I put together a storify of tweets from the May 8th #sciobeantown event:
Do you care that a rare type of freshwater mussel has been nearly wiped out? Unless you are like me in the throes of Summer and I am still looking-for-a-job-limbo, I doubt you have the time to give more than a moment of attention to the freshwater pearl mussels in Cumbria in the United Kingdom…if that. In my daily perusing of the BBC I saw this article, Rare mussels ‘almost’ wiped out and I couldn’t help but think A) how in danger is in danger enough to warrant media coverage and B) does covering close calls for endangered species result in ‘boy who cried wolf’ response from the public?
- Extinct in the Wild
- Critically Endangered
- Near Threatened
- Least Concern
- Data Deficient
- Not Evaluated
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.
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.
As I’ve mentioned before I am taking a class this semester about the extinction of species. One of the topics we recently covered (and I recently got a crash course in for the midterm) is captive breeding. Captive breeding is a conservation strategy in which animals are captured and held in a protected area, where they are then bred to another specific animal of their species to optimize the production and survival of their offspring. I just assumed that this was a more recent (meaning within the last century) trend in conservation efforts, but then I saw this BBC article about the effects of sacrifice and mummification on Egyptian species, and realized how wrong I was.
|Mummified monkey in Cairo. Source:
The ancient Egyptians would often mummify animals to be included in a person’s tomb as a sacrifice to follow the dead into the afterlife to provide company and serve as an offering to the gods. However, according to the article by Jane O’Brien, the Egyptians had favorite species that they chose to mummify. They sacrificed these animals so much that they put these species in danger of extinction. Thus, to keep up with demand captive breeding was needed to keep the number of available animals high.
Experts, like Selima Ikram a professor of Egyptology at the American University in Cairo who was quoted in the BBC article, believe that at least one bird species (the Sacred Ibis) was so popular for mummification that it was driven close to extinction. Other animals that were popular for mummification were dogs, cats, hawks, falcons, and baboons, although Ikram was quoted saying:
“Its easier to say which animals the Egyptians didn’t mummify. There are no mummified pigs as far as we know, no mummified hippos, and I think thats about it – because almost every other creature at some time or another has been mummified.”
According to the article, when the animals most sought after for mummification started to become rare in the wild, breeding programs were launched by temples (the animals were often seen as sacred or representations of the gods) and the nearby villages. Evidence of these programs shows them in place as early as 3,000BC with the height of captive breeding at 650BC-200AD.
I liked this article because it provided a little bit of context about why animals would have been slaughtered for sacrifice in such great numbers. If you just look at the fact that so many animals were killed, it seems like the Egyptians were being selfish, putting human desires (not even needs) above all these animals. However, you have to look at their religion, and how they viewed the animals. Ikram says that the Egyptians would have viewed sacrificing the animals as a great honor for the animals, because they were so revered. The focus was on life, and continuing the animals’ existence in the afterlife, not on death or killing them. I think this bit of context is a really important part of the story and I’m glad it was included in the BBC article. Captive breeding by the Ancient Egyptians… who knew?
Just want to note that the BBC piece was a plug for the Smithsonian Institution’s National Museum of Natural History’s new exhibit of mummified animals. Haven’t seen it and can’t endorse it, but it looks like it might be pretty cool to check out if you are in the DC area.