Birds use vocalizations to attract mates, defend territories, and recognize fellow members of their species. But while we know a lot about how variations in vocalizations play out between populations of songbirds, it's far less clear how this variation affects birds such as penguins in which calls are inherited. A new study examines differences in the calls of Little Penguins from four colonies in Australia and finds that disparities in habitat, rather than geographic isolation or other factors, seem to be the key driver of variation in the sounds these birds use to communicate.
Footage from penguin-mounted mini video recorders shows four species of penguin eating jellyfish and other gelatinous animals of the open ocean, a food source penguins were not previously believed to partake of, scientists report this month in the Ecological Society of America's peer-reviewed journal Frontiers in Ecology and the Environment.
Penguins are sociable. During breeding, these birds gather in large colonies on the coasts of Subantarctic islands and on the main land. Their multi-vocal calls are usually loud and heard over the entire colony. But what is their behavior while at sea foraging? To solve this mystery, Korean biologists applied video cameras on Gentoos to film and eavesdrop on the animals while at sea. The results were stunning: Even while swimming and diving, Gentoos communicate amongst each other using short calls. However, the exact nature of these calls is yet to be determined.
It is only six centimetres long, but it plays a major role in the Antarctic ecosystem: the small crustacean Euphausia superba (Antarctic krill). It's one of the world's most abundant species and the central diet of a number of animals in the Southern Ocean. For a long time, scientists have been puzzled why the size of krill stocks fluctuates so widely. In a new study headed by Prof. Bernd Blasius and Prof. Bettina Meyer, a group of scientists from the University of Oldenburg's Institute for Chemistry and Biology of the Marine Environment (ICBM) and the Bremerhaven-based Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have shown that the competition for food within the population is responsible for the variability.
Electronic tags with ‘whale cams’ deployed on humpback whales in Antarctica have revealed the secret feeding habits of the ocean giants. The small camera tags were placed on the backs of humpback whales by Australian and United States scientists working off the Antarctic Peninsula, in the Gerlache Strait.
Gentoo penguins are tough generalists and are capable to withstand the harsh Antarctic climate. However, the tremendous force of volcanic eruptions, as had happened on Deception Island, had put colonies close to extinction several times over the last 7,000 years. This is the result of a study conducted by researchers from British Antarctic Survey (BAS), which they published recently in Nature Communications.
Scientists have successfully deployed miniature GPS loggers on threatened black browed albatross on sub-Antarctic Macquarie Island to find out more about the foraging habits of the birds. Approximately 40 pairs of black browed albatross breed on the steep slopes of the remote Island, and this summer researchers attached five loggers to the breeding birds.
Scientists on sub-Antarctic Macquarie Island have used satellite tags to track the foraging behaviour of a threatened sea-bird, the grey petrel, for the first time. The grey petrel weighs one kilogram and is a burrowing seabird which breeds on Macquarie Island, half way between Australia and Antarctica.
With increasing carbon dioxide concentrations in the atmosphere, levels are also increasing in the oceans, leading to ocean acidification. In recent years environmental scientists have been dedicating much effort to predict the fate of marine calcifiers, organisms which build their shells from calcium, under future ocean acidification scenarios. A team of European researchers used a range of new technologies to look at the molecules and cells involved in shell production of the Antarctic clam (Laternula elliptica). Their results identified seven proteins from the lustrous mother of pearl shell layer, including two which were totally unique to this species.
Climate has influenced the distribution patterns of Adélie penguins across Antarctica for millions of years. The geologic record tells us that as glaciers expanded and covered Adélie breeding habitats with ice, penguin colonies were abandoned. When the glaciers melted during warming periods, this warming positively affected the Adélie penguins, allowing them to return to their rocky breeding grounds. But now, University of Delaware scientists and colleagues report that this beneficial warming may have reached its tipping point.