Newswise - In Utah, birds are being given "breathalyzer" tests. Nope,cops aren't stopping them for flying too fast?a biologist istrying to determine whether sparrows and warblers aremigrating under the influence of bayberries, gnats, or otherfoods, in an effort to help protect the habitats ofmigrating birds. It turns out that birds can get too drunkto fly, just like people can become too drunk to drive.
Kent A. Hatch analyzes bird breath for clues as to what thebirds ate earlier in the day. He fitted a small facemaskover migrating birds? beaks and captured their exhaledcarbon dioxide. The birds did not have to walk a straightline, nor answer any questions. But the researchers alsogathered their feathers, blood and feces before releasingthe animals. The study results are published in the newissue of the journal "Oecologia."
Songbirds traveling up and down the east coast of NorthAmerica need "rest stops" where they can replenish energyand protein burned during their taxing migrations. However,development encroaching on many of these sites, just as ithas for the resting place of Monarch butterflies in Mexico.Ecologists want to identify the birds? preferred diet inorder to ensure the availability of appropriate stopoverhabitats. Hatch has visited a "refueling" stop heidentified on Block Island off the southern coast of RhodeIsland.
It turns out that the birds are flexible, something peoplewho put out bird feeders need to remember in case they haveto leave home on vacation and temporarily abandon theirfeeders. Three of the species under observation maintained aconsistent diet during their migration, but white-throatedsparrows broadened their palette to include new items, suchas corn from bird feeders. Yellow-rumped warblers preferredprotein-rich insects prior to their arrival on Block Island,but their tastes turned to northern bayberries during theirpit stop.
In order to capture the songbirds, researchers hung spiderweb-like nets between vertical poles. They then brought themto a central location, where they were fitted with afacemask so they breathed pure oxygen from a squeezedballoon. The balloon captured the exhaled carbon dioxide,which was then transferred by syringe to vacuum-sealed testtube-like flasks.
What doThunderbirdseat? Are they real or mythical?Subscribers canstill listen to Whitley?s fascinating interview with Mark Hall.
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