Predation of Adélie penguins (Pygoscelis adeliae) by leopard seals (Hydrurga leptonyx) in Prydz Bay, Antarctica

1995 ◽  
Vol 73 (5) ◽  
pp. 1001-1004 ◽  
Author(s):  
T. Rogers ◽  
M. M. Bryden
Keyword(s):  
Prydz Bay ◽  
Pygoscelis Adeliae ◽  
Hydrurga Leptonyx ◽  
Fast Ice ◽  
Ice Edge ◽  
Adélie Penguins

The behaviour of leopard seals, Hydrurga leptonyx, feeding on Adélie penguins, Pygoscelis adeliae, was investigated between November 1993 and January 1994 in Prydz Bay, Antarctica. The seals were distributed along the fast-ice edge in locations where departing penguins congregated. Five different hunting techniques were observed, four of which were used through most of the summer. Individual leopard seals favoured specific hunting techniques. Hitherto, penguin hunting was believed to be carried out primarily by a few male seals; in this study, however, the predation observed involved many different individuals of both sexes. It is estimated that six leopard seals feeding in this area over a period of 120 days would consume 2.7% of the adult penguin population.

Leopard seal predation rates at penguin colonies of different size

2005 ◽  
Vol 17 (3) ◽  
pp. 335-340 ◽  
Author(s):  
DAVID G. AINLEY ◽  
GRANT BALLARD ◽  
BRIAN J. KARL ◽  
KATIE M. DUGGER
Keyword(s):  
Full Range ◽  
Well Being ◽  
Leopard Seal ◽  
Pygoscelis Adeliae ◽  
Hydrurga Leptonyx ◽  
Adélie Penguins ◽  
Penguin Species ◽  
Predation Rates

In a study designed to elucidate the factors that might differentially affect the well being and biology of Adélie penguins (Pygoscelis adeliae) that breed in colonies of different size, we investigated the predation rates on penguins by leopard seals (Hydrurga leptonyx) over a period of six years. The study colonies varied in size across the full range for this penguin species, contrasting with previous studies in which data were gathered only at very large colonies, and only in single years. The number of seals present varied directly with the amount of penguin traffic in the areas near the beach, where most predation takes place. Seals were present persistently only when penguin traffic exceeded about 250 penguins per hour. Predation rates also varied with penguin traffic in a curvilinear fashion, leveling off where traffic exceeded about 1200 penguins per hour. With respect to predation, it appears to be advantageous for Adélie penguins to nest in very small or very large colonies. At large colonies, the number of penguins moving to and from the colony ‘swamp’ the seals' predatory efforts, thus reducing the chances that an individual penguin will be taken. Small colonies are of little interest to the seals.

The impact of the giant iceberg B09B on population size and breeding success of Adélie penguins in Commonwealth Bay, Antarctica

2016 ◽  
Vol 28 (3) ◽  
pp. 187-193 ◽  
Author(s):  
Kerry-Jayne Wilson ◽  
Chris S.M. Turney ◽  
Christopher J. Fogwill ◽  
Estelle Blair
Keyword(s):  
Sea Ice ◽  
Natural Experiment ◽  
Population Decline ◽  
Pygoscelis Adeliae ◽  
Antarctic Expedition ◽  
Order Of Magnitude ◽  
Penguin Colony ◽  
Fast Ice ◽  
The Impact ◽  
Adélie Penguins

AbstractThe arrival of iceberg B09B in Commonwealth Bay, East Antarctica, and subsequent fast ice expansion has dramatically increased the distance Adélie penguins (Pygoscelis adeliae) breeding at Cape Denison must travel in search of food. This has provided a natural experiment to investigate the impact of iceberg stranding events and sea ice expansion along the East Antarctic coast. As part of the Australasian Antarctic Expedition 2013–14, the Adélie penguin colony at Cape Denison was censused to compare to historic counts. Whilst some 5520 pairs still bred at Cape Denison there has been an order of magnitude decline in Adélie numbers in the area in comparison to the first counts a century ago and, critically, recent estimates based on satellite images and a census in 1997. In contrast, an Adélie population on the eastern fringe of Commonwealth Bay just 8 km from the fast ice edge was thriving, indicating the arrival of B09B and fast ice expansion was probably responsible for the observed recent population decline. In conclusion, the Cape Denison population could be extirpated within 20 years unless B09B relocates or the now perennial fast ice within the bay breaks out. Our results have important implications for wider East Antarctic if the current increasing sea ice trend continues.

Maintenance of nest quality in Adélie penguins Pygoscelis adeliae: an additional benefit to life in the center

Polar Biology ◽  
2021 ◽  
Author(s):  
Virginia Morandini ◽  
Katie M. Dugger ◽  
Amélie Lescroël ◽  
Annie E. Schmidt ◽  
Grant Ballard
Keyword(s):  
Additional Benefit ◽  
Pygoscelis Adeliae ◽  
Nest Quality ◽  
Adélie Penguins

scholarly journals Sea-ice edge is more important than closer open water access for foraging Adélie penguins: evidence from two colonies

2020 ◽  
Vol 640 ◽  
pp. 215-230
Author(s):  
C Michelot ◽  
A Kato ◽  
T Raclot ◽  
K Shiomi ◽  
P Goulet ◽  
...  
Keyword(s):  
Sea Ice ◽  
Environmental Changes ◽  
Early Stage ◽  
Open Water ◽  
Gps Tracking ◽  
Ice Edge ◽  
Sea Ice Edge ◽  
Study Sites ◽  
The Impact ◽  
Adélie Penguins

Sentinel species, like Adélie penguins, have been used to assess the impact of environmental changes, and their link with sea ice has received considerable attention. Here, we tested if foraging Adélie penguins from 2 colonies in East Antarctica target the distant sea-ice edge or take advantage of closer open waters that are readily available near their colony. We examined the foraging behaviour of penguins during the incubation trips of females in 2016 and males in 2017, using GPS tracking and diet data in view of daily sea-ice data and bathymetry. In 2016-2017, sea-ice cover was extensive during females’ trips but flaw leads and polynyas were close to both study sites. Sea ice receded rapidly during males’ trips in 2017-2018. Despite close open water near both colonies in both years, females and males preferentially targeted the continental slope and the sea-ice edge to forage. In addition, there was no difference in the diet of penguins from both colonies: all penguins fed mostly on Antarctic krill and males also foraged on Antarctic silverfish. Our results highlight the importance of the sea-ice edge for penguins, an area where food abundance is predictable. It is likely that resource availability was not sufficient in closer open water areas at such an early stage in the breeding season. The behaviours displayed by the penguins from both colonies were similar, suggesting a common behaviour across colonies in Terre Adélie, although additional sites would be necessary to confirm this hypothesis.

A possible Adélie penguin sub-colony on fast ice by Cape Crozier, Antarctica

2019 ◽  
Vol 31 (4) ◽  
pp. 189-194
Author(s):  
Michelle Larue ◽  
David Iles ◽  
Sara Labrousse ◽  
Leo Salas ◽  
Grant Ballard ◽  
...  
Keyword(s):  
Aerial Survey ◽  
Pair Formation ◽  
Emperor Penguin ◽  
Natal Philopatry ◽  
Egg Incubation ◽  
Bright Pink ◽  
Fast Ice ◽  
Proximate Causes ◽  
High Resolution Satellite Imagery ◽  
Adélie Penguins

AbstractAdélie penguins are renowned for their natal philopatry on land-based colonies, requiring small pebbles to be used for nests. We report on an opportunistic observation via aerial survey, where hundreds of Adélie penguins were documented displaying nesting behaviours on fast ice ~3 km off the coast of Cape Crozier, which is one of the largest colonies in the world. We counted 426 Adélie penguins engaging in behaviours of pair formation, spacing similarly to normal nest distributions and lying in divots in the ice that looked like nests. On our first visit, it was noticed that the guano stain was bright pink, consistent with krill consumption, but had shifted to green over the course of ~2 weeks, indicating that the birds were fasting (a behaviour consistent with egg incubation). However, eggs were not observed. We posit four hypotheses that may explain the proximate causes of this behaviour and caution against future high-resolution satellite imagery interpretation due to the potential for confusing ice-nesting Adélie penguins with the presence of emperor penguin colonies.

Guidelines for people approaching breeding groups of Adélie penguins (Pygoscelis adeliae)

Polar Record ◽  
1998 ◽  
Vol 34 (191) ◽  
pp. 287-292 ◽  
Author(s):  
Melissa Giese
Keyword(s):  
Heart Rate ◽  
Natural Disturbances ◽  
Measurable Effect ◽  
Pygoscelis Adeliae ◽  
Heart Rates ◽  
Incubation Behaviour ◽  
Breeding Groups ◽  
Least Disturbance ◽  
South Polar ◽  
Adélie Penguins

AbstractIncreases in the number of people travelling to Antarctica has led to more frequent interactions between people and Antarctic wildlife, yet the effects of visitation on the animals has received limited scientific assessment. This study conducted experiments to measure the responses of incubating Adélie penguins (Pygoscelis adeliae) to controlled human approaches to determine which approach distances and approach styles caused the least disturbance to the birds. Three minimum approach distances were tested: 30, 15, and 5 m. Approaching penguins to 30 m had no measurable effect on either their behaviour or heart rate, while approaching as close as 15 m significantly elevated their heart rates above resting, undisturbed levels even though there was no behavioural indication of this response. Approaching penguins to 5 m significantly interrupted the penguins' incubation behaviour, with the potential to cause egg-cooling. Approaches to 5 m elevated heart rates above those measured when birds were undisturbed, approached to either 15 or 30 m, or exposed to ‘natural’ disturbances (that is, other penguins or south polar skuas, Catheracta maccormicki). The study also identified certain Adelie penguin behaviours that may be indicative of disturbance in response to human visitation. People visiting breeding penguins could learn to identify these behaviours, so they can monitor and modify any effects of their visit.

Foraging patterns of Antarctic minke whales in McMurdo Sound, Ross Sea

2020 ◽  
Vol 32 (6) ◽  
pp. 454-465
Author(s):  
David G. Ainley ◽  
Trevor W. Joyce ◽  
Ben Saenz ◽  
Robert L. Pitman ◽  
John W. Durban ◽  
...  
Keyword(s):  
Foraging Behaviour ◽  
Ross Sea ◽  
Prey Availability ◽  
Dive Depth ◽  
Remotely Operated Vehicle ◽  
Mcmurdo Sound ◽  
Minke Whales ◽  
Fast Ice ◽  
Antarctic Silverfish ◽  
Ice Edge

AbstractEvidence indicates that Antarctic minke whales (AMWs) in the Ross Sea affect the foraging behaviour, especially diet, of sympatric Adélie penguins (ADPEs) by, we hypothesize, influencing the availability of prey they have in common, mainly crystal krill. To further investigate this interaction, we undertook a study in McMurdo Sound during 2012–2013 and 2014–2015 using telemetry and biologging of whales and penguins, shore-based observations and quantification of the preyscape. The 3D distribution and density of prey were assessed using a remotely operated vehicle deployed along and to the interior of the fast-ice edge where AMWs and ADPEs focused their foraging. Acoustic surveys of prey and foraging behaviour of predators indicate that prey remained abundant under the fast ice, becoming successively available to air-breathing predators only as the fast ice retreated. Over both seasons, the ADPE diet included less krill and more Antarctic silverfish once AMWs became abundant, but the penguins' foraging behaviour (i.e. time spent foraging, dive depth, distance from colony) did not change. In addition, over time, krill abundance decreased in the upper water column near the ice edge, consistent with the hypothesis (and previously gathered information) that AMW and ADPE foraging contributed to an alteration of prey availability.

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