Surveys reveal increasing and globally important populations of south polar skuas and Antarctic shags in Ryder Bay (Antarctic Peninsula)

Published on Feb 1, 2019in Polar Biology2.002
· DOI :10.1007/s00300-018-2432-0
Richard A. Phillips50
Estimated H-index: 50
(NERC: Natural Environment Research Council),
Janet R. D. Silk15
Estimated H-index: 15
(NERC: Natural Environment Research Council)
+ 1 AuthorsKevin A. Hughes30
Estimated H-index: 30
(NERC: Natural Environment Research Council)
Despite their importance in ecosystems, population sizes and trends are unknown for many seabirds, including in the Antarctic. Here we report on the first comprehensive survey of south polar skuas Stercorarius maccormicki and Antarctic shags Leucocarbo bransfieldensis in Ryder Bay, and collate previous count data. In austral summer 2017/18, totals of 259 skuas at club sites and 978 occupied skua territories were counted in 2.3 km2 of suitable habitat at Rothera Point and adjacent islands. Based on the mean nearest neighbour distance (23.2 m), skua nest densities were comparable with colonies elsewhere. Long-term monitoring of skuas at Rothera Point indicated considerable annual variation and overall increases of 1.9 and 1.3% per annum, respectively, in breeding pairs from 1975/76 to 2017/18, and occupied territories from 1988/89 to 2017/18. In total, 405 pairs of Antarctic shags bred at two known and one newly discovered colony in 2017/18. Previous counts at the two known colonies indicated substantial annual variation and increases of 5.5 and 3.3% per annum, respectively, from 1985/86 to 2017/18 and 1989/90 to 2017/18. Factors leading to overall increases in both species, and the intermittent seasons of near-complete failure to breed, are unclear, but likely to reflect impacts of environmental change on their marine prey or sea ice. The breeding populations of south polar skuas and Antarctic shags in Ryder Bay represent 10.3 and 3.5%, respectively, of revised global estimates of 9500 and 11,684 breeding pairs. We recommend that the breeding colonies be included as important bird areas (IBAs) and within the Antarctic Specially Protected Area (ASPA) system, and provision made to conserve foraging areas at sea.
  • References (50)
  • Citations (0)
📖 Papers frequently viewed together
4 Citations
33 Citations
82 Citations
78% of Scinapse members use related papers. After signing in, all features are FREE.
#1Michael Schrimpf (SBU: Stony Brook University)H-Index: 1
#2Ron NaveenH-Index: 13
Last. Heather J. Lynch (SBU: Stony Brook University)H-Index: 23
view all 3 authors...
2 CitationsSource
#1Alex Borowicz (SBU: Stony Brook University)H-Index: 1
#2Philip McDowall (SBU: Stony Brook University)H-Index: 3
Last. Heather J. Lynch (SBU: Stony Brook University)H-Index: 23
view all 14 authors...
Despite concerted international effort to track and interpret shifts in the abundance and distribution of Adelie penguins, large populations continue to be identified. Here we report on a major hotspot of Adelie penguin abundance identified in the Danger Islands off the northern tip of the Antarctic Peninsula (AP). We present the first complete census of Pygoscelis spp. penguins in the Danger Islands, estimated from a multi-modal survey consisting of direct ground counts and computer-automated c...
14 CitationsSource
#1Christian Che‐Castaldo (SBU: Stony Brook University)H-Index: 5
#2Stephanie Jenouvrier (WHOI: Woods Hole Oceanographic Institution)H-Index: 24
Last. Heather J. Lynch (SBU: Stony Brook University)H-Index: 23
view all 11 authors...
Colonially-breeding seabirds have long served as indicator species for the health of the oceans on which they depend. Abundance and breeding data are repeatedly collected at fixed study sites in the hopes that changes in abundance and productivity may be useful for adaptive management of marine resources, but their suitability for this purpose is often unknown. To address this, we fit a Bayesian population dynamics model that includes process and observation error to all known Adelie penguin abu...
10 CitationsSource
#1Peter T. Fretwell (BAS: British Antarctic Survey)H-Index: 21
#2Paul Scofield (Canterbury Museum)H-Index: 9
Last. Richard A. Phillips (BAS: British Antarctic Survey)H-Index: 50
view all 3 authors...
This study is the first to utilize 30-cm resolution imagery from the WorldView-3 (WV-3) satellite to count wildlife directly. We test the accuracy of the satellite method for directly counting individuals at a well-studied colony of Wandering Albatross Diomedea exulans at South Georgia, and then apply it to the closely related Northern Royal Albatross Diomedea sanfordi, which is near-endemic to the Chatham Islands and of unknown recent population status due to the remoteness and limited accessib...
15 CitationsSource
#1Caitlin Black (University of Oxford)H-Index: 3
#2Andrea Raya Rey (CONICET: National Scientific and Technical Research Council)H-Index: 16
Last. Tom Hart (University of Oxford)H-Index: 11
view all 3 authors...
ABSTRACT When monitoring species with extensive ranges in harsh climates, comprehensive studies across a species' range are both logistically and technically challenging and therefore rare. Such scarcity in data collection is particularly true in the polar regions where sea ice and weather constraints prevent widespread access to sites for much of the year, specifically during winter. Penguins (Spheniscidae) show large variations in winter strategies with many species migrating long distances wh...
5 CitationsSource
#1Deborah J. Wilson (Landcare Research)H-Index: 13
#2Philip O'b. Lyver (Landcare Research)H-Index: 10
Last. David G. AinleyH-Index: 58
view all 10 authors...
In the Ross Sea region, most South Polar Skuas (Stercorarius maccormicki) nest near Adelie Penguin (Pygoscelis adeliae) colonies, preying and scavenging on fish, penguins, and other carrion. To derive a relationship to predict skua numbers from better-quantified penguin numbers, we used distance sampling to estimate breeding skua numbers within 1000 m of 5 penguin nesting locations (Cape Crozier, Cape Royds, and 3 Cape Bird locations) on Ross Island in 3 consecutive years. Estimated numbers of s...
3 CitationsSource
#1Richard A. Phillips (NERC: Natural Environment Research Council)H-Index: 50
#2Rosemary GalesH-Index: 23
Last. Anton Carl WolfaardtH-Index: 2
view all 10 authors...
Seabirds are amongst the most globally-threatened of all groups of birds, and conservation issues specific to albatrosses (Diomedeidae) and large petrels (Procellaria spp. and giant petrels Macronectes spp.) led to drafting of the multi-lateral Agreement on the Conservation of Albatrosses and Petrels (ACAP). Here we review the taxonomy, breeding and foraging distributions, population status and trends, threats and priorities for the 29 species covered by ACAP. Nineteen (66%) are listed as threat...
46 CitationsSource
#1John TurnerH-Index: 69
#2Hua LuH-Index: 19
Last. Pranab DebH-Index: 5
view all 10 authors...
Here it is shown that the late twentieth century warming trends in the Antarctic Peninsula have ceased, with the Peninsula having instead been cooling for most of the twenty-first century, underscoring the considerable internal variability within the Antarctic climate system.
179 CitationsSource
#1Ana P. B. Carneiro (University of Cambridge)H-Index: 8
#2Andrea Manica (University of Cambridge)H-Index: 50
Last. Richard A. Phillips (NERC: Natural Environment Research Council)H-Index: 50
view all 3 authors...
In this study, we investigate the numbers, productivity and territory distribution of the two species of skuas (brown Stercorarius lonnbergi and south polar Stercorarius maccormicki) breeding at Signy Island, South Orkneys, and compare the results with trends elsewhere. Comparison with previous counts indicates a biphasic increase in brown skuas at Signy Island; much faster from 1958/1959 to 1982/1983 (3.3 % per annum), than in subsequent years (0.4 % per annum from 1983/1984 to 2013/2014). Rela...
3 CitationsSource
#1Johannes Krietsch (FSU: University of Jena)H-Index: 2
#2Jan Esefeld (FSU: University of Jena)H-Index: 4
Last. Hans-Ulrich Peter (FSU: University of Jena)H-Index: 17
view all 5 authors...
Marine ecosystems face a variety of threats induced by environmental changes and anthropogenic activities. Seabirds are predators often used as indicator species to monitor the status and health of their communities and the environment. Here, we present the results from a 35-year monitoring time series of Brown Skuas (Catharacta antarctica lonnbergi) and South Polar Skuas (C. maccormicki) breeding sympatrically in the Maritime Antarctic on Fildes Peninsula and Potter Peninsula, King George Islan...
4 CitationsSource
Cited By0
#1W. Chris OosthuizenH-Index: 10
#2Lucas Krüger (Instituto Antártico Chileno)
Last. Andrew D. LowtherH-Index: 12
view all 4 authors...
Monitored seabird populations—useful sentinels of marine ecosystem health—have been declining worldwide at a rapid pace. Yet, lack of reliable long-term monitoring data constrains assessment of the conservation status of many seabird populations. Unmanned aerial vehicles (UAVs) have the potential to increase survey efficiency and count precision of seabird populations, especially where time constraints or inaccessible terrain, such as sea stacks, limit meaningful ground-based surveys. Furthermor...