Friday, June 12, 2009

Grass, Sky, Song Illustrated:
"Lethal Dose"

Loggerhead shrike photo courtesy of John Carlson

This chapter of Grass, Sky, Song is about pesticides. The loggerhead shrike is an endangered species in Canada for a variety of reasons but pesticides have likely played a role. Farmers and naturalists first noticed their numbers thinning in the early 1960s after the new organochlorine pesticides (including DDT) came to the prairie. In the 1970s we banned DDT, but then started using Carbofuran for the next twenty years. It too has finally been banned, but the damage has been done. The prairie population of loggerhead shrikes has dropped by 80% in the last 35 years.

Doing the research for this chapter I went to the University of Lethbridge to meet Dan Johnson, Canada Research Chair in Sustainable Grassland Ecosystems, and one of the continent's foremost grasshopper researchers. Take a look at this web page where Dan shows some of his work on grasshoppers and grassland species at risk.

This lovely photo of burrowing owl eating a grasshopper was taken by Dan. Click here for a look at an great series of shots of this owl eating 'hoppers.

Dan sits on the recovery team for burrowing owls, in part because the owls eat a lot of grasshoppers and feed their nestlings on them. Dan does a lot of good by speaking to people in the world of agriculture who have trouble seeing grasshoppers and other insects as anything but pests. Here is a link to a lecture he gave on the subject at Simon Fraser university.

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