Antarctic killer whales’ unique calls

This 19 February 2020 video says about itself:

Calls of Antarctic Type C killer whales in McMurdo Sound, Ross Sea.

Want to hear what Antarctic Type C killer whales sound like?🎶Here is a sneak peek to some vocalising orca in McMurdo Sound recorded by our research team in the 2012 and 2013 season.

Recorded in the Ross Sea, this study will help with management tools of the RossSea MPA. More details on their sounds can be read in our recently published paper in Royal Society Open Science journal. Free to download from here.

From Curtin University in Australia:

New research sheds light on the unique ‘call’ of Ross Sea killer whales

February 26, 2020

New Curtin University-led research has found that the smallest type of killer whale has 28 different complex calls, comprising a combination of burst-pulse sounds and whistles, which they use to communicate with family members about the changing landscape and habitat.

The research, published in Royal Society Open Science, analysed data collected in 2012 and 2013 to better understand the call repertoire of Ross Sea killer whales, also known as Type C, which are found in the McMurdo Sound in Antarctica.

Lead author PhD candidate Rebecca Wellard, from Curtin’s Centre for Marine Science and Technology (CMST), said the remoteness of the Ross Sea can make it difficult to monitor and record the movements of killer whales, but it is essential to better understand their behaviour and acoustic repertoire.

“In Antarctic waters, there are five different types of killer whales, with Type C being the smallest, growing up to 6.1 metres in comparison to Type A males who can grow up to almost 10 metres long,” Ms Wellard said.

“By using passive acoustic monitoring, our team was able to analyse recordings from nine separate encounters with approximately 392 Type C killer whales, including adults, sub-adults and calves.

“We were able to identify that the calls of the Type C killer whale are multi-component, meaning that many calls transition from burst-pulse sounds to whistles. We also found that 39 per cent of the call types started with a series of ‘broadband pulses’.”

Ms Wellard explained that the most common killer whale behaviours observed in the study were travelling and foraging under the ice and socialising at the surface, which could explain the increase in call rate.

“During the calls, often two of the sounds occurred at the same time, also known as biphonation. These types of calls could be used to locate where other members of the pod may be. Due to the shifting and changing habitat in McMurdo Sound, calves could also be using biophonic calls to communicate with family members about available breathing holes,” Ms Wellard said.

“Our findings provide an initial step towards comparing and distinguishing Type C killer whale acoustics with those of other killer whale populations in the Southern Hemisphere.”

The research was co-authored by researchers from the CMST, Project ORCA, National Marine Fisheries Service and Oregon State University.

Antarctic climate change damages English Arctic terns

This June 2017 video from England is called Arctic tern, Farne Island.

From Newcastle University in England:

Impact of climate change on Arctic terns

November 18, 2019

Summary: New study shows how change in Antarctic sea ice is driving one of the world’s smallest seabirds to forage further for food.

Data collected from electronic tags retrieved from 47 journeys made by the Farne Island Arctic terns, has revealed for the first time how climate change might affect their behaviour.

Arctic terns spend their breeding and non-breeding seasons in polar environments at opposite ends of the world and are our longest-migrating seabird.

Spending their non-breeding season in the Antarctic, the remoteness of this part of the world means that until now we have had a very limited understanding of their behaviour and distribution while they are there.

Analysing the data from 47 migrations over two study years, 2015 and 2017, the team found:

  • Arctic Terns live on the Antarctic ice for one third of their annual lifecycle.
  • Analysis of their feathers shows their main food source is krill or similar crustaceans.
  • There were marked differences in the bird’s behaviour and distribution between those tagged in 2015 compared with those tagged in 2017. This coincided with a substantial change in ice conditions, with high ice cover in 2015 followed by unusually warm conditions which led to the break-up of the ice in late 2016 and lower ice cover than normal throughout the following year.

Dr Chris Redfern, of Newcastle University, UK, who has led the study explained:

“Sea ice is an important habitat for juvenile krill as it provides protection from predators and from the intense light of the Antarctic summer.

“We now know that krill are the main food source for the terns so it seems likely the warmer weather during 2016/2017 led to reduced krill abundance and so the birds were forced to forage in different areas.

“And in fact, in that second year, the birds converged on the Shackleton Ice Shelf rather than being spread out along the East Antarctica coastline.

Polar regions are particularly sensitive to climate change and even small shifts can have major implications throughout the entire food web.

“This is why it is critical to understand how seabirds such as the Arctic Terns are affected by environmental change, both short and long term.”

Co-author Professor Richard Bevan, of Newcastle University, adds:

“In the course of this study, we have been continuously amazed by the incredible journeys that these seabirds make each year and now we are beginning to get a glimpse into what they are doing in their wintering areas in Antarctica.

“Arctic Terns are one of the few non-breeding birds that are present in Antarctic waters during the summer. This means the birds are not constrained to a nest site but can move to where the best feeding sites are located.

“By following the journeys made by these birds, we can monitor changes in the location of these hot spots and get some insight into environmental changes that are taking place in these very remote locations; areas to which few scientists ever venture or monitor.”

The data were collected as part of a landmark study led by Newcastle University in collaboration with the National Trust, BBC Springwatch and the Natural History Society of Northumbria.

The first data retrieved from the study highlighted the incredible journey travelled by these seabirds, with one flying an estimated 96,000Km (almost 60,000 miles) from its breeding grounds on the Farne Islands, off the Northumberland coast, to its winter quarters in Antarctica.

Mapping in unprecedented detail the route and stop-off points from the Farnes to Antarctica for the winter and back again to breed, the team tracked:

  • An 8,000 km, 24-day, non-stop flight over the Indian Ocean, feeding on the move
  • An overland detour from the Farne Islands to the Irish Sea and over Ireland to the Atlantic
  • A short stay on the New Zealand coast before completing the final leg of their journey
  • A stop-off at Llangorse Lake, in the Brecon Beacons National Park, during their return journey in the Spring

“The Arctic Tern’s dependence on the ice throughout their non-breeding period in Antarctica highlights the vulnerability of the species to climate change,” says Dr Redfern.

“It is well known that Arctic Terns have relatively shorter legs than other tern species and in light of what we now know, this may be an adaptation to life associated with low temperatures — the freezing point of sea water is -1.8 C and the daily average minimum temperatures recorded by the birds’ data loggers was between 0 to -5 C.

“The trackers have given us a unique glimpse into the lives of these incredible birds, surviving against all the odds, and highlights how precarious their future is in the light of anthropogenic climate change.”

Agroecology is a revolution! How the Nicaraguan Rural Workers Association is confronting the climate crisis through developing agroecological farming and food sovereignty: here.

Antarctic giant petrels, heroes or villains?

This 29 October 2019 video says about itself:

Giant Petrels: Heroes or Villains? | Seven Worlds, One Planet | BBC Earth

Giant petrels are aggressive, fearless and aren’t afraid of some gore. But they’re also called ‘the vultures of Antarctica‘ thanks to their clean-up characteristic of feeding on carrion. So are giant petrels heroes or villains?

Antarctic marine life, video

This 27 October 2019 video says about itself:

The Enchanted World Beneath the Antarctic Ice Sheet | Seven Worlds, One Planet | BBC Earth

The Seven Worlds, One Planet crew dived beneath the surface of the Antarctic ice sheet with only a tiny bore hole for escape. Discover the wonders they found in the frozen seas.

Chinstrap penguins drive away skua egg thief

This 26 October 2019 video from the Antarctic says about itself:

Chinstrap Penguins Chase Off Daring Egg Thief | Seven Worlds, One Planet | BBC Earth

Skuas will eat penguin eggs if they get the chance, but these chinstrap penguins are having none of it! Behind the scenes from David Attenborough‘s Seven Worlds, One Planet.

Antarctic marine life recovery after dinosaurs’ extinction

This August 2016 video says about itself:

Fossil hunters want to know what life was like when dinosaurs became extinct 66 million years ago. We join an Aussie [Australian] palaeontologist on a US expedition searching for dinosaur fossils in Antarctica, the most challenging place to explore the end of their ancient world.

From the British Antarctic Survey:

Antarctic marine life recovery following the dinosaurs’ extinction

June 19, 2019

A new study shows how marine life around Antarctica returned after the extinction event that wiped out the dinosaurs.

A team led by British Antarctic Survey studied just under 3000 marine fossils collected from Antarctica to understand how life on the sea floor recovered after the Cretaceous-Paleogene (K-Pg) mass extinction 66 million years ago. They reveal it took one million years for the marine ecosystem to return to pre-extinction levels. The results are published today (19 June 2019) in the journal Palaeontology.

The K-Pg extinction wiped out around 60% of the marine species around Antarctica, and 75% of species around the world. Victims of the extinction included the dinosaurs and the ammonites. It was caused by the impact of a 10 km asteroid on the Yucatán Peninsula, Mexico, and occurred during a time period when the Earth was experiencing environmental instability from a major volcanic episode. Rapid climate change, global darkness, and the collapse of food chains affected life all over the globe.

The K-Pg extinction fundamentally changed the evolutionary history of life on Earth. Most groups of animals that dominate modern ecosystems today, such as mammals, can trace the roots of their current success back to the aftermath of this extinction event.

A team of scientists from British Antarctic Survey, the University of New Mexico and the Geological Survey of Denmark & Greenland show that in Antarctica, for over 320,000 years after the extinction, only burrowing clams and snails dominated the Antarctic sea floor environment. It then took up to one million years for the number of species to recover to pre-extinction levels.

Author Dr Rowan Whittle, a palaeontologist at British Antarctic Survey says:

“This study gives us further evidence of how rapid environmental change can affect the evolution of life. Our results show a clear link in the timing of animal recovery and the recovery of Earth systems.”

Author Dr James Witts, a palaeontologist at University of New Mexico says:

“Our discovery shows the effects of the K-Pg extinction were truly global, and that even Antarctic ecosystems, where animals were adapted to environmental changes at high latitudes like seasonal changes in light and food supply, were affected for hundreds of thousands of years after the extinction event.”