Dingoes, which were once present across Australia, are known to prey upon kangaroos, emus and feral goats and it’s thought they also deter foxes and feral cats.
Photograph: AAP/Supplied by Invasive Animals Cooperative Research Centre
by Oliver Milma
Australia’s lengthy “dingo fence” should be altered to allow dingoes into a national park to test whether they can help reverse the precipitous decline of native wildlife, a group of conservation experts has recommended.
The bold experiment would involve remodelling the dingo-proof fence that stretches from eastern Queensland to the South Australian coastline. At more than 5,500km long, the barrier, originally constructed in the 1880s to keep out rabbits, is the longest fence in the world.
Altering the fence’s boundary would enable dingoes to enter the Sturt national park in New South Wales, allowing scientists to assess whether dingoes, long reviled by many people as dangerous to livestock and even humans, could in fact act as saviours for threatened native animals.
Dingoes are known to prey upon kangaroos, emus and feral goats and it’s thought they also deter foxes and feral cats – the two introduced predators blamed for causing massive declines in animals such as bilbies, bandicoots and bettongs across Australia.
But while dingoes were once present across Australia, the combination of the dingo-proof fence and culling of the animals to stop them attacking livestock means they are now not found in large areas of New South Wales, Victoria and South Australia.
A paper published in Restoration Ecology by Australian ecologists suggests the reintroduction of dingoes could prove beneficial to native wildlife.
“Predation by foxes and feral cats is the key driver of extinctions, so we need to change what we’ve previously done and look at if the dingo can help,” said Dr Thomas Newsome of the University of Sydney, the report’s lead author.
An adult ‘I’iwi (Scarlet Honeycreeper), once common, but now very rarely seen below the upper reaches of Hawai’i Volcanoes National Park. Photograph by Dale McBeath.
by David Maxwell Braun
KIPUKAPUAULU–Within an area Hawaiians hold sacred, the realm of the gods thousands of feet above the ocean on Big Island, a spectacular biodiversity hot spot known locally as “Bird Park” is an excellent place to observe and hear the avian species of Hawai’i Volcanoes National Park.
Kipuka is the Hawaiian term for an “island” of old-growth trees surrounded by recent lava flows.
Kipukapuaulu is a fine example of lush forest of towering trees, grasses, and plants of every kind to feed and shelter birds and insects.
Kipukapuaulu has not been without serious environmental setbacks.
At one time the area was used to ranch cattle. That was stopped decades ago, but the legacy is many introduced species of plants, animals, insects and birds that still impact the area today, in spite of valiant efforts by the park authorities to bring them under control.
Bottlenose dolphins leap from the water in the Caribbean Sea.
Photograph by Stuart Westmorland, Corbis
Believe it or not, how dolphins can swim so fast has been something of a riddle for researchers since the 1930s.
But a new study has laid to rest one of the most vexing questions plaguing scientists about dolphin speed: How can their muscles produce enough thrust for such high speeds? “It’s been controversial for a while,” said Frank Fish, a marine biologist at West Chester University in Pennsylvania.
Now he has the answer: Bottlenose dolphins can produce the power they need to swim circles around whatever they wish by using their powerful tails, new experiments show. The paradox began in 1936 with a British researcher named Sir James Gray, who conducted the first study on dolphin swimming, said Fish, a co-author of the study published online January 15 in the Journal of Experimental Biology.
Gray had observed a dolphin swimming around a ship at 33 feet (10 meters) per second for seven seconds, and wondered how the animal could move so quickly. (See National Geographic’s videos of dolphins and porpoises.)
Physics theory states that for something the size of a dolphin—and for the speed with which it travels through the ocean—water flow over the animal should be turbulent rather than smooth, Fish said.
That turbulent flow creates a lot more drag that needs to be overcome than smooth flow does. But when Gray input his variables into his equations and assumed a turbulent flow, “he found the animal didn’t have enough muscle mass to produce the power it needed to swim at that speed,” said Fish.”This became Gray’s paradox,” Fish said—sparking a decades-long search for an explanation of how dolphins powered through the water.
Gray assumed that the dolphin must have been doing something to turn the turbulent flow over its body into a smooth flow. But scientists hadn’t been able to figure out how the mammals did it.
The German ichthyologist M.H.C. Lichtenstein described the goliath grouper as Serranus itajara in an 1822 publication regarding the natural history of Brazil.
In an 1884 work, “The fishes of the Florida Keys,” David Starr Jordan proposed the inclusion of the goliath grouper in Epinephelus (Bloch 1793) and this combination remains in use today. Of incidental note is the fact that various authors have incorrectly spelled the specific epithet “itajara” as “itaiara.”
The genus name comes from the Greek epinephelos translated as cloudy. Synonyms of E. itajara include Serranus guasa Poey 1860 and Serranus quinquefasciatus Bocourt 1868.
A number of authors treat the name Promicrops itajara as valid taxonomy for the goliath grouper.
The goliath grouper occurs in the western Atlantic Ocean from Florida south to Brazil, including the Gulf of Mexico and the Caribbean Sea.
It is also found in the eastern Atlantic Ocean, from Senegal to Congo although rare in the Canary Islands.
The species is also present in the eastern Pacific Ocean from the Gulf of California to Peru.