Biology Reference
In-Depth Information
HOW LOW CAN YOU GO?
Observers at lighthouses and other vantage points note that certain migrants com-
monly travel at altitudes of a few feet to a few hundred feet above sea or land. Sand-
pipers, Red-necked Phalaropes, pelicans, and various sea ducks have been seen flying so
low they were visible only as they topped the waves.
Radar observations indicate that birds on long-distance flights move along at higher
altitudes than short-distance migrants. Advantageous tail winds of greater velocity are
found higher up, along with cooler air that helps birds dissipate the heat they generate
under the exertion of flying.
Q What's the fastest bird? The slowest?
A The fastest bird may be the Peregrine Falcon, which has been clocked with various
tools,includingpoliceradar,goingatleast180milesperhour(290kmperhour)andper-
haps over 200 mph (322 kph). No one has clocked the White-throated Swifts that have
successfully eluded peregrines —they're certainly slower than a diving peregrine but are
great at evasive maneuvers.
If we count the slowest bird as one that can remain in flight for many minutes going
zero miles per hour, I suppose we could give that distinction to various hummingbirds. If
we count the slowest bird beating its wings in forward flight without stalling out, Amer-
ican Woodcocks and Eurasian Woodcocks have both been clocked at just 5 mph (8 kph)
in courtship flights. But American Woodcocks don't always fly so slowly; they've also
been clocked at 13 mph (21 kph) and even 42 mph (68 kph).
Q How far can a bird fly without resting?
A In terms of normal migration, flight distance depends on the species. Many Ruby-
throatedHummingbirdstakeofffromtheTexasandLouisianagulfcoastsandflynonstop
to the Yucatán Peninsula, a minimum of almost 600 miles (965 km) with nowhere to rest
or feed en route. Blackpoll Warblers migrate over the Atlantic Ocean from the northeast-
ern United States to Puerto Rico, the Lesser Antilles, or northern South America. This
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