We all know that our hair turns gray as we get older, but did you know that hair color can also change with age in various other species throughout the animal kingdom? The silverback mountain gorilla is one of the most well-known examples, where the hair on a male’s back will change from black to silvery-gray when he matures at around 12 to 14 years of age. These types of coat color changes are one way that researchers can estimate the ages of individuals in a wild population without having to examine them up close, and are considered a type of biomarker.Fred Bercovitch, a wildlife biologist and professor at the Primate Research Institute and Wildlife Research Center at Kyoto University, along with his colleague Phil Berry, study this phenomenon in a lesser-known color-changing species—giraffes. More accurately, Thronicroft’s giraffes (Giraffa camelopardalis thornicrofti), which are a less-common subspecies that live in the Luangwa Valley in Zambia.
Like all giraffes, these have brown geometric blotches all over their bodies, and each individual has a different pattern of these blotches. However, the markings on male Thornicroft’s giraffes darken and become coal black as the animals age—and according to a new study published in this month’s Journal of Zoology, this darkening, especially in the case of males, occurs within a limited time span as the animals age. This knowledge, in addition to the extensive observations made during the study, can help researchers better construct the animals’ life histories without knowing their exact ages.
“Not all subspecies blacken,” says Bercovitch. “So the ones you’ve seen in zoos might not change color with age.” He explained that as far as he is aware, no zoo in the world has Thornicroft’s giraffes; the most common types in captivity seem to be Reticulated and Masai.
“It’s actually pretty amazing,” he mused, “that people like seeing giraffes in zoos, they like seeing them in the wild, they are famous in the media such as in the movie Madagascar and on the Toys ‘R Us logo, but yet, very little research has been conducted on them in the wild.”
Now, this study is the first of its kind that followed known wild individuals over the course of their lifetimes, in addition to documenting color changes that ended up being especially prominent in males.Bercovitch explained that co-author Berry has been a game ranger, safari guide, and a leader in rhino anti-poaching efforts for over 40 years, among many other jobs. He is also particularly skilled at recording giraffe data, and a lot of the information that he collected, which included relative blotch color of the males, as well as herd size, composition, and a slew of other details over the course of 33 years, were particularly useful in this study. Plus, since most of the collected information is in the form of field notes, the data is unbiased towards this particular study.
There are only a few other ways to tell the age of a giraffe if it is unknown. The first is by looking at the teeth, which erupt as the animal grows and wear down with age, much like horses. Unfortunately in the field, it is extremely hard to see the teeth, so it is really only helpful if you find a dead individual. Another method is looking at the relative sizes of the giraffes. For example, if a male is taller than a female, he is most likely at least 6 years old. If a female is seen nursing a calf, she is also most likely at least 6 to 7 years old. Finally, photographs can be compared. Since each giraffe’s coat pattern is different, if you find an old photo of an animal that matches up with a recent one, you can calculate an estimated minimum age based on when the photos were taken. Bercovitch and Berry also used a large amount of photographic records to identify and determine the ages of individuals.
Based on their long-term extensive observations, the giraffes’ color changes, and analysis of photographic records, Bercovitch and Berry were able to conjecture that male Thornicroft’s giraffes actually don’t live as long as previously thought. They found that they are weaned from their mothers and become independent by 2 years of age, then head out on their own when they are between 4 – 8 years old. Their color begins to darken later in life, when they are about 7 – 8 years old. It then takes another 1 – 2 years for them to completely blacken and become mature around 10 years of age. Most literature has suggested that male longevity is at least 25 years, but it is now known that male Thornicroft’s giraffes rarely live longer than 21 or 22 years, and their average life span is around 16 years of age. Bercovitch and Berry also determined that females on the other hand, can live up to 28 years, and have a longer reproductive life. Their color change however, is not as pronounced.
“We hope that this [new information] will not only help researchers [better determine giraffe ages] in the wild, but also can provide a basis for comparisons across locations in Africa to see if coat color changes differ depending on where these giraffe subspecies live,” says Bercovitch. In addition, they hope that by using observations of color changes, researchers may be able to gather better and more accurate data on herd composition and general ages of populations which will be important when it comes to conservation management efforts.
Giraffes are generally not considered endangered, but there are actually two other subspecies that are listed as endangered on the IUCN Redlist. These are the Nigerian AKA: West-African giraffe (Giraffa camelopardalis peralta) and the Rothschild AKA: Ugandan giraffe (Giraffa camelopardalis rothschildi). Not only are humans encroaching on their habitats causing there to be fewer and fewer large areas for them to wander across, but they are also poached in many areas.
Bercovitch hopes that this work will stimulate more interest in giraffe research, since not a lot has been undertaken in the past. He explained how important it is to *achem*… stick our necks out for these amazing and truly unique creatures. “Plus,” he said, “if the report stimulates people to go to Africa to see giraffes, that may help inspire them to save them!!”
Yeah, yeah, NASA budget, blah blah blah. I know, I really do. I wish NASA had the budget the Department of Defense currently enjoys and I wish we lived in a world where the DoD didn’t need a budget at all. We’ll get there, not tomorrow, but we’ll get there.
In the mean time, while space exploration isn’t as far along as space enthusiasts wish, exciting stuff is still happening. Specifically, one of the boldest missions NASA has ever attempted is about to reach its most nail-biting moment. First, you should sit down. Good. Now slide forward until you’re on the edge of your seat. No? Well, whatever.
Here’s the thing: A one-ton, nuclear powered, laser wielding, six-wheeled robot the size of a small car is going to land on Mars in less than a month. There. I said it. And I’m not making it up. This robot is called the Curiosity rover. Docile-sounding name? Yes. But here’s how I picture the rover:
Okay, now here’s what Curiosity really looks like (Curiosity is the 6-wheeled guy with the Wall-e head to the immediate right of two engineers having a picnic):
On Nov. 26, 2011, right around the time people on the East Coast of the U.S. were pouring their second cup of morning coffee, the Mars Science Laboratory launched from Cape Canaveral. When the craft arrives on Mars Aug. 6 it will have traveled 352 million miles.
The rover is powered by a Multi-Mission Radioisotope Thermoelectric Generator, or MMRTG (pronounced: muh-muh-ER-tig … just kidding). That loosely translates to “nuclear generator that runs on plutonium dioxide.” The rover really is equipped with a drill and a laser (see drawing above), as well as an arsenal of cameras, spectrometers, detectors and sensors. The purpose of Curiosity’s permanent visit to the Red Planet is to determine whether the planet ever had conditions capable of supporting microbial life. But that purpose only bears fruit if Curiosity survives its arrival at Mars.
The process through which Curiosity will land on Mars is laughably complex, and at the same time awe-inspiring. Here’s NASA’s sci-fi-style computer-generated animation of Curiosity, from when it enters the Martian atmosphere to when it touches down. Remember those charming touches of realism in the 2009 Star Trek film, or in the Firefly series, such as lens flare, zooming in and out, and a little bit of wobbly camera action? Yeah, they’ve got that:
Regardless, the Curiosity rover reaches Mars in less than a month. Maybe all the engineers’ calculations were solid and nothing goes wrong. Or, maybe something does go wrong. I’d prefer the former but will accept the latter. That a group of people planned and attempted such a complex project is good enough for me. Success or failure, we learn. If Curiosity does set foot on Mars and get on with the mission, hold your breath. It probably won’t find life or signs of life (I just have a feeling, or maybe I’m trying not to get my hopes up) but it will find something, probably something groundbreaking or Earth-shaking. This is science in action. Don’t miss it.
You can follow the Mars Science Laboratory on Twitter here and on Facebook here. Want to see where the space probe is now? Or would you like to see the countdown clock to Curiosity’s arrival on Mars? Click here. And set aside some time Aug. 6 to watch a little NASA TV. I imagine they’ll provide live coverage of the rover’s successful or unsuccessful landing here. I’ll be watching too, but my mind will be hundreds of millions of miles away.
I was one of a lucky few at CERN this past Wednesday, when they announced the discovery of a shiny new particle that validates physicists’ best guess on the origin of mass. I won’t play it down: It was exhilarating, both to be present for a historical moment and to see years of hype reach a triumphant climax. I’m also a former political journalist and copy editor, now working as a science writer for a public information office. So I felt something peculiar: like I was watching science and storytelling collide from a neutral spot.
Unless you’ve been sleeping for two or three days, you’ve probably caught wind of the Higgs boson discovery news. But here’s a quick rundown just in case. The Higgs boson is a particle first proposed in the 1960s. Physicists have long had a hunch it’s there because the standard model of particle physics predicts it should be there, bestowing mass unto all the other particles. But it is impossible to see the Higgs directly, because it only exists for the fraction of a fraction of a blink of an eye.
The only way to pinpoint the Higgs is to look for what it decays into — for simplicity’s sake think of decaying as a transformation. But there are a lot of other particles that are unstable like the Higgs and decay really fast. These particles often decay into the same particles the Higgs decays into. So the wild world of decaying particles is full all sorts of ruckus and noise, making the Higgs really difficult to find. Physicists have to calculate the details of the noise so they can filter it out and find anything hiding inside — like you might use a sieve (hey!) to find gold nuggets in the dirt.
So the scientists sifted out all the Higgs-impersonators and found a bump in the remaining data from a particle that looks a hell of a lot like the Higgs ought to look. It walks like a Higgs. It quacks like a Higgs. It must be the Higgs! Right?
Probably. But it could be a variation on Higgs boson that isn’t exactly like the standard model predicts. They have yet to find out. But one thing is for certain, they’ve got a new particle and it fits the Higgs picture. And even if it doesn’t fit nice and snuggly into the standard model, it’s still something new, interesting and Higgslicious.
I was there for the announcement because I currently work at the International Centre for Theoretical Physics, a research institute in Italy that helps scientists from developing countries. They also have some researchers working on the ATLAS project, one of the Large Hadron Collidor’s detectors. So they sent me to CERN for the big news event.
From what the CERN physicists told me, the previous few hours had resembled the madness surrounding the opening of a blockbuster movie. Some scientists even camped out overnight outside the seminar room to get the best seats for the big announcement. Everyone who wasn’t willing to sacrifice their comfort to that extreme had to watch the seminar from elsewhere on the CERN site. That’s where I wound up. I joined a pack of about 150 young physicists gathered in one of several basement rooms to watch the seminar on a projector screen. When each detector project revealed the Higgsy-looking bump in their data, the room burst into hooting and applause. So did the official seminar room where the hardcore Higgs fans were watching. It was about as close to the Super Bowl as physics can get.
When the seminar was done I migrated to the press conference. Even if you’re not into physics in particular, but curious about the relationship between science and journalism, I recommend you watch it. For one thing, you’ll see an excellent cross-section of questions ranging from thoughtful to pretty weak. You’ll also see the somewhat-differing interests of science journalists and scientists at play. Up on stage were the folks who want the discovery to be known as precisely as possible. Out in the crowd were the folks who want to tell a good, important, enticing story to their audiences.
The strangest moment is when a reporter asks, “For the other laymen out there, about SIX BILLION OF THEM, what does this mean?” (I’m pretty sure he hit a mental caps lock key as he was speaking.) There was also the dreaded justify-your-funding question, a brief appearance by the graviton, some questions about what’s next, and a little (perfectly fair) pleading to Peter Higgs to say something, anything to quote.
The “God Particle” term also made its inevitable appearance as part of a general question asking for more metaphors. My favorite part of the whole press conference was CERN physicist Joe Incandela’s response: “I don’t know that I have metaphors exactly. But as I said before the interesting thing about this particle is it’s different from any other. It has a different place. It actually has a relationship to the state of the universe, and so it’s very profound.”
The funny thing is, watch the video, and you’ll see that several metaphors get lobbed out there before the question even came up. As science writers it’s easy to love metaphors. They have a poetic quality, and they are a direct route to bridging the gap between the technical stuff and familiar things. But sometimes we love them too much. The wise thing to recognize here was that any more metaphors would have been gratuitous. Sometimes, to say something simply, all you really need to do is say it simply.