[The title
was written by my editor.]
The sight of a hummingbird brings joy to almost any observer, but new
research shows a weakness in their graceful hovering.
by John
Tyburski
Copyright © Daily
Digest News, KPR Media, LLC. All rights reserved.
Hummingbirds
dazzle observers with their seemingly precise, darting movements and ability to
hover in place with furiously beating wings. However, new research indicates
that the little birds have some trouble remaining steady in their hovering
maneuvers when background motion is visible to them.
Benjamin
Goller and Douglas Altshuler, both of the University of British Columbia, show
in a new report that background motion disrupts the hummingbird’s ability to
hover at food sources.
“Despite
the urge to feed, the birds seemed unable to adapt to the moving images,”
explained Goller in a statement.
The
researchers studied the effects of background motion on hummingbird feeding by
projecting images on a surface positioned behind a feeder in a controlled
arena. As hummingbirds attempted to feed, the scientists projected images of
rotating spirals. The result was that the birds’ flight became more salutatory,
and the birds drifted away from the feeder as they extended their beaks to try
to sip of the liquid meal.
Even
though the birds became accustomed to the images in the background, they could
not overcome this drifting away from the feeder while hovering. Each time their
beaks lost contact with the feeder, the birds moved to a starting position in
their hover, tried to feed again, drifted away, and repeated this pattern.
Regardless, the images never seemed to inhibit the birds from trying to feed.
The
researchers conclude that the birds attain stable hovering by stabilizing their
visual fields.
The results were published
this week in the Proceedings of the National Academy of Sciences.
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