414 Recent Literature. [jiily 



Allen's ' The Red-winged Blackbird.'' — Dr. Allen has presented in 

 this monograph one of the best ecologic studies that has j^et appeared, one 

 that many other ' ecologists ' would do well to take as a model^^if they would 

 save this line of research from degenerating into what has been aptly styled 

 an " elaboration of the obvious." The author points out the correlation of 

 the distribution of certain species of birds and other animals with certain 

 environments and certain plant associations, and adds; " What are the 

 adaptations of each species to its pecuhar habitat, and how has each 

 become dependent upon it? Questions such as these demand an intimate 

 knowledge, not only of every phase of the Life history of each bird, but also 

 of every condition that might be imposed by its surroundings." With 

 this prelude he proceeds to study one species, the Red-winged Blackbird 

 (Agelaius phccniceus phceniceus) in a cat-tail marsh near Ithaca, N. Y. 

 The detail and thoroughness of his studies are praiseworthy although, he 

 states, that they form merely an introduction to a true knowledge of the 

 life history of the bird and its relation to its environment. 



The environment of the marsh is first considered and the area is divided 

 into seven associations the characteristic plants, birds, mammals, reptiles 

 and amphibians being Usted under each. Temperature records for an 

 entire year bring out the rather surprising fact that the average tempera- 

 tuns of the marsh and the adjacent upland differ by 15ss than a degree. 



In the study of the Redwing, migration, mating, song, nesting, young, 

 fall migration, enemies, molt and plumage, food and food supply, and cor- 

 relation of changes in food and stomach structure, and in the reproductive 

 organs are considered. Published data on each subject are briefly quoted, 

 followed by the results of the author's investigations. Incidentally one is 

 impressed with the very httle that subsequent writers have added to the 

 accounts of Wilson, and NuttaU bearing upon many of these topics and 

 what an opportunity for original contributions has been neglected. Under 

 migration, Dr. Allen considers the arrival of four categories of birds inde- 

 pendent of males and females which are well known to migrate inde- 

 pendently. He distinguishes (1) " vagrants " — very early arrivals, 

 representing irregular winter residents from not very far southward, (2) 

 migrant [i. e. transient] adults, (3) resident adults, and (4) resident 

 immatures. The last do not arrive till the " adults " have built their 

 nests and consequently extend the breeding season over a considerable 

 space of time. These facts of migration form another argument against 

 the accuracy of comparisons based upon single first-arrival dates which the 

 writer has emphasized elsewhere. 



Dr. Allen's conclusions are that the Redwing is independent of the 

 marsh so far as food is concerned, feeding mainly outside of its lunits, 

 that it has taken to nesting in the marsh for the shelter that is afforded 



I The Red-vpinged Blackbird: A Study in the Ecology of a Cat-tail Marsh. 

 By Arthur A. Allen. Abstract of Proceedings of the Linneean Society of New York. 

 Nos. 24-25, 1911-131 pp. 43-128. April 15, 1914. 



