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Spring 2012

"Not Just for the Birds: How ecological land management could prevent us from getting sick"
  • Presented by John Swaddle, Professor of Biology
  • April 24, 2012 in the Undergraduate Admission theatre

Click to view larger versionHere's how it works: A mosquito bites a bird, sucking up a virus along with the blood. Later, the mosquito bites you, transferring the virus to your bloodstream.

That's how you get West Nile disease.

In this scenario, biologists refer to the bird as the "host," while the mosquito is the "vector." Illnesses transmitted to humans from animal hosts through vectors are responsible for some of the most serious disease outbreaks in history. Bubonic plague is transmitted from rat hosts by flea vectors, for instance. Many of us have contracted Lyme disease, typically developed in small mammals and transmitted by tick vectors. Another current example is West Nile, the bird-mosquito combination that is the focus of Professor Swaddle's research.

When it comes to hosting vector-borne diseases, not all bird species are created equal. Some species are more effective hosts—and areas rich in these birds are more likely than others to have outbreaks of vector-borne diseases. Many of the bird species that are effective hosts for West Nile also happen to be common species such as sparrows and finches—the kinds of birds that are most likely to thrive in developed areas.

Professor Swaddle's solution is simple: increasing diversity of bird species will mean fewer sparrows and finches, effectively diluting the pool of effective hosts. A few changes in land management can give us victory over the vectors. It's not just for the birds; it's for us as well.