Smithsonian.com

Image: Paul-W

Humans love a good, well-monitored interaction with nature. For stingrays at Stingray City—a string of Grand Cayman sandbars that’s become a famous tourist destination—the deal isn’t half bad, either. Humans feed the rays every day, to ensure that they’ll come back and slide their slippery wings along visitors’ legs. But there might be a dark side to this “interactive ecotourism” business. Researchers who looked at Stingray City show that the rays there are diverging from their wild kin in ways that make them dependent on humans.

This isn’t all that surprising. First, wild stingrays are nocturnal. Stingrays at Stingray City are not. Wild stingrays are solitary. About 164 rays now live in the the quarter square mile that makes up Stingray City. In the wild, rays avoid one another, mate once a year and very rarely show aggression towards other rays. At Stingray City, they’re pregnant all year round, rub up against one another and bite each other relatively frequently. All this surprised the researchers. They say in a press release:

“We saw some very clear and very prominent behavioral changes, and were surprised by how these large animals had essentially become homebodies in a tiny area,” said study co-author Mahmood Shivji, director of the Guy Harvey Research Institute and NSU Oceanographic Center professor, who led the study.

Which probably isn’t good for the stingrays, really. “There are likely to be some health costs that come with these behavior changes, and they could be detrimental to the animals’ well-being in the long term,” Shivji told the press office. The researchers are hoping that by studying the ways an ecotourism destination like Stingray City changes stingray behavior, managers can better design the experience for both humans and their winged friends. The study reports:

Because feeding of marine wildlife on a regular and sustained basis for tourism is widespread and continuing to expand, understanding the impacts of these activities on the target marine organisms and associated ecosystems will be useful to help managers plan mitigating measures where these activities exist, and exercise precautionary policies where new feeding sites are proposed.

Changing the ways of ecotourism will be hard though. Each individual stingray at Stingray City generates $500,000 each year in tourism for the area. Guy Harvey, researcher and founder of the Guy Harvey Research Institute, said that understanding these animals is key:

“Right now, these animals have no protection at all,” Harvey said. “Without more studies like these, we won’t know what that means for the wildlife or if we need to take action. It’s unclear how much of the stingray’s daily diet comes from tourism provided food, but the good news is we have seen the animals forage when tourists are absent suggesting that these animal are not completely dependent on these handouts.”

Because should humans suddenly develop a fondness for parrots rather than rays, and leave these poor fish alone, they would probably die.

More from Smithsonian.com:

Swim Like a Stingray

Pope Francis waves to the crowd from the central balcony of St. Peter’s Basilica at the Vatican, Wednesday, March 13, 2013. Cardinal Jorge Bergoglio who chose the name of Francis is the 266th pontiff of the Roman Catholic Church. (AP Photo/Gregorio Borgia)

In Vatican City today, Jorge Mario Bergoglio, 76, became the new Pope Francis. After Catholic cardinals debated the options earlier today, a puff of white smoke issued from the Sistine Chapel’s chimney indicated that the decision was complete, the New York Times reports.

Pope Francis I, the 266th Pontiff of the Roman Catholic church, is the first South American to hold the position, and by choosing Bergoglio, the Church shows its support to the Global South, where most of the world’s Catholics reside, the Times writes. Born to Italian emigrant parents, Bergoglio grew up in Buenos Aires and formerly led the church’s Jesuit order. He is the first person born outside of Europe to be elected pope since the Byzantine era. Popes once hailed from Africa, Syria, Israel and parts of the Byzantine Empire; the last pope to come from outside of Europe was Gregory III, of Syria, who was elected pope by acclimation in 731.

Gregory III faced controversies over religious issues like the use of holy images. The host of troubles facing the newest pope include proper management of the Vatican banks. The Times writes that the cardinals who elected Pope Francis were looking for “a pope that understands the problems of the Church at present”—many of them bureaucratic—and who is strong enough to tackle them.

More from Smithsonian.com:

In the Entire History of the Catholic Church, Only a Handful of Popes Have Ever Resigned 
How to Become the Pope 

Photo: Center for International Forestry Research

With temperatures rising and rainfall patterns shifting with global climate change, scientists are worried what may be in store for world’s tropical rainforests, home to the richest diversity of life on the planet. But a new study by the UK Center for Ecology and Hydrology’s Chris Huntingford and colleagues found that these rainforests should actually be quite resilient to the effects of climate change—at least at the broad scale.

Based on earlier research, scientists thought that the Amazon rainforest would be likely to dry out and die off as the world warms. “But in the light of new data and of improved modelling, the drying now seems a lot less probable,” says Nature.

“This has been a big issue in science for many years,” says forest ecologist Daniel Nepstad, who directs the Amazon Environmental Research Institute in San Francisco, “and the emerging view is that there is less sensitivity in tropical forests for climate-driven dieback”.

In the new study, Hungtingford and colleagues found that, in the vast majority of their simulations, the forests will actually contain more biomass—the total amount of plant life—by the end of the century. Using a range of computer models and drawing on differing assumptions of how the forest and the climate interact, the team found that in only one of these set-ups did the amount of biomass in tropical rainforests shrink. Even then it was only for those in the Americas—Africa’s and Asia’s forests stood strong. But this boost doesn’t last forever:

Forest biomass carbon stocks in Asia and Africa are projected to be greater in year 2100 than at the present day, in all simulations. This is also true for the Americas/Amazon, except for the HadCM3 climate model. There is however a decreasing ability to sequester carbon in biomass; many pathways have a Cv peak towards the end of the twenty-first century.

The scientists say that the biggest uncertainty here is whether or not they properly understand exactly how the plants will respond to rising temperatures, changing rainfall patterns and all the other consequences of climate change.

It’s important to keep in mind that the scientists found only that the total amount of biomass in the forests isn’t expected to decrease. In aggregate, the forests will remain roughly the same size, or even grow a little. This doesn’t mean, however, that the individual species that make up the current forest will not be affected or that these ecologically sensitive regions will contain the same biological diversity.

And even though the long-term effects of climate change on tropical rainforests may not be as bad as we thought, the threat of deforestation from farming, logging, mining and other practices remains a serious risk to rainforest biodiversity.

More from Smithsonian.com:

Most Arctic Animals Should Deal With Climate Change Just Fine

Photo by Valter Campanato/Agência Brasil

After a long battle with cancer, Hugo Chavez, the president of Venezuela for the last 14 years, has died. He was 58 years old.

The socialist leader had been elected to another term last October, but was never sworn in because of his failing health. The Associated Press writes:

A self-described “subversive,” Chavez fashioned himself after the 19th-century independence leader Simon Bolivar and renamed his country the Bolivarian Republic of Venezuela.

He called himself a “humble soldier” in a battle for socialism and against U.S. hegemony. He thrived on confrontation with Washington and his political opponents at home, and used those conflicts to rally his followers.

Chavez came into the public eye in 1992 in a failed attempt to overthrow then-President Carlos Andres Perez. Over the next six years, his populist views gained popularity with Venezuelans, who elected him president in 1998. During his presidency, the military officer-turned-politician took control of the country’s massive oil industry and launched anti-poverty campaigns. He also built friendships with the Castro brothers and other leftist leaders in Latin America, much to the United States’ chagrin.

In the months before his death, little was known about the leader’s health. Aside from several pictures released by the government, Chavez had been unseen by the public for months. He had four operations since June 2011, and was undergoing further treatment at a hospital in Caracas.

Three days before his final surgery last December, Chavez named Vice President Nicolas Maduro, who announced the president’s death, as his chosen successor.

More from Smithsonian.com

Venezuela Steers a New Course

Image: Axel Kwet

The males of the species Rhinella proboscidea, a small type of frog found in the Amazon, may be the most determined lovers on the planet. Overzealous, they form huge mating balls that sometimes suffocate females trapped in the middle, writes Ed Yong for National Geographic.

Although a potential mate may be dead, the males will not be deterred. In the end, they get what they’re after by squeezing the eggs out of the dead female’s body, then fertilizing them. Thiago Izzo, a scientist at the National Institute of Amazonian Research in Brazil, dubs this unique mating strategy “functional necrophilia.” (Pictured below—although, fair warning, it’s a little bit disturbing to see.)

A male having his way with a dead female by squeezing her eggs out. Photo: Izzo et al., Journal of Natural History

As Yong describes, hundreds of males gather during a two or three day mating window and await any female who might show up. When she does, the males pounce on her and begin wrestling for the right to do the deed. The female winds up at the bottom of this squirming ball of lust, often drowning in the affections of her would-be lovers.

Izzo has found several of these explosive balls of hormones and lust. In one ball, he discovered around one hundred males and twenty dead females; another revealed some fifty males and five females. All of the females, however, were missing their eggs. He solved this puzzle when he witnessed the necrophillic act first hand: a male grasped a dead female, squeezing her belly until eggs began popping out, which the male then scrambled to fertilize. Yong writes:

Izzo saw the same behaviour again and again. On one occasion, the male pushed his dead partner around the pond, “apparently to avoid other males”. The eggs that emerge are quickly fertilized—Izzo kept an eye on them and saw that they eventually developed into embryos.

For males, this act is clearly beneficial, since they succeed in passing on their genes. For the female, it’s a bit tougher to find a positive spin, but Izzo points out that, despite being dead, she still gets to pass on her genes to the next generation. It’s an interesting twist: usually in the animal kingdom, if anyone is going to be killing their mate, it will be male-gobbling cannibalistic females.

More from Smithsonian.com:

When Is the Right Time to Mate?  
For Female Golden Moles, Size Does Matter