Smithsonian.com

Roosters are funny-looking creatures. They have a red bit that sticks out from the top of their heads—the comb—and another that dangles beneath their chin—the wattle. And then they perform this little dance called “tidbitting” (see first part of video below), in which they make sounds (food calls) and move their head up and down, picking up and dropping a bit of food.

Why does a rooster have a wattle?

Research has shown that when hens are choosing a mate they prefer roosters that have larger, brighter combs and ones that frequently perform the tidbitting behavior. This makes sense because the characteristics of the comb have been shown to correlate with how healthy the male is, and tidbitting behavior provides the hen with nutritionally important food items and shows the male’s status. But the presence of the wattles has long been a puzzle because they haven’t been shown to serve a similar purpose.

Carolynn Smith (a friend and former colleague) and her current colleagues at Macquarie University in Australia set out to discover the purpose behind the wattle by studying red junglefowl (Gallus gallus), which are the wild brethren of the chickens we eat (their study appears in the journal Animal Behaviour). Cutting off the wattles of roosters and seeing how the behavior of hens changed wasn’t an option. Instead, Smith created four animated roosters. The animated roosters (see second part of the video below) all acted the same, performing the tidbitting routine over and over, and they all looked the same, except for their wattles. One had a normal wattle, one was missing his, a third had a wattle that didn’t move, and the fourth had an extra floppy wattle.

A test chicken would be placed inside a test pen with two “audience hens,” a couple of buddies intended to make the test hen more comfortable in the less familiar surroundings (fowl are social creatures). One of the videos was then played for the test chicken and her response was recorded: How quickly did she respond to the animated rooster? How quickly did she start searching for food (the normal response to a male tidbitting)? And how long did she search for food?

The test hens responded more quickly to the tidbitting males that had the normal or stationary wattles, less quickly to the one with the extra floppy wattle (the wattle moved so much that it swung up the side of the rooster’s head and appeared much smaller than it was) and slowest to the male lacking wattles. After the hen’s attention was gained, though, she reacted about the same to each of the four animated chickens. Smith suggests that the wattle helps a rooster gain a hen’s attention when he is tidbitting, rather like a human guy wearing flashy clothes while doing his best dance moves to try and pick up chicks.

Photos and video courtesy of Carolynn Smith.

weed chainsaw massacre (courtesy of flickr user 19melissa68)

Here’s a shocker: Horror films like Texas Chainsaw Massacre don’t get the chainsaw spatter right, according to the Journal of Forensic Sciences.

The reason for the study is sad—a woman was reported missing in 2005, and the police found evidence that she had been killed and dismembered in her basement (a few dabs of fresh paint on the walls, small pieces of bone, a receipt for an electric chainsaw). The investigators, possibly having watched a few too many horror films, didn’t think that there was enough blood and tissue spatter in the small room if a human body had been dismembered there by someone wielding a small chainsaw. And there was the question of whether or not the chainsaw itself was powerful enough to accomplish the job without getting stuck in flesh and bone.

A University of South Dakota pathologist got involved. He obtained the same kind of chainsaw indicated in the receipt and a 200-pound female pig, deceased, and created a room the approximate size of the basement using white sheets. He let the pig rest for two days to simulate the time between when the woman had been reported missing and when the chainsaw was purchased. And then he started hacking away.

The chainsaw was certainly powerful enough to cut through the tissue and bone. And the pathologist discovered that if the blade was held parallel to the floor there was very little spatter, similar to what was found at the crime scene. (Vertical positioning of the blade or use of a freshly killed pig increased the amount of spatter on the sheets.) The researcher concluded:

These experiments have shown that a human body may be easily dismembered with a chainsaw, even a smaller electric-powered model….Despite popular beliefs fueled by crime scene shows on television and recent Chainsaw Massacre movies, postmortem dismemberment does not necessarily produce a large amount of blood spatter at a dismemberment scene….With a horizontally oriented chainsaw, therefore, the majority of the tissue and blood will be found on the ground beneath the saw. If the chainsaw discharge chute, however, is not directed towards the ground, then a large volume of blood and tissue, and subsequent spatter, could be expected some distance from the saw.

Something to consider when writing or filming your next scary movie.

H1N1 (swine) flu is in the news again (courtesy of flickr user Dr Craig)

Around the country, people are lining up to be vaccinated against the H1N1 flu virus. Surprising Science has spent the last three days discussing the history and science of vaccines (see A Brief History and How Vaccines Work, Success Stories, and A History of Vaccine Backlash). Today we answer some of the more common questions about the swine flu vaccine.

Who should get the H1N1 flu vaccine?

There is currently not enough vaccine for everyone who wants it. Vaccines take time to produce and this one has been rolling off the line for just a few weeks. As of Tuesday there were about 22.4 million doses available around the United States. The goal is to have 250 million doses by the end of flu season next spring. The Centers for Disease Control and Prevention have recommended that certain groups get vaccinated first:
•    pregnant women
•    people who live with or care for children under six months of age
•    young people age six months to 24 years
•    people 25 to 64 who are at higher risk for flu complications due to a health condition or compromised immune system
•    health care and emergency medical service personnel

Why are these groups first?

Pregnant women and young people seem to be especially vulnerable to the H1N1 virus. Babies under six months of age cannot be vaccinated, so it is important to limit their exposure to the virus by vaccinating people who care for them. People with certain health conditions or who have a compromised immune system have a higher risk of having serious flu complications if they get the flu. And medical personnel are the people most likely to come in contact with the virus.

What if I’m not in one of these groups?

Wait your turn. There will be enough vaccine eventually. And if you get the H1N1 flu, it won’t be fun but also probably won’t do you long-term harm. In the meantime, the CDC recommends taking everyday preventative actions like hand washing and avoiding contact with sick people. (And if you get sick, please stay home.)

Is the vaccine safe?

The H1N1 vaccine is made the same way as the seasonal flu vaccine. The manufacturers just tweaked the recipe with the new virus. The Food and Drug Administration approved the vaccine in September. People with allergies to chicken eggs, however, should not be vaccinated as eggs are used to make the vaccine.

I got a seasonal flu vaccine last month. Why won’t that work against H1N1?

For the same reason that your flu vaccine from last year doesn’t protect you from this year’s seasonal flu: There are many different types of flu virus, and they mutate over time. When you are exposed to one type, your body’s immune system learns to protect you from that type only. The others are too different to register with your immune system as the same virus.

I’ve heard that in other countries the vaccine contains squalene. What is it and why is it in their vaccine and not ours? And what about thimerosal?

Squalene is a type of naturally-occurring oil found in plants and animals (including humans). Squalene is a component of some adjuvants of vaccines. Adjuvants help a vaccine’s effectiveness by boosting the immune response. Some countries have added the squalene-containing adjuvant to their vaccine mix for H1N1 because it causes a lower dose of vaccine to be effective; that is, it will allow people to get more doses out of the same batch of vaccine. The World Health Organization has found no evidence of any adverse events in vaccines containing the squalene adjuvant.

The United States government chose not to use any adjuvants in the H1N1 mix in this country. However, some formulations of the vaccine do contain thimerosal, a mercury-based preservative that has been used in vaccines for decades. Getting mercury injected into your body may sound a little scary. But concerns about safety of thimerosal are unfounded. Some parents worry that thimerosal may cause autism in young children, but there is no evidence of this. Several studies in recent years have examined the possibility, but no association has ever been found.

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La Vaccine, 1827 (courtesy of the National Library of Medicine)

In light of President Obama’s declaration of “national emergency” imposed by the outbreak of the H1N1 virus, Surprising Science is setting this week aside to discuss the history and science of vaccines and their importance in battling viruses and diseases, including swine flu.

More than two millennia ago in China or India, someone noticed that people who suffered and recovered from certain diseases never became reinfected. In a leap of logic, the person who noticed the connection tried to prevent the disease by inoculating themselves (or perhaps someone else) with a bit of infected matter.

That idea, now called vaccination, bumbled along through history until 1796. That’s when an English physician named Edward Jenner noticed that milkmaids rarely got smallpox, though they often had blisters from cowpox, which they caught from their cows. Jenner thought that the cowpox might prevent the women from getting smallpox. To test his idea, he took some material from the cowpox blister of a milkmaid and inoculated 8-year-old James Phipps. Six weeks later, Jenner injected young Phipps with fluid from a smallpox sore; Phipps didn’t contract smallpox.

Over the next decades, smallpox vaccination spread, and it was a common practice by the end of the 19th century. Around that time, two more vaccines were developed—by Louis Pasteur—against anthrax and rabies. The 20th century would see the development of vaccines for more than a dozen other diseases, including polio, measles and tetanus.

Long after Jenner’s first discovery, biologists would discover how vaccines work to prime our immune systems to fight off infections:

Though the original smallpox vaccine used a related virus, cowpox, most vaccines use a weakened or dead form of whatever disease they’re meant to prevent. Some of these vaccines will also include a substance called an adjuvant that boosts the effectiveness of the vaccine. (Scientists figured out the workings of alum, one type of adjuvant, last year.)

When the vaccine is injected, a person’s immune system recognizes it as a foreign substance. Immune cells called macrophages digest most of the foreign material, but they keep a portion to help the immune system remember it. These identifying molecules are called antigens, and macrophages present these antigens to white blood cells called lymphocytes (which come in two types: T cells and B cells) in the lymph nodes. A mild immune response occurs, and even after the vaccine material is destroyed, the immune system is primed for a future attack.

The next time that a microbe with those antigens enters the body, the lymphocytes are ready to quickly recognize the microbe as foreign. When that happens, B cells make antibodies that attack the invading microbe and mark it for destruction by macrophages. If the microbe does enter cells, T cells attack those infected cells and destroy them before the disease can multiply and spread. The microbe is defeated before it can get a foothold in the body, before the person gets sick.

Tomorrow–Vaccine Week, Day 2: Success Stories

Look to Orion tomorrow morning to see the meteor shower (illustration courtesy stardate.org)

Right now, the Earth is traveling through a trail left behind by Halley’s comet, which last passed through our neighborhood in 1986 (it will return in 2061). These little bits of debris produce a yearly meteor shower, the Orionids, named so because they appear to originate in the constellation Orion.

The best time to see this little light show—around 15 to 20 green and yellow meteors each hour during peak in the Northern Hemisphere—is tomorrow morning before dawn when the crescent moon is below the horizon and its light cannot overpower the streaky meteors. Observers in the Southern Hemisphere will get an even better show, according to meteorshowersonline.com.

The discovery of the Orionid meteor shower should be credited to E. C. Herrick (Connecticut, USA). In 1839, he made the ambiguous statement that activity seemed to be present during October 8 to 15. A similar statement was made in 1840, when he commented that the “precise date of the greatest meteoric frequency in October is still less definitely known, but it will in all probability be found to occur between the 8th and 25th of the month.”

The first precise observation of this shower was made by A. S. Herschel on 1864 October 18, when fourteen meteors were found to radiate from the constellation of Orion. Herschel confirmed that a shower originated from Orion on 1865 October 20. Thereafter, interest in this stream increased very rapidly—with the Orionids becoming one of best observed annual showers.

StarDate Online recommends going to a city or state park, away from the lights, and lying down to get the best view of the sky. “If you can see all of the stars in the Little Dipper, you have good dark-adapted vision.” And if it’s cloudy where you live, you can’t get to a dark enough spot or you oversleep, don’t worry–you’ve got a few more chances to view a meteor shower in the coming months:

Leonids
Parent comet: 55P/Tempel-Tuttle
Dates: November 17 (night) and 18 (morning)

Geminids
Parent: 3200 Phaeton
Dates: December 13 and 14

Quatrantids
Parent comet: 2003 EH1
Dates: January 3 and 4

Watch the video above. Did you yawn? Contagious yawning occurs when someone around you yawns and you yawn in response. It’s an involuntary response. Humans do it, and so do chimpanzees. In chimps, researchers have linked the behavior with empathy, so researchers studying empathy in chimps sometimes end up studying contagious yawning, as did a group of Emory University primate scientists who recently created an animated chimp for their experiments.

Animal behavior researchers in recent years have realized that animations and robots can make for better experiments. These fake animals perform the same action in the same way each time on command, something that real animals never do. But will the live animal respond to a cartoon in the same way it would to another live animal? It’s the first question that has to be answered if a scientist wants their experiments to be legitimate. So to answer that question in chimpanzees, the Emory University researchers turned to the contagious yawning experiment. Their results appear in the Proceedings of the Royal Society B.

The Emory scientists created 3-D animations of a chimp, some in which a cartoon chimp yawned widely and others in which a control cartoon chimp made other, non-yawning movements with its mouth. They then played the animations for 24 live chimpanzees. The live chimps were far more likely to yawn in response to the yawning cartoon chimp than when they saw the control cartoon chimp.

This is an introductory experiment that the researchers say has demonstrated the utility of animations in behavioural experiments.

In his future work, [lead researcher Matthew] Campbell would like to pin down exactly how these measurable behaviours are related to the more difficult to measure phenomenon of empathy.

“We’d like to know more about behaviours related to empathy, like consolation – when an individual does something nice to the victim of aggression,” he told BBC News.

The researchers don’t think that the chimps were completely fooled by the animation and thought that they were looking at real chimpanzees. But the experiment does bring up interesting questions about how children interpret cartoons on TV or in video games.

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An orchid at the Smithsonian. Photo by Sarah Zielinski

Forget about birds and bees—if you want to learn about the varieties of sexual practices in the wild, study orchids. They’re the most rich and varied family of flowers by far, with about 24,000 species (another estimate is 30,000 species). And many of those species have evolved elaborate tricks to get hapless birds and bees and other pollinators to lovingly embrace their flowers.

Some orchid flowers look just like their pollinators and thereby lure the real thing. In a special issue on orchids in the Annals of Botany this month, an introduction points out that Carl Linnaeus appreciated one superb mimic:

Its flowers bear such a resemblance to flies, that an uneducated person who sees them might well believe that two or three flies were sitting on a stalk. Nature has made a better imitation than any art could ever perform.

(See for yourself here.)  Linnaeus didn’t figure out what the orchid was up to, but Darwin did. The National Museum of Natural History had a gorgeous exhibit of live orchids this spring called Orchids Through Darwin’s Eyes, which Sarah photographed.

Botanists recognized orchids’ visual mimicry first, but lately they’ve uncovered even more interesting scent-based mimicry. Basically, the orchids emit chemicals that smell, to a male insect, just like the sex pheromones emitted by the female of his species. In an interesting twist last year, researchers found that a bee-pollinated orchid produced chemicals that are similar but not identical to a female bee’s scent. It’s not that the orchid is a bad mimic, they researchers conclude, but that male bees are most attracted to a scent that’s not too familiar.

Aside from feeling used, do pollinators suffer from being tricked by orchids? Maybe so. As a paper in the American Naturalist last year pointed out:

While some sexually deceptive orchid species require only pollinator gripping or brief entrapment for effective pollination, other orchid species coerce their pollinators into energetic copulation. Although these copulations are often described as “pseudocopulations,” the vigorous response of pollinators suggests that true matings with ejaculation and costly sperm wastage may indeed occur.

Sure enough, they found that male wasps pollinating Australian tongue orchids do indeed ejaculate, which is a waste of time and energy for the wasps.

For the orchid, the relationship with pollinators is all about sex; but for the pollinators, sometimes it’s about food. A study that comes out in Current Biology later this month shows that a Chinese orchid mimics the scent of a honeybee’s distress signal—a scent that attracts honeybee-eating hornets. Wicked!

But orchids don’t always need pollinators. Sometimes they have sex with themselves. A study a few years ago showed that another Chinese orchid, if no wind or pollinators are around, will twist its pollinia into its own stigma:

Here we describe a new type of self-pollination mechanism in the tree-living orchid Holcoglossum amesianum, in which the bisexual flower turns its anther against gravity through 360° in order to insert pollen into its own stigma cavity — without the aid of any pollinating agent or medium.

The temperature doesn’t tell you much about climate change (courtesy of flickr user jo3design)

Seattle and the Pacific Northwest are frying under a heat wave this summer. In New York, it’s so cool that the New York Times has called it “the summer that isn’t.” And Texas is suffering under the most severe drought since the 1950s.

What does this all mean for climate change?

Absolutely nothing.

Every time we write about climate change, someone writes in saying that they are shocked that Smithsonian would perpetuate such a myth. Don’t we know about the record cold/snow/rain/etc. in Minnesota/North Carolina/Utah/etc.? Obviously, there are some people who do not understand the difference between weather and climate. Let’s start with the dictionary definitions:

Weather: the state of the atmosphere with respect to wind, temperature, cloudiness, moisture, pressure, etc.

Climate: the composite or generally prevailing weather conditions of a region, as temperature, air pressure, humidity, precipitation, sunshine, cloudiness, and winds, throughout the year, averaged over a series of years.

In short, weather is a data point. Climate is a collection of data.

You can think of it like the economy. I can tell you that the Dow is up 112.61 as I write this, at 9,284.22. This is the weather (partly sunny, 84 F). But it doesn’t tell you anything useful about the economy as the whole (like the weather conditions don’t tell you anything useful about climate). A graph of the Dow over the last year, showing a terrifying decline followed by a steady rise, begins to tell the story of the last year. But to get a true picture of the economy, we’ll need to look at lots of other bits of data, like consumer confidence, unemployment rates and durable goods orders. It’s complicated, messy and hard to understand. That’s climate.

Now, if you make changes to the country’s economic situation, for example, by raising taxes, that is going to have some effect on the economy as a whole. Economists will crunch the numbers and come out with predictions. They won’t all be the same, but they will probably trend toward some particular end.

Adding carbon dioxide to the atmosphere is akin to raising taxes. We’ve changed the climate situation. And while these climate models—which are far simpler than economic models and more certain—may not agree on the specifics, the general trend is that temperatures are going to rise.

And they have been rising. And more than that, we can already see the effects of that rise. Just read the magazine: We’ve featured melting glaciers, melting permafrost and changes in plant and animal distributions in the Andes and, closer to home, the Northeast, to name a few.

So please don’t write to us to say that we’re neglecting the latest weather superlative. We’re not. We just have our eyes on the bigger picture—climate.