Tracking wildlife

Anyone with any interest in British wildfowl will remember Sacha Dench's epic flight with the swans.The intrepid sportswoman shared by paramotor Bewish's swans' flyway from their Arctic breeding-grounds to the UK as part of a WWT research project.

That was not the craziest or most dangerous wildlife tracking scheme, however. A recent Discover magazine article surveys some of the most egregious methods naturalists use for tracking animals, from the formidable elephant seal and great white shark to delicate mice and humming-birds. My favourite story concerns the latter. Care has to be taken to ensure that any tags to monitor an animal species must not inhibit the subject's normal behaviour. The general rule of thumb is that an animal should never carry an instrument that weighs more than 5 percent of its body weight. Theodore Zenzal, a research ecologist with the U.S. Geological Survey in Lafayette, Louisiana, and his colleagues tried out several types of tags on ruby-throated hummingbirds held temporarily in an aviary. They settled on a tag that weighed just 220 milligrams — less than half the weight of a Tic Tac.

Zenzal attaches the transmitters to hummingbirds’ backs using a tiny drop of superglue and a larger dab of eyelash glue, which is nontoxic and will eventually come off without hurting the birds. To decide what type of eyelash glue to use, one of Zenzal’s colleagues stuck fake eyelashes to her arm with various glues and drove down the highway with the window down. The glue that held the longest was Revlon Fantasy Lengths, although Zenzal noted that mentioning this did not imply an endorsement by the federal government.

Unfortunately, said Zenzal, the glue can only be purchased in a kit that also includes fake eyelashes. He used to buy dozens of such kits at the drug store — until the cashier started recognizing him.

“After that I ordered them online,” he said.

The whole article is most enjoyable, though those of a nervous disposition might care to skip a couple of the paragraphs.