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THE FUNCTION OF THE HEAD‐COLORATION OF THE NESTLING COOT AND OTHER NESTLING RALLIDÆ.
Author(s) -
Boyd H. J.,
Alley Ronald
Publication year - 1948
Publication title -
ibis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 80
eISSN - 1474-919X
pISSN - 0019-1019
DOI - 10.1111/j.1474-919x.1948.tb01720.x
Subject(s) - subspecies , zoology , biology , head (geology) , ecology , paleontology
Summary. Several hypotheses as to the function of the head‐coloration of nestling Coot are discussed with reference to the behaviour of the young. The evidence presented supports the view that the bright coloration serves to emphasize the signal‐movements employed by the young in obtaining food from adults. A review of the literature on the colouring of sixty other species and subspecies of the family Rallidæ reveals the prevalence of bright bill‐colours and the occurrence of bright head‐markings in several genera. It is suggested that bright bills represent the first stage in the development of emphatic coloration such as is highly developed in the Coot. Several intermediate stages have been described. Bright head‐markings are limited to those species in which the need for procryptic coloration is no longer paramount.