Helpers Among Birds

Twenty-five years ago, I published a paper (1935) on “Helpers at the Nest,” in which I gave short accounts of the breeding of three species of birds whose nestlings were attended by individuals other than the two parents. In addition, I mentioned one other species in which I had found a helper and a few instances of similar behavior that had come to my attention in books. In the quarter-century that has elapsed since this paper was written, I have watched helpers of 16 additional species, and scores of similar instances have been described in print. The purpose of the present paper is to give a comprehensive survey of the occurrence of helpers among birds, indicating the range of their activity and analyzing the circumstances that promote it. The first part contains a general discussion of the subject, and this is followed in the second part by a systematic list of instances of helpers known to me. This listing of cases which have come to my notice over the years does not pretend to be complete. Although most of the examples presented come from ornithological books and journals, others were found in books of a more general nature, in popular magazines of natural history, and even in the daily press. I doubt if I have noticed a third or even a quarter of the helpers which have been reported in print in all parts of the world. However, I believe that the examples cited give a fair notion of the range and variety of helpfulness among birds and indicate the groups and the circumstances in which helpers are most likely to be found. To avoid needless duplication, I have omitted scientific names and citations of literature in the first part of this paper whenever these are to be found in the Annotated List which immediately follows.

[1]  A. C. Bent.  Life Histories of North American Wood Warblers , 1963 .

[2]  H. Ouellet.  A Grasshopper Sparrow near Quebec, Province of Quebec , 1960 .

[3]  R. Selander.  Polymorphism in Mexican Brown Jays , 1959 .

[4]  Alexander F. Skutch.  ROOSTING AND NESTING OF ARACARI TOUCANS , 1958 .

[5]  D. Lack,et al.  The Nesting of the Long-Tailed Tit , 1958 .

[6]  I. Rowley.  Co-operative Feeding of Young by Superb Blue Wrens , 1957 .

[7]  J. Cullen.  Plumage, Age and Mortality in the Arctic Tern , 1957 .

[8]  Amelia R. Laskey.  Some Tufted Titmouse Life History , 1957 .

[9]  H. Young.  Breeding Behavior and Nesting of the Eastern Robin , 1955 .

[10]  G. Sutton,et al.  NESTING OF THE GREENLAND WHEATEAR ON BAFFIN ISLAND , 1954 .

[11]  J. Oliver,et al.  Unusual Nesting Behavior of the Brown-Headed Nuthatch , 1954 .

[12]  J. Warham.  The behaviour of the Splendid Blue Wren. , 1954 .

[13]  Stanley M. Richmond.  THE ATTRACTION OF PURPLE MARTINS TO AN URBAN LOCATION IN WESTERN OREGON , 1953 .

[14]  W. Sladen,et al.  The Adelie Penguin , 1953, Nature.

[15]  V. Wynne-Edwards.  Zoology of the Baird Expedition (1950) I. The Birds Observed in Central and South-East Baffin Island , 1952 .

[16]  Robert L. Eberhardt.  Northern Phalaropes and Xantus Murrelet Associated with Fishes , 1952 .

[17]  H. Brackbill.  A JOINT NESTING OF CARDINALS AND SONG SPARROWS , 1952 .

[18]  W. Fox.  Behavioral and Evolutionary Significance of the Abnormal Growth of Beaks of Birds , 1952 .

[19]  Malcolm W. Davis.  Captive Raven Carries Food to Non-Captive Black Vulture , 1952 .

[20]  H. Thomas.  Notes on the Pied Butcher-bird. , 1951 .

[21]  T. Riney.  Relationships between Birds and Deer , 1951 .

[22]  A. O. Gross.  Nesting of the Mexican Jay in the Santa Rita Mountains, Arizona , 1949 .

[23]  H. Fitch.  Sparrow Adopts Kingbirds , 1949 .

[24]  A. C. Bent.  Life histories of North American nuthatches, wrens, thrashers and their allies , 1948 .

[25]  Herbert Elftman,et al.  SECTION OF BIOLOGY1: Experimental Studies on the Dynamics of Human Walking , 1943 .

[26]  D. E. Davis.  The Phylogeny of Social Nesting Habits in the Crotophaginae , 1942, The Quarterly Review of Biology.

[27]  XXXIII.—Hornbill Studies. , 1940 .

[28]  E. C. Raney.  Robin and Mourning Dove Use the Same Nest , 1939 .

[29]  R. Moore.  Discovery of the Nest and Eggs of the Tufted Jay , 1938 .

[30]  Alice Baldwin Addicott.  Behavior of the Bush-Tit in the Breeding Season , 1938 .

[31]  A. C. Bent.  Life histories of North American cuckoos, goatsuckers, hummingbirds and their allies , 1932 .

[32]  A. C. Bent.  Life histories of North American flycatchers, larks, swallows, and their allies , 1927 .

[33]  F. A. Leach.  Communism in the California Woodpecker , 1925 .

[34]  H. Hales.  Peculiar Traits of Some Scarlet Tanagers , 1896 .

[35]  C. Darwin.  The Descent of Man and Selection in Relation to Sex: INDEX , 1871 .