shrikes, timed with the speedometer of an automobile, have been 

 found to fly 22 to 28 miles per hour, whereas some of the flycatchers 

 fly at only 10 to 17 miles per hour. Even such fast-flying birds as the 

 mourning dove rarely exceed 35 miles per hour. A peregrine falcon 

 will have difficulty catching a pigeon during a level chase at 60 miles 

 per hour, but this predator can probably exceed 200 miles per hour 

 during a swoop from a greater height onto its prey. 



The speed of migration is quite different from that attained in 

 forced flights for short distances. A sustained flight of 10 hours per 

 day would carry herons, hawks, crows, and smaller birds from 100 to 

 250 miles, while ducks and geese might travel as much as 400 to 500 

 miles in the same period (without the aid of a tail wind). Measured as 

 straight line distances, these journeys are impressive and indicate 

 birds could travel from the northern United States or even from 

 northern Canada to winter quarters in the West Indies, Central, or 

 South America in a relatively short time. It is probable that 

 individual birds do make flights of the length indicated and that barn 

 swallows seen in May on Beata Island, off the southern coast of the 

 Dominican Republic, may have reached that point after a nonstop 

 flight of 350 miles across the Caribbean Sea from the coast of 

 Venezuela. 



Radar has given us some of our best estimates of ground speeds for 

 migrating flocks, especially at night. Radar echoes, identified as 

 shorebirds migrating off the New England coast, moved steadily 

 about 45 miles per hour for several hours; songbird echoes typically 

 traveled around 30 miles per hour (Drury 1960). Some birds appear 

 to reduce flight speed in proportion to the degree of assistance or 

 resistance. The literature is in some disagreement on the flight speed 

 of birds and the influence of wind, but good radar observations 

 coupled with accurate measurements of winds aloft will help give us 

 a more accurate estimate of migrating speeds for different species 

 under varying wind conditions. 



The intensity of migration depends on circumstances including the 

 need for haste. In fall the flights are more likely to be performed in a 

 leisurely manner, so that after a flight of a few hours the birds often 

 pause to feed and rest for one or several days, particularly if they find 

 themselves in congenial surroundings. Some indication of this is 

 found in the recoveries of banded birds, particularly waterfowl. If we 

 consider only the shortest intervals between banding in the North 

 and subsequent recovery in the South, it is found that usually a month 

 or more is taken to cover straight-line distance of a thousand miles. 

 For example, a black duck banded at Lake Scugog, Ontario, was 

 killed 12 days later at Vicksburg, Mississippi. If the bird was taken 

 shortly after its arrival, the record would indicate an average daily 

 flight of 83 miles, a distance that could have been covered in about 2 

 hours' flying time. Among the thousands of banding records of ducks 

 and geese, evidences of rapid migrations are decidedly scarce, for 

 with few exceptions, all thousand-mile flights have required 2 to 4 

 weeks or more. Among sportsmen, the blue-winged teal is well 



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