ol4 Recent IAterature. \nri 



lApril 



RECENT LITERATURE. 



Baldwin's 'Bird-Banding by Means of Systematic Trapping.' 1 — 



One of the most important contributions to bird-banding activities and 

 the study of bird migration, of recent years, is Mr. S. Prentiss Baldwin's 

 report of his operations at Thomasville, Georgia, and Cleveland, Ohio, 

 during the years 1914-1918, which constitutes the principal article in the 

 thirty-first 'Abstract of the Proceedings' of the Linnaean Society of New 

 York, for the year ending March 11, 1919. 



Mr. Baldwin found that a far greater number of "return" records could 

 be obtained from the systematic trapping of birds in connection with 

 banding them than by limiting one's operations to the banding of young 

 birds in the nest and trusting to their possible discovery elsewhere. His 

 paper is so full of valuable information and suggestions that everyone 

 interested in the matter should read it in its entirety and we shall here 

 quote only some of his more important results. 



The work at Thomasville was carried on for from four to six weeks 

 during three winters. Government sparrow traps were used, two the 

 first two years and five the third. The birds seemed to regard the traps 

 as feeding stations and were not frightened by being caught and handled, 

 in fact the problem was rather to keep some individuals out of the traps 

 than to entice them to enter. Some birds were in the trap every day, and 

 out of 65-4 individuals taken 441 were records of birds that were taken 

 more than once. 



Two White-throated Sparrows banded at the Thomasville trap in 1915 

 were retaken in 1916 and another one in 1917, while four of those banded 

 in 1916 were taken at the same place in 1917. No less than 25 of the 

 birds banded in 1916 and six in 1915 were trapped again in 1917. Mr. 

 Baldwin has thus demonstrated that migrants come back to the same place 

 to winter year after year, and others have proven that they come back 

 to the same spot to nest. He has also shown however that they do not 

 always do so and he states that the average observer is all too prone to 

 regard a pair of birds occupying a certain box or hole as the same pair 

 that occupied it the year before. The chance he considers is about one 

 in five that one of the pair will return and perhaps one in twenty-five that 

 they both return. 



In the case of House Wrens he shows that a pair reared a brood on his 

 farm near Cleveland while a second brood in the same box was found 

 to be the offspring of one of the original pair and a new mate, the other 

 parent of the first brood, having also secured a new mate, was caring for 

 a brood in another box. These facts as well as the return of birds to the 



1 Abstract of the Proceedings of the Linnaean Society of New York. For the 

 year ending March 11. 1919. No. 31, 1918-1919. Issued December 23. 1919. 



