Bugging Birds

For birds, getting hauled out of a nest by a scientist and poked with a needle ? an increasingly common occurrence in this season of bird flu ? is pretty stressful. Some German ornithologists who study terns worried that such unpleasant encounters were biasing their research results. So taking a cue from nature, they put a tropical blood-sucking bug, Dipetalogaster maximus, on the job to do their dirty work for them. Credit: Getty Images: D Maximus courtesy of Christian Voigt"> Credit: Getty Images: D Maximus courtesy of Christian Voigt "I had used the bugs to bleed captive bats," says Christian Voigt of the Institute for Zoo and Wildlife Research in Berlin, who describes the technique in the German Journal of Ornithology (E-pub, vol. 147, 2006). "Their blood vessels are so tiny, it is close to impossible to hit them." To adapt the method for wild terns, he and his colleagues put larvae of the bug into a hollow artificial egg with an oval opening. Netting over the hole kept the insect from escaping. The researchers waited for the whole colony of terns to take to the air. They then removed the entire clutch of a breeding pair and replaced it with the bug-filled egg, along with some other epoxy look-alikes. The birds didn't seem to notice the exchange when they returned, and continued incubating the false eggs. It took a hungry bug typically no more than half an hour to push its long piercing proboscis through the netting and help itself to a blood-meal from the bird incubating the fake egg. After replacing the original clutch, the researchers were able to collect 78 blood samples from 59 individual birds; 68 of these samples yielded more than 100 microliters, an ample supply for many tests. Initial analyses of the blood tests, which have not been published yet, further validate the research, says Voigt: "Our findings indicate that the bugged birds have indeed reduced levels of stress hormone compared to birds that were caught and bled with traditional methods." A bit of trickery and a bug with a long piercing proboscis are all you need to bleed birds.">A bit of trickery and a bug with a long piercing proboscis are all you need to bleed birds. John Lovette, a professor at the Cornell Lab of Ornithology, initially thought the bug idea was "a bit wacky," but he has warmed to it. Lovette isn't worried about stressed-out birds, but he says the method could be put to good use to outsmart some very clever research subjects: American crows. One of his graduate students is investigating the relationships between different individuals in a group of crows. She traps the birds to get blood samples for genetic tests but has run into trouble. "Crows are so smart," says Lovette. "You have a one-shot chance with each trapping device. After we've caught one, all the other members of the group know to stay clear of the trap." Nevertheless, Lovett advises caution before introducing the technique on a large scale. He suggests that only male bugs be used for studies in the wild to ensure that the insect doesn't invade new territory. Voigt and his colleagues meanwhile have learned to stay clear of D. maximus, which will feed on any warm-blooded species available. "Adults reach a size of two to three centimeters," says Voigt, "and they will sip up to 4 milliliters of blood at one sitting."

Bugging Birds

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