ANN ARBOR — The fossilized fangs of saber-toothed cats hold clues to how the extinct mammals shared space and food with other large predators 9 million years ago.
Led by the University of Michigan and the Museo Nacional de Ciencias Naturales in Madrid, a team of paleontologists has analyzed the tooth enamel of two species of saber-toothed cats and a bear dog unearthed in geological pits near Madrid. Bear dogs, also extinct, had dog-like teeth and a bear-like body and gait. (more…)
Ear-bone ‘tree rings’ provide evidence of connectivity
Ocean scientists have long known that juvenile coral reef fishes use coastal seagrass and mangrove habitats as nurseries, later moving as adults onto coral reefs. But the fishes’ movements, and the connections between different tropical habitats, are much more complex than previously realized, according to a study published September 3 in Proceedings of the National Academy of Sciences. The findings have important implications for management and protection of coral reefs and other marine environments.
A number of studies have demonstrated a strong relationship between the presence of coastal wetlands and offshore fish abundance and fisheries yield, but it has proved difficult to develop quantitative assessment of habitat use by fish or their movement among different habitats. “The rationale for this study,”says Simon Thorrold, a biologist at Woods Hole Oceanographic Institution (WHOI), “was to determine the relative importance of different nursery habitats to reef fishes that spend their adult lives on coral reefs but may spend at least part of their juvenile residency elsewhere.” (more…)
When a carnivore becomes extinct, other predatory species could soon follow, according to new research.
Scientists have previously put forward this theory, but a University of Exeter team has now carried out the first experiment to prove it.
Published today (15 August 2012) in the Royal Society journal Biology Letters, the study shows how the demise of one carnivore species can indirectly cause another to become extinct. The University of Exeter team believes any extinction can create a ripple effect across a food web, with far-reaching consequences for many other animals. (more…)
At nearly four feet tall, the Emperor penguin is Antarctica’s largest sea bird—and thanks to films like “March of the Penguins” and “Happy Feet,” it’s also one of the continent’s most iconic. If global temperatures continue to rise, however, the Emperor penguins inTerre Adélie, in East Antarcticamay eventually disappear, according to a new study by led by researchers from the Woods Hole Oceanographic Institution (WHOI). The study was published in the June 20th edition of the journal Global Change Biology.
“Over the last century, we have already observed the disappearance of the Dion Islets penguin colony, close to the West Antarctic Peninsula,” says Stephanie Jenouvrier, WHOI biologist and lead author of the new study. “In 1948 and the 1970s, scientists recorded more than 150 breeding pairs there. By 1999, the population was down to just 20 pairs, and in 2009, it had vanished entirely.” Like in Terre Adélie, Jenouvrier thinks the decline of those penguins might be connected to a simultaneous decline in Antarctic sea ice due to warming temperatures in the region. (more…)
What’s the best way to study the Antarctic’s ecosystem? Follow the penguins.
Scientists are tracking penguins on land, under the sea, and even from space to unravel the environmental dynamics in the West Antarctic Peninsula as the region experiences climate change.
“We’re not just down there bird watching,” said Matthew Oliver, assistant professor of oceanography in UD’s College of Earth, Ocean, and Environment. “This is a concerted effort to put the whole ecosystem together.” (more…)
ANN ARBOR, Mich. — The ongoing spread of non-native mussels in the Great Lakes has caused “massive, ecosystem-wide changes” throughout lakes Michigan and Huron, two of the planet’s largest freshwater lakes, according to a new University of Michigan-led study.
The blitzkrieg advance of two closely related species of mussels—the zebra and quagga—is stripping the lakes of their life-supporting algae, resulting in a remarkable ecological transformation and threatening the multibillion-dollar U.S. commercial and recreational Great Lakes fisheries. (more…)
