIGURES 21 iii

6 I. INTRODUCTION In 1973 the Pacific Flyway Council (Pacific Flyway Council 1973) adopted and published a management plan for the dusky Canada goose (Branta canadensis occidentalis). This plan is a revision of the 1973 plan. It provides guidelines for cooperative management of the dusky Canada goose popul ation. Dusky Canada geese are known to nest only on the Copper River Delta of south-central Alaska, and winter from coastal British Columbia to California (Figure 1). The primary wintering area is in the Willamette Valley of western Oregon and on the f l oodplain of the lower Columbia River in western Oregon and Washington. During the last 35 years, midwinter estimates indicate that duskys have increased from a low of 10,000 in the 1950's, fluctuated up to 25,000 through 1979, and declined steadily to the present level of 7,500. Major influences on the population include broad ecological changes on the breeding grounds caused by the "Good Friday Earthquake" of 1964, agricultural changes and establishment of federal refuges on the wintering grounds, and annual harvest management. Although the relationships of ecological changes on the breeding grounds (hydrology, nutrients, vegetation, wildlife use patterns) to productivity of duskys have not been studied in depth, a gradual long- term decline in the population has been predicted. In addition to an outlook of lower productivity, management of duskys on their wintering grounds is difficult because of concurrent use by other Canada goose subspecies <! taverneri,! parvipes, ~ minima, B. c. fulva, B. c. moffitti). This mixing of Canada goose subspecies causes problems in conducting winter counts, designing optimal harvest regulations, controlling winter counts, designing optimal harvest regulations, controlling crop depredations, and assessing carrying capacity of winter habitats, for all Canada geese. Social and ecological patterns of duskys on the wintering grounds have been studied, showing a markedly higher susceptibility to harvest than other Canadas. Thus, status information and management objectives outlined in this plan are closely related to those in the Lesser Canada Goose Management Plan (Pacific Flyway Council In prep.) II. GOALS AND OBJECTIVES The goal of this management plan is to maintain and enhance the dusky Canada goose population for all of its values to society. Objectives of this plan are to: A. Achieve and maintain a wintering population of 20,000 dusky Canada geese (3-year average) as part of an overall wintering population of Canada geese in northwestern Oregon and southwestern Washington of at least 40,000 but no more than 75,000, as measured by annual winter population estimates. 1

7 B. Maintain the nesting, migration, and wintering habitats in sufficient quantity and quality to meet and maintain the population objectives, recognizing that ecological chang~s are altering the nesting habitat, food resources, and extent of predation. C. Manage the wintering habitat to provide optimum food, water, and sanctuary conditions for dusky Canada geese and to provide optimum geographical distribution of geese. D. Manage the dusky goose population and those other Canada goose populations with which they sometimes mix, to provide optimal hunting and other recreational uses. III. STATUS Taxonomy Although Palmer (1976) combined Vancouver Canada geese with dusky Canada geese under the binomial B. c. occidentalis, most authorities agree with Delacour (1954) who identlfi;d 11 subspecies of Canada geese and distinguished between dusky Canada geese (B. c. occidentalis) and Vancouver Canada geese (~. ~ This plan-addresses dusky Canada geese as being that population which summers on the Copper River Delta. Numbers and Distribution From 1951 to 1962 the postseason population of dusky Canada geese varied between 10,000 and 17,000 geese, based on winter inventories (Hansen 1968). From 1963 to 1969, coincident with the establishment of Willamette Valley National Wildlife Refuges, the dusky population varied between 14,000 and 27,000 geese. Since 1970 the postseason population has ranged from 7,500 ( ) to 26,500 (1975) geese and averaged 19,503 (Table 1). The 3-year average for was 11,533. Nesting and Production The Copper River Delta, near Cordova, Alaska, is the only known natural nesting area of dusky Canada geese (Figure 2). Prior to 1964, the low elevation of the delta and periodic flooding during high tides maintained broad expanses of sedge meadow dissected by a reticulate pattern of drainage channels and sloughs. A mixed forb/low shrub community was found on slightly elevc;tted slough banks. Brackish conditions significantly influenced productivity of waters and controlled the composition of plant communities. Early surveys (Trainer 1959) showed that dusky Canada geese strongly selected mixed forb/low shrub nest sites, and that flooding was the major cause of nest losses. Nest predation by gulls was slight, and mammalian predators were considered rare on the outer delta. Overall, nest suc,cess was usually high. 2

8 The 1964 earthquake uplifted the Copper River Delta by 2 to 6 feet, drastically altering the frequency of tidal inundation and promoting drying of slough banks and meadows. The drier conditions and lack of suppression by saltwater have "released" the growth of shrubs, such as alder and willow, that are now feet tall and much more extensive. The apparent succession toward forest has occurred before, as is evident from two buried forest horizons dated from 750 and 1,700 years ago, and also reflects long-term buildup and subsidence phases of large deltaic systems. Reduced salinity in now-perched, discrete ponds and marshes is thought to have altered nutrient regimes and aquatic productivity, especially affecting ducks, but also perhaps affecting food resources for geese and their broods. By changes in vegetation physiognomy and composition were evident. Bromley (1976) documented substantial nesting by dusky geese in mesic sedge habitats, although traditional shrub habitats were selected for, relative to availability. He also reported on the effects of weather, nest density, and population age structure on productivity. Avian predation was the most significant cause of nest losses and mammalian predators were quite active on the nesting grounds, but flooding was no longer an important factor in nest success. Parameters of nesting, measured on permanent plots are shown in Table 2. A decline in nest density, evident since 1979, parallels a downward trend in the population (Table 1), but the proportion of breeding-age birds in the population is unknown. During the same period, nest success has fallen below the long-term mean. In recent years, increases in activity and documented nest predation by brown bears (Ursus arctos) and coyotes (Canis latrans) have had major impacts on goose production, although the intensity is variable from year to year. The availability of alternative predator food resources, such as cyclic vole populations, may moderate or intensify nest losses. The productivity of dusky Canada geese is apparently affected by gradual long-term ecological changes induced by the 1964 earthquake, annual conditions such as weather, and the size and age structure of the population. Current investigations in Alaska are focusing on the relationships between nest habitat selection, predator habitat use, predator behavior, buffer prey abundance and dusky goose production. A small resident population, numbering a few hundred birds, is present at Willapa National Wildlife Refuge on the Washington coast. This population originated from geese captured on the Copper River Delta or crippled during the hunting season and propagated at the refuge. However, the population may not be pure B. c. occidentalis because geese of unknown origin have been added to the flock. Migration Although the migration routes of dusky Canada geese are poorly known, it appears that they migrate along the Pacific coast of Alaska, British Columbia, and Washington. During the fall, a majority of the geese migrate inland following the Columbia and Willamette Rivers. Few staging or stopover areas have been identified between the nesting grounds and the wintering grounds, so migration may be relatively short and direct. 3

9 Wintering Grounds In recent years most duskys have wintered in the area between the mouth of the Columbia River and Fern Ridge Reservoir at the southern end of the Wi:lamette Valley (Figure 3). The Willamette Valley National Wildlife Refuges are located in the mid-valley area. In recent years, goose use has increased in the lower Columbia River area near Portland. Several hundred geese that appear to be dusky Canada geese winter on islands along the Oregon coast. Despite the recent decline in the numbers of dusky Canada geese, winter populations of Taverner's Canada geese (~. taverneri) increased dramatically in southwestern Washington and western Oregon. The total number of all Canada geese in the area has reached record highs. During the winter of 1984 an estimated 15% of the 69,000 Canada geese on the wintering grounds were dusky's and most of the other 85% were Taverner's geese. Public Use The dusky Canada goose population is subject to a relatively heavy harvest, and is not traditionally used by native Americans for subsistence. Hunting is the major source of mortality to dusky Canada geese. Annual harvest rates have averaged over 25%. Based on band returns during , an average of 69% of the harvest occurs in Oregon with Alaska, British Columbia, and Washington harvesting 10%, 10%, and 11% respectively (Table 3). Through the mid-1960's dusky Canada geese comprised 80% or more of the goose harvest in western Oregon. As the population of Taverner's Canada geese increased in that area, the proportion of dusky Canada geese of the total goose harvest decreased. However, a combination of traditional hunting practices and behavioral differences between dusky geese and Taverner's geese has resulted in a higher proportion harvested than expected based on their population size. From , dusky Canada geese were 48% of the Canada geese harvested at the five state and federal management areas. During that same period, the percentage of Canada geese wintering in the area that were duskys ranged from only 12% to 24% (Table 4). During and , duskys were 2.8 and 2.6 times as vulnerable to harvest as Taverner's (Simpson and Jarvis 1979). From through an average of 190 duskys was harvested for every 100 Taverner's even though there were only 62 duskys for every 100 Taverner's on the wintering grounds (Jarvis and Cornely In press). In addition to hunting, dusky Canada geese provide numerous recreation opportunities to nonconsumptive users. Thousands of people visit the Willamette Valley NWRs and Sauvie Island Wildlife Management Area to see or photograph dusky geese. Students and teachers from numerous universities, colleges, and public schools use the areas for environmental education. Each year students from Oregon State University undertake class projects, independent studies, or volunteer work related to goose management. 4

10 Scientific Use Dusky Canada geese have been the subject of a number of studies both on the nesting and wintering areas. Their population dynamics and harvest have been studied (Chapman 1967, Chapman et al. 1969, Henny 1967a,b, Cornely et al. 1985), nesting and nesting habitat (Trainer 1959, Bromley 1976, Cornely et al. 1985), effects of winter grazing on grass seed yield (Clark 1979, 1978), winter ecology (Simpson 1979, Simpson and Jarvis 1979, Havel 1984, Havel and Jarvis In press), and staging ecology (Hawkings 1982). Timm et al. (1979) reviewed the management strategy for dusky Canada geese. Jarvis and Cornely (In press) summarized recent changes in populations of Canada geese on the wintering grounds and are involved in on-going studies of Canada geese in the Willamette Valley. The staff of the Alaska Department of Fish and Game is conducting nesting studies and investigating the impact of brown bears on nesting geese. Management Active management of dusky Canada geese began in the early 1950's. Production assessments and banding were conducted on the breeding grounds and midwinter inventories on the wintering grounds. In the late 1950's it was recognized that mortality of dusky Canada geese from hunting was very high and that a large percentage of the population was concentrated in a relatively small area of the wintering grounds. As a result, the U.S. Fish and Wildlife Service established a refuge complex in the Willamette Valley during the mid-1960's. The refuges provide suitable wintering habitat and were responsible, in part, for a gradual increase in the dusky population during the 1970's. Nearly all of the nesting habitat of the dusky is under the management authority of the U.S. Forest Service (USFS) within the Chugach National Forest. In 1962 USFS and ADF&G entered into the Copper River Delta Cooperative Management Agreement, recognizing wildlife and fisheries as the most important resources of the Delta, and clarifying agency roles in management. In 1978 the state of Alaska created the Copper River Delta Critical Habitat Area, encompassing federal, state and private lands, to facilitate management of biological resources and habitats. The Alaska National Interest Lands Conservation Act of 1980 (ANILCA) provided that "the conservation of fish and wildlife and their habitat shall be the primary purpose for the management of the Copper/Rude River addition [to the Forest] and the Copper River-Bering River portion of the existing Chugach National Forest " These actions have established policy direction and frameworks for cooperative management of dusky Canada goose nesting habitat. A Dusky Canada Goose Subcommittee of the Waterfowl Study Committee was formed by the Pacific Flyway Council in The Subcommittee developed guidelines for management of the population (Pacific Flyway Council 1973). These guidelines, with revisions, have been followed since

11 The daily Canada goose bag limit in the Willamette Valley has been two since 1971, and two in all of western Oregon since In Alaska, British Columbia and Washington the limits have been four, four and three, respectively. In Washington reduced the bag limit to two in several southwestern counties. The effective season length in Washington and Oregon (post November 5) from varied from about 7 weeks to 11 weeks. The season length has been adjusted at times according to the size of the fall flight. Seasons on the Willamette Valley Refuges have not begun until mid-november, therefore, averaging about a month shorter than the Oregon waterfowl season. In 1984 the state of Alaska delayed the opening of the season in the dusky goose nesting area by 2 weeks to allow time for most of the geese to migrate out of the area. At the same time, a bag limit of one was established for western Oregon and for Clark and Cowlitz Counties, Washington, with the exception of selected management areas. A 1-month season was adopted starting in mid-november. An experimental season was tested at Sauvie Island ~~and Ridgefield, Ankeny, Baskett Slough, and W. L. Finley ~~Rs. The objective of the experiment was to encourage the shooting of Taverner's Canada geese while reducing the dusky kill. The dusky harvest was still unacceptably high and an emergency closure of the goose season was declared by the States of Washington and Oregon based on the unanimous recommendation of the Dusky Canada Goose Technical Subcommittee. Several factors probably contributed to the lack of success of the experimental season. Hunters could legally shoot a dusky goose and then quit hunting for the day. Dusky geese are not easy to distinguish from the other subspecies under the average hunting conditions in the wintering area. A complete closure of the cackling Canada goose season apparently influenced some hunters to shoot the larger geese (duskys) rather than chance an illegal kill. In the final analysis, many hunters either couldn't or wouldn't make the distinction between duskys and other subspecies of Canada geese. That, combined with the inherent vulnerability of duskys to hunting, led to an early closure of an already severely restricted season. IV. PROBLEMS Nesting Grounds A. The increase in woody vegetation on the Copper River Delta that resulted from the uplift during the 1964 earthquake has provided cover for mammalian predators in the nesting areas. Nest predation has resulted in significantly lower nest success and recruitment even in years with favorable spring weather. The specific relationships between habitat, predator activity, nest success, recruitment, and buffer prey populations are not known. B. Successional changes in vegetation may be reducing the quality and quantity of nesting, foraging, and brood rearing habitats. c. There is no information on the age structure of the nesting dusky population since Such information is needed in order to determine the reproductive status and potential of the population. 6

12 D. E. Although human distrubance on the Copper River Delta during the period of dusky goose use (mid-april to October) is currently low, increased human activity could adversely affect the population. Increases in low-level aircraft activity, summer recreation, and research activity have been noted. Potential road construction and oil exploration could cause adverse impacts to goose habitat and the goose population. Linkage of Cordova with the state highway system and/or any major economic development in the region could substantially increase the number of residents and visitors using the Copper River Delta for hunting and other recreation. Oil spills may occur from offshore oil drilling and oil tanker traffic, resulting in chronic or catastrophic damage to geese and their habitats, especially during goose molting and brood rearing periods. Wintering Grounds A. B. c. The primary mortality factor affecting fledged dusky Canada goose population is sport harvest. Because of the recent reduction in productivity of the population, mortality has exceeded production for 6 of the past 7 years (1979, ) resulting in a declining population. Dusky Canada geese are about 2.5 times more vulnerable to hunting than the more numerous Taverner's Canada geese. This ratio has remained remarkably constant even though the proportion of duskys in the wintering population decreased from 50% in to 12% in The difference in vulnerability of dusky and Taverner's Canada geese appears to be a function of differences in behavior and habitat use patterns. The large population of Taverner's and their relatively low vulnerability to hunting complicates control of the harvest of duskys. Current goose harvest estimates are calculated by subtracting the midwinter population estimate from the fall flight estimate. This method is dependent on the accuracy of winter counts, the subspecies composition of the wintering goose flocks derived from aerial photographs, and the estimated fall flight. The estimated fall flight is in turn highly dependent upon the previous year's winter population estimate. Annual harvest of geese is estimated by the states of Alaska, Washington, and Oregon, and the USFWS by means of questionaires mailed to a percentage of the hunters. The sample size is quite small and the estimates do not provide a breakdown of the harvest by subspecies. Very good information is derived from hunter checkstations at Sauvie Island Wildlife Management Area and the National Wildlife Refuges, but a reliable estimate of harvest in other areas is badly needed. A reliable estimate of total dusky Canada goose harvest independent of population estimates would be invaluable. 7

13 D. E. Currently, the winter population estimates are used to compare the population size with the objective in this plan. However, censusing of the wintering population has been complicated by the dramatic increase in the numbers of Taverner's Canada geese. Refinement of the photographic flock composition methods used in recent years is on-going. The method requires exacting weather conditions, good coordination between pilot and photographer, and considerable c~perience. At the present time, there is no alternative available, although methods of censusing the breeding population are being tested on the Copper River Delta. If the Taverner's Canada goose population continues to increase, a point may be reached where crop depredations become a significant problem. The present harvest rate is apparently not sufficient to regulate Taverner's Canada goose numbers. V. RECOMMEl\TDED HANAGEHENT PROCEDURES AND RESEARCH The following management procedures are recommended, given that the degree and timing of their implementation by the various agencies are influenced by manpower, fiscal and legislative constraints beyond the scope of this plan. ~~en possible, the management procedures in this plan should be coordinated with and incorporated into those recommended in plans for other species and populations of Pacific Flyway birds. Habitat 1. Breeding Grounds a. Quantify and describe vegetation communities and earthquakeinduced changes in cover composition on the Copper River Delta. Mapping and classification efforts should be comparable to previous work done by the University of Minnesota (Potyondy et al. 1975) and should cross reference the state-wide vegetation classification (Viereck et al. 1982) and National Wetland Inventory (USFWS). USFS Participating: ADFG, USFWS ASAP b. Monitor and describe changes in nest site selection and nest success on permanent plots as related to changes in vegetation, habitat quality or composition. ADFG Participating: USFS, USFWS 8

14 c. Host lands selected under the Alaska Native Clains Settlement Act have been conveyed into private OY."Tiership. Pursue implementation of cooperative land management agreements among private landowners and agencies, designed in part to protect dusky goose habitat. ADFG, USFS Participating: USF\\'S, private landowners d. Continue a policy of stringent protection from habitat degredation, other than by natural processes, to enhance goose production on USFS lands and the state Critical Habitat Area on CRD. USFS, ADFG 2. Higration.--Encourage habitat identification, cataloging, and protection along migration routes through resolution from the Flyway Council and/or individual agencies and through cooperative agreements with other land management agencies. Council, CWS, BC, ADFG, WDG, ODFW, USFWS Priority: 2 3. Wintering a. Haintain existing state and federal areas for goose resting, feeding, and sanctuary. WDG, ODFW, USFWS b. Identify additional goose use areas in the lower Columbia River and the Willamette Valley as potential sanctuary areas for resting and feeding. Such areas would help achieve and maintain population and distribution objectives. The acquisition, development, and maintenance of these areas should be pursued by state, federal, and private organizations. ODFW, WDG, USFWS Participating: Other federal, state and private agencies will be invited to participate. Priority: 2 9

15 Public Use 1. Harvest.--Guidelines to be used in recommending changes in hunting regulations are: a. The winter population objective is 20,000 dusky Canada geese based on a 3-year average. When the winter population is belo~ 20,000 harvest adjustments should be made to allow the population to reach the objective level. b. When the estimated winter dusky goose population is 10,000 or less, the hunting season on dusky Canada geese will not be opened. Resumption of limited hunting will be considered when the winter population has attained at least 13,000 geese. c. Harvest information will be collected at federal NWRs and state ~~s. An effort will be made to improve the harvest estimates for other areas. ADFG, WDG, ODFW, USFWS 2. Interpretive Programs.--Observing dusky Canada geese is an important form of recreation throughout the bird's range. State and federal wildlife agencies should develop written and pictoral information on the life history and management of the dusky Canada goose. ADFG, WDG, ODFW, USFS, USFWS Priority: 2 Depredation Control a. Crop depredation problems will be handled on an extension basis informing private landowners of the techniques and devices available to minimize the impact of geese on croplands. USFWS Participating: Other federal and state agencies and private landowners will be invited to participate. b. Cropland management practices on state and federal waterfowl management areas will maximize the production and maintenance of goose food crops throughout the wintering period to help prevent and alleviate depredation problems on privately owned lands. 10

16 USTI\S, ODF\\, HDG c. A cooperative study of crop depredations by Canada geese in western Oregon and southwestern Washington will be conducted to assess the extent and severity of damage to crops and pastures in the area. WDG, ODFW, USFWS Participating: Other state and federal agencies and private parties will be invited to participate as needed Inventories 1. Breeding Grounds a. Monitor permanent plots established on the Copper River Delta to determine nest densities and nest success. ADFG Participating: USFS, USFWS Annually in May and June b. Aerial production surveys will be completed annually in July. w~en possible, the results will be provided to the Subcommittee prior to the July meeting. Using the production estimate, a fall flight forecast will be developed and transmitted to the Subcommittee and the Pacific Flyway Study Committee. ADFG Participating: USFWS c. Geese will be banded annually. In addition, geese may be collared to monitor distribution and extent of the harvest, age structure of the population, and to estimate survival rates. Band recovery analysis will be updated and summarized annually. 11

17 ADFG Participating: USFS, USFWS Annually in July d. An effort to develop a reliable method of estimating the size of the goose population on the Copper River Delta will be continued. In addition, an attempt will be made to develop a method to estimate the ratio of breeders/non-breeders. ADFG, USFWS Participating: USFS 2. Wintering Areas a. Periodic inventories will be conducted in western Oregon and southwestern Washington from November through early April. The January survey will serve as the midwinter inventory. USF\\S Participating: ~~G, ODFW b. Periodic aerial photo surveys will be conducted to determine the subspecific composition of the goose flocks on the wintering grounds. One of these surveys will be used in conjunction with the midwinter inventory to estimate the post-season population size of dusky Canada geese. USFWS Participating: WDG, ODFW c. State and federal personnel will monitor the occurrence, distribution, and movements of color marked dusky Canada geese throughout the wintering area. USFWS Participating: WDG, ODFW 12

18 Research 1. The Subcommittee will make recommendations for research and review research proposals. Priority will be given to proposals that address high priority management problems. Dusky Canada Goose Subcommittee 2. Describe and evaluate the interactions between habitat change, predator ecology, and nest success and recruitment rate of dusky Canada geese on the Copper River Delta. ADFG Participating: USFS, USFWS, ODFH 3. Investigate the patterns of foraging by wintering Canada geese and the nutritional value of the available forage in the Willamette Valley. USFWS, Oregon State University 13

19 Annual Review of Plan The Subcommittee shall meet twice annually, or as needed, to review progress toward achieving the goal and objectives of this plan and to recommend actions and revisions. The Subcommittee shall report to the Pacific Fly way Study Committee on accomplishments and shortcomings of the cooperative management efforts. This Subcommittee shall coordinate management activities with those of the Lesser Canada Goose (taverneriparvipes) Subcommittee and the Pacific Population of Western Canada Goose Subcommittee during either spring or summer meetings of the Pacific Flyway Study Committee. The Subcommittee shall be comprised of a representative from Canadian Wildlife Service, U.S. Fish and Wildlife Service, and state and provincial agencies having management responsibility for this population. It shall be the responsibility of those members to assure that the objectives and procedures of this plan are integrated and coordinated with those plans and activities'of the various wildlife and land management agencies and local planning systems within their agency's purview. Chairmanship shall be appointed biennially and rotated among member agencies. The Subcommittee will exercise its prerogative to invite to attend and participate (ex officio) at meetings any individual, group, agency, or representative whose expertise, counsel, or managerial capacity is required for the coordination and implementation of management programs. Lead Agency/Group: Subcommittee Twice annually--at the March meeting of the Pacific Flyway Study Committee and at the July meeting to be held in the western Oregon/southwestern Washington area. Schedule for rotation is: Beginning October 1, Oregon Washington Alaska British Columbia cws USFWS etc. 14

20 VI. LITERATURE CITED Bromley, R. G. H Nesting and habitat studies of the dusky Canada goose (Branta canadensis occidentalis Baird) on the Copper River Delta, Alaska. M.S. Thesis, Univ. of Alaska, Fairbanks. 81 pp The energetics of migration and reproduction of dusky geese (Branta canadensis occidentalis). Ph.D. diss., Oregon St. Univ., Corvallis. 116 pp. Chapman, J. A Population characteristics, hunter kill and other productivity of dusky Canada geese. M.S. Thesis, Oregon St. Univ., Corvallis. 82 pp. Chapman, J. A., C. J. Benny and H. M. Wight The status, population dynamics and harvest of the dusky Canada goose. Wildl. Monogr pp. Clark, S. L Effects of winter grazing by geese on ryegrass seed yield. M.S. Thesis, Oregon St. Univ., Corvallis. 18 pp. Clark, S. L. and R. L. Jarvis geese on yield of ryegrass seed. Effects of winter grazing by Wildl. Soc. Bull. 6(2): Cornely, J. E., B. H. Campbell, and R. L. Jarvis. mortality, and status of dusky Canada geese. Wildl. Nat. Resour. Conf., In press Productivity, Trans. No. Amer. Crow, J. H Plant ecology of the Copper River Delta, Alaska. Ph.D. Thesis, Washington St. Univ., Pullman. 120 pp Earthquake-initiated changes in the nesting habitat of the dusky Canada goose. In the great Alaska earthquake of 1964: biology. Natl. Acad. Sci. Publ pp. Delacour, J The waterfowl of the world. Limited, London. 284 pp. Vol. 1, Country Life, Gabrielson, I. N. and S. G. Jewett Birds of Oregon. Oregon State Coll., Corvallis. 650 pp. Hansen, H. A Canada geese of coastal Alaska. Trans. N. Amer. Wildl. Nat. Resour. Conf. 27: Pacific Flyway Canada goose management - Federal and State cooperation. Pages In R. L. Hine and C. Schoenfeld, eds. Canada goose management: current continental problems and program. Dembar Educ. Res. Serv., Madison, Wisconsin. Havel, L. H Formation of feeding flocks during winter by dusky and Taverner's Canada geese in Oregon. M.S. Thesis, Oregon St. Univ., Corvallis. 81 pp. Havel, L. H., and R. L. Jarvis. In press. Formation of mixed feeding flocks of two subspecies of Canada geese in Oregon. In M. W. Weller, ed., Waterfowl in winter. 15

21 Benny, C. J. 1967a. Population characteristics of the dusky Canada as determined from banding data. M.S. Thesis, Oregon St., Univ., Corvallis. 98 pp. 1967b. Estimating band-reporting rates from banding and crippling loss data. J. Wildl. Mgmt. 31: King, J. G. and C. J. Lensink An evaluation of Alaskan habitat for migratory birds. U.S.D.I., Bur. Sport Fish Wildl., Washington D.C. Unpubl. admin rept. 72 pp. Jarvis, R. L. and J. E. Cornely. In press. Recent changes in wintering populations of Canada geese in western Oregon/southwestern Washington. In M. W. Weller ed., Waterfowl in Winter. Pacific Flyway Council Guidelines for management of the dusky Canada goose. 12 pp. Palmer, R. S., Ed Handbook of North American Birds, Vol. 2. Waterfowl (Part 1). Yale Univ. Press, New Haven, Conn. 520 pp. Potyondy, J. P., M. P. Meyer and A. C. Mase, Jr Hydrologic response of the Copper River Delta-Controller Bay Area, Alaska to land emergence and uplift. U.S.D.A. Contract 08-DNN-74. Univ. Minnesota, St. Paul. 81 pp. Reimnitz, E Effects in the Copper River Delta. In the great Alaska earthquake of 1964: oceanography and coastal engineering. Nat. Acad. Sci. Pub pp. Shepherd, P. E. K A preliminary evaluation of earthquake damage to waterfo~vl habitat in south-central Alaska. Ann. Conf. West. Assoc. State Game and Fish Comm. 9 pp. Simpson, S. G Comparative ecology of several subspecies of Canada geese during winter in western Oregon. M.S. Thesis, Oregon St. Univ., Corvallis. Simpson, S. G. and R. L. Jarvis Comparative ecology of several subspecies of Canada geese during winter in western Oregon. In R. L. Jarvis and J. C. Bartonek, eds. Management and biology of Pacific Flyway geese. Oregon St. Univ. Bookstore, Inc., Corvallis. Timm, D. E., R. G. Bromley, D. E. McKnight and R. S. Rodgers Management evaluation of dusky Canada geese. In R. L. Jarvis and J. C. Bartonek, eds., Management and biology of Pacific Flyway geese. Oregon St. Univ. Bookstore, Inc., Corvallis. Trainer, C. E The 1959 western Canada goose (Branta canadensis occidentalis) study on the Copper River Delta, Alaska. In Ann. waterfowl rep., Alaska. U.S. Fish Wildl. Serv., Juneau. 9 pp. Viereck, L.A., and c. T. Dyrness Preliminary classification system for vegetation of Alaska. USDA, For. Serv., PNW For. and Range Exper. Sta., 38 pp. 16

22 Table 1. Summary of population data for dusky Canada geese, Winter Spring (a) Young Fall (b) Hinter Year Population Population Produced Flight Mortality ,800 19,060 3,690 22,750 4, ,900 17,230 2,045 19,275 3, ,800 15,210 8,560 23' 770 5, ,600 17,900 18,935 36,835 10, ,500 25,510 5,565 31,075 8, ,000 22,140 6,975 29' 115 5, ,100 23,200 18,460 41,660 17, ,000 23,100 7,635 30,735 5, ,500 24,545 4,680 29,225 7, ,000 21,175 6,575 27,750 4, ,000 22,140 4,830 26,970 9, ,740 17,075 5,310 22,385 5, ,000 16,360 2,890 19,250 9, ,100 9, 720 2,180 11' 900 4, ,500 7, (a) Winter population minus mortality (Chapman et al. 1969). (b) Fall flight forecast minus winter population estimate. 17

23 Table 2. Dusky Canada goose nest densities, nesting success and young on the West Copper River Delta, Alaska as determined by various studies, Kest Density Ko. 2 % % % Year Source Kests Per Hi Successful Destroyed Young 1959 Trainer (1959) ADF&G (1973) ADF&G (1973) ADF&G (1973) Trainer (1967) ADF&G (1973) ADF&G (1973) ADF&G (1973) ADF&G (1973) ADF&G (1973) Bromley (1976) Bromley (1976) Timm (1977) Bromley (unpubl.) Bromley (unpubl.) Bromley (unpubl.. ) ADF&G (1982) ADF&G (1983) ADF&G (1983) ADF&G (1984) ADF&G (unpubl.) a ADF&G (unpubl.) X a Preliminary data pending final analysis 18

24 Table 3. Distribution of band returns from dusky Canada geese since 1951 as of August 3, 198~. Hunting British Season K Alaska Columbia Washington Oregon Other o.sl) / / * / l.q / ; l/ / l.q ~ X 10.3 (±_5.5) 9.5(±_7.8) 10.8(:!).9) 69.0(±8.4)!:/California!:_/Minnesota 1/utah!!_/Idaho *Incomplete recovery listing for this year. A corrected listing has been requested from the BBL and an update will follow. This may change, slightly, the distribution in previous years. 19

25 Table 4. Subspecies composition of Canada geese harvested in western Oregon and southwestern Washington, Dusky Taverner's Area Number t! (%) tt (%) Finley NWR 1, (46%) 613 (51%) Baskett Slough ~~R (57%) 26 7 (39%) Ankeny NWR (20%) 487 (75%) Ridgefield NWR (33%) 376 (35%) Sauvie Island ~~ 2,857 1,674 (59%) 1 '004 (35/~) Total 6,201 3,006 (48%) 2, 747 (44%) 20

26 L 50 c 0 Ill ;.. f Figure 1. Primary range of dusky Canada geese. 21

27 M"" -~~-~( ':\.\,... \'"i I""' C "...,, -:::::-.>-:::_;:_:-'( _i! -) Low llill Medium flli," High ~ b._:] ~~"~) ~. ~~ ~.. ~---- _..! Kok~nhltnik _ \ ' &olr '~,. ~-... ~1~, ~~~~ 'r....;, Figure 2. Copper River Delta, Alaska, showing areas of low, medium, and high nesting densities of dusky Canada geese. 22

28 t Q = Concentration a.regs * = Mdnagement areas ~= Possible sanctuaries z C(... u 0 u... u ~ Wm. L. Finley..._ Figure 3. Principal wintering areas of dusky Canada geese in the Willamette Valley of Oregon and along the lower Columbia River in Oregon and Washington. i ~u~c;r.. / c: \..\ I lc'i 1 '.J -. ;\~let--. ~ ~;.:; ~ '/ i',.~" -... '..,~.., '/ ~ :~." '.. 23