Lynch et al.: Penguin, shagContributed and giant petrels Papers on the Antarctic Peninsula 83 CENSUSES OF PENGUIN, BLUE-EYED SHAG PHALACROCORAX ATRICEPS AND SOUTHERN GIANT PETREL MACRONECTES GIGANTEUS POPULATIONS ON THE ANTARCTIC PENINSULA, 2001–2007 HEATHER J. LYNCH,1 RON NAVEEN2 AND WILLIAM F. FAGAN3 1Department of Biology, University of Maryland, College Park, Maryland, 20742, USA ([email protected]) 2Oceanites, Inc., PO Box 15259, Chevy Chase, Maryland, 20825, USA 3Department of Biology, University of Maryland, College Park, Maryland, 20742, USA Received 22 July 2007, accepted 30 January 2008 SUMMARY LYNCH, H.J., NAVEEN, R. & FAGAN, W.F. 2008. Censuses of penguin, Blue-eyed Shag Phalacrocorax atriceps and Southern Giant Petrel Macronectes giganteus populations on the Antarctic Peninsula, 2001–2007. Marine Ornithology 36: 83–97. Here, we report census results for Adélie Penguin Pygoscelis adeliae, Gentoo Penguin P. papua, Chinstrap Penguin P. antarctica, Blue-eyed Shag Phalacrocorax atriceps, and Southern Giant Petrel Macronectes giganteus collected as part of the Antarctic Site Inventory project during 2001–2007. We report on new breeding populations of Gentoo Penguins in the Yalour Islands, Galindez Island and Cape Tuxen (Antarctic Peninsula), which reflect the southernmost known breeding colonies of this species. We also document range expansion and population increases for Gentoo Penguins throughout the Antarctic Peninsula. Further, we report on the continuing population decline of Adélie Penguins in the Antarctic Peninsula, and present records of all three pygoscelid penguins breeding at Booth Island, the fifth known site where these species nest contiguously on the Antarctic Peninsula. Key words: Censuses, Antarctic Peninsula, penguins, Blue-eyed Shag, Southern Giant Petrel INTRODUCTION determine whether any detected changes are naturally occurring or are anthropogenic, perhaps caused by tourism or other human Fieldwork by the Antarctic Site Inventory (ASI) began in November activities (Naveen 1996). Potential impacts may be short-term or 1994, examining whether opportunistic visits can be used to long-term, immediate or cumulative (Benninghoff & Bonner 1985, • effectively and economically detect possible visitor-caused Abbott & Benninghoff 1990, Emslie 1997, Hofman & Jatko 2002). changes in the physical features, flora and fauna of sites on the Antarctic Peninsula being visited repeatedly by ship-based In this paper we report on the last six years’ worth of census data tourists; collected to update earlier efforts reported in Naveen et al. (2000). The ASI is conducted by researchers placed on tour ships, and site • collect baseline information necessary to detect possible changes censuses are taken during zodiac landings or, occasionally, during in the physical and biologic variables being monitored; and zodiac tours. The advantages of this approach include wide spatial • determine how best to minimize or avoid the potentially negative coverage of the western Antarctic Peninsula, and a negligible effects of tourism and governmental and non-governmental “footprint” on the landscape. The disadvantage is that the timing activities in the Antarctic Peninsula area. of censuses is opportunistic, and census counts are not always timed with the peak of egg laying or chick crèching as required by The ASI has collected information on Antarctic Peninsula visitor the Commission for the Conservation of Antarctic Marine Living sites frequently and cost-effectively, relying opportunistically on Resources Ecosystem Monitoring Program (SCCAMLR 2004). expedition tour vessels and, occasionally, the United Kingdom ice Off-peak bias corrections are currently being developed (Lynch patrol vessel HMS Endurance for logistics support. Well-timed et al. in prep.), but even uncorrected census counts, as reported visits by trained researchers have proved an effective means of in this paper, add tremendous spatial and temporal coverage to characterizing sites and collecting relevant biologic data (Naveen existing census records and can be used in population analyses 1997, Naveen et al. 2001, Naveen 2003). (e.g. Woehler et al. 2001, Sander et al. 2007). Data collected by the Inventory are intended to assist the STUDY AREA implementation of the 1991 Protocol on Environmental Protection to the Antarctic Treaty, which, among other things, requires a As reported elsewhere (Naveen et al. 2000), the Inventory divides priori environmental impact assessments for all human activities, the Antarctic Peninsula into six subareas (Fig. 1), designations that including tourism, and monitoring to assess and verify predicted are followed here. environmental impacts. The goal is to develop a baseline against • South Orkneys (SO), including Laurie, Coronation, and Signy which changes in the ecosystem can be assessed and, if possible, Islands Marine Ornithology 36: 83–97 (2008) 84 Lynch et al.: Penguin, shag and giant petrels on the Antarctic Peninsula • Elephant Island and nearby islands (EI) The present paper provides new census data from each of the • South Shetland Islands (SH), including Deception, Low, and six subareas for Adélie Penguin Pygoscelis adeliae, Gentoo Smith Islands (see Fig. 2) Penguin P. papua, Chinstrap Penguin P. antarctica, Blue-eyed Shag Phalacrocorax atriceps, and Southern Giant Petrel Macronectes • Northeast Antarctic Peninsula (NE), from Cape Dubouzet giganteus. These long-term data are particularly important now (63°16′S, 64°00′W) and Joinville Island (63°15′S, 55°45′W) to that Antarctic Treaty parties have begun to adopt site specific James Ross Island (64°10′S, 57°45′W) (see Fig. 3) management guidelines for key visitor locations. • Northwest Antarctic Peninsula (NW), from Cape Dubouzet (63°16′S, 64°00′W) to northern end of the Lemaire Channel CENSUS DATA (65°04′S, 63°57′W) (see Fig. 4) • Southwest Antarctic Peninsula (SW), from the northern end of The census data reported in Tables 1–5 have been reported in a the Lemaire Channel to the northern part of Marguerite Bay manner consistent with the census compilations of Woehler (1993) (68°18′S, 67°11′W) (see Fig. 5) and Woehler and Croxall (1997): In 13 seasons from November 1994 through February 2007, the N1 Nests individually counted, accurate to better than ±5% Inventory has made 758 visits and collected data at 115 Antarctic N2 Nests counted in a known area, and then extrapolated over Peninsula locations. Inventory researchers have repeatedly visited total colony area, accurate to 5%–10% all those sites that are most heavily visited by expedition tourists, N3 Accurate estimate, accurate to 10%–15% and all sites that exhibit high species diversity or are especially N4 Rough estimate, accurate to 25%–50% prone to environmental disturbance from human visitors (Naveen C1 Chicks individually counted, accurate to better than ±5% 1997, Naveen et al. 2001, Naveen 2003). C2 Chicks counted in a known area, and then extrapolated over total area, accurate to 5%–10% Fig.1. Map of the Antarctic Peninsula region, indicating the six subareas and their abbreviations, as divided by the Antarctic Site Inventory: the South Orkney islands, Elephant Island and nearby islands, the South Shetland Islands, the Northeast Antarctic Peninsula, the Northwest Antarctic Peninsula, and the Southwest Antarctic Peninsula. Marine Ornithology 36: 83–97 (2008) Lynch et al.: Penguin, shag and giant petrels on the Antarctic Peninsula 85 C3 Accurate estimate, accurate to 10%–15% l between the “baseline” count in year t1 and the most recent count C4 Rough estimate, accurate to 25%–50% in year t1 + T (Ebert 1999), A1 Estimates based on counts of total birds or adults individually counted, accurate to better than ±5% A2 Estimates based on counts of total birds or adults individually , [1] counted, accurate to 5%–10% and its error δl (see Taylor 1982), A3 Estimates based on counts of total birds or adults individually counted, accurate to 10%–15% A4 Estimates based on counts of total birds or adults individually counted, accurate to 25%–50% , [2] where δN/N represents the fractional error of the census (e.g. 0.05 The site censuses represent all the birds at a particular site, except for N1, 0.10 for N2) and T represents the time difference between where indicated by a map. Where multiple nest or chick censuses the two censuses. (or both) are available for a site in any given year, we report the largest December nest count and the largest January chick count RESULTS AND DISCUSSION available. If no December nest count is available, we give January nest counts priority over November nest counts, and February chick With respect to Adélie Penguins (Table 1), the Inventory continues counts priority over December chick counts. to document the population decline of this species in the western Antarctic Peninsula region, most strikingly in the southwestern We report on 81 censuses taken at 52 different sites. Among these region subarea (Fig. 6). Inventory data suggest population declines are 24 census reports that are new to the ASI project. In addition, at the Berthelot Islands (65°20′S, 64°09′W), Booth Island (65°05′S, we note changes from the most recent available census before 2001, 64°00′W), Petermann Island (65°10′S, 64°10′W), and the Yalour and use census that to estimate the annual rate of population change Islands (65°14′S, 64°10′W). Fig. 2. Map of the South Shetland Islands and parts of the Northwest Antarctic Peninsula region. Marine Ornithology 36: 83–97 (2008) 86 Lynch et al.: Penguin, shag and giant petrels on the Antarctic Peninsula With respect to Gentoo Penguins, the Inventory continues to declined significantly throughout their range. We report declines document the population increase of this species in the Antarctic at Cecilia Island (62°25′S, 59°43′W), Entrance Point (63°00′S, Peninsula (Naveen et al. 2000), and for the first time we report the 60°33′W), Georges Point, Ronge Island (64°40′S, 62°40′W) and expansion of this species south of their historic range into the Yalour Hydrurga Rocks (64°08′S, 61°37′W). Islands (65°14′S, 64°10′W), Galindez Island (65°15′S, 64°15′W), and Cape Tuxen (65°16′S, 64°08′W).