30 eH RE AUD UB OUNS BU, Dyes ia 
BIRD MIGRATION, by Donald R. Griffin. Doubleday & Company, Inc., 
Garden City, New York. 180 plus xv pages, 27 black and white figures. 
LOG64 eS ole2o: 
This paper-backed pocket book is #S87 in the Anchor Books Science 
Study Series, whose aim is to present science topics within the grasp of the 
young student or layman. The author is a Professor of Zoology at Harvard 
who has conducted experiments on bird migration. The chapters are: I. The 
Extent of Bird Migrations; II. Bird Watching by Radar; III. The Seasonal 
Timing and Energetics of Migrations; IV. Bird Navigation; V. Homing Experi- 
ments; VI. Bird Watching from Airplanes; VII. Experimental Analysis of 
Bird Navigation, and VIII. Celestial Navigation. 
The author relates the known facts concerning bird migration and then 
describes many experiments devised to understand how birds know where 
to go when they migrate. Some figures show the distances that birds travel 
on each migration. Most of this data is furnished by the trapping and re- 
covery of some of the 15 million birds that have been banded in North 
America and Europe in the last 60 years. Besides mentioning the well-known 
distance champions — Arctic Tern, Golden Plover, and Wilson’s Petrel — 
the author gives the following interesting figures: Blue-winged Teal — 
3300 miles at a rate of 122 miles/day; Dowitcher — 2300 miles at 125 miles/ 
day; Lesser Yellowlegs — 19380 miles at 322 miles/day; and Blue Geese — 
1700 miles at 680 miles/day. 
Also interesting were the results of tagging monarch butterflies near 
Toronto, Ontario: The longest distance traveled was 1870 miles and the 
fastest was 1345 miles at a rate of 82 miles/day. One autumn, radar at 
Cape Cod showed what was thought to be Blackpoll Warblers starting over 
the ocean for the Lesser Antilles or South America, over 2000 miles away. 
The Cape Cod radar shows that the most common altitude for migrating 
birds is 1500 to 2500 feet, with 10% over 5000 feet and less than 1% 
higher than 10,000 feet. There are records of geese flying at an estimated 
29,000 feet in the Himalayas. Radar also shows that fast flyers, like sand- 
pipers and plovers, travel at a rate of 45 m.p.h., while small songbirds fly at 
AD0UtsO0NMN- Dap: 
Some reasons for birds migrating to the far north are probably fewer 
predators and the long daylight hours. A pair of robins in Umiat, Alaska 
brought their brood off the nest in % of the time required here because 
they were able to hunt for food 21 hours of the day instead of 16 hours. 
Shortly before migrating, birds store up extra fat in their bodies to be used 
as fuel. The percentage of fat increases from 2% to 4 times the normal 
amount. Before migrating 500 miles over the Gulf of Mexico, hummingbirds 
usually add as much as 2 grams of fat which constitutes over 40% of the 
body weight. It is calculated that 1.3 grams of fat are used, providing there 
are no adverse winds. This is not a large margin of safety. 
The experiments described are those of Rowan and Wolfson on the 
effect of daylight length on breeding condition; several aspects of bird 
navigation in which the author, Hitchcock, Matthews and Kramer conducted 
‘homing’? experiments; Kramer and Hamilton conducted ‘‘sun-compass 
orientation’? experiments; Sauer and Hamilton conducted ‘“‘star-compass 
orientation”? experiments; and the author, Bellrose, Perdick, Ruppell, Rowan 
and Goldsmith conducted ‘‘directional orientation’? experiments. There are 
2 pages of references for further reading. 
Paul A. Schulze, 622 South Wisconsin, Villa Park, Illinois 
