Spring Staging of Waterfowl Along the Naknek River, Alaska Peninsula, Alaska April - May, 1991

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SPRING STAGING OF WATERFOWL ALONG THE NAKNEK RIVER, ALASKA PENINSULA, ALASKA APRIL - MAY, 1991

By:

Toby A. Burke

Rey Words: Alaska Peninsula, Naknek River, waterfowl, migration, aerial surveys, ground surveys, radio telemetry, tundra swans, white- fronted and Canada geese, mallards, northern pintails, wigeon, canvasback, eiders, scoters, goldeneye, mergansers

U. S. Ftsh & Wildlife Service Alaska Peninsula/Becharof National Wildlife Refuge Complex P. 0. Box 277 Ring Salmon, Alaska 99613

February 1992 TABLE OF CONTENTS ii LIST OF TABLES iii LIST OF FIGURES

LIST OF APPENDICES v

ABSTRACT 1

INTRODUCTION 1

METHODS AND STUDY AREA 33 Study Area 3 Methods 3 Aerial Survey 4 Ground Survey 8 RESULTS AND DISCUSSION Species Accounts - Abundance and Timing of Staging 8 19 Aerial Survey vs. Ground Survey 21

Species Composition 22 Distribution 28 Greater white-fronted goose Telemetry 28 CONCLUSIONS 28 Spring Waterfowl Staging Trends 31 Methodology and Analysis 31 Disturbances 33 RECOMMENDATIONS 34 ACKNOWLEDGMENTS 35 LITERATURE 37 APPENDICES LIST OF TABLES

Pane No. Title

Highest recorded abundance of waterfowl by species for each year of aerial and ground surveys on the Naknek River, Alaska Peninsula, Alaska, March-May, 1983-1988, 1991 10

Highest recorded abundance of waterfowl by species on surveys of the Naknek River, Alaska Peninsula, Alaska, March-May, 11 1983-1988, 1991

ii LIST OF FIGURES Pace No. Title

Naknek River aerial survey segments, Alaska Peninsula, Alaska 2

Ground survey points, upper route, Naknek River, Alaska Peninsula, Alaska 6 Ground survey points, lower route, Naknek River, Alaska 7 Peninsula, Alaska Tundra Swans observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991 9

Geese observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991 9

Green-winged teal, northern shovelers, and gadwalls observed during ground surveys on the upper route Naknek River, Alaska 12 Peninsula, Alaska, 1991

Green-winged teal, northern shovelers, and mallards observed during ground surveys on lower route of Naknek River, Alaska 12 Peninsula, Alaska, 1991 Mallards, Eurasian wigeon, and American wigeon observed during ground surveys on upper route of Naknek River, Alaska 14 Peninsula, Alaska, 1991 Northern pintails observed during ground surveys on upper 14 route of Naknek River, Alaska Peninsula, Alaska, 1991

Canvasback, greater scaup, and black scoters observed during ground surveys on upper route of Naknek River, Alaska 16 Peninsula, Alaska, 1991 Greater scaup, oldsquaws, and black scoters observed during ground surveys on lower route of the Naknek River, Alaska 16 Peninsula, Alaska, 1991

Common goldeneyes, common mergansers, and red-breasted mergansers observed during ground surveys on upper route of 18 Naknek River, Alaska Peninsula, Alaska, 1991

Common goldeneyes, common mergansers, and red-breasted mergansers observed during ground surveys on lower route of 18 Naknek River, Alaska Peninsula, Alaska, 1991

Waterfowl observed during aerial survey on Naknek River, 20 Alaska Peninsula, Alaska, 1991

iii LIST OF FIGURES (continued) Pane No. Title

Swan distribution observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991 24

Goose distribution observed during ground surveys on upper 25 route of Naknek River, Alaska Peninsula, Alaska, 1991

Dabbling duck distribution observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991 26

Dabbling duck distribution observed during ground surveys on lower route of Naknek River, Alaska Peninsula, Alaska, 1991 27

Diving duck distribution observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991 29

Diving duck distribution observed during ground surveys on lower 30 route of Naknek River, Alaska Peninsula, Alaska, 1991

iv LIST OF APPENDICES Paae No. Title

I. Geographical description of ground survey observation points along the Naknek River, Alaska Peninsula, 38 Alaska, April - May 1991 ABSTRACT

A spring waterfowl survey was conducted from 3 April to 23 May along the Naknek River of the Alaska Peninsula. This monitoring continues the series of annual surveys initiated in 1983, with the addition of comprehensive ground surveys. The purpose of these surveys was to determine species composition, abundance, phenology, and distribution and relate these variations to human disturbances along the river and migration phenology. Overall waterfowl numbers remained relatively stable as compared to previous spring surveys, with staging peaking in late April for swans, geese, and dabbling ducks. Diving duck numbers peaked a week earlier. Numbers of geese staging on the Naknek River decreased, while dabbling ducks increased due to higher numbers of northern pintails (Anas acute). Ground surveys provided much new information concerning waterfowl species diversity during spring staging on the Naknek River. Common (Somateria mollissima) and king (S. spectabilis) eiders, harlequin duck (Histrionicus), and Barrow's goldeneyes (Bucephala islandica) were documented for the first time during spring surveys. Brant (Brenta bernicula), Eurasian wigeon (Anas penelope), and canvasbacks (Avthva valisneria) though seldom seen during previous spring surveys, were all observed this spring. Of these species, Eurasian wigeon and canvasback were considered, in the past, to be rare migrants on the Alaska Peninsula, but were encountered more frequently suggesting their status to be "uncommon" rather than "rare" migrants. Also because of ground surveys, common (Merous merganser) and red-breasted (Hs serrator) mergansers were distinguished from each other which allowed delineation of their notably dissimilar phenologies and distribution on the Naknek River for the first time. Red-breasted mergansers arrived much later than common mergansers, arriving as common mergansers were peaking. Generally speaking common mergansers preferred the upper river and red-breasted mergansers the lower river. The most valuable staging area on the Naknek River was the Big Creek/Paradise Point area which also is subject to numerous human disturbances. Of these disturbances motor boat traffic was observed to be more intrusive than jet aircraft.

INTRODUCTION

The management and conservation of waterfowl is a mandate of the U.S. Fish & Wildlife Service (FWS). In April and May, thousands of swans, geese, ducks, and other water birds stage during spring migration on the Naknek River, located on the northern Alaska Peninsula, adjacent to King Salmon (Fig. 1). Spring aerial waterfowl surveys have been conducted on the Naknek River every year from 1983 to 1988, but were not conducted for 1989 and 1990 due to the diversion of refuge personnel and resources to the Exxon Valdez oil spill surveys. This spring, surveys were resumed on the Naknek River with the addition of comprehensive ground surveys to supplement the aerial surveys, in accordance with the Wildlife Inventory Plan of Alaska Peninsula/Becharof National Wildlife Refuge Complex. Ct Ct

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2 The purpose of the these surveys have been: to establish a historical record of species composition, abundance, and phenology during spring migration; to monitor annual variations, especially in abundance of common species; and relate these variations to factors such as human disturbances along the river and migration phenology.

STUDY AREA AND METHODS

STUDY AREA The Naknek River is located at the northern base of the Alaska Peninsula, and connects the communities of King Salmon, Naknek, and South Naknek. It lies north of Becharof National Wildlife Refuge and west of Katmai National Park and Preserve. The river drains out of Naknek Lake within Katmai National Park and flows westward for 32 mi (51.2 km) where it empties into the northern end Bristol Bay. Bristol Bay's tidal influence affects the lower two-thirds of of the river from the mouth to Rapid's Camp, 22 mi (35.2 km) upstream. The upper third of the river, above Rapid's Camp to Naknek Lake lies above tidal influence.

METHODS Aerial surveys historically have been the primary method of surveying waterfowl on the Naknek River. In 1986, ground surveys were conducted to get an idea of the species that are overlooked or undercounted during the aerial were conducted simultaneously with the aerial surveys. The ground surveys surveys which resulted in poor ground counts and identification due to the flushing caused by the aerial survey. Additionally, the ground surveys were very limited in scope because counts were conducted from only 2 observation points on the river. After 1986, the ground surveys were discontinued due to the difficulty in coordinating and staffing the 2 simultaneou s surveys, and the reliability of the results (D. Mumma, FWS, King Salmon, Ak., pers. commun.). During spring 1991, a more comprehensi ve ground survey was designed to augment the aerial survey. This ground survey was conducted on a much more frequent basis, utilized more observation points, and was conducted independent of the aerial survey alleviating problems of manpower and flushing.

Aerial Survey Preliminary surveys from 1983 to 1988 indicated the peak of abundance, for staging swans, geese, and most dabbling ducks, to be at the end of April. of weather influences on migration timing, 3 or 4 aerial surveys Because due to scheduled at weekly intervals were conducted to allow for contingencie s weather. The goal of aerial surveys was to document peak numbers of common species (e.g., swans, white-fronte d geese, pintails, mergansers). Three river surveys were conducted + or - 1 hour of low tide, during daylight hours of the last 2 weeks of April and the first week of May. Tide tables for the Nushagak District - "Naknek Air Base" were used for reference. A Cessna 185 aircraft (chartered through Windy's Mag Air, Naknek, Ak) was used for the survey, flown at approximately 60 knots and 150-300 feet above ground level (adjusted accordingly to minimize disturbance of waterfowl). The survey usually began at the mouth of the river so that it could be flown into the prevailing head- winds. The aerial survey was broken into 2 separate flights. First, the entire river was surveyed for swans and geese. Then we returned to the survey's starting point and began again, censusing ducks. Breaking the aerial survey into 2 flights helped reduce confusion when encountering large, mixed flocks of numerous species. This greatly enhanced the surveys precision in regard to species abundance and composition. Each flight required approximately 45 min or 90-100 min total. When encountering large concentrations of ducks, it was not always possible to record all species present with great accuracy. In these cases, primary species such as pintails, mallards, goldeneyes and mergansers were focused on and other minor species recorded as best possible. Our most reliable information over the years will come from trends established by monitoring the most common and abundant waterfowl species.

The front right seat and rear left seat observers used small hand-held tape recorders to record all observations. Special care was taken with the tape recorders to use fresh batteries and appropriate tape speed. Clipboards with paper were brought along for back up in case of tape recorder failure.

The river was divided into 10 segments, all of which were surveyed (Fig. 1). Observers recorded the starting and ending time for the entire survey as well as the starting time for each segment. The same observers were used for the entire series of spring aerial surveys. The aircraft was flown down the middle of the river. In the wider stretches of the lower river, the pilot covered 1 side of the river and then doubled back and covered the opposite side to ensure thorough coverage. Generally, waterfowl tend to occur on mudflats or along river banks, requiring special attention to those areas. When large concentrations were encountered, typically along segments numbers 4-8 (Fig. 1), additional passes were made to ensure a thorough count and proper species identification. The observers requested, of the pilot a second pass when the first pass did not provide adequate coverage. When this became necessary, the front seat observer and pilot coordinated a strategy for additional coverage (altering flight altitude, flight speed, and or the flight line).

The results of each survey were transferred from tape to paper and compiled for use in an annual spring waterfowl report.

Ground Survey Ground surveys began soon after ice break-up, when the first waterfowl appeared on the upper river. Historically, break-up on the Naknek usually occurs in early-April, but it can vary widely, with break-up occurring as early as mid-March. Previous surveys (1983-1988) indicated the peak of abundance of staging waterfowl occurs about the end of April. The goal of this survey was to obtain a count of the highest numbers of all waterfowl species on the Naknek River during the peak of occurrence. Greater concentration was paid to species identification than on aerial surveys, which concentrated exclusively on common species. Ground surveys identified those species that occurred in moderate to low numbers as well, which were overlooked on aerial surveys, and positively identified those species that were indistinguishable from the air. Delineating species composition more accurately enabled a more detailed and accurate migration phenology for the river. Ground surveys were not intended to cover the entire river as thoroughly as aerial surveys, but rather to concentrate on areas that historically supported larger concentrations of waterfowl. Because those concentration areas vary according to ice coverage and species phenology, special attention was paid when establishing the fixed survey points. An area supporting little or no waterfowl in April might support major concentrations in May (e.g., Rapids Camp). Data from previous aerial surveys (1983-1988) aided in establishing those areas of waterfowl preference and their variations. Once the survey points (Appendix I) were firmly established, they were not changed to avoid biasing the data. Ground surveys were conducted + or - 1 hour of low tide, using tide tables for the Nushagak District - "Naknek River" as a reference. Surveys were timed to make optimal use of tidal fluctuations for observing birds on the exposed mudflats and river banks. Survey points up river from Rapids Camp are not tidally influenced. The Naknek River was divided into 2 ground survey routes because of time constraints and waterfowl distribution. The lower route covered from the mouth of the Naknek River to Paul's Creek, within this route there were 9 survey points (Fig. 2). The upper route covered from Ring Salmon Creek to the outlet of Naknek Lake. Within this route there were 8 survey points (Fig. 3). The more productive upper route was surveyed 3-4 times a week, where the lower route was sampled only 1-2 times a week. Despite its overall lower waterfowl productivity, the lower route occasionally contained exceptionally large concentrations of diving ducks, and species of sea ducks that seldom appeared in the upper route. Waterfowl was recorded separately for each survey point, species by species. The ground survey utilized 10x binoculars, 15x-60x spotting scope, and when weather permitted, a Questar terrestrial telescope. A 2-wheel drive pick-up truck provided access to all ground observation points except observation Point 15 which required a walk of 1.5 mi (round-trip). If desired, Point 15 can be accessed more quickly on an 4-wheeler using the existing trail.

A ground based telemetry survey was conducted on staging greater white-fronted geese in conjunction with the waterfowl counts on the Naknek. The purpose of the survey was to provide Alaska Fish and Wildlife Research Center, Migratory Birds Division with information on locally staging birds. The telemetry was performed on a daily basis from the first appearance of geese until the survey's conclusion. Complete coverage of the 2 ground survey routes was attempted concentrating efforts on the more productive upper route especially in areas where the geese were visible. Also, when geese were visible, the flock was carefully scanned for individuals with neck collars and or tarsus bands to record individual identification.

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6 7 RESULTS AND DISCUSSION

Species Accounts - Abundance and Timing of Staaina 1Phenolocnil

After a mild winter, the Naknek River broke free of ice in mid-March, much earlier than the historical average of early-April. After a few preliminary surveys in late March and the beginning of April, the survey formally began 3 April and concluded 23 May. (Note: No figures [graphs] are provided for Swans, geese, and northern pintails for the lower route of the Naknek River because they occurred there sporadically and in insignificant numbers).

Tundra swans (Cvanus columbianus) (Fig. 4) were first sighted on 29 March, with a pair sighted adjacent to the river. Swan numbers slowly increased until late-April. Swans peaked when 2,379 were counted on the 25 April aerial survey, which paralleled numbers encountered during previous years (Table 1). From late April to mid-May, swans started departing the river for breeding areas. By the end of May only non-breeders were left on the river. Stabilization of numbers in late May could be attributed to the high proportions of non-breeding swans that remain in large flocks along coastal estuaries like the Naknek drainage (Bellrose 1980).

Greater white-fronted geese (Anser albifrons) (Fig. 5) first arrived on 5 April, 1 week behind the first tundra swans. Historically, white-fronted geese generally arrive shortly after the first tundra swans. Goose numbers climbed moderately and peaked at 277 on the 19 April aerial survey. Geese stayed on the river for a week and then numbers declined rapidly until late May, when only a few pairs remained. White-fronted geese numbers were comparable to those of 1988 when only 124 were recorded, but 1991 numbers remained far below records from the early and mid-80's when over 2400 staged on the Naknek (Table 1). Brant (Branta bernicla) (Table 2) were observed only once, on 23 May, when 4 were seen feeding along the banks of the lower Naknek. This was only the second year brant had been observed during spring waterfowl surveys of the Naknek (1983-1991). Canada geese (Branta canadensis) (Fig. 5) were first observed on 11 April in a mixed flock with white-fronted geese. Their numbers peaked at 38 geese, during the 19 April aerial survey. Numbers slowly declined until they were last observed on the 3 May aerial survey. This year's peak was one of the lowest recorded since service sponsored waterfowl surveys began on the river. Prior to the mid-80's, over 800 Canada geese were reported to stage on the Naknek; however, in recent years, numbers staging have remained far lower (Table 1). Green-winged teal (Anas crecca) (Figs. 6 and 7) were first observed on 5 April, scattered among larger flocks of other dabbling ducks. Teal peaked at 32 during the third week of April and continued to be present in minor numbers throughout the survey until its conclusion. The variability in numbers (47 were seen during 3 May aerial survey) observed can partially be attributed to their constant movement between the river and the adjacent lakes and creeks. 1.6 1.5 - 1.4 - 1.3 - 1.2 1.1 - o 1 — 3 -0 c 0.9 - o o 0.8 o o 0.7 0.6 0.5 - 0.4 - 0.3 - 0.2 -

°. 01 11 1 1,11 1819 51105122 4/03 4/04 4/05 4/09 4/10 4/11 4/15 4/16 4/18 4/22 4/23 4/26 5/1 5/3 5/6 Observation Dotes Fig. 4. Tundra Swans observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991.

260 240 220 200 180 160 140 120 100 80 60 40 20 0 4/03 4/04 4/05 4/09 4/10 4/11 4/ 5 4/16 4/ 8 4/22 4/23 4/26 5/I 5/3 5/6 5/8 5/9 5/14 5/20 5/22 Observation Dates M. White—fronted Geese E22 Canada Geese Fig. 5. Geese observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991. Table 1. Highest recorded abundance of waterfowl by species for each year of aerial and ground surveys on the Naknek River, Alaska Peninsula, Alaska, March - May 1983- 1988, 1991. (Taylor 1984; Hood 1985, 1986, 1987a, 1987b, 1988, 1989; Wilk 1985a, 1985b; Wilk and Wilk 1988).

1983 1984 198 1986 987 1-:8 1991 S•ecies Aerial Aerial eria Ground Aerial Aerial Aeri I Ground

Tundra Swan 720 2625 2776 M 145 PRI 1970 PHI 1 4 Gr wh t -fron d •oose 63 2453 16 0 ST 758 30- 124 277 25 E •eror •oose Brant 1 Canada •oose 40 182 846 234 52 111= 68 SIMI 4 Green- d teal 7 13 -fl 47 32 Mallard 280 600 263 •50 44 r171. 199 539 2 2 Northern •intail 640 1638 1319 1704 n 5573 3983 5183 Northern shoveler 2 50 75 4 38 Gadwal 4 2 urasi wi•eon 3 4 6 America wi•eon 354 30 375 35 WI 9 MT= 06 Canv back 3 6 11 Redhead 2 Min reater scat'. 42 17 150 En 32 Ern 156 19 Common eider 75 Kin• eider 500' Harl • in duck 6 Old • aw 2 2 4 9 410 Black scoter 50 1 20 357 White-wined scoter 20 5 2 Surf scoter Scoter ••. 42 2 Bufflehead 25 1 4 3 11 Common •o dens e 315 1102 733 171 82 66 265 285 Barrow's •oldene e 2 Common me *anger 199 8:6 Red-breasted mer•anser 3 28 Mer • anser s• . . 2075 1558 1644 WWII 771 908

10 Table 2. Highest recorded abundance of waterfowl by species on surveys of the Naknek River, Alaska peninsula, Alaska, March - May 1983-1988, 1991. (Taylor 1984; Hood 1985, 1986, 1987a, 1987b, 1988, 1989; Wilk 1985a, 1985b; Wilk and Wilk 1988).

Species Number Year

Tundra Swan 2903 1987 Gr. white-fronted goose 2453 1984 Emperor goose 1 1985 Brant 4 1991 Canada goose 846 1985 Green-winged teal 114 1986 Mallard 650 1986 Northern pintail 5573 1988 Northern shoveler 150 1986 Gadwall 25 1985 Eurasian wigeon 6 1991 American wigeon 375 1985 Canvasback 11 1991 Redhead 2 1986 Greater scaup 193 1991 Common eider 75 1991 King eider 5000 1991 Harlequin duck 6 1991 oldsquaw 410 1991 Black scoter 357 1991 White-winged scoter 25 1991 Surf scoter 6 1991 Bufflehead 25 1984 Common goldeneye 1102 1984 Barrow's goldeneye 2 1991 Common merganser 2075° 1983 Red-breasted merganser 833 1991

a On 3/28/83, 2075 mergansers were recorded on an aerial survey, though not specifically identified as common mergansers during the survey, they are all assumed to be common mergansers since red-breasted mergansers do not typically appear in significant numbers until late April.

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_o 6 5 4 3 2 1 0 4/12 4/24 4/30 5/02 5/03 5/07 5/13 5/15 5/23 Observation Dates IM Green—winged Teal Northern Shovelers EZ2 Mallards Fig. 7. Green—winged teal, northern shovelers, and mallards observed during ground surveys on lower route of Naknek River, Alaska Peninsula, Alaska, 1991.

12 Mallards (Anas platvrhvnchos) (Figs. 7 and 8) were among the first dabbling ducks to arrive and were first observed in late March. They slowly increased during the first week of April, and then increased dramatically, peaking at 539 on the 25 April aerial survey. Throughout May, they persisted in only small numbers until the survey's conclusion. This year's counts were larger than the last survey in 1988, but similar to earlier surveys (Table 1). Mallards are typically found among large flocks of northern pintails and other dabbling ducks.

Northern pintails (Anas acuta) (Fig. 9), like mallards, were typically among the first dabbling ducks to arrive. They were first sighted in late March and slowly increased until mid-April, when their numbers climbed dramatically. Pintails peaked at 5,185 on 23 April, when they began to decline steadily until late May. During May, they were dispersed widely up and down the river in only small numbers. The dramatic decline in pintail observed on 1 May and their immediate rebound observed 3 May can be attributed to a severe wind storm which caused masses of pintails to leave the open river and take shelter out of sight and in the protection of vegetation along river banks and uplands. This years peak was similar to that of 1988 and significantly larger than numbers surveyed during the early and mid-80's (Table 1).

Northern shovelers (Anas clvoeata) (Figs. 6 and 7) typically were among the later arriving dabbling ducks and were not sighted until 26 April. Though never abundant on the river, their numbers were continuing to increase when the survey concluded; 38 were counted on 22 May. Northern shovelers were found associating with larger flocks of dabbling ducks, especially among large concentrations of American wigeon.

Gadwalls (Anas strenera) (Fig. 6) are usually one of the last ducks to arrive on their breeding grounds in spring (Bellrose 1980). They are an uncommon spring migrant and breeder in southwest Alaska but are a common fall migrant along the north side of the Alaska Peninsula (Kessel and Gibson 1978). Gadwall were first observed on 9 May and were last sighted on 20 May, only a few isolated pairs were found during this period.

Eurasian wigeons (Anas peneloue) (Fig. 8) (Table 2) were first observed on 16 April with a peak count of 6 on 1 May. Typically, 1 to 5 were found among groups of 30 or more American wigeon. Though never abundant, Eurasian wigeon were consistently present from mid-April until the survey's conclusion. This spring was the first time Eurasian wigeons were recorded having a constant presence on the Naknek River as opposed to the scattered and random sightings of the past. Historically, the Eurasian wigeon is considered a rare migrant on the Alaskan Peninsula (Kessel and Gibson 1978), yet I am confident that if further comprehensive ground surveys are continued, they will reveal that the Eurasian wigeon is more likely an "uncommon" migrant on the Alaska Peninsula rather than a rare migrant. This is a significant finding and hopefully future spring surveys will be able to further verify their presence.

American wigeons (Anas americana) (Fig. 8) first appeared on 9 April and slowly increased until peaking at 206 on 9 May. American wigeon appeared approximately 2 weeks later than the first mallards and northern pintails and also peaked approximately 2 weeks later.

13 260 240 - 220 - 200 - 180 160 - 140 120 - 100 - 80 - 60 - 40 - 20 - 0 111 I r' P IL 4/034/04 4/054/09 4/104/11 4/15 4/16 4/18 4/22 4/23 4/2 5/1 5/3 5/6 5/6 5/9 5/ 1 5/ 0 5/ Observation Dates NM Mallards Ea Eurasian Wigeon I= American Wigeon Fig. 8. Mallards, Eurasian wigeon, American wigeon observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991.

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14 Canvasbacks (Avthva valisineria) (Fig. 10) (Table 2) were observed 4 times during the spring surveys. Twice during ground surveys; on 23 April a pair was sighted and on 26 April, 11 birds were sighted. Twice during aerial surveys; on 25 April, 1 was sighted and on 3 May, 6 birds were seen. These observations were significant since canvasbacks are considered a rare migrant in the Bristol Bay area (Kassel and Gibson 1978). This was only the second year that canvasback were observed on spring waterfowl surveys of the Naknek River, the other being 1986. Like the Eurasian wigeon, future comprehensive ground surveys should reveal the canvasback to be an "uncommon" migrant on the Alaska Peninsula rather than a rare migrant. Contributing to the scarcity of sightings is the canvasback's habit of migrating directly and quickly, tarrying very little along their migration route (Bellrose 1980).

Greater scaup (Avthva marila) (Figs. 10 and 11) (Table 2) were first observed on 11 April. Their numbers peaked during the first week of May. On 1 May, 156 were counted on the upper route, on 3 May, 156 were counted on an aerial survey, and on 7 May, 193 were counted on the lower route in the mouth of the river. All during May, greater scaup were dispersed along the river's length, but only near the river's mouth could they be seen concentrated in rafts.

Common eiders (Somateria mollissima) (Table 2) were sighted only once, when a raft of 75 were observed near the mouth of the river on 12 April.

King eiders (Somateria spectabilis) (Table 2) were observed only once, on 24 April, when a spectacular flock of 5,000 was sighted rafting in the river's mouth, just prior to being disturbed by barge traffic.

Harlequin ducks (Histrionicus) (Table 2) were repeatedly sighted just days after the formal conclusion of the spring waterfowl surveys. The first observation was on 26 May when 6 were sighted down stream of Lake Camp where their preferred nesting habitat is met, adjacent to swift, turbulent water.

Oldsquaws (Clam:luta hvemalis) (Fig. 11) (Table 2) were first observed on 24 April, when a raft of 410 was sighted in the mouth of the river. This was also the largest sighting. Oldsquaw frequented the mouth of the river commonly in numbers of 10-50, but were rarely sighted further up river. They were usually seen associating with scoters and occasionally with greater scaup and eiders.

Black scoters (Melanitta niara) (Figs. 10 and 11) (Table 2) were by far the most common scoter on the river, with the first sighting occurring on 24 April when 9 were seen in the mouth of the river. Their numbers steadily increased during May and were still increasing when the survey ended (on 23 May 357 were observed on the lower river). The largest numbers typically occurred on the lower river, rafting in the mouth along with other scoters, oldsquaw, greater scaup, and occasionally eiders. They were also observed regularly on the upper river during the final week of the survey, as they began to break into smaller groups and disperse for courtship and mating.

White-winged scoters (Melanitta fusca) (Table 2) were sighted only once during the survey, when 25 were found on 20 May in a mixed flock of black scoters and greater scaup at the outlet of Naknek Lake.

15 160 150- 140 - 130 - 120 - 110 - co —6 100 - o90 - 9' 80 - 70- o 60 50 - 40 - 30 - 20 - 10 - n 0 , i i i i Ell i 1 t 4/03 4/04 4/05 4/09 4/10 yn 4/15 4/16 4/18 4/22 4/23 4/26 5/1 5/3 5/6 5/8 5/9 5/14 5/20 5/22 Observation Dates Canvosbacks pm Greater Scaup 1=2 Black Scoters Fig. 10. Canvasbacks, greater scaup, and black scoters observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991.

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16 Surf scoters (Melanitta perspicillata) (Table 2) were sighted twice during the course of the survey. On 24 April, 3 were observed and on 13 May, 6 were observed. Both observations were near the mouth of the river among larger numbers of black scoters.

Buffleheads (Bucephala albeola) were seen sporadically on both the upper and lower river. They were first observed on 15 April and continued to be sighted about once a week until survey's end. On 26 April, 11 were seen but they usually occurred in small groups of 1-4.

Common goldeneyes (Bucephala clangula) (Figs. 12 and 13) along with common mergansers are the first waterfowl to appear on the river. They usually arrive as soon as the first open water appears. They were already present on the river in significant numbers when the survey began; 191 were observed on 3 April. Goldeneye numbers slowly increased and peaked at 285 on 15 April along the upper river. Their numbers steadily decreased during the remainder of April. During May, they were sporadically present on the upper river and completely absent from the lower river. This year's peak was higher than the last 3 previous years' surveys but far lower than the peaks in 1984 and 1985 when 1,102 and 733 were respectively observed (Table 1). Goldeneye numbers tend to peak in early to mid-April and have often been under counted in previous years because spring surveys had not begun early enough.

Barrow's goldeneyes (Bucephala islandica) (Table 2) were observed once, on 26 April, when a pair was seen among a larger group of common goldeneyes at Lake Camp. Barrow's goldeneye is probably more abundant than spring surveys indicate but is difficult to distinguish at a distance from the more numerous common goldeneye.

Common mergansers (Marque merganser) (Figs. 12 and 13) were already present on the river in large numbers when the survey began; 547 were counted on 3 April. Their numbers continued to climb during the first 2 weeks of April and on 16 April 886 were counted on the upper river. On the 19 April aerial survey, 1,552 mergansers were counted and were assumed to be primarily common mergansers since red-breasted mergansers were not yet observed on a regular basis during the ground surveys. After peaking, their numbers plummeted until only a few widely scattered individuals remained by 1 May. The last common mergansers were observed on 13 May.

Red-breasted mergansers (Nereus serrator) (Figs. 12 and 13) (Table 2) arrived much later than common mergansers; they begin to arrive as common mergansers numbers were peaking. The first red-breasted mergansers were observed on 15 April and their numbers steadily increased until the first week of May. On the 3 May aerial survey, 833 mergansers were counted and is assumed that nearly all of these were red-breasted mergansers, since only 6 common mergansers were observed on ground surveys conducted earlier that day. After peaking, their numbers steadily declined until last observed on 20 May.

Mergansers numbers, if taken as a whole, were similar to numbers surveyed during the 1980's (Table 1). Like goldeneyes, common mergansers tend to peak early and have often been under counted for the same reasons. Also, future ground surveys should continue to provide needed data on these 2 unique populations which have previously been treated as one.

17 900

800 -

700 -

600 -

500 -

400

300 -

200 -

100

4/03 4/04 4/05 4/09 4/104/11 4/15 4/16 4/12 4/22 4/23 4/26 5/1 5/3 5/6 5/8 5/9 5/14 5/20 5/22 Observation Dates 11= Common Goldeneyes Common Mergansers EZ21 RB Mergansers Fig. 12. Common goldeneyes, common mergansers, and red—breasted mergansers observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991.

500

450

400

350 Su) uD 300 C co, 250

0 200

150

100

0 1 1 I I 4/ 12 4/24 4/30 5/02 5/03 5/07 5/ 13 5/ 15 5/23 Observation Dates Common Goldeneyes Common Mergansers 1771 RB Mergansers Fig. 13. Common goldeneyes, common mergansers, and red—breasted mergansers observed during ground surveys on lower route of Naknek River, Alaska Peninsula, Alaska, 1991.

18 Aerial Survey vs. Ground Survey

Aerial surveys have been the principal method of surveying spring waterfowl on the Naknek River. However, this year it was decided that aerial surveys would be augmented by ground surveys. Ground surveys in combination with aerial surveys presented a more comprehensive effort to accurately survey staging waterfowl. Aerial and ground surveys each contributed unique advantages and perspectives, and when used in concert, provided a more thorough survey than the exclusive use of 1 method.

The principle advantage of aerial surveys was the ability to cover the entire river from bank to bank. Hence, aerial surveys allowed a more thorough survey of the river in regard to recording sheer numbers of waterfowl (Fig. 14) and distribution patterns. One of the inherent disadvantages is the financial costs involved in conducting the spring aerial surveys. Each individual survey requires approximately 1.5 hours of flight time at $200/hr (chartered Cessna 185). Ideally the aerial surveys should be conducted as often as possible during the migration period but the expense of such an undertaking is prohibitive, making 3 (and up to 5) aerial surveys more practical. Another inherent disadvantage was the limiting factor of weather; weather problems can delay a survey by several days or even as much as an entire week. Because one of the principle aims of the survey was to determine the timing and magnitude of the peak of staging, any substantial delay can be a major problem because of the very nature of the staging ,which is concentrated during a relatively short period. Poor weather can often reduce the total number of aerial surveys flown. These 2 disadvantages stress the principle limitation of exclusive reliance on aerial surveys; the inability to conduct them on a more frequent basis either for reasons of economy or because of the lack of suitable flying weather.

Augmenting 3 to 5 aerial surveys with daily ground surveys is more cost effective than an intensive series of aerial surveys alone. Also, ground surveys can be conducted despite the high winds or low cloud ceilings that can limit aerial surveys. Because aerial surveys are usually conducted at 7 to 10 day intervals, they frequently miss important aspects of waterfowl migration such as arrivals, peaks, and departures. This was evidenced by this year's surveys when aerial surveys yielded peak northern pintail counts of 3,365 on 19 April and 3,983 on 25 April. While ground surveys documented a peak of 5,183 on 23 April. Thus, the higher frequency of ground surveys made them more sensitive to population fluctuations over the migration period. The lower frequency aerial surveys often cannot provide an accurate and detailed phenology if they are the sole method.

Ground surveys typically revealed a significantly greater diversity of waterfowl species than did aerial surveys. Aerial surveys allow only for the identification down to genus of similar waterfowl species, such as, red- breasted and common mergansers, which make up a considerable portion of the spring waterfowl. Furthermore, the inability to delineate these 2 taxonomically similar species on aerial surveys results in them being lumped together, preventing an accurate, detailed phenology of similiar species that have notably dissimilar phenologies. Also, due to the speed of the survey flight, it is more difficult to identify uncommon and rare species, when they

19 5000 4500 4000 3500 3000 .6, 2500

2000 1500 1000

500 0

4/19 4/25 5/3 Observation Dates

MI Dabbling Ducks Yr A Diving Ducks NM Swans 2Z2 Geese

Fig. 14. Waterfowl observed during aerial survey on Naknek River, Alaska Peninsula, Alaska, 1991.

20 occur within a larger flock. For example, the few individual Eurasian wigeon that were commonly found among larger flocks of American wigeon on ground surveys, were completely overlooked on aerial surveys. Even species that occur in moderate numbers are frequently overlooked on aerial surveys, especially when they are dispersed within a larger flock of a major species. Disturbances to waterfowl were also more easily detected and monitored during ground surveys.

Species Composition

For comparative purposes, species composition for waterfowl on the Naknek River were based on the aerial surveys; allowing a direct comparison with previous years' data. The most important comparisons are made between staging peaks (on average the end of April) for the respective years.

Swans Tundra swans, as usual, were the only species of swans observed on the Naknek this year. On the 19 April survey, swans composed 15% of all waterfowl observed. During the 25 April survey, swan numbers peaked with overall waterfowl numbers and constituted 29% of all waterfowl. On 3 May, after overall waterfowl numbers declined by nearly half from the previous survey, swans made up 23% of the total. Compared with previous years' surveys, 1991 swan numbers have been stable in both absolute numbers and as a proportion of overall waterfowl numbers. Historically, swans have constituted 20-30% of all waterfowl observed at staging peak.

Geese Greater white-fronted geese and Canada geese were observed on the Naknek during all 3 aerial surveys. On the 19 April survey, 4% of all waterfowl were geese. During the 25 April survey, goose numbers peaked but only constituted 4% of all waterfowl. Geese were only 2% of waterfowl on the 3 May survey. Compared with surveys conducted during the mid-80's, goose numbers have remained extremely low on the Naknek after plummeting during the late 80's. In 1984 and 1985 goose numbers respectively accounted for 26% and 27% of all staging waterfowl on the Naknek. This year greater white-fronted geese were 90% of the goose flock and Canada geese 10%. In previous years, Canada geese constituted approximately 30% of staging geese. The reasons for the decline in geese staging on the Naknek is unexplained. During 1984 and 1985, when both greater white-fronted geese and Canada geese populations on the Pacific flyway were extremely low (Canadian Wildlife Service and U.S. Fish & Wildlife Service 1986), spring staging numbers on the Naknek were extremely high. Conversely, now that greater white-fronted geese and Canada geese populations on the Pacific flyway are significantly higher than 1984 and 1985 (Childress and Rothe 1990), spring staging numbers on the Naknek are extremely low.

Dabbling Ducks Northern pintail, mallard, American wigeon and green-winged teal constituted the majority of dabbling ducks on the Naknek. Northern pintails and mallards made up 99% of dabbling ducks on the 19 April and 25 April surveys. Northern pintail were 87% of all dabbling ducks, and mallards were 12%. On the 3 May survey, after the peak, dabbling ducks consisted of: 86% northern pintail, 7% American wigeon, 5% mallard, and 2% green-winged teal. In previous years, the relative proportion of northern pintail has fluctuated widely, from 56% in

21 1983 to 97% in 1988.

Dabbling ducks represented 55% of all waterfowl on 19 April, 57% on 25 April, and 51% on 3 May. On surveys conducted from 1983-87, dabbling ducks averaged 20-25% of all waterfowl observed, compared to this spring's 57%, and 63% during the last previous survey (1988). The increase in staging of dabbling ducks on the Naknek reflects the increase in staging northern pintails, as the other dabbling duck numbers have remained relatively stable. Northern pintails, alone, accounted for 49% of all waterfowl observed this spring at peak; by far the most numerous waterfowl species staging on the Naknek. Currently, the reason(s) for the increase in staging northern pintail are not known.

Diving Ducks Common mergansers, red-breasted mergansers, and common goldeneyes constituted the majority of diving ducks on the Naknek. On the 19 April survey, at the peak for diving ducks, they consisted of; 84% common merganser, 14% common goldeneye, and 2% greater scaup. The 25 April survey revealed 34% common merganser, 34% red-breasted merganser, 18% greater scaup, 11% goldeneye, and 2% black scoter. The 3 May survey revealed 79% red-breasted merganser, 15% greater scaup, and 4% common goldeneye. During the first 3 weeks of April common mergansers were the most common diving duck. In the latter part of April the departing common mergansers and the arriving red-breasted mergansers were the co-dominant diving ducks. In early May, red-breasted mergansers were the dominant diver. Over the years mergansers have comprised approximately 60%-80% of all divers at peak and common goldeneyes approximately 15%-30%. Thus, the species composition of diving ducks has remained fairly stable over the years, as opposed to the species composition of dabbling ducks and geese.

On the 19 April, 25 April, and 3 May surveys; diving ducks respectively represented 26%, 10%, and 24% of all waterfowl on the Naknek. Unlike swans, geese, and dabbling ducks; the peak of staging for diving ducks is not consistently the end of April. It tends to occur during mid-April, but it has occurred as early as 28 March and as late as 24 April. Thus, it is difficult to compare the typically early peaking diving duck numbers with those of the later peaking swans, geese, and dabbling ducks. Taking this flaw into account, diving ducks historically represent 10-25% of waterfowl numbers during the overall staging peak in late April. (It tends toward 25% if their peak corresponds with the overall waterfowl peak and 10% if it doesn't; and as noted it usually doesn't). Despite this flaw, an absolute comparison can be made by comparing the annual diving duck numbers, at their peak, rather than the portion diving ducks represent during the overall waterfowl peak. This reveals that absolute diving duck numbers have remained fairly stable despite the significant annual fluctuations in their representative proportion of overall peak waterfowl numbers.

Distribution

The ideal time to observe the distribution of waterfowl on the Naknek River is at low tide + or - 1 hour. Swans, geese, and dabbling ducks feed mostly during low tide when exposed tidal flats and shallow waters are at their maximum. At this time, diving ducks are frequently found roosting along the

22 river banks. Areas of principle importance in supporting the greatest concentrations of spring staging waterfowl are: Naknek Lake outlet, Rapids Camp, Big Creek, Paradise Point, Grassy Point, King Salmon Creek, and the mouth of the Naknek River. All of these areas are, the notable exception being the Naknek Lake outlet, tidally influenced and have significant tidal flats. The degree to which each concentration point is used is dependant not only on tidal and ice conditions, but also on the phenology of each individual species utilizing them. Generally, swans, geese, and dabbling ducks use the upper portion of the Naknek, while diving ducks use both the upper and lower portions.

Swans Initially, during spring staging, swans were found near Big Creek and continued to use this area almost exclusively until mid-April. In mid-April, as other areas of the Naknek became ice free and swan numbers increased, swans began to also concentrate at the outlet of Naknek Lake and at Rapids Camp. In late April, when swan numbers were peaking, they were concentrated at 5 principle areas of the upper Naknek: Naknek Lake outlet, Rapids Camp, Big Creek area, Paradise Point, and Grassy Point. From early May, after the peak of swan staging, until the conclusion of the survey, the remaining swans (mostly non-breeders) concentrated at Rapids Camp, Big Creek, and Paradise Point (Fig. 15).

Geese Geese first appeared on the tidal flats between Big Creek and Paradise Point and used this area exclusively until other areas of the Naknek became ice free in mid-April. From mid to late April, geese concentrated on tidal flats and river banks from Grassy Point to Eskimo Creek. After peaking in late April, geese were present on the river in small numbers and were widely dispersed along the upper half of the Naknek. Because goose numbers were very small this spring, compared to their former levels, it may be misleading to say geese concentrated at all. As a result of the decline, traditional goose concentration points this spring were either sparsely used or completely unused by geese. For example, the Naknek Lake outlet was formerly a high concentration area for geese and this spring it hosted only a few scattered individuals (Fig. 16).

Dabbling Ducks Dabbling ducks first appeared in the Big Creek area in late March and continued to use the area almost exclusively during the first 2 weeks of April. From mid to late April, most of the dabbling ducks continued to stage near Big Creek. At the peak of staging, nearly 4,000 dabbling ducks or 70% of all dabblers were observed between Big Creek and Paradise Point, with the Naknek Lake outlet and Rapids Camp as other significant staging areas. During the first 2 weeks of May, after the peak, dabbling ducks concentrated principally at Rapids Camp and to a lesser extent at Big Creek. From mid-May until the conclusion of the survey, the few hundred remaining dabbling ducks were dispersed evenly over the entire river (Figs. 17 and 18). Diving Ducks Diving ducks were already present on the Naknek in significant numbers when the survey was initiated. In March, they concentrated in the ice free lower

23 1600 1500 1400 1300 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 4/3 4/4 4/5 4/9 4/10 4/11 4/15 4/16 4/18 4/22 4/23 4/26 5/1 5/3 5/6 5/8 5/9 5/14 5/20 5/22 Observation Dates Pt 10 Pt 11 222 Pt 12 Pt 13 NM Pt 14 Pt 15 Pt 16 Pt 17

Fig. 15. Swan distribution observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991.

24 300 280 - 260 - 240 - 220 - 200 - 180 - 160 - 140 - 120 - 100 - 80 - 60 - 40 - 20 - 0 4/3 4/4 4/5 4/9 4/10 4/11 4/15 1/16 4/18 4/22 4/23 0/26 5/1 5/3 5/6 5/8 5/9 5/14 5/20 5/22 Observation Dates IIMI Pt 10 EZI Pt 11 2Z2 Pt 12 ESN Pt 13 I= Pt 14 ME Pt 15 Pt 16 Pt 17 Fig. 16. Goose distribution observed during ground surveys on upper route of Naknek River, Alaska Peninsula, 1991.

25 6

-L ., 4 - to o P 0' 0 C D 3 -0 0 _0 _c H- 0 2 -

4/3 4/4 4/5 4/9 4/10 4/11 /15 4/16 4/18 4/22 4/23 4/26 5/1 5/3 5/6 5/8 5/9 5/14 5/20 5/22 Observation Dates NM Pt 10 Pt 11 EZZI Pt 12 EN Pt 13 Pt 14 VA Pt 15 I= Pt 16 6299 Pt 17

Fig. 17. Dabbling duck distribution observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991.

4/12 4/24 4/30 5/2 5/3 5/7 5/13 5/15 5/23 Observation Dates MI Pt 1 [872 Pt 2 [222 Pt 3 I= Pt 4 Pt 5

Pt 6 Pt 7 I Pt 8 MIN Pt 9 Fig. 18. Dabbling duck distribution observed during ground surveys on lower route of Naknek River, Alaska Peninsula, Alaska, 1991.

27 portion of the river, especially from Horseshoe Point to Rocky Point (Point 8- Wolverine Rd.), which typically is the first section of the river to open. As the upper portion of the river opened, concentrations of diving ducks shifted to these areas. During the first week of April, diving ducks were concentrated at Big Creek, Paradise Point, and Grassy Point. During the second week of April, diving ducks, predominately common mergansers, concentrated at King Salmon Creek where they would roost at low tide. When dabbling duck numbers peaked the third week of April, the major area of concentration had again shifted to the Big Creek area where diving ducks were actively feeding rather than roosting. During that third week, diving ducks were also concentrated in smaller numbers at Paradise Point and King Salmon Creek. After the peak, the remaining diving ducks were dispersed evenly along the entire river. During the final 2 weeks of the survey, diving duck numbers in the lower portion surpassed those of the upper portion. The major concentration point during that period was the mouth of the Naknek River. Notably, the early staging common mergansers generally preferred the upper portions of the river, while the later staging red-breasted mergansers generally preferred the lower portions of the river (Figs. 19 and 20). Greater White-fronted Goose Telemetry

This spring a ground based telemetry survey was conducted on staging greater white-fronted geese in conjunction with the waterfowl counts on the Naknek. This survey was conducted to identify locally staging birds. The ground based telemetry was performed along the Naknek on a daily basis from 5 April until the survey's conclusion on 23 May. Despite numerous hours and thorough coverage, no signals were received. The equipment and its operation were tested repeatedly to assure that neither were a factor in the disappointing results. Additionally, there were no birds observed with neck collars or tarsus bands. Neither finding should be surprising considering the very low numbers of staging greater white-fronted geese this year.

CONCLUSIONS

Spring Waterfowl Staoina Trends

Overall, staging waterfowl numbers on the Naknek River have remained relatively stable as compared to previous spring surveys (1983-88). Taken alone however, the overall numbers are misleading as they hide changes in species composition, such as the decrease in staging geese and the increase in staging dabbling ducks. Any discernible decline in overall waterfowl numbers during spring staging, when comparing the mid-80's to this spring, can principally be attributed to the decline of staging geese.

The reason(s) behind the decrease in staging geese on the Naknek are unknown. During the mid-80's, when Pacific flyway populations of greater white-fronted geese and Canada geese were extremely low, numbers staging on the Naknek were very high. Now, Pacific flyway populations have increased significantly over the last few years, and the number of staging geese on the Naknek has dropped. Perhaps the decline of geese staging on the Naknek more accurately reflects a change in migration patterns versus a trend in the population.

28 1200 1100 1000 900 800 700 600 500 400 300 200 100 0 4/3 4/4 4/5 4/9 4/10 4/11 4/15 4/16 4/18 4/22 4/23 4/26 5/1 5/3 5/6 5/8 5/9 5/14 5/20 5/22 Observation Dates

MN Pt 10 132323 Pt 11 EZZI Pt 12 ES) Pt 13

Pt 14 Pt 15 Pt 16 Pt 17 Fig. 19. Diving duck distribution observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1991.

29 700

600

500

400

300

200

100

0 4/12 4/24 4/30 5/2 5/3 5/7 5/13 5/15 5/23 Observation Dates

Pt 1 Pt 2 EZ3 Pt 3 ESN Pt 4 EKJ Pt 5

r /I Pt 6 N Pt 7 I I Pt 8 F77:71 Pt 9

Fig. 20. Diving duck distribution observed during ground surveys on lower route of Naknek River, Alaska Peninsula, Alaska, 1991.

30 Though not as puzzling as the decline in staging geese on the Naknek, the reason(s) behind the increase in staging dabbling ducks, primarily northern pintail, on the Naknek are not completely clear either. Northern wetlands, such as those of Alaska, are especially important to waterfowl during years when drought displaces them from their traditional breeding grounds further south (Dufresne et al. 1964). The increase on the Naknek could be a reflection of this periodic phenomenon. But local increase could reflect, in part, a larger, long term change in spring staging for dabbling ducks in North America. It is probable that the quantitative decline of breeding habitat due to wetlands conversion for agricultural purposes, coupled with an increasing frequency of severe drought, in the high plains states of the "lower 48" and the prairie and parkland provinces of Canada, North America's prime duck breeding area, has caused many species of dabbling ducks to rely more heavily upon their more northerly breeding grounds.

Another reason, though less probable, may be related to local causes such as the local decline in staging geese. Since dabbling ducks and white-fronted and Canada geese share nearly identical foraging habitat on the river, it is possible that habitat formerly occupied by geese and left vacant is now being occupied and exploited by dabbling ducks. Whether there is a direct correlation between the these remains to be proven; it may be more than mere coincidence that the decrease in geese and commensurate increase in dabbling ducks occurred nearly simultaneously.

Methodoloov and Analysis

In the past, aerial surveys on the Naknek were conducted with the main purpose of determining the overall staging peak and using that survey to determine overall waterfowl numbers and their trends. Because individual species do not always peak simultaneously, erroneous conclusions can be drawn when relying exclusively on the magnitude of the overall staging peak as the definitive measure of overall staging waterfowl numbers. A more accurate measure of overall waterfowl numbers would be the sum-total of all the numerical staging peaks for each individual species as determined by the various aerial surveys. Because aerial surveys allow a more thorough coverage of the entire river than do ground surveys, they usually reveal the highest staging population peaks. Yet, when a ground survey reveals a peak substantially higher than from an aerial survey, then it should be recorded instead, since the high frequency ground surveys can reveal peaks that occurred before or after the low frequency aerial surveys. Thus, the emphasis should be placed on determining the peaks of each species and the sum-total of those peaks and in the future these can be used to determine waterfowl population trends on the Naknek. Disturbances

The most common disturbances to spring staging waterfowl on the Naknek are from boat traffic, airplane traffic and the human development of prime staging areas. Contrary to popular opinion, waterfowl in the Big Creek/Paradise Point area (adjacent to the busy King Salmon Airport and far and away the most valuable waterfowl staging area) were disrupted more by small boat traffic than by departing jet aircraft.

Airplane traffic did cause observable disturbances but the staging waterfowl

31 seemed to tolerate all but the lowest and loudest flying aircraft. When military aircraft, specifically F-15 fighter planes, altered their take off trajectory by either climbing rapidly or banking left or right, their disturbance to waterfowl was minimal. Thus, by altering their takeoff pattern during peak waterfowl staging, the military can also benefit by reducing the hazard of bird-plane collisions.

Small boat traffic through this area, though not previously viewed as a major disturbance, was in fact more intrusive than jet aircraft. When a boat traveled through the area most species of waterfowl were disturbed in varying degrees; diving ducks, dabbling ducks, and geese usually flushed but typically returned as soon as the boat departed. But swans appeared to be even more sensitive, flushing from the river and typically not immediately returning after the boat departs. They either flew to another part of the river or leave and roost on uplands adjacent to the Big Creek/Paradise Point area, similar to what they did at high tide. Obviously, the greatest disturbances occurred at low tide when waterfowl were concentrated and actively foraging. Boat noise was a factor but the more important factor is that a speeding boat does not allow the waterfowl in its path to passively escape. When boats proceeded through this area at moderate to slow speeds, they minimized their impact on waterfowl by allowing them time to swim clear of the intrusion rather than flushing off the river.

For the most part, human development along the Naknek River corridor has spared most of the prime waterfowl staging habitat. Since most of this habitat is in the upper half of the river, it is this section that is in greatest need of protection. One significant staging area on the upper half of the river has already been lost, that being the mouth of Eskimo Creek. In 1987, a hotel, with a float plane dock and foot bridge was built bringing increased human activity. Since then, this tidal flat no longer attracts large concentrations of swans and geese, as it did prior to development (Wilk 1988). Currently, the Grassy Point area appears to be the next staging area that is being threatened. If the riverfront development of King Salmon continues to sprawl further east it will begin to encroach upon this staging area as well.

Frequent disturbances may have implications on waterfowl behavior, which could affect reproductive potential and success. Energy necessary for courtship, nesting, laying, and incubating is expended during repeated flushing and valuable foraging opportunities are also lost. The Naknek River has been specifically identified as critical habitat, recommended for protection, for both staging tundra swans and white-fronted geese during spring migration (Bowers et al. 1983).

32 RECOMMENDATIONS

Emphasis should be placed on determining the magnitude of each staging peak for each individual species and use the sum-total as the definitive measure of overall waterfowl abundance, rather than using the overall waterfowl staging peak as the definitive measure of waterfowl abundance.

Three spring aerial surveys have been conducted in the past - on the third and fourth week of April, and the first week of May. Ideally this should be increased to 4 with the additional survey being conducted the second week of April. This additional survey should determine the peak of diving ducks, which historically peaked earlier than swans, geese, and dabbling ducks. Aerial surveys must be conducted in strict accordance with low tide.

Conduct at least 1 similar aerial survey (during the goose staging peak) on the Egegik, Ugashik, and Kvichak rivers, for comparative purposes, to test for changes in geese staging distribution.

Ground surveys should continue to focus on the more productive upper river route. The surveys should be conducted at least 3 times per week on the upper route and once per week on the lower route. Ground surveys must be conducted in strict accordance with low tide.

Ground surveys should be started as soon as the river breaks free of ice and continued at least until mid-May. For purposes of familiarization, 1-2 preliminary surveys should be conducted before the survey formally begins.

Aerial surveys should continue as the primary method of determining overall waterfowl abundance, specifically the most common species. Ground surveys should continue as the primary method of determining waterfowl phenology and detecting human disturbances. Both methods of survey when combined will give a more complete understanding of species composition and distribution.

Observers must be proficient at waterfowl identification. Specifically, in preparation for aerial surveys observers should re-familiarize themselves with waterfowl upper wing patterns.

Efforts should be made to limit development along the upper half of the Naknek, specifically to prevent further encroachment on staging concentration points.

Efforts should be made to reduce low level flights by aircraft over the upper Naknek and alter the take-off pattern for F-15 fighter planes, during the peak of waterfowl staging.

Efforts should be made to reduce boat speeds by introducing a "No Wake" zone on the section of the Naknek between Paradise Point and Big Creek during the peak of swan staging. This will reduce engine noise but more importantly it allows waterfowl time to passively escape from the path of the on coming boat.

33 ACKNOWLEDGEMENTS

Greatly appreciated was the assistance provided by Wildlife Biologist Donna Dewhurst and Student Conservation Association Volunteer Michael Moore. Donna Dewhurst provided guidance during the survey and throughout the entire report writing process. Michael Moore provided assistance creating the report graphics. Administrative support and advice was provided by Refuge Manager Ronald Hood and the other staff members of the Alaska Peninsula/Becharof Refuge Complex.

34 LITERATURE CITED

Bellrose, F. C. 1980. Ducks, geese and swans of North America. Third ed. Stackpole, Harrisburg, Pa. 540pp.

Bowers, F., E. Halpin, and J. Parker, editors. 1983. Migratory birds and marine mammals of the Bristol Bay Region. U.S. Fish & Wildl. Serv., Admin. Rep., Anchorage, Ak. (Unpubl). 84pp.

Canadian Wildlife Service and U. S. Fish & Wildlife Service. 1986. North American waterfowl management plan. U.S. Dept. of the Int., Washington, D.C. 31pp.

Childress, D. and T. Rothe. 1990. Management of Pacific flyway geese: an exercise in complexity and frustration. Pages 327-332 in R. E. McCabe, editor. Goose Management in the '90s. Wildl. Manage. Inst., Washington, D.C.

Dufresne, F., R. H. Smith, and H. A. Hansen. 1964. Northern watersheds and deltas. Pages 51-66 in J. P. Linduska, editor. Waterfowl tomorrow. U.S. Fish & Wildl. Serv., Washington D.C.

Hood, R. E., editor. 1985. Alaska Peninsula/Becharof National Wildlife Refuges - 1984. U.S. Fish & Wildl. Serv., Ann. Narr. Rep., King Salmon, Ak. (Unpubl). 107pp.

editor. 1986. Alaska Peninsula/Becharof National Wildlife Refuges - 1985. U.S. Fish & Wildl. Serv., Ann. Narr. Rep., King Salmon, Ak. (Unpubl). 179pp.

editor. 1987a. Alaska Peninsula/Becharof National Wildlife Refuges - 1986. U.S. Fish & Wildl. Serv., Ann. Narr. Rep., King Salmon, Ak. (Unpubl). 233pp.

1987b. Naknek River spring aerial surveys. U.S. Fish & Wildl. Serv., Admin. Memo., King Salmon, Ak. (Unpubl). 2pp.

editor. 1988. Alaska Peninsula/Becharof National Wildlife Refuges 1987. U.S. Fish & Wildl. Serv., Ann. Narr. Rep., King Salmon, Ak. (Unpubl). 155pp.

editor. 1989. Alaska Peninsula/Becharof National Wildlife Refuges - 1988. U.S. Fish & Wildl. Serv., Ann. Narr. Rep., King Salmon, AK. 168pp.

Kassel B. and D. D. Gibson. 1978. Status and distribution of Alaskan birds. Cooper Ornith. Soc., Los Angeles, Ca. 100pp.

Taylor, J. T., editor. 1984. Alaska Peninsula/Becharof National Wildlife Refuges - 1983. U.S. Fish & Wildl. Serv., Ann. Narr. Rep., King Salmon, Ak. (Unpubl). 95pp.

35 Wilk, R. J. 1985a. Naknek River aerial survey #1. U.S. Fish & Wildl. Serv., Admin. Memo., King Salmon, Ak. (Unpubl). 2pp.

1985b. Second survey, 1985 - Naknek River aerial waterbird survey. U.S. Fish & Wildl. Serv., Admin. Memo., King Salmon, Ak. (Unpubl). 3pp.

1988. Naknek River aerial survey in spring. U.S. Fish & Wildl. Serv., Admin. Memo., King Salmon, Ak. (Unpubl). 6pp.

and K. I. Wilk. 1988. Composition and abundance of waterfowl on the Naknek River, Alaska, 25 April and 8 May, 1988. U .S. Fish & Wildl. Serv., Admin. Rep., King Salmon, Ak., (Unpubl). 7PP.

36 APPENDICES

37 Appendix I. Geographical description of ground survey observation points along the Naknek River, Alaska Peninsula, Alaska, April - May 1991.

Lower Route

Point 1 - Mouth of Naknek River Departing from the King Salmon USFWS office, drive 0.2 mi and turn left onto the King Salmon - Naknek Road, follow road west 15.3 mi into and through Naknek to where road dead ends in front of FISHERMAN'S BAR. Turn left onto gravel road, follow road as it turns right, proceed 0.2 mi, take right turn onto gravel road across from INLET SALMON, follow 0.8 mi and take right turn onto gravel road across from sewage lagoon. Follow this road (Monsen Creek Road) 0.9 mi to a small gravel parking lot overlooking the Bristol Bay. Walk 70 yards from parking lot down the road and on to 20 foot high bluff overlooking the beach. From this point, record all waterfowl located in the mouth of the river as well as all adjacent tidal flats of the Bristol Bay. Point 2 - Sewage Lagoon and Overlook From observation Point 1, return down Monsen Creek Road turning right at stop sign. Follow road 0.4 mi to where it ends in a turn-around adjacent to sewage lagoon. Park and walk 70 yards south to the edge of a high bluff overlooking the mouth of the river. From this point, record all waterfowl in river and its mouth not visible from Point 1. Additionally, record waterfowl observed in both settling/leaching ponds of the sewage lagoon complex. Point 3 - End of State Road From observation Point 2, return down sewage lagoon access road where road meets INLET SALMON and turn right. Proceed 0.2 mi until reaching sign marked "STATE MAINTENANCE ENDS", adjacent to PETER PAN CANNERY. From this point overlooking the cannery and river, record all waterfowl not visible from Point 2.

Point 4 - Municipal Barge Dock From observation Point 3, return to FISHERMAN'S BAR and turn right onto the paved King Salmon - Naknek Road. Proceed east 1.3 mi, turn right onto gravel drive across from cargo storage lot and follow drive 0.2 mi down to dock facility. Walk to the end of the dock and record all visible waterfowl on the river.

Point 5 - Leader Creek From observation Point 4, return to King Salmon - Naknek Road and proceed east 1.8 mi, turn right at NAKNEK MARINE CENTER "LUMI" sign. Follow gravel road 0.2 mi to its end near boat ramp at river's edge. From the gravel lot above the boat ramp, record all visible waterfowl, concentrating on tidal flats in the mouth of Leader Creek.

Point 6 - Martin Monsen Park From observation Point 5, return to King Salmon - Naknek Road and proceed east 1.9 mi, turn right onto gravel road across from Martin Monsen Park sign. Follow road 0.2 mi to where it forks into 3 separate driveways, follow the middle driveway 0.2 mi to its end at Martin Monsen Park. From atop the 30 foot bluff, at the picnic table area, record all visible waterfowl (principally from Telephone Point to Kunsiniali Point).