FILE COPY Tihtenv4l
Total Page:16
File Type:pdf, Size:1020Kb
FILE COPY tihtenv4L SPRING STAGING OF WATERFOWL ALONG MAJOR DRAINAGES OF BRISTOL BAY WITH AN EMPHASIS ON NAKNEK RIVER, ALASKA MARCH - MAY 1997 By: Gretchen Ruhl Key Words: Aerial surveys, Alaska Peninsula, American wigeon, Canada geese, c anvasback, disturbance, Egegik River, eiders, Eurasian wigeon, goldeneyes, greater scaup, ground surveys, Kvichak River, mallards, mergansers, migration, Naknek River, northern pintails, radio telemetry, redheads, scoters, tundra swans, Ugashik River, waterfowl, white-fronted geese. U. S. Fish & Wildlife Service Alaska Pen insula/Becharof National Wildlife Refuge Complex P.O. Bcx 277 King Salmon, Alaska 99613 October 1997 TABLE OF CONTENTS i LIST OF FIGURES ii LIST OF TABLES AND APPENDIX 1 ABSTRACT 1 INTRODUCTION 1 STUDY AREA 3 METHODS 3 Aerial Surveys 3 Ground-based Surveys 4 Disturbance 7 RESULTS 7 Weather 7 Abundance and Timing of Staging 7 Species Accounts 16 Species Composition on the Naknek River 16 Distribution on the Naknek River 19 Aerial Surveys 19 Disturbance to Waterfowl 19 DISCUSSION.:.. 19 Methodology 21 Species Composition and Relative Abundance 21 Annual Variations 22 Other Area Rivers 22 Disturbance 23 RECOMMENDATIONS 24 ACKNOWLEDGMENTS 25 LITERATURE CITED 27 APPENDIX LIST OF FIGURES Rivers included in the 1997 spring waterfowl surveys, and aerial survey segments of the Naknek River, Alaska Peninsula, Alaska 1997 2 Ground survey points, lower route, Naknek River, Alaska Peninsula, Alaska 5 Ground survey points, upper route, Naknek River, Alaska Peninsula, Alaska 6 Total waterfowl observed during ground surveys on upper route of the Naknek River, Alaska Peninsula, Alaska, 1997 8 White-fronted and Canada Geese observed during ground surveys on upper route of the Naknek River, Alaska Peninsula, Alaska, 1997 11 Swans and geese observed during ground surveys on upper route of the Naknek River, Alaska Peninsula, Alaska, 1997 11 American and Eurasian wigeon observed during ground surveys on the upper route of the Naknek River, Alaska Peninsula, Alaska, 1997 13 Common goldeneyes, common mergansers, and red-breasted mergansers observed during ground surveys on upper route of Naknek River, Alaska Peninsula, Alaska, 1997 15 Common goldeneyes, common mergansers and red-breasted mergansers observed during ground surveys on lower route of the Naknek River, Alaska Peninsula, Alaska, 1997 15 Seasonal changes in composition of waterfowl staging on the Naknek River, Alaska Peninsula, Alaska, 1997 17 Dabbling vs. diving duck abundance on upper route of Naknek River, Alaska Peninsula, Alaska, 1997 18 Dabbling vs. diving duck abundance on lower route of Naknek River, Alaska Peninsula, Alaska, 1997 18 13. Total waterfowl observed during aerial surveys, Alaska Peninsula, Alaska, 1997 20 LIST OF TABLES AND APPENDIX Tables I. Arrival and peak dates of waterfowl observed during the spring aerial and ground surveys of the Naknek River, Alaska Peninsula, 9 Alaska, March - May, 1991-1997 2. Highest recorded abundance of waterfowl by species for each year of spring aerial and ground surveys on the Naknek River, 10 Alaska Peninsula, Alaska, March-May, 1983-1988, 1991-1997 Appendix I. Geographical description of ground survey observation points along the Naknek River, Alaska Peninsula, Alaska, March - 28 May 1997 ii ABSTRACT A spring survey of staging waterfowl along the Naknek River of the Alaska Peninsula was conducted 17 March - 16 May, 1997. This year's survey continued annual surveys initiated in 1983. For the seventh consecutive year, ground surveys were performed in conjunction with aerial surveys. Additional aerial surveys were conducted along the Kvichak, Ugashik and Egegik rivers for comparative purposes. Both the Ugashik and Egegik rivers showed greater than a 300% increase in total waterfowl. Naknek River waterfowl numbers in 1997 were generally low compared to 1991-1996, (possibly the result of an early spring thaw and increased availability of open water elsewhere on the Peninsula or the diversion of waterfowl to the Ugashik and Egegik rivers.) Twenty-five species of waterfowl were observed during the 1997 survey, plus an unusual sighting of a single Tufted duck (Aythya fuligula). The highest number of white-fronted geese (Anser albifrons frontalis) was recorded since the initiation of the ground surveys in 1991 (1343), although that was still lower than the aerial survey counts of 1984-1986 and 1995. Independent of the waterfowl counts, a survey of disturbance to waterfowl, both natural and man- made, was conducted along the Naknek River. 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 on the Naknek River, northern Alaska Peninsula (Fig. 1) during spring migration. From 1983 to 1988, aerial surveys, conducted annually in spring by the Alaska Peninsula/Becharof National Wildlife Refuge Complex (Complex), were the primary method of surveying waterfowl on the river. Ground surveys were conducted simultaneously with aerial surveys for the first time in 1986 because of concern that some species may be overlooked or undercounted from the air. These infrequent ground counts were problematic due to use of only 2 survey sites and the constant flushing of waterfowl by the aircraft performing aerial counts. After only one season, the ground surveys were discontinued due to staffing logistics and concern about validity. Waterfowl surveys were not conducted during 1989 and 1990 due to diversion of Complex personnel and resources to efforts involving the Exxon Valdez oil spill. During spring 1991, the first comprehensive ground survey was designed and conducted. This survey used multiple observation points, with more frequent monitoring over a longer time, and was independent of aerial surveys. It broadened the scope of the spring surveys in order to increase understanding of species composition, abundance, habitat use, and phenology. These surveys have been continued annually through 1997. The purpose of the these surveys are to: Establish a historical record of species composition, abundance, and phenology on the Naknek River during spring waterfowl migration; Monitor annual variations, especially in abundances of common species; Relate annual variations to factors such as human disturbance along the river and weather patterns; and, Quantify human disturbance to waterfowl staging on the Naknek River. STUDY AREA The Naknek River is located at the northern end of the Alaska Peninsula and 1 Fig. 1. Rivers included in 1997 spring waterfowl surveys, and aerial survey segments of the Naknek River, Alaska Peninsula, Alaska. 2 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 51.2 km (32 mi) where it empties into the northern end of Bristol Bay (Fig. 1). Bristol Bay's tides influence the lower two-thirds of the river [from the mouth to Rapids Camp, 35.2 km (22 mi) upstream], exposing large mudflats when low. The Kvichak River lies 48 km (30 mi) north of the Naknek River and flows 113.6 km (71 mi) southwest from Iliamna Lake into Bristol Bay. The Egegik River lies 65.6 km (41 mi) south of the Naknek River and flows westward for 40 km (25 mi) from Becharof Lake into Bristol Bay. The Ugashik River lies 128 km (80 mi) south of the Naknek and flows westward for 65.6 km (41 mi) from Lower Ugashik Lake to Bristol Bay. Communities located along the rivers surveyed include Egegik (pop. 122) on the Egegik River, Levelock (pop. 105) and Igiugig (pop. 33) on the Kvichak River, Ugashik (pop. 7) and Pilot Point (pop. 53) on the Ugashik River, and King Salmon/Naknek/So uth Naknek (combined population 1305) all on the Naknek River. Most swell to 1-10 thousand during commercial fishing season in the summer. Figure 1 shows relative locations of each of those communities. METHODS Aerial Surveys In 1997, the aerial survey on the Naknek River was conducted once as suggested by Moore (1996) on 23 April. The Kvichak, Egegik, and Ugashik rivers were surveyed once each on 22 April. Methodology described by Burke (1992) was used for all surveys. Flights were conducted within 1 hour of low tide, during daylight hours. A Cessna 206 was flown 45-150 m (150-500 ft) above ground level at approximately 115 kph (70 mph), with flight altitude adjusted to minimize disturbance to waterfowl. Naknek River surveys were separated into 2 flights. In the first pass, the entire river was surveyed for tundra swans (Cygnus columbianus) at an altitude of 125-150 m (400-500 ft). The second pass censused ducks and geese from an altitude of 45-60 m (150-200 ft), except for the section of the river that runs through the populated area of Naknek. Because of aviation regulations, higher flight altitudes are required over these areas which are considered congested (Moore, 1996). For all Naknek River surveys, the river was divided into 10 segments so that portions visible from ground surveys could be compared. Ground-based Surveys Ground surveys in 1997 began March 17. The route consisted of survey points established in 1991 and videotaped in November 1992 and May 1993 (tapes on file in the Complex office in King Salmon). The 1997 ground survey route (Appendix I) followed the 1996 model with one exception. As suggested (Buhl and Moore 1996), Point 9B was added in order to count the area between the upper and the lower sections of the river. While counting the waterfowl at point 9B special care was taken to only count the area which could not be seen from the previous or following points. Point 16B was included again for the second year. Although waterfowl numbers were recorded, they were not included in the totals when compared to earlier years. 3 The Naknek River was divided into 2 ground survey routes because of time constraints.