Seabird Colony Survey of South and East Kodiak Island, Alaska, June 2001

SEABIRD COLONY SURVEY OF SOUTH AND EAST KODIAK ISLAND, ALASKA, JUNE 2001

Shawn W. Stephensen, Dennis C. Zwiefelhofer, and Rebecca J. Howard

Key words: Alaska, Aleutian tern, arctic tern, Beringian Seabird Colony Catalog, black-legged kittiwake, breeding population, census, double-crested cormorant, Kodiak Island, pelagic cormorant, pigeon guillemot, red-faced cormorant, seabird colony, survey

U.S. Fish and Wildlife Service Migratory Bird Management 1011 East Tudor Road Anchorage, Alaska 99503-6199

April 2002

Cite as: Stephensen, S.W., D.C. Zwiefelhofer, and R.J. Howard. 2002. Seabird Colony Survey of South and East Kodiak Island, Alaska, June 2001. U.S. Fish and Wildlife Service Report. Migratory Bird Management Anchorage, Alaska. 23 pp.

SEABIRD COLONY SURVEY OF SOUTH AND EAST KODIAK ISLAND, ALASKA, JUNE 2001

Shawn W. Stephensen, Dennis C. Zwiefelhofer, and Rebecca J. Howard

U.S. Fish and Wildlife Service Migratory Bird Management 1011 East Tudor Road Anchorage, Alaska 99503-6199

April 2002

___ Cite as: Stephensen, S.W., D.C. Zwiefelhofer, and R.J. Howard. 2002. Seabird Colony Survey of South and East Kodiak Island, Alaska, June 2001. U.S. Fish and Wildlife Service Report. Migratory Bird Management Anchorage, Alaska. 23 pp.

TABLE OF CONTENTS Page ABSTRACT ...... i

INTRODUCTION ...... 1

METHODS ...... 2 Expedition Log ...... 3

RESULTS ...... 4

DISCUSSION ...... 5

ACKNOWLEDGMENTS ...... 6

LITERATURE CITED ...... 7

LIST OF FIGURES Figure Page

1 Seabird colonies censused on the south and east side of Kodiak Island, Alaska during June 2001 ...... 8

LIST OF TABLES Table Page

1 Present and historical arctic and Aleutian tern counts (individual birds) at colonies on the south and east side of Kodiak Island, Alaska ...... 9

2 Present and historical red-faced, pelagic, and double-crested cormorant counts (individual birds may be derived from nest counts) at colonies on the south and east side of Kodiak Island, Alaska ...... 11

3 Present and historical pigeon guillemot counts (individual birds) at colonies on the south and east side of Kodiak Island, Alaska ...... 13

4 Count of nests or individual breeding birds at colonies on the south and east side of Kodiak Island, Alaska during June 2001 ...... 17

5 Common and scientific names of bird and marine mammal species observed on the south and east side of Kodiak Island, Alaska during June 2001 ...... 21

6 Count of sea otters, Steller sea lions, and harbor seals near seabird colonies on the south and east side of Kodiak Island, Alaska during June 2001 ...... 22

7 Location and counts of waterfowl and shorebird species on the south and east side of Kodiak Island, Alaska during June 2001 ...... 23 SEABIRD COLONY SURVEY OF SOUTH AND EAST KODIAK ISLAND, ALASKA, JUNE 2001

ABSTRACT

Migratory Bird Management, Kodiak National Wildlife Refuge, and Alaska Maritime National Wildlife Refuge personnel cooperatively conducted a seabird colony survey of the south and east side of Kodiak Island, Alaska during June 2001. The purpose of the survey was to aid in determining if breeding populations of cormorants, terns, and pigeon guillemot are declining at portions of Kodiak Island. In addition, all other known diurnal colonial nesting seabirds were censused in the study area. We surveyed 165 km of shoreline by boat and 166 km2 of island area by plane and recorded approximately 51,400 birds and 850 marine mammals. A total of 70 seabird colonies were censused. Cormorants and terns have declined in the study area compared to historical estimates. Eight previously documented cormorant colonies were inactive and 6 new colonies were observed. Only 3 of the 14 historically documented tern colonies were active and no new colonies were discovered. Pigeon guillemot breeding population numbers are comparable to previous censuses. The seabird colony data collected during this survey will be stored in the Beringian Seabird Colony Catalog database.

INTRODUCTION

The U.S. Fish and Wildlife Service (USFWS) utilizes seabird distribution and abundance data to aid in seabird conservation. The Beringian Seabird Colony Catalog (Catalog) computer database, maintained by Migratory Bird Management (MBM), stores current and historical seabird colony data on breeding population size, species composition, and location data of Alaska and Russia Far East (USFWS 2002). Seabird colony data are gathered, stored, and made available whenever needed. Seabird colony surveys are conducted to replace old or low quality data and to maintain the reliability of the Catalog (Stephensen and Mendenhall 1998).

Kodiak National Wildlife Refuge (KNWR) personnel conduct annual near shore surveys of seabirds and marine mammals during February, May, and August at selected areas of Kodiak Island. The surveys conducted in May and August provide distribution and abundance data needed to determine species aggregations and possible seabird colony locations.

Breeding populations of cormorants (red-faced, pelagic, and double-crested), terns (arctic and Aleutian), and pigeon guillemot may be declining in Alaska. To date, little data are available to assess population trends of terns and guillemots. Generally, colonies that are monitored annually or intermittently are used to assess trends, but currently USFWS monitors few tern and pigeon guillemot colonies. Cormorants populations at colonies are monitored by USFWS throughout Alaska (Dragoo et al. 2000).

Historically, large colonies of cormorants, terns, and pigeon guillemot were observed on and around Kodiak Island (U.S. Fish and Wildlife Service 2002). MBM in cooperation with KNWR and Alaska Maritime National Wildlife Refuge (AMNWR) initiated a survey of seabird colonies on the south and east side of Kodiak Island in June 2001. The primary objective of the survey was to census arctic and Aleutian tern colonies. The secondary objective was to census cormorant and pigeon guillemot colonies, and the tertiary objective was to census all other diurnal colonial seabirds nesting along the east shore of Kodiak Island. The data will be used to update the Beringian Seabird Colony Catalog with new colony data and aid in determining if cormorants, terns, and pigeon guillemots are declining.

In this report, we compare present and historical cormorant, tern, and pigeon guillemot colony

ii data. Breeding population estimates of all other colonial nesting species are included for sites where data were gathered during this survey.

METHODS

Kodiak Island is located in the Gulf of Alaska, 50 km east of the Alaska Peninsula and 140 km southwest of the Kenai Peninsula. The study area included portions of shoreline and adjacent islands on the east and south side of Kodiak Island (Figure 1).

The survey crew included KNWR biologist/ship operator Dennis C. Zwiefelhofer, MBM biologist Shawn W. Stephensen, and AMNWR biological technician Rebecca J. Howard. The 48 ft vessel Ursa Major II and 16 ft aluminum skiff were provided by KNWR. The Ursa Major II, piloted by Zwiefelhofer, was the support vessel and the skiff was used while conducting the shoreline surveys.

Throughout the survey, we focused on shoreline areas with potential seabird breeding habitat and where birds were noted previously during KNWR May and August coastal surveys. Surveys were generally conducted in the morning and early afternoon, to avoid strong day breezes that commonly developed in the afternoon. We traveled in the 16 ft skiff 20-100 meters offshore and counted the number of birds or nests by 1's with the aid of binoculars. Also, observers counted all waterfowl, shorebird, and marine mammals detected in a sampling window 100 m on either side, 100 m ahead, and 100 m overhead of the skiff. Observers counted groups of birds and nests by 10's at West Boulder Bay, a large black-legged kittiwake colony. Ugak Island was surveyed from the flying bridge of the Ursa Major II. All birds were identified to species and counts were made between egg-laying and fledging. A Nikon 35 mm camera was used to photograph the colonies and the photographs are archived at MBM office for future reference. All colony data will be entered in the Catalog.

A laptop computer connected to a hand-held Global Positioning System (GPS) were used onboard the 16 ft skiff to record the latitude and longitude of each bird observation and skiff track. Bird observation data were entered directly onto the computer while censusing and the data files were downloaded daily from the laptop to 3.5 inch disks as backup.

We chartered a float plane from Sea Hawk Air, Inc., Kodiak, Alaska and flew to the south end of the island to survey 3 tern colonies. The pilot landed the plane on the water near each colony, then we traveled by foot and counted birds by 1's within each colony. We also searched for nesting terns at historical breeding sites from the air by low flight and circling with the plane.

Each seabird colony in the Catalog is assigned a unique 6-digit number for identification purposes. The unique colony numbers along with the colony name will be used throughout this report. New colonies documented during this survey are referred to as “New” followed by a sequential number and will be assigned a 6-digit number when entered in the Catalog.

This report summarizes seabird colony data collected in 2001 and compares 2001 results with previous years. Data collection methods differ between years, therefore, no statistical analyses were performed and only species presence, absence, abundance and distribution are inferred. Some historical data were not included because of poor quality and reliability issues. Please refer to the Catalog and archived material for complete data descriptions.

Expedition Log

Stephensen and Howard arrived at Kodiak on June 13 and stayed at the Buskin River Inn from June 13 - 18. An aerial survey of 3 tern colonies historically located on Tugidak Island (032- 006), Aiaktalik Island/Marsh (032-015), and Akhiok Bay (032-004) was conducted June 14 by Stephensen and Howard.

Pigeon guillemot colonies in Chiniak Bay with historical breeding populations of >20 birds were surveyed by Stephensen and Howard with the skiff June 15 - 16. Areas surveyed included Long Island, Zaimka Island, Popof Island, Puffin Island, Mary Island, Queer Island, and Middle Island. Chiniak Island and Rocks were surveyed on June 25 by Zwiefelhofer, Stephensen, and Howard.

Supplies (food, fuel, charts, etc) and equipment needed for the survey was gathered June 18 and loaded on the Ursa Major II. The vessel departed Kodiak Harbor the morning of June 19 and traveled to Japanese Bay, where we anchored for the night.

On June 20, we circumnavigated Twoheaded Island and surveyed the shoreline suitable for nesting seabirds in Kaguyak, Japanese, and Kaiugnak bays. The colonies censused were 033-003 (Jap Bay), 034-070 (Kaiugnak Bay), 034-115 (Mid Kaiugnak Bay), and 034-002 (Avnulu Creek). Our anchorage for the night was at the head of Kaiugnak Bay, west side of the spit.

Colonies surveyed on June 21 included 033-001 (Cape Kiavak), 034-001 (Kiavak Triangle), 034- 049 (Puffin Island), 034-103 (Rolling Bay Lagoon), 034-50 (Middle Triangle), 034-051 (Natalia Point Rock), and 034-003 (John Island). We counted birds along the south shoreline of Kiavak Bay, then crossed the strait to Puffin Island, southwest tip of Sitkalidak Island. The entire shoreline of Rolling Bay was surveyed in search of a tern colony. We also covered the shoreline of the western edge of Natalia and Newman Peninsulas. Lastly, we traveled back across the strait to John Island and censused a large multiple species colony. At the end of the day, we traveled to Sitkalidak Strait and anchored in Amee Bay. We censused many smaller colonies in Sitkalidak Strait on June 22 since they were within close proximity to each other. The colonies censused were 034-004 (Sheep Island), 034-053 (Cub Island), 034-054 (Amee Island), 034-055 (Granite Islands), 034-056 (Nut Island), 034-005

3 (Cathedral Island), 034-098 (Cormorant Head), 034-006 (Ghost Rocks). During KNWR May and August near shore surveys, terns were noted in McDonald Lagoon (NE Sitkalidak Island), so we surveyed the entire shoreline of the lagoon. We moved the Ursa Major II to the spit at the entrance of McDonald Lagoon and anchored.

The morning of June 23, we circumnavigated and censused birds at Table Island (034-052). Table Island is located at the northeast end of Sitkalidak Island and surrounded by offshore rocks. The island is exposed and susceptible to high winds and seas, which makes surveying efforts difficult. The remainder of the day was spent in the Kiliuda Bay area. We censused Southwest Left Cape (034-119), Left Cape (034-057), Southwest Pivot Point (034-116), Coxcombe Point (034-063), Ladder Island (034-007), Nest Island (034-062), Dusk Island (034-061), and Ermine Point Islands (034-060). We spent the night in a cove at Shearwater Bay, a small bay on the north side of Kiliuda Bay.

On June 24 we censused the largest black-legged kittiwake colony on Kodiak Island, West Boulder Bay (034-008). Other colonies censused nearby were Inner Right Cape Islets (034-059) and Outer Right Cape Islets (034-058). We moved the Ursa Major II to Gull Point at the head of Ugak Bay and surveyed the colony at Gull Point (034-010). We anchored there for the night. We traveled across Ugak Bay and surveyed Long Island (034-067) to complete the days work.

The last survey date was June 25. We censused the remainder of the colonies in Ugak Bay; Cat Triangle (034-064), Mesa Island (034-065), Shark Point (034-066), Pasagshak Bay (034-068), and Pasagshak Point (034-069). We departed Gull Point and traveled to Ugak Island. We circumnavigated Ugak Island with the Ursa Major II and counted birds from the flying bridge. Chiniak Island and Rocks (034-014) was the last colony surveyed on the way back to Kodiak. We arrived at Kodiak Harbor later that evening.

RESULTS

We censused 52 documented and 18 previously undocumented seabird colonies on the south and east side of Kodiak Island, Alaska during June 2001 (Figure 1, Table 4). We recorded approximately 51,400 individual birds of 13 seabird, 5 waterfowl, and 2 shorebird species and 850 individuals of 3 marine mammal species. A species list (Table 5), marine mammal accounts (Table 6), and waterfowl and shorebird species accounts (Table 7) are included.

Approximately, 102 miles (165 kilometers) total shoreline was surveyed non-continuously (only shoreline area with potential seabird breeding habitat) by boat. North Tugidak Island, Akhiok Bay Islands and southwest Aiktalik Island were surveyed (~64 mi2 or 166 km2) by plane. Actual flight time was 3.1 hours and standby (time pilot spent waiting for observers to conduct the census) was 1.5 hours.

Arctic and Aleutian terns were censused at 14 historical breeding sites (Table 1). Only 3 of the 14 colonies were active (breeding adults and nests with eggs observed); Akhiok Bay, Aiktalik Marsh/Island, and Head of Kalsin Bay. The breeding populations of both species declined at the

4 active colonies in comparison to previous surveys, with the exception of Aleutian terns at Aiktalik Marsh/Island. We found no evidence of new tern colonies within the entire survey area.

We surveyed 19 cormorant colonies (Table 2). Cormorant species were found nesting at 6 new locations; Dusk Island, Outer Right Cape Islets, Amee Island, West Boulder Bay, NW of Gull Point, and Lagoon Point. Eight previously documented colonies were inactive. Double-crested cormorants were observed nesting at Gull Point and Inner Right Cape Islets, a species not previously identified as breeders on the east side of Kodiak Island. Cathedral Island and Gull Point were the largest colonies with 136 and 168 breeding birds respectively. The breeding populations of the remaining active colonies contained <50 individuals at each site.

Pigeon guillemots were observed at 54 colonies, including 30 previously unrecorded locations (Table 3). One historical breeding site, Puffin Island in Chiniak Bay, was inactive. Twoheaded Island and Chiniak Island/Rocks were the largest colonies with 234 and 221 birds respectively.

Other colonial nesting seabird breeding population data collected during the survey are included (Table 4). Black oystercatcher, parakeet auklet, horned puffin, and tufted puffin populations are comparable to previous censuses. The glaucous-winged gull population appeared to have increased and several new colonies were documented. The nest and bird numbers of West Boulder Bay black-legged kittiwake colony were 5,690 and 4,440 respectively. A decline compared to previous years.

DISCUSSION

Arctic and Aleutian tern numbers have declined in the study area in comparison to historical accounts. Our total best estimates for arctic and Aleutian terns in the late 1970's is 5,163 and 1,559 individuals respectively, compared to our 2001 estimate of 56 arctic and 144 Aleutian tern individuals. Eleven of fourteen colonies have completely disappeared. Our data are consistent with recent surveys (summers 1999 and 2000) of tern colonies in Prince William Sound, where significant breeding population declines and disappearance of entire colonies have been documented (USFWS unpublished data). Another study in Prince William Sound revealed tern population declines in pelagic and coastal areas. Summer densities of birds showed significant negative trends throughout the Sound, suggesting a decline in population (Stephensen et al. 2001). Analyses of marine bird surveys conducted in the Sound in July 1972 were compared to surveys in July 1989, 1990, 1991, and 1993 and indicated that several taxa of marine birds (including sterna spp.) have declined (Agler et al. 1999).

However, terns are known to shift nesting locations between years, so it is difficult to interpret the change in counts. A possible explanation of the birds disappearance is, some colonies may have relocated and the birds are nesting inland. An extensive inland survey must be conducted to confidently interpret a true decline.

KNWR personnel surveyed seabirds and marine mammals from Kaguyak Bay to Kiliuda Bay during May, August, and February from 1998 to 2000. The survey was not conducted in

5 February 1998 due to hull repair on the Ursa Major II. Terns were observed at all historical breeding areas during both May and August. May tern numbers ranged from 142 - 217 and 198 - 599 in August (USFWS unpublished data). In addition, during an overnight anchorage at Amee Island in May 2001 on a return trip from Alitak, Zwiefelhofer noted terns appeared to be initiating the breeding process. However, the terns were not present when we arrived in June 2001. Further investigation must be implemented to fully understand the birds behavior.

The cormorant breeding population has declined in the survey area in comparison to data collected in the late 1970's. During 1976-77, 1,776 individual cormorants (all species combined) were counted in the survey area. In 2001, we counted a total of 466 cormorants, which represents an order of magnitude decline. A similar trend has occurred at Chiniak Bay, an annual monitoring site of the USFWS. The populations of red-faced and pelagic cormorants have declined and remain low compared to the 1970's levels and complete nesting productivity failure has been noted the past few years (Dragoo et al. 2000). Cormorants are also noted for moving to different breeding grounds annually. This may partially explain the reduced numbers observed at historical breeding locations.

The number of pigeon guillemot colonies have increased in comparison to previous locations documented in the Beringian Seabird Colony Catalog. The breeding population changes at each colony vary and appear to have an overall increase. However, this may not be a true increase since historical surveys did not focus primarily on this species. Past surveys conducted by KNWR personnel recorded similar bird numbers and locations (USFWS unpublished data) in comparison to what we observed.

The number of black-legged kittiwakes at West Boulder Bay colony is the lowest ever recorded. In 1977, observers estimated 40,000 birds, whereas, we counted 5,690 birds and 4,440 nests. This is a dramatic reduction in bird numbers and the colony should be closely monitored.

The historical data presented in tables 1, 2, and 3 in the results section were obtained from the Beringian Seabird Colony Catalog. The survey methods, timing, and observers vary between years, therefore, the data quality and reliability also vary. Caution should be used when comparing between year differences.

ACKNOWLEDGMENTS

The cooperative efforts of MBM, KNWR, and AMNWR personnel were successful and resulted in optimal use of time, equipment, and personnel. We would like to thank pilot Rolan Ruoss of Sea Hawk Air, Inc. He provided invaluable assistance during the aerial portion of our tern survey by warmly sharing his considerable knowledge of Kodiak Island and introducing us to local residents also willing to share their knowledge of local wildlife.

LITERATURE CITED

Agler, B.A., S.J. Kendall, D.B. Irons, and S.P. Klosiewski. 1999. Declines in marine bird populations in Prince William Sound, Alaska coincident with a climatic regime shift. Waterbirds 22 (1): 98-103.

Dragoo, D.E., G.V. Byrd, and D.B. Irons. 2000. Breeding status and population trends of seabirds in Alaska in 1999. U.S. Fish and Wildlife Service Report AMNWR 2000/02.

Stephensen, S.W. and V.M. Mendenhall. 1998. Alaska Seabird Colony Recensus Plan. Unpublished Report, U.S. Fish and Wildlife Service, Anchorage, Alaska. 153 pp.

Stephensen, S.W., D.B. Irons, S.J. Kendall, B.K. Lance, and L.L. McDonald. 2001. Marine bird and sea otter population abundance of Prince William Sound, Alaska: Trends following the T/V Exxon Valdez oil spill, 1989-2000. Exxon Valdez Oil Spill Restoration Project Annual Report (Restoration Project 00159). U.S. Fish and Wildlife Service, Anchorage, Alaska. 144 pp.

U.S. Fish and Wildlife Service. 2002. Beringian Seabird Colony Catalog computer database. U.S. Fish and Wildlife Service, Migratory Bird Management, Anchorage, Alaska 99503.