Island King Research Articles

The current trajectory of king penguin (Aptenodytes patagonicus) chick numbers on Macquarie Island in relation to environmental conditions

Abstract Macquarie Island's king penguin (Aptenodytes patagonicus) population has changed dramatically over recent centuries. Following near decimation from commercial exploitation during the 19th and early 20th centuries, chick numbers increased rapidly from 1930–1980. Since then, the population's trajectory has remained unreported, and environmental factors potentially influencing the population are poorly understood. From 2007–2020, king penguin chicks were censused annually. Chick numbers fluctuated between years, ranging from 33,513–78,714. Overall, the numbers decreased at 1.06 ± 0.03% per annum. While further studies are required to infer causality, annual chick numbers were negatively correlated with environmental conditions on land and at sea. Heavy rainfall, total rainfall, and maximum east coast wave height during incubation correlated with fewer chicks that year. Warmer sea surface temperatures in the foraging region of adult king penguins during incubation and early chick-rearing also correlated with lower chick numbers. While interannual variability and the long generation time of king penguins makes it unclear if the decrease in chick numbers represent a decrease in the breeding population, it is clear the late 20th century rapid increase in Macquarie Island's breeding population has ceased. Ongoing monitoring will establish if this is indicative of the population stabilising or an ongoing population decline.

Fifty years of geophysical researches of glaciers in Institute of Geography, the Russian Academy of Sciences, 1966–2016

In 1967‑2015, Institute of Geography of the USSR/Russian Academy of Sciences together with other organizations carried out field expeditions in different areas of mountain and polar glaciations in many regions: the Polar Urals, Caucasus, Pamir, Zailiysky and Jungar Alatau, Tien‑Shan, Pamir‑Alai, the Kamchatka Peninsula, the Pyrenees, the Arctic – Spitsbergen, Novaya Zemlya, Franz Josef and Severnaya Zemlya, and Antarctica – on the ice flow B, and in the sub‑Antarctic – Islands King George, Galindez, and Livingston. The gravimetric and ground and aerial radar observations were made in these expeditions. About 300 glaciers of different morphological types and sizes with cold, subpolar and temperate thermal regime were studied. Basic results of these studies are the following: (1) the new data on the ice thicknesses, ice volumes, subglacial relief, internal structure, and thermal state of the glaciers were obtained; (2) the two‑layered (polythermal) glaciers consisting of the upper layer of cold ice and the lower layer of temperate water‑filled ice had been revealed in Svalbard for the first time; spatial distribution of cold, polythermal and temperate glaciers had been determined; (3) the evidences were obtained that measured changes in thickness of the upper cold ice layer in polythermal glaciers can be used to estimate the long‑period variations of regional climates and serve as regional paleothermometers; (4) methods for estimating the water content in temperate and polythermal glaciers from the RES data were developed; and its space‑time variations in temperate ices of the Svaldbald glaciers were estimated since even small water content inside of them can noticeably change their dynamic behavior; (5) methods for estimating the ice volume within glaciers in large regions of mountain and polar glaciations had been created; the ice storages were estimated in Svalbard, Franz Josef Land, Dzhungrsky Alatau, the Great Caucasus, and Mt. Elbrus; (6) detailed data on the ice thicknesses and the subglacial relief had been obtained for 40 glaciers in framework of different national and international programs and projects; the data can be used to solve a wide range of practical and theoretical problems, including numerical modeling. These studies demonstrated the following: (1) the use of monopulse radars VIRL‑6 and VIRL‑7 of decameter range (the central frequency is 20 MHz) with digital recording of the radar and GPS data is quite efficient for ground‑based and airborne (from helicopters) radio‑echo sounding of mountain and polar glaciers with their ice thicknesses up to 500–600 m; (2) it was found that thicknesses of glaciers in the Caucasus and Tien Shan can reach 330–430 m, while in regions of mountain, ice‑sheet and transitional glaciation on the Spitsbergen Archipelago – 300, 560 and 600 m, respectively, on the ice caps of the Franz‑Josef Land and Severnaya Zemlya – 450 and 813 m, and on King George and Livingston Islands (Sub‑Antarctica) – 330 and 500 m; (3) large parts of ice caps and outlet glaciers in Svalbard, Franz Josef Land, Severnaya Zemlya which beds were located below the sea level were found. Precisely these parts can be undergone quick shortening due to climate warming, and, thus, cause formation of icebergs making threats for ships and gas‑oil marine platforms in the Barents and Kara seas; (4) data of the measurements made possible to calculate volumes of a number of investigated glaciers and ice caps and to estimate the ice storages in large areas of mountain and polar glaciations (the Jungar Alatau, Great Caucasus, Spitsbergen, Franz Josef Land); (5) decreasing of glacier volumes on the Franz Josef Land and some Spitsbergen glaciers for the last decades had been estimated. Analysis of the data obtained had shown that considerable part of polythermal glaciers in Spitsbergen belong to type of surging glaciers; they have the winter englacial runoff and form the near‑glacier icings. It allows considering such glaciers as dynamically unstable, predisposed to surges as well as possible sources of winter water supply and additional sources of paleoinformation about long‑period variations of regional climate.

Habitat, predation, growth, and coexistence: Could interactions between juvenile red and blue king crabs limit blue king crab productivity?

Since the 1970s, dominance of the shallow water Pribilof Islands king crab populations has shifted from blue king crab (Paralithodes platypus) to red king crab (Paralithodes camtschaticus), potentially influenced by interactions at the juvenile stage. In laboratory experiments, we determined whether habitat and temperature could mediate competitive and predatory interactions between juveniles of both species. We examined how density and predator presence affect habitat choice by red and blue king crabs. Further experiments determined how temperature and habitat affect predation by year-1 red king crab on year-0 blue king crab. Finally, long-term interaction experiments examined how habitat and density affected growth, survival, and intra-guild interactions between red and blue king crab. Red king crabs had a greater affinity for complex habitat than blue king crabs and the presence of predators increased preference for complex habitat for both species. Predation on year-0 blue king crabs by year-1 red king crabs was lower in complex habitats and at colder temperatures. When reared alone, red king crab survival was higher at low densities and in complex habitats. When reared with blue king crab, survival of red king crab was higher in complex habitats and in the presence of blue king crab. Blue king crab survival was substantially lower in the presence of red king crabs regardless of habitat. In both rearing experiments, differences in changes in crab size appeared to be driven by mortality rates and size-selective predation. This demonstrates that interactions between juvenile red and blue king crabs are primarily driven by intra-guild predation and not competition for resources. These results, suggest that juvenile red king crabs have an advantage over blue king crabs which could lower productivity of the Pribilof Islands blue king crab stock since the former became dominant in that system.

A Political History of Nagriamel on Santo, Vanuatu

ABSTRACT This article relates the political history of the Nagriamel movement on Santo, Vanuatu, and tries to account for its traditionalist excesses by reference to biographical aspects of its charismatic leader Jimmy Stevens. Stevens was the main architect in the unification of the ‘dak bus pipol’ (communities living in the island's remote interior) under a form of custom (kastom) he himself partially devised. This review of the life of this unusual character, who started as a ‘boy’ serving his colonial masters and became an ‘island king’, a self‐proclaimed ‘Prince’ of ‘Santo Custom’, and of the way he exploited the nativist assertions of his indigenous supporters, will also provide an opportunity to take a fresh look at the troubled period surrounding Independence in the Republic of Vanuatu.

Tracking the Polar Front south of New Zealand using penguin dive data

Nearly 36,000 vertical temperature profiles collected by 15 king penguins are used to map oceanographic fronts south of New Zealand. There is good correspondence between Antarctic Circumpolar Current (ACC) front locations derived from temperatures sampled in the upper 150 m along the penguin tracks and front positions inferred using maps of sea surface height (SSH). Mesoscale features detected in the SSH maps from this eddy-rich region are also reproduced in the individual temperature sections based on dive data. The foraging strategy of Macquarie Island king penguins appears to be influenced strongly by oceanographic structure: almost all the penguin dives are confined to the region close to and between the northern and southern branches of the Polar Front. Surface chlorophyll distributions also reflect the influence of the ACC fronts, with the northern branch of the Polar Front marking a boundary between low surface chlorophyll to the north and elevated values to the south.

Cephalopod prey of king penguins ( Aptenodytes patagonicus) breeding at Volunteer Beach, Falkland Islands, during austral winter 1996

The beaks of 10 cephalopod species were found in the diet of foraging and moulting king penguins ( Aptenodytes patagonicus) from a breeding colony at Volunteer Beach, Falkland Islands during austral winter (September/October 1996). A total of 486 lower cephalopod beaks were collected , identified and measured (LRL: lower rostral length). Six cephalopod families occurred in the penguins’ diet with Onychoteuthidae being the most abundant (256 lower beaks) and represented by Moroteuthis ingens (168; LRL range 2.1–6.8 mm), Moroteuthis knipovitchi (79; LRL range 1.9–5.5 mm), and Kondakovia longimana (9; LRL range 2.1–7.4 mm). Other families were Ommastrephidae (135) with Martialia hyadesi (127; LRL range 2.6–8.7 mm), Illex argentinus (6; LRL range 5.0–6.0 mm), and Ommastrephes bartrami (2; LRL range 7.9–8.8 mm); Loliginidae with Loligo gahi (60; LRL range 0.8–2.1 mm); Gonatidae with Gonatus antarcticus (28; LRL range 1.3–3.3 mm); Neoteuthidae with Alluroteuthis antarcticus (4; LRL range 2.4–3.9 mm), and Histioteuthidae with Histioteuthis eltaninae (3; LRL range 3.3–3.4 mm). Allometric equations were used to relate lower rostral beak length with cephalopod body size and mass. M. ingens was the dominating cephalopod prey in terms of numbers ( n=168), whereas M. hyadesi was most important in terms of biomass (64 682 g). The present study provides first information on the cephalopod prey of Falkland Islands king penguins. The data suggest that penguins take squid at coastal islands slope regions as well as in oceanic waters which demonstrates their ability to forage in a wide geographical area and to alternate between specific foraging sites. Possible competition with the commercial squid fishery off the Falkland Islands is discussed.

Planktonic ostracods (Crustacea) along the coasts of the South Shetland Islands King George and Elephant (Antarctic Ocean) during spring season 1994

Ostracod samples were taken from coastal waters of the South Shetland Islands (King George and Elephant) northeast of the Antarctic Peninsula. The population structure of the planktonic ostracods in the upper 200-m water column is described. In total 77 samples were taken quantitatively by RMT-1 hauls predominantly containing Alacia hettacra, A. belgicae and Metaconchoecia isocheira. The dominance of A2, A1 and adult stages supports Kock's conclusion of an upward-directed ontogenetic migration.

The impact of avian predator‐scavengers on King Penguin Aptenodytes patagonicus chicks at Marion Island

While ashore King Penguins Aptenodytes patagonicus are fed upon by a guild of five predator‐scavenger seabirds. During the winter (April‐October) male Southern Giant Petrels Macronectes giganteus killed an estimated 6430 (11.2%) of Marion Island's King Penguin chicks, although most birds only scavenged in the colonies. The rate of predation varied, with peaks in April‐May and in September. The proportion of successful attacks was 22.7%. There was a strong correlation between colony size and the rate of accumulation of chick corpses. Kelp Gulls Larus dominicanus and Lesser Sheathbills Chionis minor also scavenged penguin corpses but Northern Giant Petrels M. halli and female Southern Giant Petrels rarely entered the colonies. During the summer predation was mainly by Sub‐Antarctic Skuas Catharacta lonnbergi which took eggs and small chicks.