Category Archives: Conservation

Crocodile Die-Off in Kruger National Park

Crocodiles have been dying in large numbers on the Olifants River in Kruger National Park, the crown jewel of the South African Parks System.  The article rather casually states that the die-off is attributable to environmental pollutants:

There is growing consensus that the croc die-off is a result of a confluence of low level toxins, which has lead to endocrinal [sic] abnormalities (that is, hormonal changes) in croc tissues.

As the moderator for the promedmail wrote, however, it would be nice to have some specific details explaining why this consensus is apparently growing:

The article does not specify chemicals, pesticides, or heavy metals, or their amounts, yet the article boldly states, “Long term exposure to these and other toxins may well be conspiring towards the crippling condition suffered by Olifants River crocodiles.” So apparently, the specifics of the chemicals, pesticides and/or heavy metals are known. It would be much more beneficial to publish what has been found and the levels of those alleged toxins, then those doing research or having experience in the area would be able to suggest a possible solution.

It certainly seems possible, particularly given the diversion of water from the Olifants River and from new mining operations in Mozambique, but it would still be nice to have some more details. One of the striking features of the dead crocs is the fact that they have hardened yellow fat deposits in their tails. The article suggests that cause of death is pansteatitis, a disease caused by excessive consumption of unstabilized polyunsaturated fatty acids (often found in rotting fish).  There is no evidence of correspondingly large fish die-off, which could complete the causal story.  How the environmental contamination story fits in with pansteatitis seems an important missing link in understanding this problem.

Cattle that eat threadleaf groundsel can die of a disease that induces hard yellow liver, providing more suggestive evidence that an environmental poison might be responsible for the croc die-off.  Maybe…? 

This is a disturbing story, the resolution of which I will follow closely.

The Requirements for an Ecological Anthropology Curriculum

A question was posted today on the ecological anthropology listserv: What are the basic requirements for an ecological anthropology graduate program? I don’t claim to be qualified to say what these are for the field as a whole, but I am qualified to say what we have decided on in setting up our new ecological and environmental anthropology Ph.D. program at Stanford. Here I include an edited version of the reply I sent to the thread.

At the risk of essentializing, there are, broadly speaking, two general classes of ecological anthropologists: (1) those who use human relationships with the environment as a lens through which to study problems in cultural anthropology (e.g., agency, social structure, the construction of meaning, etc.), and (2) ecologists who study humans as their primary organism. The majority of practitioners currently falling under the latter category are probably human behavioral ecologists, though I can think of some notable exceptions to this. This is the approach our program emphasizes.

In addition to departmental requirements, EE students are required to take the following:

  • Evolutionary Theory
  • Research Methods in Ecological Anthropology
  • Data Analysis in the Anthropological Sciences

All students need to know how to integrate theory, method, and application, but the specific nature of the courses in which they learn that doesn’t matter that much. Therefore, we require three courses from a list of theory-driven graduate classes, including (but not limited to):

  • Advanced Ecological Anthropology
  • Human Behavioral Ecology
  • Conservation and Evolutionary Ecology
  • Demography and Life History Theory
  • Environmental Change and Emerging Infectious Disease

Required classes deal with what you know, but equally important is how you know. We expect our students to engage in research from the outset of their graduate studies. Students attend weekly lab meetings. These can be within the Anthropology department (e.g., Rebecca Bird and I run a joint meeting or we have a joint spatial interest meeting this quarter) or in other departments (e.g., Biology, Woods Institute).  Students also attend a colloquium (comprised of visiting speakers) one quarter out of the year.

We’re big on methods, but we don’t legislate what methods students learn (other than research design and statistics).  Most students are interested in remote sensing and GIS, but we also have students working on social network analysis, demographic methods,  and advanced statistical methodology.

So, that’s our idea for a graduate program.  We will have  a proper web page describing the program in detail some time in the future.

Multi-Species Outbreak of Yellow Fever

There is a troubling outbreak of yellow fever currently affecting a number of South American countries, including Brazil and Paraguay.  Yellow fever is a multi-host infection that can be transmitted between monkeys and humans.  It is almost always fatal for species in the genera Alouatta and Ateles (howler and spider monkeys respectively).  The Wildlife Conservation Society (WCS) has taken note of the real conservation concerns that arise for small populations of these monkeys in the context of the continuing yellow fever outbreak.  In a world of increasingly fragmented local wildlife populations, where human-wildlife contact increases from human intrusion of forests and other ecosystems, control multi-host epidemics is likely to become an integral part of the conservation ecologist’s portfolio.