New model more accurately describes migratory animals' extinction risk

 Researchers at the University of Georgia and Tulane University have developed a mathematical model that may make such predictions more accurate. Their work appears in the early online edition of the Royal Society journal Biology Letters."The concern is that for a lot of species, we don't know very much about their wintering grounds," said Richard Hall, assistant research scientist in the UGA Odum School of Ecology. "Here in the U.S. we do a pretty good job of conserving breeding habitat for species of concern, but often we have no idea what kinds of threats are facing their non-breeding areas."Hall and Tulane University's Caz Taylor developed a new model that builds upon a theory of population dynamics known as metapopulation theory. Metapopulation theory describes the fraction of suitable habitat patches occupied by a species. Individuals from a sub-population emigrate from their original site to colonize previously unoccupied patches of new habitat where they either survive or die out. When the rate of successful colonization exceeds the rate of extinction, the proportion of occupied patches rises and the metapopulation is likely to persist.

No single cause for mass extinctions

 A recently published study suggests that neither climate change nor human factors accounts for mass extinctions of large mammals, during the Ice Age.The inter-disciplinary research team, which included 40 institutions from around the world, included Professor Alan Haywood, a paleoclimatologist from the University of Leeds, who helped provide climate simulations for the project. A subject of much debate in recent decades, the study helps scientists know whether humans or climate change caused the mass extinctions of a third of large mammals in Eurasia and two thirds in North America.  The study concluded that neither humans nor climate change alone caused mass extinctions in the Ice Age, effectively putting an end to debate on the possibility of a single-cause.  However, despite the large amount of data used in this study, the reasons why some species survived while others went extinct remains unclear, making predictions about existing mammals’ response to future global climate change difficult.

Eating fish can reduce the risk of diabetes

A study analyses the dietary patterns of the adult Spanish population with high cardiovascular risk. The results reveal a high consumption of both red meat and fish. However, whilst eating lots of cured meats is associated with greater weight gain and a higher obesity rate, the consumption of fish is linked to lower glucose concentrations and a smaller risk of developing diabetes. Mercedes Sotos Prieto, lead author of the study which forms part of the Preformed study (Prevention with a Mediterranean Diet) and researcher at the University of Valencia explains how "in Mediterranean countries, consumption of foods that typically form part of the diet here has decreased in recent decades. The consumption of saturated fats mainly from red meats and industrial baking has increased and this is really worrying." So next time you go to a restaurant you might want to consider a seafood not a stake.

Hooking fish, not endangered turtles

A tuna fisherman has tahimself to make the seas safer for sea turtles, animals ken it upon that are threatened or endangered with extinction worldwide. He’s designed a new hook that he says will make bait and the lethal barb that secures it unavailable to marine birds and turtles until long after it’s sunk well below the range where these animals venture to eat.  He’s created a large round shield that crews snap over a fairly standard baited hook. A typical longline deployed by tuna fleets might run up to 150 kilometers. A single line may carry from 1,000 to 3,000 barbed hooks one spaced every 50 meters or so. “Tuna longline fishing sets over 2 billion of these hooks globally each year,” Jusseit says. “We’ve shown in tests on longline boats in Australia that fishermen catch more fish using this hook,” Jusseit reports. One reason: Seabirds and turtles typically abscond with up to 15 percent of the bait. The heavy new guards also will substitute for pricy sinkers used to initially pull the hooks down to the target depths, he says.  

Climate change causing massive movement of tree species across the West

"In an enormous display of survival of the fittest, the forests of the future are taking a new shape." Says the writer of the article, according to the article scientists outline the impact that a changing climate will have on which tree species can survive, and where. The study suggests that many species that were once able to survive and thrive are losing their competitive footholds, and opportunistic newcomers will eventually push them out. So according to what the article says in the future the natural trees you see around you will probably die out and be found in unnatural places. For example we might start finding palm trees in colder places. "In some cases, once-common species such as lodgepole pine will be replaced by other trees, perhaps a range expansion of ponderosa pine or Douglas-fir," says the writer. The article also says that some areas may shift completely out of forest into grass savannah or sagebrush desert. In central California, researchers concluded that more than half of the species now present would not be expected to persist in the climate conditions of the future. 

How mammoths lost the extinction lottery

 Researchers who studied the fate of six species of 'megafauna' over the past 50,000 years found that climate change and habitat loss were involved in many of the extinctions, with humans playing a part in some cases but not others. But there was no clear pattern to explain why the animals died off, and it proved impossible to predict from habitat or genetic diversity which species would go extinct. For a more consistent picture, scientists charted the population dynamics of woolly mammoths, woolly rhinos, wild horses, reindeer, steppe bison and musk ox. As the climate  warmed, woolly rhinos, woolly mammoths and the Eurasian populations of musk oxen went extinct as populations became more and more isolated from one another. But these extinctions happened thousands of years apart, and the animals' ranges changed in different ways. So at the end scientists concluded that temperature and human interaction were the main causes for mammoth extinction.

Birds Fly in the Face of Climate Change Expectations

 Researchers in California were surprised to find that West Coast birds have been growing larger in recent decades. “The finding that birds are getting bigger draws into question what’s driving the change in size.” Ms. Goodman and her colleagues analyzed data dating back 40 years from two different California bird observatories. Body mass and wing-span measurements of nearly 33,000 birds representing dozens of species collected from 1971 to 2010 were analyzed for variations over time.The researchers found that wing length had been steadily increasing and body mass had expanded. Some of the species migrate between Alaska and Latin America, while others breed locally or are short-distance migrants, but the rate of change in size did not depend on where the birds spent the majority of their longitudinal time. Ms. Goodman laid out a number of hypotheses. "More severe West Coast weather events may favor larger birds that are better able to cope with prolonged stresses since they have greater stores of energy" she said.