Bee shortage? What bee shortage?

An article in the New York Times this week suggests that the current scare over colony collapse disorder is nothing extraordinary. It has happened before and will probably happen again. What has been missing from the debate, some scientists say, is historical context. Records show that colonies were vanishing in the 19th century, when the cause was seen as lack of moral fibre. Bees that weren’t returning to their hives had “weak character”. And it happened in the late 1970s, when it was called “disappearing disease”. The disease too disappeared, and no cause was ever isolated.

One day we may know, and extra money for long-term monitoring (none has been forthcoming) may help. In the meantime, if the “crisis” has helped people appreciate the importance of bees as pollinators, and prompted deeper investigations, then that is surely A Good Thing. To prove the point, two deeply fascinating papers have been published in the past month showing that genetic diversity in honeybees and other social insects is also A Good Thing.

This is counterintuitive, because the reason social insects are social is that they are genetically uniform.

Continue reading “Bee shortage? What bee shortage?”

Surveying diversity

The kind of survey where a researcher turns up at farmers’ houses and starts asking a lot of standard, rigid questions about the problems they have been having with their crops and livestock has been somewhat unfashionable of late. In fact, one of the reasons for the explosion of rapid rural appraisal (RRA) methodologies in the 1980s, followed by more participatory, often qualitative, methods (PRA) in the 1990s, was so-called “survey slavery: questionnaires surveys which took too long, misled, were wasteful, and were reported on, if at all, late.” ((See this note prepared for participants in a workshop on PRA.))

A way — in fact, a whole menu of ways — was found, as a result of the pioneering work of some NGOs and universities, of allowing people, even marginalized groups, to set the very agenda of research, as opposed to just answering a bunch of questions that researchers thought interesting.

But there is a place for well-designed, carefully tested and sensitively-administered surveys to document and analyze the ways farmers manage their resources — including their agrobiodiversity — and to provide a baseline against which to gauge the effectiveness of interventions or other possible changes. I want to talk about two recent papers that use farmer surveys to characterize farming systems, as examples of the kind of thing there might be more of in agricultural biodiversity work.

The first paper, on surveys of smallholder families in northern Pakistan, focuses on livestock production. ((Abdur Rahman, Alan J. Duncan, David W. Miller, Juergen Clemens, Pilar Frutos, Iain J. Gordon, Atiq-ur Rehman, Ataullah Baig, Farman Ali and Iain A. Wright. Livestock feed resources, production and management in the agro-pastoral system of the Hindu Kush-Karakoram-Himalayan region of Pakistan: The effect of accessibility. Agricultural Systems, In Press, Corrected Proof, Available online 5 July 2007. http://dx.doi.org/10.1016/j.agsy.2007.05.003)) The surveys were done along two transects which contrasted markedly in their transport infrastructure. One of the things the researchers looked at was the percentage of cross-bred animals per household. They found that there was a higher proportion of such improved animals in the transect with well-developed transport links and more accessible markets than in the more isolated area. As the roads get better in this latter area, the researchers think that “the proportion of traditional, unimproved animals … is likely to diminish,” and there are also likely to be “changes in land use towards higher-value commodities such as potatoes.” An interesting conclusion about likely genetic erosion — in both crops and livestock — in the region. One could imagine using this kind of information to identify areas throughout the country which are at high risk of genetic erosion due to impending road building or improvement.

The second paper looked at the adoption of soil conservation practices in Kajado district, in the Rift Valley province of Kenya. ((Jane Kabubo-Mariara. Land conservation and tenure security in Kenya: Boserup’s hypothesis revisited. Ecological Economics, In Press, Corrected Proof, Available online 9 July 2007. http://dx.doi.org/10.1016/j.ecolecon.2007.06.007)) The researcher, Jane Kabubo-Mariara of the University of Nairobi, was particularly interested in whether population density and land tenure arrangements had an effect on the likelihood of farmers constructing soil bunds and terraces and planting trees. She found that as population pressure increases, there is a “significant shift towards increased individualization of tenure” and also a “higher probability of adoption of soil bunds and planting drought-resistant vegetation.” Now, that’s fascinating enough, but what caught my attention was the dog that didn’t bark. Wouldn’t it have been interesting to know whether farmers in high density areas grew more or fewer crops, and more or fewer varieties of each?

Is the kouprey a species?

The kouprey is a very elusive wild bovid that is said to roam the Southeast Asian jungle. It was only discovered by outsiders at the beginning of the last century, but it has seldom been seen since and there are concerns that it may, in fact, already be extinct. (It is currently listed on the IUCN Red List of Endangered Species). As if that wasn’t bad enough, there is now a vigorous debate about whether the kouprey is — or was — in fact, a separate species at all, or merely some type of feral hybrid.

A report published some months ago in the Journal of Zoology showed that a comparison of mitochondrial DNA obtained from several banteng revealed some homology — similarity — with a previously published DNA sequence from a kouprey. ((Galbreath et al., 2006. J. Zool. 270:561)) The banteng is another bovid that has to some degree been domesticated, but can also still be found in the wild in several Southeast Asian countries.  Based on their analysis, the authors concluded that the kouprey is more than likely just a hybrid originating from crosses between zebu cattle and the banteng. Now, some might argue that it is pretty bold to reach such a profound conclusion based on a very small sample size, and not surprisingly some have indeed so argued. They have pointed out that anatomical and even DNA evidence from their own studies did not support stripping the kouprey of its species status. ((Grigson, 2007. J Zool. 271:239; Hassanin and Robiquet, 2007. J. Zool. 271:246)) An alternative explanation might simply be that there has been introgression of DNA from one species into the other by occasional matings. And there is ample evidence that this has happened in other species. Cattle DNA is commonly found in the American bison, for example, because of past attempts by cattle breeders to generate what they thought would be more viable bison-cattle hybrids. ((Rasmussen et al., 2005. Mol. Reprod. Dev. 70:228))

What is clearly needed to settle the matter is additional analysis of nuclear DNA obtained from more than one kouprey. But if the animal has, indeed, already disappeared, that may prove to be difficult. ((Contributed by Michael Kubisch))