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Some ecotourism offers visitors close   with different species. But new research suggests that these activities may not be so great for the animals. Researchers tagged stingrays in Stingray City in the Cayman Islands to   their movements and behavior. Compared to stingrays outside of the tourism area, those in Stingray City switched their activity   from night to day, when tourists handed out food, and mated year round instead of seasonally. The stingrays also had more bite  , which suggests increased aggression towards one another. The study is in the journal PLoS ONE. Past research has found increased and more intra- and inter- species aggression among animals that have been fed by humans. Interactive tourism is a growing business. But researchers say that more study is needed to   the health and safety of humans and animals alike. Ecotourism may be good for a given species, as humans become engaged in its . But for the individual members of that species tasked with   with people, it may not be a walk in the park.

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Millions of roses get handed out on Valentine's Day. But growing roses has an  impact worse than many other crops. Start with climate change: most roses in the U.S. and Europe are from warmer climes. All that flying and trucking adds thousands of metric tons of carbon dioxide to the atmosphere. Then there's all the water needed to, well, water the flowers. And the runoff fouled by copious  of pesticides needed to make the roses look perfect. There's also the wildlife and workers poisoned by all that fumigation. Add to that habitat  where floral plantations displace native forest and wetlands. Finally, there's the refrigeration needed to keep those blooms fresh. The   is often produced by burning fossil fuels, and the refrigerant gases also exacerbate climate change. A more sustainable and, possibly, more romantic   is to go with flowers certified by outfits like VeriFlora, or even better, whatever flowers are in season locally. Of course, that's not much help for those of us in wintry climes. Maybe try writing a poem. Let's see: Roses are red, violets are blue…

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Let's say you've saved up 200 grand for a trip to space with Virgin Galactic. Lucky you. But are you healthy enough to fly? You'll have to talk with your doctor. A new study in the BMJ  the role that general practitioners will have to play in  spaceflight. After all, astronauts typically have to be in tip-top shape. But opening the door to the paying public means that less healthy individuals will soon have access to space, too. And the stress of spaceflight,  with the negative effects of weightlessness on muscle and bone, could cause real problems. It may be up to your personal physician to make the go/no-go call based on your  history. Among the potential hypotheticals floated in the BMJ study: “Can my patient with stable angina and a pacemaker for complete heart block  in a suborbital Virgin Galactic flight? What is the maximum allowable time that my patient with osteoporosis can spend on a planned  at a space hotel?” There are no official answers, yet. But the study's authors note that such questions may be in the air—or lack thereof—in the not-too-distant future.

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Ladybugs love to snack on aphids and other pests. So people began  an Asian species called the harlequin ladybird as natural pest control. But in their new environments, the harlequins wiped out native ladybugs. And they have their parasites to thank. That's according to research in the journal Science. A parasite called microsporidia lies dormant in the circulatory  of harlequin ladybirds. But when scientists injected microsporidia into a common European ladybug species, the insects died within two weeks. When the ladybugs were injected with dead microsporidia or a control substance most . Harlequin ladybirds' immune systems, on the other hand, have learned to deal with microsporidia— which lets the insects use them as biological . Because one way ladybugs compete is by consuming the eggs and larvae of rival species. When European ladybug species eat the harlequin ladybird eggs and larvae, they also  the microsporidia. And die. The discovery  an important role of immunity in evolutionary selection. And it shows that there are many ways to lose a food fight.

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It's a given that most babies wear diapers, in western cultures anyway. But diapers may trap more than waste—they may also confine a baby's  to walk. Scientists compared the walking gaits of 60 babies who were either naked, wore a thin disposable diaper or a thick cloth diaper. Half the babies were 13-month-old novice walkers and the other half 19-month-old  walkers.When the 30 13-month-olds walked naked only 10 fell, but while wearing the cloth diaper 21 of them fell, and while wearing the disposable 17 of them fell.Among the 19-month-olds only four fell while naked or wearing disposables, while eight fell when wearing cloth diapers. But both age groups took wider and shorter steps while wearing diapers as  to walking naked. The research is in the journal Developmental Science, the study cannot predict if wearing diapers has a long-term impact. Nonetheless, the researchers believe walking naked would speed up walking  . But then we are left with the issue of covering the entire house in plastic and relying heavily on the child's ability to  his or her elimination intentions.

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Unless you're at a Chaucer convention, speaking middle English is not going to impress a potential  partner in 2013. Similarly, male Savanna sparrows have to make sure their vocalizations are up to date. Researchers  three decades of  of male Savanna sparrows.And birds that changed their tune over the years did better with the ladies. The research is in the journal Animal Behaviour. While introductory notes of the sparrow's song stayed the same, the middle and end parts changed over time. In the 1980's, songs  with longer, high-pitched trills. More recent songs  a series of clicks in the middle and a shorter, low-pitched trill at the end. Researchers found that the male sparrows that  the newer songs had higher rates of sexual reproduction. Because you don't want to be seen as behind the times. Indeed, Chaucer might have had his pick of the ladies in the 14th  . But few today can make heads or tails of his tales.

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In planet formation, as in adolescence, you've got your late bloomers. Such is the case for a  star called TW Hydrae. At some three million to 10 million years of age, it's relatively old for a young star. That is, TW Hydrae  much more recently than our sun but is past the point at which most fledgling stars are still encircled by a  disk of dust and gas—the stuff of planet formation. But a new analysis shows that TW Hydrae retains a surprisingly hefty circumstellar disk,  that the star could still be forming giant planets. The study appears in the journal Nature. Researchers from the U.S., Germany and the Netherlands  the European Space Agency's orbiting Herschel Space Observatory at TW Hydrae to investigate the star's disk. They  a heavy hydrogen molecule called hydrogen deuteride.From that  they were able to estimate the abundance of ordinary hydrogen, which makes up the bulk of the disk. The result: TW Hydrae still has enough raw material left to make 60 Jupiters or so,  its maturity. For aging stars, then, perhaps 10 million is the new 30.

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Roosters greet the rising sun with crowing sound. But they also crow at other times. So are they  to the light? Or do they simply know that it's morning? New research says the latter: roosters crow because of internal time cues.The finding is in the journal Current Biology. Scientists  the light levels in rooster habitats. For two weeks, the birds experienced 12 hours of light followed by 12 hours of dim light.  with the pre-dawn noises observed in wild fowl, the roosters began to crow about two hours before their rooms lit up. Then, for two weeks, the roosters lived in  dim light. Yet they continued to crow about once a day—at intervals of 23.7 hours to be precise. Even without morning light, their circadian rhythms told them when dawn should be breaking. The birds also  in response to sudden light, and to the sounds of other roosters. But they were more likely to react when those stimuli  near dawn. Showing that you can't really keep a rooster in the dark about the time.

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Advertising and media companies often get lobbied to use models that  the average woman's body— rather than ultra-thin models, whose images may influence some women to have an unhealthy  with food. Now a study supports that idea that observed images affect what people consider to be acceptable body types. The report is in the journal PLoS ONE. Researchers surveyed subjects about their  of their own bodies and those of others. Then they presented the subjects with photos of large or thin women. Some photos were of beauty queens in evening gowns or other high-status clothing. Other photos were of women who were either very large or very thin,  neutral grey leotards. Following those viewings, the subjects were again surveyed about their body preferences. Subjects who originally preferred thin bodies only increased their preference for thinness after being shown photos of thin women. But they  their preference for thin bodies after being shown photos of larger women. And the attire of the women in the photos made no difference to the subject's latter preference.The researchers say that this study provides strong evidence that images of female bodies  by the media and ad agencies could have a real  on women's preference and subsequent thoughts about body type

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When summer hits, I dread jogging outside.But a study finds that elephants can be in true danger in the heat. As  get bigger, they have smaller surface-area-to-body-volume ratios. Fully grown Asian elephants thus pack a lot of mass into a body with a relatively small surface area. And surface area  how much body heat you can dissipate. For the study, two female elephants in the Audubon Zoo in New Orleans walked around a half-mile track under various conditions. The outdoor temperature during these  ranged from a chilly 8 degrees Celsius to a scorching 35 degrees. Sunny hot days were the worst. The already limited hide is now itself heated by the sun. With the  of a busted radiator, the elephants retained 56 to 100 percent of their body heat internally. Which could make a mere four hours of  fatal. The research on elephant exertion is in the Journal of Experimental Biology. Fortunately, elephants have ways to beat the heat: shift activity to after dark and, of course, go for a dip

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