Mad cows, happy birds, and distant butterflies

Western Meadowlark at Strawberry Lake Community Pasture, T. Herriot

Try a Google search today for the words “mad cow, birds” and you will get a barrage of hits all stemming from a scientific paper published a couple of days ago in the Proceedings of the National Academy of Sciences. The Canadian researchers responsible for this hubub, J.J. Nocera and H.M. Koslowsky, have either got a very good publicist or their topic has tapped into a zeitgeist the rest of us have underestimated. I think it may be the latter.

Remember the Butterfly Effect? Well, this paper posits a cascade of effects that ties together the outbreak of Mad Cow disease in Europe with an increase in certain grassland birds in North America. Here is the way an article in The Scientist describes the paper’s argument:

After examining data on bird populations, hay production, cattle exports, and European cattle outbreaks extending all the way back to the 1960s, Nocera noted a recurring three-year pattern that starts with an outbreak of mad cow disease in Europe and ends with a jump in North American grassland birds.

The outbreak would result in increased cattle exports from the US and Canada the following year, which in turn reduced the standing herd sizes of cattle in North America, thereby reducing the demand for hay and saving the grassland birds' habitat.

Years of field research to show direct and demonstrable causation (proving, for example, that replacing native grass with crested wheatgrass reduces grassland bird nest success) is ho-hum, but put some numbers in a computer and extrapolate a set of trends caused by remote socio-economic factors and the media will flap their butterfly wings enough to make you a star.

I know, that sounds cynical, and even a little ungracious for someone who has in the past complained that grassland birds get no attention. Heck, this week, even the Regina Leader-Post ran a piece on this story. Here is one that came out in The Vancouver Sun. It is good to see this kind of uptake by the media and blogosphere, but it would be nice if it were based on a stronger piece of science.

On the other hand, there is something fascinating here, not so much about birds as about humanity’s increasing awareness of and passion for anything that shows our lives and ecosystems to be intricately interwoven and interconnected. We are thrilled to live in a world where the flap of a butterfly wing can have far-reaching ripple effects, and we should be. It is a wonderment to be immersed in such a matrix of sunlight and carbon, but we need that wonder and awareness to mature into respect and begin to inform our decisions, both as private citizens and as communities and nations.

This paper has already been criticized in the science community for its lack of rigour, for not really proving anything it presents as correlation. That tearing down is how scientists keep one another heading toward new knowledge that can be defended and upheld. Once research of this kind gets out to the public, though, it contributes to popular awareness, which is always a mixed bag of self-serving distortion and useful education. The teachable moment captured here is the insight that there are important connections between the food we eat and the wild creatures that are hanging on for dear life in the agricultural landscape.

Mad cows and butterflies aside, let us turn our thoughts to our next meal and consider whence it came. If we could cut down our consumption of grain-fed livestock products by 10%, and increase the demand for ecologically-raised, grass-fed beef by the equivalent amount, the birds would do their part.


a much better Western Meadowlark photo, courtesy of Hamilton Greenwood