Logging of data using animal-attached archival units (bio-logging) involves potential sources of subjectivity that are reviewed in the present paper. Subjectivity may be the result of technical limitations of which the selection of the... more
Logging of data using animal-attached archival units (bio-logging) involves potential sources of subjectivity that are reviewed in the present paper. Subjectivity may be the result of technical limitations of which the selection of the correct sampling frequency is particularly critical. Mistakes or aberrant data can also result from transitory defaults in the loggers functioning. Similarly, the use of purpose-written software
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Antarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future... more
Antarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the horizon’ to identify the highest priority scientific questions that researchers should aspire to answer in the next two decades and beyond. Wide consultation was a fundamental principle for the development of a collective, international view of the most important future directions in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientific questions through structured debate, discussion, revision and voting. Questions were clustered into seven topics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world, iii) ice sheet and sea level, iv) the dynamic Earth, v) li...
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We examined the question, does foraging behaviour of Adélie penguins, Pygoscelis adeliae, change in accord with the prey captured? To provide an answer, we attached instruments that record foraging behaviour to free-ranging Adélie... more
We examined the question, does foraging behaviour of Adélie penguins, Pygoscelis adeliae, change in accord with the prey captured? To provide an answer, we attached instruments that record foraging behaviour to free-ranging Adélie penguins foraging, off Adélie Land, during the late breeding season 1997. Depth of foraging was recorded for nine birds whose diet ranged from krill only to predominantly
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A new mandibular sensor is presented here based on the use of a Hall sensor, attached to one mandible, opposite a magnet, attached to the other mandible. Changes in sensor voltage, proportional to magnetic field strength, and thus... more
A new mandibular sensor is presented here based on the use of a Hall sensor, attached to one mandible, opposite a magnet, attached to the other mandible. Changes in sensor voltage, proportional to magnetic field strength, and thus inter-mandibular angle, are recorded in a logger. This system was tested on seven captive Adélie penguins (Pygoscelis adeliae) and three gentoo penguins
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Little Penguins, Eudyptula minor, breed in several small colonies in New Zealand and Australia. In this study, we compare the birds’ diving performances at different sites situated throughout their breeding range. Environmental conditions... more
Little Penguins, Eudyptula minor, breed in several small colonies in New Zealand and Australia. In this study, we compare the birds’ diving performances at different sites situated throughout their breeding range. Environmental conditions and breeding success vary drastically amongst colonies, but all birds feed on similar types of prey and face similar limitations on their foraging range. We examined several
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We investigated the 3-dimensional foraging behaviour of little penguins Eudyptula minor breeding on an artificially constructed breakwater near dredged shipping channels in Port Phillip Bay, southern Australia. Breeding penguins were... more
We investigated the 3-dimensional foraging behaviour of little penguins Eudyptula minor breeding on an artificially constructed breakwater near dredged shipping channels in Port Phillip Bay, southern Australia. Breeding penguins were fitted with either satellite trackers or time- depth recorders during the 2006-2007 breeding season to record foraging locations and diving be- haviour, which were then compared with local bathymetry. Diving appeared to be both mid-water and demersal, and on 1 d trips penguins reached a mean maximum distance from the colony of 13.8 km. Penguins were recorded in locations containing artificially constructed shipping channels, and examination of their diving profiles suggests that they probably forage within these channels. Little penguins at this urban colony have benefited from anthropogenic alterations in the terrestrial environment, but their location exposes them to many potential anthropogenic threats in their marine environment, including a large-s...
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ABSTRACT The Cape cormorant Phalacrocorax capensis is unusual among cormorants in using aerial searching to locate patchily distributed pelagic schooling fish. It feeds up to 80 km offshore, often roosts at sea during the day and retains... more
ABSTRACT The Cape cormorant Phalacrocorax capensis is unusual among cormorants in using aerial searching to locate patchily distributed pelagic schooling fish. It feeds up to 80 km offshore, often roosts at sea during the day and retains more air in its plumage and is more buoyant than most other cormorants. Despite these adaptations to its pelagic lifestyle, little is known of its foraging ecology. We measured the activity budget and diving ecology of breeding Cape cormorants. All foraging took place during the day, with 3.6 ± 1.3 foraging trips per day, each lasting 85 ± 60 min and comprising 61 ± 53 dives. Dives lasted 21.2 ± 13.9 s (maximum 70 s), attaining an average depth of 10.2 ± 6.7 m (maximum 34 m), but variability in dive depth both within and between foraging trips was considerable. The within-bout variation in dive depth was greater when making shallow dives, suggesting that pelagic prey were targeted mainly when diving to <10 m. Diving ecology and total foraging time were similar to other cormorants, but the time spent flying (122 ± 51 min day−1, 14% of daylight) was greater and more variable than other species. Searching flights lasted up to 1 h, and birds made numerous short flights during foraging bouts, presumably following fast-moving schools of pelagic prey. Compared with the other main seabird predators of pelagic fish in the Benguela region, Cape gannets Morus capensis and African penguins Spheniscus demersus, Cape cormorants made shorter, more frequent foraging trips. Their foraging range while feeding small chicks was 7 ± 6 km (maximum 40 km), similar to penguins (10–20 km), but less than gannets (50–200 km). Successful breeding by large colonies depends on the reliable occurrence of pelagic fish schools within this foraging range.
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... Seabirds, fisheries, and cameras. David Grémillet 1, 2 , Ralf.HE Mullers 2 , Christina Moseley 1 , Lorien Pichegru 1 , Janet C. Coetzee 3 , Philippe S. Sabarros 4 , Carl D. Van Der Lingen 3 , Peter G. Ryan 1 , Akiko Kato 5 , Yan... more
... Seabirds, fisheries, and cameras. David Grémillet 1, 2 , Ralf.HE Mullers 2 , Christina Moseley 1 , Lorien Pichegru 1 , Janet C. Coetzee 3 , Philippe S. Sabarros 4 , Carl D. Van Der Lingen 3 , Peter G. Ryan 1 , Akiko Kato 5 , Yan Ropert-Coudert 5. (2010). ...
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... Rory P. Wilson 1 6 , F. Hernán Vargas 2 3 , Antje Steinfurth 3 4 , Philip Riordan 2 , Yan Ropert-Coudert 5 , and David ... Great Auk Alca impennis), apparently for the same reason (Livezey 1988), and the three species of flightless... more
... Rory P. Wilson 1 6 , F. Hernán Vargas 2 3 , Antje Steinfurth 3 4 , Philip Riordan 2 , Yan Ropert-Coudert 5 , and David ... Great Auk Alca impennis), apparently for the same reason (Livezey 1988), and the three species of flightless steamer ducks (Tachyeres; Humphrey and Livezey ...