Sentinel Species, Range, and New Orleans

Science and literature are different languages to express similar concepts about humanity. This blog post is an attempt to explore the relationship of science and literature in the context of some class concepts. Weeks ago, Beth (1) mentioned the concept of “the canary and the coal mine.” We did not unpack it at the time, but that moment made me think about range, as discussed in my Biogeography class and When the Levees Broke.

Before I get into my ideas, I’d like to deconstruct the allusion of “the canary and the coal mine” for anyone unfamiliar or forgetting. It refers to the (now outdated) practice of miners taking a canary down to their mine shaft. They did this because canaries have a higher sensitivity to carbon monoxide. The purpose was if the canary stopped singing, that usually mean it had fainted or died. This indicated a gas leak, prompting miners to exit their mine shaft. This concept has since evolved into an idiom for any situation (not just environmental) where sensitive individuals signal danger or wrongdoing.

In this case, the canary is a sentinel species. Sentinel species are “organisms… used to detect risks to humans by providing advance warning of a danger…  some … may be more susceptible or have greater exposure to a particular hazard than humans in the same environment… people have long observed animals for signs of impending hazards or evidence of environmental threats.” (2) The canary is the classic, popularized example for sentinel species, but there are actually dozens of researched examples (3), showing that they are perpetuated in our environment and that we are dependent on biodiversity. In fact, I would argue that almost every species has indirectly or directly acted as a sentinel for the human population.

Sentinel species are often confused with indicator species, with the only difference being that sentinel species are indicator species that signal something to humans specifically. I think that’s important to note as we think about how humans use animals and how humans use “other” humans (key weird “other” in reference to groups of “Us” and groups of “Them.”

All of the above got me thinking about climate change. Scientists agree that the populations experiencing effects from climate change are mostly mutually exclusive from the populations causing large proportions anthropogenic climate change. I.e. China and the US are the biggest emitters of greenhouse gases but less developed and/or smaller countries in Central Africa, South (and Southeast) Asia, and the Pacific Islands are experiencing the most effects. For example, the Maldives, a nation known for being a tropical tourist destination (yet not a large contributor of greenhouse gases!), is making plans to buy land from India so as to relocate the nation when the time comes.

One last scientific thing: I’ve also been learning a lot about range, or the area where a species can live. As seen in the figure below, the range area with the most ideal conditions is where most of the species lives. The farther you get away from this zone, the closer you are to the limiting factors (limits that cause a species to not be able to live in a place). This is called the stress zone because you are more vulnerable to external pressures. Such pressures include larger predator population, less access to food, negative influence from humans, and…. the effects of climate change. It really struck me when my professor (4) said that “when those in the stress zone are threatened, they must either retreat towards the optimal zone or die.”

When I heard this, I thought of the aforementioned human populations who are losing their countries due to climate change and are forced to “migrate” or “emigrate” to other countries. Not only must they retreat to the optimal zone or die, but they are losing their land, culture, etc. in the process. These populations are condemned by countries who fear “outsiders” despite the fact that they are doing the world a service by signalling incoming dangers. In other words, these populations are sentinel “species” in the sense that the loss of their country serves as a  signal of underlying issues of war, oil crises, and the consequences of modern capitalism.

If you’ve read this far you get to watch me try to bring it all together. The residents of New Orleans were in the “stress zone,” (not helped at all by the levee failure of course) so when Katrina hit they really felt it. Those in the stress zone must “move towards the optimum zone or die.” We’re very familiar with the images of the traffic leaving the city and the buses being loaded. We’re also very familiar with images of those who fall into the “or die” category.  But of all involved, the dead, the survivors (including those labelled as “refugees” in Texas/Alabama/Utah/etc), they serve the nation and the world as a sentinel “species.” The aftermath of Katrina brought up a lot of really important discussions on government, movement, the environment, and policy in general. Additionally, the prosperity of those not affected by the storm in some cases depended on the destruction of those who were affected, and so we are back to the canary dying so the miner can escape.


1 Please correct me if I’m falsely attributing!

Thanks, Wikipedia!

Dancing cats in Japan indicated a neurological condition from methylmercury in the water; Bees are sensitive to air pollution; Fish are caged in rivers to check for chemicals (same is done with samples of Bivalves like mussels and oysters); Smalling digging animals (i.e. moles) and birds are checked for soil contaminants; Same is done with deer and sheep for plant contaminants. (Source)

James Kernan of the Geography department!

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