Rare dolphin spits to catch its prey, scientists find

Australian snubfin dolphin fires jets of water from its mouth to round up fish, WWF discovers

Toni O'Loughlin, guardian.co.uk 14 Apr 09;

A rare species of Australian dolphin has been found to catch its fish prey by spitting water, according to research by WWF. The small snubfin dolphins hunt in groups and use their spitting technique to round up fish they have chased to the surface by firing jets of water from their mouths.
The unusual behaviour has only been observed in one other dolphin species, the Irrawaddy dolphin, which lives throughout south and south-east Asia.

"This is incredibly unusual behaviour, first seen in Australia off the Kimberley Coast," said WWF Australia's marine and coasts manager, Lydia Gibson. "It also confirms the snubfin dolphin is a fascinating animal, one which we know so little about."

The snubfin dolphin (Orcaella heinsohni) was discovered in 2005 and is Australia's only endemic dolphin species, meaning that it is unique to northern Australia. Virtually nothing is known about its behaviour or habits.

First sighted off the Kimberley coast near the resort town of Broome and dubbed "snubby" because of its blunt dorsal fin and rounded snout, the snubfin is struggling to survive.

New research by WWF indicates that Australia's heavily populated coastline and rapidly expanding tourist developments near environmental wonders, such as the Great Barrier Reef, could see this species disappear before it is properly understood.

Classified as near threatened by the IUCN 'red list' of endangered species, WWF's research shows the dolphin is particularly vulnerable to pollution, viruses and bacteria. It is also more likely than other dolphins to be ensnared by fishing nets because it prefers inshore estuarine habitats where river-nets are set.

"There are already development proposals – like the extension of the Townsville port – that could have major impacts on these species," said Gibson. Dying mangroves, rising sea levels, dam construction and dredging of estuaries are also pushing the snubfins to the edge of extinction, according to the WWF.

New research reveals extraordinary habits of rare Aussie dolphin
WWF 17 Apr 09;

A preliminary study on Australia’s mysterious snubfin dolphin has given researchers new insight into the mammal’s habits and behaviour, including that it uses an extraordinary spitting technique to catch prey.

The research, funded by ING DIRECT, has given an overview of the life and habits of this very rare marine mammal, affectionately named ‘snubby’ by researchers, which lives in tight-knit social groups along the northern coastlines of Australia.

The small dolphins hunt in groups and use a spitting technique to catch their prey - chasing fish to the surface of the water, and rounding them up by shooting jets of water from their mouths, said WWF-Australia’s Marine and Coasts Manager Lydia Gibson.

“This is incredibly unusual behaviour, first seen in Australia off the Kimberley Coast, has only been noted before in Irrawaddy dolphins, which are closely related to this species,” Gibson said. “It also confirms the snubfin dolphin is a fascinating animal, one which we know so little about.”

Gibson said the WWF/ING DIRECT research has been collating existing information from many sightings over the years while also gathering new valuable data about snubfin habitats across northern Australia.

The ten key findings from the research so far show that:

• Threats to mangrove systems from rising sea levels predicted with climate change and from human impacts such as dam construction, dredging and other destructive activities are the greatest threat to the snubfin. Where mangrove systems are destroyed or damaged, the snubfins will lose their food and their habitat/home.

• Snubfins are very susceptible to chemical pollution, viruses and bacteria because they live close to shore and have a relatively small range. A parasite found in cat faeces (Toxoplasma gondii) is of particular concern, as it was found - via contaminated run-off - to be the cause of death of three Indo-Pacific humpback dolphins recovered around Townsville in the period 2000-2001.

• Snubfin dolphins are more likely than other dolphins to be caught in gill nets because they prefer inshore estuarine habitats where river-nets are set.

• Snubfin families appear to spend much of their lives in very small territories close to shore. This means snubfin populations can be heavily impacted by habitat destruction and unsustainable development.

“These top ten facts were uncovered to better understand what we do and do not know about the snubfin dolphin. They will provide us with the benchmark we need to inform conservationists, government and scientists about how best to conserve and manage this unique and threatened species for future generations.”

Ms Gibson said that habitat destruction was the key threat to these coastal dolphins.

“There are already development proposals around the Great Barrier Reef that could affect their habitat – like the extension of the Townsville Port – that could have major impacts on these species. We must work with all relevant stakeholders to initiate a strategic environment assessment of future developments close to snubfin habitats.”

Australia’s largest online bank, ING DIRECT, joined WWF-Australia’s flagship species conservation program to help fund research into the snubfin dolphin, primarily in Queensland.

“We are even more proud now that we have been able to help researchers uncover a range of remarkable facts and insights that may help preserve this remarkable creature long into the future,” said Christian Bohlke, ING DIRECT Head of Branding and Communications.

ING DIRECT’s funded research has not only given insights into the, until now, secret lives of these dolphins, it has also revealed the threats they face from man.

“This overview sets the stage for the ongoing research needed to help us discover ways to minimise our impact on these unique Australian creatures. Companies like ING DIRECT that fund this research are helping us preserve an extraordinary creature and are building a legacy that will be enjoyed by Australians for generations to come,” Bohlke said.

Rare "Snubby" Dolphins Spit to Hunt
Brian Handwerk, National Geographic News 20 Apr 09;

Spitting in public isn't rude in snubfin dolphin society—it's expected.

The rare marine mammals hunt together by chasing fish to the surface and then "spitting" water at them to herd them for the kill, researchers with the conservation nonprofit WWF recently discovered.

As their name implies, snubfin—or "snubby"—dolphins have especially short dorsal fins, but they may be more recognizable by their melon-like heads and beakless profiles. The social animals dwell in groups of six or more.

The six-foot-long (two-meter-long) snubfins are now the second dolphin species known to use a cooperative hunting technique in which they shoot jets of water from their mouths to drive fish toward other dolphins.

"It's incredibly unusual behavior that has only been noted before in Irrawaddy dolphins," said WWF-Australia's marine and coasts manager, Lydia Gibson.

"It's a bizarre kind of technique. Some were seen spitting water high into the air and [others] straight along the surface of the water. It's a fascinating behavior, but we still know so little about them and about exactly how they do it."

Snubfin and Irrawaddy dolphins were thought to be the same species until 2005, when scientists learned that snubfins were a unique species swimming the mangroves, rivers, estuaries, and coastal waters of northern Australia.

Snubfins are coastal dwellers and appear to inhabit small territories, so they may be especially susceptible to pollution, coastal development, and other threats to mangrove ecosystems, Gibson noted.

"Their presence is an indicator of a healthy ecosystem, so we have an [important] opportunity" to learn more about the mysterious dolphin's lifestyle and thus make better decisions about preserving its habitat, she said.

"It's critical to do what we can to protect our coastal ecosystems."