Deep diving penguins and deeply passionate penguin experts

Diving emperor penguins during a
foraging trip from the Cape
Washington colony in Antarctica.
Credit: Paul Ponganis, University
of California.

Emperor penguins can dive to depths of over 500m and stay underwater for up to 27 minutes – deeper and longer than any other bird species. Now research has revealed that one of the factors behind their amazing dives is their ability to slow their heart rate. ­

Researchers Alexandra Wright and Dr Paul Ponganis from the University of California will present their new findings this week at the 8th International Penguin Conference (IPC), which is being held in Bristol from 2 to 6 September.

The study was carried out on emperor penguins at the Cape Washington colony in Antarctica. The researchers investigated the heart rate response of the birds as they made foraging trips to sea from their colony and found that the penguins slowed their heart from the normal rate of around 70 beats per minute to as low as 10 beats per minute.

Emperor penguins also have unusually structured hemoglobin that can function at low oxygen levels, solid bones to reduce barotrauma (physical damage to body tissues caused by a difference in pressure between a gas space inside, or in contact with the body, and the surrounding fluid) and the ability to reduce metabolism and shut down non-essential organ functions.

The profound decline in heart rate – known as bradycardia – decreases oxygen consumption, conserves the respiratory and blood oxygen stores, and isolates muscle, which must rely instead on its own oxygen store which is bound to the muscle protein, myoglobin.

This heart rate response is different from other birds and land mammals, but similar to the dive response of marine mammals.

Alongside emperor penguins’ diving abilities, other papers that IPC delegates can sample this week range from ‘monitoring global penguin population change’ to ‘the power of poo’.

The IPC is being hosted by the University of Bristol and Bristol Zoo Gardens, and it is the first time the conference has been held in Europe. It is also the largest IPC to date, with 200 delegates from 30 countries sharing their latest research and knowledge. It was launched by a special video message recorded by Archbishop Desmond Tutu.

With five penguin species listed as endangered and a further six as vulnerable, work to ensure the survival of penguins in the wild has never been more important. Over 60 presentations at the IPC will help to share new research, new conservation techniques and improved husbandry methods to try to prevent these species from becoming extinct.

The IPC is being chaired by Professor Peter Barham, Professor of Physics at Bristol University, who helped to devise an automatic penguin recognition system which will reduce the need for potentially harmful banding of birds.

‘It’s a great honour to be hosting the conference in Bristol. It will be the largest gathering of its kind to date and between them the delegates work with penguins on all seven continents,’ Professor Barham said.

‘Penguins are such fascinating creatures and they appear in many films and adverts, but the true picture is perhaps not as rosy as people think. There’s so much work going on to help protect them and all the delegates are very keen to share their passion for penguins.

‘Hopefully the conference and public events will encourage as many people as possible to understand these precious birds.’

Neil Maddison, Head of Conservation Programmes at Bristol Zoo Gardens, said, ‘We are thrilled to be co-hosting such an exciting conference, and Bristol Zoo is proud to be involved in a conference that is so important to the development of the conservation of penguins.’

Bristol Zoo Gardens will be hosting a Penguin Day on Saturday 7 September to help to educate the public about the important work that goes on to preserve the species. Penguin Day will provide zoo visitors with an opportunity to learn more about the African penguin, with family-friendly activities and the chance to meet scientists and conservationists who work with African penguins in South Africa and Namibia.

Another way that members of the public can get involved in the IPC is by attending Penguins on Film, which is being held at Bristol University on Wednesday 4 September. At this free event, a world leading panel of experts will discuss their experiences working with penguins. The panel will include Elizabeth White, one of the directors of the popular Frozen Planet series.

There will be a screening and discussion of BBC Natural History Unit footage of Adelie penguins stealing stones from their neighbours’ nests to elevate and protect their eggs from run-off when the Antarctic ice melts. There will also be captivating slow motion footage of emperor penguins ‘flying’ – getting airborne by swimming at speed towards the surface of the water and landing back on the ice.

Sources
How emperor penguins stay underwater for 27 minutes [press release], 2 September 2013, Bristol University
World-leading penguin experts come to Bristol [press release], 22 August 2013, Bristol University