Tuesday, December 27, 2011

Siku the Polar Bear and the Power of Biophilia

Since my last polar bear post, about intraspecies cannibalism, was a little graphic I wanted to share a cute polar bear video that has recently been tearing up the internet. Siku is a polar bear cub who was abandoned by his mother. The cub was born on November 22, 2011 and is currently being cared for at Denmark's Scandinavian Wildlife Park. I just want to rub his belly. I justify putting up a cute polar bear video with the fact that biophilia, Edward O. Wilson's idea that human love of animals is rooted in our biology, explains why the cuteness so easily creates an internet sensation.

Biophilia is an interesting concept that I first learned about when reading Hal Herzog's book Some We Love, Some We Hate, Some We Eat for Patricia McConnell's human and animal behavior class in Spring 2010. Biophilia can be applied to animals, but goes further into human attachment to all things natural, including whole environments. For more information you can check out Wilson's original 1984 book. Or, just enjoy the polar bear video, which I think will pretty much explain how biophilia works.

Sunday, December 11, 2011

Polar Bears Resort To Cannibalism

If a picture is worth a thousand words, for me this one is worth a thousand nightmares:
Photograph by Jenny Ross.
The photograph was captured by Jenny Ross, an environmental photojournalist working in Olgastretet, a part of the Svalbard archipelago, located in the Arctic north of Norway. Ross co-authored a paper with Dr. Ian Sterling a biologist with Environment Canada and a professor at the University of Alberta, about the photographs and observed instances of cannibalism among polar bears. 

For anyone who reads Science Decoded regularly, I don't have to tell you that polar bears are sort of my thing. I've written about them being Irish, mysteriously dying, having osteoarthritis, status as endangered, and their habitat needs. I make no bones about the fact that they are my favorite and I love them. I've loved them since I was a little kid, and have a large collection of polar bear themed...stuff. From earrings to ice cream scoops, I've got it all. My collection doesn't include nightmare inducing, zombie-evoking images of polar bears eating each other. The child in me is horrified by what I now know to be a normal occurrence.

Yes, that's right. While the above photograph might be some of the most jarring evidence to date about intraspecies polar bear predation, the behavior isn't abnormal. In fact, according to Dr. Stirling instances of infanticide (killing baby bears) and predation on older bears, in addition to cannibalism have been known to Inuit hunters in Canada and Greenland and reported in scientific literature. In these instances, the bear doing the killing is always an adult male, which would have the advantage over young bears, old bears, and even adult females.

In the paper with Ross, Stirling reports on three instances of what is most likely intraspecific killing and subsequent cannibalism by adult male polar bears. The instances were all observed on the sea ice in Svalbard in midsummer and early autumn. Each incident was photographed (see above). The victims in each case were killed by more than one bite to the head. This is an instantly lethal way to take down prey, and the way that polar bears would take down seals, their typical food source.

According to Stirling, the instances of cannibalism described in the paper, published in the journal Arctic, are different than the normal instances of intraspecies predation. The bears that did the killing appeared to be in good physical condition, not obviously thin which is typically the case in intraspecies killings. Stirling and Ross concluded that the behavioral and ecological factors present in the instances of killing they describe in their paper show that by late summer, when available ice and the number of seals to hunt are significantly reduced, young polar bears may become a source of prey for adult males to still hunt from the surface of the remaining sea ice. While this type of behavior may be relatively normal, Stirling says that as climate continues to warm and reduce sea ice the frequency of kills like this may increase.

I asked Stirling what we should take away from these photographs, and the instances of polar bear cannibalism, and this is what he said:
"Climate-driven concerns for polar bears are real. The bottom line is that polar bears need ice to hunt from and without that, most bears will not be able to survive. At present, it looks like the last ice will be in the area of the northern Canadian Arctic and in Greenland. Some relatively small, but unknown, number of bears may survive there for some time after they cannot continue in more southerly areas."
So basically, cannibalism is a natural behavior for polar bears. It happens. But due to climate change and the changes that are occurring to sea ice, it is likely that cannibalism is going to get worse. Which leads me to think, do we really want a unique and charismatic species that many people are working to protect to be eating itself? It seems somewhat backwards to invest in conservation and then just watch the bears duke it out amongst themselves. I wish there was a solution I could offer but climate change is its own beast entirely. I will say that intraspecies cannibalism wasn't something I had on my mind when thinking about conservation, but I'll definitely remember it next time.

Saturday, December 10, 2011

Science For Six-Year-Olds: The Butter Experiment

This semester I took a multimedia journalism class, and decided that it would be great to get my blogging buddies from Mrs. Podolak's first grade class involved in my work. So, I paid a visit to their classroom to document just what goes on during a science experiment, and what makes science in the classroom so important, even for the primary grades.

From Liquid to Solid, First Graders Learn The States of Matter

In the elementary school classroom science lessons showcase the ability to engage students through different types of learning.

The first grade students at Lincoln-Hubbard Elementary School in Summit, NJ are optimizing their opportunities to learn by participating in a hands-on educational experience. If you ask them though they will tell you they are having a fun, and tasty, time. The students are learning the states of matter by making, and then sampling, butter to exemplify the transition from a liquid to a solid. Science is a core subject for students at all levels, but it holds special significance for students in the primary grades. 

“Starting at the primary level, teachers are immersing their students in the scientific process and encouraging their role as scientists,” says Matt Carlin, Principal, Lincoln-Hubbard Elementary School. “As scientists, students develop an understanding of the elements and relationships in the natural world. They engage in observations, form a hypothesis, and test through experimentation to arrive at a conclusion. These experiences are invaluable at the primary level because they establish a foundation of learning that will develop through a child's academic career, and in many cases beyond as they enter the work force.”

According to Carlin, the basis for any curriculum design is to provide students with a learning experience that is both meaningful and engaging. Carlin cites Howard Gardner’s 1983 theory of multiple intelligences, which states that there are various aspects of intelligence, to explain why for some primary students, science lessons are particularly useful. Gardner’s theory includes the naturalistic learner, a student who feels a greater sense of connectedness and understanding with the environment. Carlin says this is an area of strength for some students that can be optimized during scientific experimentation.

“A hands-on approach to science instruction immerses our students in the role of being a scientist and also attends to the different learning styles and preferences that are so highly evident in our classrooms,” says Carlin.

The inherent hands-on nature of science experimentation has known benefits for young students. For well over a decade educators have been tying knowledge of childhood brain development into educational practices to create learning environments that are optimized for each level of schooling. According to Kenneth Frattini, Vice Principal of Milburn Middle School and former elementary curriculum facilitator, the hands-on nature of scientific inquiry and experimentation is precisely what children at the elementary level need to help improve their absorption of information.

“Children have an enormous and natural curiosity regarding the world around them. In educational terms; students who have learning experiences through experimentation and self-discovery appear to retain and apply more information,” says Frattini.

In Susan Podolak’s first grade classroom at Lincoln-Hubbard, it can be surprising just how much complex information primary students can understand. In their liquid to solid experiment the children were able to grasp that on the molecular level there are “air bubbles” that help cream keep its form as a liquid. When these air bubbles are removed, in the case of their experiment by shaking the cream, the liquid will change states and transform into a solid.

This complex idea was still approachable for six-year-old students due to what Principal Carlin describes as the student’s ability to figure things out on their own, within the confines of the right curriculum. Appealing to different types of learner, and reinforcing information through hands-on experiences aren’t the only things science lessons have to offer primary students. According to Carlin, science lessons also have value for primary students because they make learning fun.

“In all likelihood, these are the experiences that students will retain, transfer, and use in future learning situations,” says Carlin. 

Tuesday, December 6, 2011

Goodbye Western Black Rhino: A Conservation Failure

Over the summer I posted about the recovery of the Arabian Oryx and how refreshing it was to see a conservation success story. Since then I started studying conservation biology, in particular the extinction of species in one of my classes this semester. While it was great to be able to talk about conservation in positive terms with the oryx, we are once again confronted with the loss of a species to extinction. A subspecies of Black Rhinoceros, the Western Black Rhinoceros (Diceros bicornis longipes) was declared extinct in early November, having last been seen in the wild in 2006.

A Black Rhino in Africa's Ngorongo Crater.
Source: Wikimedia Commons/Flikr:farmgirl
According to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, the Black Rhino (overall) was first listed as endangered in 1986, it has remained on the list transitioning to critically endangered in 1996. Various rhinoceros species are threatened by poaching because their horns are extremely valuable for ornamental reasons, in addition to its use in traditional Chinese medicine. Demand for rhino horn, compounded by the rarity of the animal and upheaval in its native range has caused the cost to increase on the black market. 

The latest update to the IUCN's Red List shows that 25% of mammals are at risk of extinction. Though the Western Black Rhino is already lost, there are other species of rhino that are also facing extinction including the Northern White Rhino (which may already be extinct in the wild,) and the Javan Rhino. In a statement chair of the IUCN species survival commission, Simon Stuart said:
"In the case of the western black rhino and the northern white rhino the situation could have had very different results if the suggested conservation measures had been implemented. These measures must be strengthened now, specifically managing habitats in order to improve performance and prevent other rhinos from facing extinction." 
In my extinction of species class we've been talking a lot about what motivates people to undertake conservation efforts. I would have thought that a species as charismatic as the rhino would have garnered a lot of public support either through funds or volunteers to implement the necessary conservation measures. Losing large mammals like rhinos should in my mind be a wake up call for everyone that we need to take conservation seriously or we will lose these species. However, I see a problem in the fact that what we lost with the Western Black Rhino was a subspecies of Black Rhino. I feel like people can look at that fact and think, well we've got other rhinos so its not such a big deal.

I've been thinking about conservation a lot in the last few months, but unfortunately I think I still have more questions than answers. One of the biggest issues that I've been struggling with is responsibility. Who should be responsible for species conservation? Non-governmental organizations (NGOs) seem to be the most effective, but there are so many factors that have to be reconciled including making sure that people in the countries where the species we want to protect live aren't detrimentally impacted by conservation efforts.

The successful recovery of the Arabian Oryx and the loss of the Western Black Rhino can both serve as a reminder that Earth's biodiversity isn't stagnant. Human activities have a direct impact for better or for worse, and no matter what type of management is undertaken or policy put into place everything we do will have some kind of outcome.

Sunday, December 4, 2011

Making Bone With An Ink Jet Printer. Well...Bone-ish.

Reading the headline, "Engineers Pioneer Use of 3D Printer To Create New Bones" from the BBC I can't help but imagine your standard ink jet spitting out layers of human bone until you come up with a whole femur. In case you aren't familiar with 3D cell printing, let me be the one to tell you that isn't the case. I think the BBC's headline leaves out a crucial piece of information: what the printer in question creates is a scaffold of bone-like material.

The research in the article was conducted at Washington State University, and I find their PR headline "3D Printer Used To Make Bone-like Material" more specific. I think 3D printing, tinkering with a printer so that it can make different kinds of biomaterials, is interesting in its own right. I'm okay with the fact that the material being made is only bone-ish and not really bone. Although and argument could be made for the BBC's headline... which I'll explain later.

Printing the bone scaffold via WSU
Here is the research rundown: led by Susmita Bose, professor of mechanical and materials engineering, WSU researchers used a 3D printer to to create a scaffold of calcium phosphate, silicon and zinc. When paired with actual bone, this scaffold provides a structure for new bone to grow on, to specifically manufacture the desired bone. The scaffold dissolves with no reported adverse effects, according to the researchers' in vitro tests in rats and rabbits.

Described in the journal Dental Materials, (according to the PR*) the printer works by having the inkjet spray a plastic binder over a layer of the calcium phosphate, silicon and zinc powder in very thin layers (about 20 microns, comparable to the width of a human hair). A computer directs the printer to create the scaffold in the desired shape and size. The researchers found that after a week in a medium containing immature human bone cells, the scaffold was able to support new bone cell growth. According to the researchers, the material is likely most suitable for low load bearing (so, not a femur) and could be available for human use in a few years time.

So back to the BBC's headline about the 3D printer creating new bone. Ultimately, that is what happens. New bone is grown around the scaffold, so the end product is real human bone. However, the printer is not itself printing bone. In my humble opinion, that doesn't make this research any less cool. While the BBC's headline wasn't itself inaccurate, I think it leaves a lot of wiggle room for assumptions (or at least imaginations like mine getting carried away with themselves) and accuracy is the end all and be all of science stories, isn't it? Something like "3D Printer Creates Scaffold For New Bone Growth" isn't as pretty as either headline used, but I think it would get to the heart of what this story is a little bit better.

For more information about the technology check out this video from WSU's press page:

*I am typically loathe to post about a paper that I haven't at least looked at the abstract, but I cannot find this paper online anywhere. If someone has a link, that would be awesome.