THE BIRD DEPARTMENT 



275 



With birds that travel such enormous distances, it is 

 interesting to note their rate of advance. While it is 

 possible for birds to travel great distances without rest, 

 as witnessed by the fall flights of the turnstone from 

 Alaska to Hawaii or of - the golden plover from Labrador 

 to northern South America, distances of over 2,000 miles 

 across the open sea, they do not ordinarily progress far 

 in single flights. The spring advance of the robin, for 

 example, averages only 13 miles a day from Louisiana 

 to southern Minnesota. The rate increases gradually to 

 ol miles a day in southern Canada, 52 miles per day by 

 the time it reaches central Canada and a maximum of 70 

 miles per day by the time it reaches Alaska. It should 

 not be inferred from this that each robin does not ever 

 migrate less than 13 or more than 70 miles in a single day. 

 Probably they often fly more than a hundred or two hun- 

 dred miles in a single flight, as do, undoubtedly, many of 

 the smaller birds, but after each flight they dally about 



A PIED BILLED GREBE 



The mother bird and two youngsters out for a swim. This bird spends 

 its winters from the southern States southward and arrives in the 

 the northern States during the last days of March. 



their resting place for several days before starting on 

 again, and this brings down the general rate of advance. 



The rate of speed at which birds travel is rather diffi- 

 cult to estimate except for the homing pigeons which 

 can be timed from one place to another or the ducks and 

 geese whose conspicuous flocks traveling high over cities 

 and towns can easily be followed. The championship 

 speed for homing pigeons has been recorded as 55 

 miles per hour for a period of four hours. A great blue 

 heron has been timed by a motorcyclist keeping directly 

 below it and found to be 35 miles per hour. A 

 flock of migrating geese has been found to be traveling 

 at a speed of 44.3 miles per hour and a flock of ducks at 

 47.8 miles. The speed of flight of smaller birds is usually 

 less although when they mount high in the air and start 

 on their migratory flight, they doubtless travel faster 

 than the birds one so often passes flying parallel to a 

 passenger train or suburban car. 



The vast majority of birds migrate during the night; 

 some mitgrate both by day and night, and others only by 



day. The latter are, for the most part, birds that find 

 their food in the open and can feed as they travel. Such 

 are the robin, the kingbird and the swallows. Other birds, 

 like the sparrow, vireos, warblers and march birds, that 

 find their food in the seclusion of trees of dense vegeta- 

 tion, migrate entirely by night. The necessity for this is 

 shown when they arrive at the Gulf of Mexico or other 



REDWIXGED BLACKBIRDS 



These birds spend their winter in southern United States and arrive in 

 the northern States during the last of February or the first part of 

 April. The males often arrive two weeks to a month in advance 

 of the females. 



large bodies of water where it is impossible to get food 

 of any kind. If they started early in the morning so as 

 to be across by night, they would not be able to secure 

 much food before starting, and by the time they reached 

 the Mexican side, it would be dark and again impossible 

 to feed. Thus an interval of thirty-six hours would 

 elapse without food, a period that might result disas- 

 trously for many birds because of their high rate of 

 metabolism. If, however, they spend the day feeding 

 and migrate by night, their crops are full and when they 

 arrive at the other side of the Gulf, it is daylight and 

 they can begin again to glean their living. 



During these night migrations birds are attracted by 

 any bright steady light, and every year hundreds and 

 thousands dash themselves to death against light 

 houses, high monuments and buildings. While the torch 

 in the Bartholdi Statue of Liberty was kept lighted, as 

 many as 700 birds in a month were picked up at its base. 

 On some of the English lighthouses where bird de- 

 struction was formerly enormous, "bird ladders" have 

 been constructed forming a sort of lattice below the 

 light where the birds can rest instead of fluttering out 

 their lives against the glass. Again in crossing large 

 bodies of water, they are often overtaken by storms and 

 as their plumage becomes water-soaked, they are beaten 

 clown to the waves and drowned. Sometimes thousands 

 of birds are killed by a single storm. But of course the 

 vast majority sweep on and arrive at their destinations 

 in safety. 



