642 ^ CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



Selous correctly pointed out that there was little information available on birds 

 except about their plumages, nests, eggs, and distribution. He stressed the need 

 for studies of behavior and the need for interpretation of habits, in addition to 

 mere factual recitation. His viewpoint was Darwinian and his interpretations of 

 behavior were in terms of selection and survival. 



Two years later, H. Eliot Howard (b. 1873, d. 1940) began his studies of 

 the British warblers (1907-1915). Howard was concerned primarily with the 

 investigation of nesting and brood care. His study of the several species of Brit- 

 ish warblers permitted comparison of the breeding biology of a group of closely 

 related species. In 1910 Howard called attention to the fact that the males in 

 many species took up a territory and defended it against intruders. He de- 

 veloped the territorial concept, apparently unaware of the work of Altum (1868), 

 and in 1920 devoted an entire volume. Territory in Bird Life, to the subject. 

 Howard's carefully documented theory had an immense effect on the ornitholo- 

 gists of the entire world. Others had recognized the general facts and had even 

 stated the elements of the theory of territory but Howard's emphatic presenta- 

 tion became the starting point of a new era in the study of avian behavior. 

 Among the many important studies which have utilized and expanded the ter- 

 ritorial concept since 1920 are two which rank as classics. As a result of several 

 years of intensive work on the song sparrow {Melospiza melodia) near Colum- 

 bus, Ohio, Margaret Morse Nice published two volumes (1937, 1943) dealing 

 with its life history and behavior. Mrs. Nice's familiarity with the literature 

 of avian behavior permitted a truly comparative presentation and her methods 

 have served as the model for numerous subsequent investigations. In 1941 Mrs. 

 Nice prepared a valuable review of the territorial concept which includes a com- 

 prehensive bibliography of the subject. 



The well-founded tradition of field natural history characteristic of present- 

 day England, begun by Gilbert White (1789) and nurtured by Edmund Selous, 

 is today led by David Lack. Lack's fine study (1939) of the life history of the 

 English robin {Erithacus rubecula) ntilized the techniques of observation of 

 marked individuals (color-banded) and the experimental use of stuffed speci- 

 mens. His work served to focus attention on the value of the intensive study of 

 single species. 



The first to bridge the gap between behavior and systematics was Oscar Hein- 

 rotli (b. 1871, d. 1945), who presented the idea (1910) that voice and behavior 

 were clues to relationship. Heinroth's interest was in the living bird and many 

 of his behavior studies were on captive birds in the Berlin Zoo. Heinroth laid 

 the foundation for further research in comparative behavior and crowned his 

 life's work with the remarkably detailed three-volume work, Die Vogel 3Iittel- 

 europas (1924-1928), with his wife as coauthor. This ambitious project was in 

 preparation for twenty years and included nearly three thousand photographs 

 and descriptions of the details of behavior, development, and other phases of 

 life history. 



The study of instinctive behavior received a new impetus with the work of 

 Konrad Lorenz in the 1930's. At his home in Altenberg, Austria, Lorenz studied 

 free-living, semitame birds of several species. His work on the behavior of the 

 jackdaw {Corvus monedula) started in 1925 with a single bird. A flock was 

 gradually built up which provided research material for a number of ethologi- 



