[10] BIRDS OF OREGON 



cation, but by taking averages and placing them on maps, Professor 

 Cooke was able to forecast with remarkable accuracy the date of probable 

 first arrival of the birds in a given locality and to plot their migration 

 routes. This work is still going on, and the records from individual 

 observers in the same locality, sometimes running back for many years, 

 furnish a remarkable picture of the ebb and flow of the migratory move- 

 ments at that particular point. 



BlRDBANDING A FACTOR IN PLOTTING ROUTES 



MORE RECENTLY, the work of banding birds, started many years ago by 

 individuals, has been systematized and greatly extended by the Biological 

 Survey, until now the country is covered with a network of stations. The 

 Survey acts as a clearing house for information, furnishes bands to co- 

 operators, and develops traps of various kinds. Many individuals have 

 also developed traps for special uses. The work is carried out entirely on 

 a cooperative basis, volunteer workers doing the banding solely to assist 

 in getting vital information. Banding stations are maintained on many of 

 the migratory waterfowl refuges. To date (1940), more than three million 

 birds have been banded, and the returns have been great enough to allow 

 the plotting of migration routes with remarkable accuracy. 



As a result of this work, two facts stand forth increasingly clear. First, 

 the normal behavior of migratory birds traveling hundreds or thousands 

 of miles is exceedingly stereotyped. Banded birds are retrapped in the 

 same breeding location year after year, and wintering birds return for 

 many seasons to the same locality and even to the same field to spend that 

 season. For example, White-throated Sparrows and juncos, two birds 

 that winter commonly and widely over the eastern United States, are 

 caught season after season in the same stationary trap. The bands furnish 

 an invaluable means of identification and have revealed some remarkable 

 histories of movements and behavior of individual birds. For example, 

 one much-publicized Common Mallard hen has returned for eight con- 

 secutive seasons to build her nest on the same shed roof in northern 

 Nebraska. 



The second fact brought out by birdbanding is that, although the 

 normal behavior of birds, as stated, is apparently to follow the same line 

 of travel and to spend the summer and winter in the same localities each 

 year, there are many interesting cases of birds that have wandered far 

 afield. Two Black-headed Gulls, banded on July 18, 1911, at Rossitten, 

 Germany, were recaptured, one at Bridgetown, in the Barbadoes, in 

 November 1911, and the second at Vera Cruz, Mexico, in February 1912.. 

 Two kittiwakes were banded at the Fame Islands, England, on June 2.8, 

 192.3, and June 30, 192.4. The first was killed in Newfoundland on August 

 12., 1914, and the second in Labrador on October 2.8, 19x5. An American 



