Warming Climate Bugs Birds
© Tim Fitzharris / Minden Pictures
Global climate change could spell disaster for some South American birds as more rain and warmer temperatures cause the populations of parasites that plague them to explode.
Researchers studying nesting forest birds such as great kiskadees in Santa Fe, Argentina, found increasing numbers of fly larvae on chicks. The larvae burrow into the skins of the baby birds to feed, impairing the chicks’ growth and increasing their chances of dying.
Between 2006 and 2008, researchers examined 715 chicks in the nests of 41 different bird species and found parasites on half of the species studied—particularly the great kiskadee, the greater thornbird, the little thornbird and the freckle-breasted thornbird. One chick had as many as 47 larvae on its body.
“This is a striking example of the kind of negative effects on wildlife that can arise as a result of climate change,” says Pablo Beldomenico of the Wildlife Conservation Society, which backed the study.
New Turtle Turns Up
Usually when scientists discover a new species, it’s in an exotic locale a world away—not in our own backyard. But that’s where a recently discovered turtle turned up. Found in the Pearl River, which flows through Mississippi and Louisiana before it enters the Gulf of Mexico, the newly—and aptly—named Pearl map turtle had been mistaken for a turtle native to a neighboring river.
Like the turtle it was mistaken for—the Pascagoula map turtle—this new saucer- to plate-sized turtle is imperiled by pollution, habitat destruction and the pet trade.
Researchers observed variations between the turtles in the Pearl and the Pascagoula rivers, which prompted them to do DNA tests that showed the turtles were two distinct species. “You’d expect to see similar aquatic species in these rivers due to their proximity,” says Jeff Lovich, a turtle expert at Northern Arizona University who aided in the research. “However, with sea-level changes associated with glacial and interglacial periods in the past, animals in these rivers were periodically separated for tens of thousands to millions of years.”
Menopause: Good for the Group
HOT FLASH: Scientists finally have a new clue about the evolutionary role of menopause, and it comes from what might seem an unlikely source—whales.
Like humans, female pilot whales and killer whales stop breeding relatively early in their life spans. To understand why, researchers at Britain’s Exeter and Cambridge universities looked at the behavior of the three species, the only ones known to cease reproduction with decades of life stretching ahead of them.
Although the social systems of the three species are very different, the researchers found a common link: As they grow older, the females become increasingly genetically related to the individuals they live with. “This predisposes females of our species, and those of killer whales and pilot whales, to the evolution of menopause and late life helping,” says Michael Cant of the University of Exeter’s School of Biosciences. The aging females are motivated to do what is best for the survival of those around them: stop breeding to allow younger females easier access to resources, and start sharing their parenting knowledge to boost the breeding and child-rearing success rate.
In other words, older women and whales assume the role of grandmother for the good of the group.
Tigers’ Last Chance?
Tigers are disappearing. A new study offers the grim details, along with a simple and affordable plan for turning the tide.
Fewer than 3,500 of the big cats remain in the wild today, relegated to just 6 percent of their former habitat by poachers, loggers and other usurpers of habitat. Only a third of these tigers tucked away in small pockets of Asian forest are breeding females.
The study by the Wildlife Conservation Society and other groups identifies 42 sites with breeding tiger populations in Russia, Nepal, Bangladesh, India, Indonesia, Malaysia, Thailand and Laos. The groups recommend securing these sites and intensifying basic conservation efforts to save the world’s largest cat.
Governments and international groups are already spending about $42 million annually to conserve these sites, the groups note. An additional $35 million each year for more extensive population monitoring, stronger law enforcement and increased community organizing could help prevent the hunting of tigers and their prey and give the big cats a chance to double their numbers in these last strongholds.
Fortunately, one of the world’s top financiers, the World Bank, is also solidly behind tiger conservation. The bank is working with leaders in the 13 tiger-range countries to promote saving tigers as an investment that benefits other important species, entire ecosystems and the health, wealth and ecological security of human populations.
Conservationists are banking on the new findings and financial interest to refuel tiger recovery and keep this critically endangered species from tanking.
Nothing Cuckoo About This Ploy
In the case of the European cuckoo, the early bird catches not only the worm but the nest and the parents.
European cuckoos are brood parasites—they dump their eggs and full responsibility for raising their young in the nests of other species. Cuckoos succeed at this parasitic ploy because their eggs hatch first. The newly hatched chicks push the eggs of their hosts right out of the nest and get all the worms and other food the foster parents offer.
How cuckoos manage to pull off this egg-drop coup has long perplexed scientists. Now a team of researchers at England’s University of Sheffield has finally figured it out. The European cuckoo can do something previously thought impossible for a female bird: it can hold its fully formed egg inside for an extra 24 hours.
The internal incubation “gives cuckoo chicks that crucial head start in life,” says research team leader Tim Birkhead, “allowing them to dispose of their nest mates—a superb adaptation to being a brood parasite.” By eliminating the competition and making it all about them, these early birds have hatched a winning survival strategy.