BY ROBERT L. MERZ University of Kansas Lawrence 1963 University of Kansas Publications, Museum of Natural History Editors: E. Raymond Hall, Chairman, Henry S. Fitch, Theodore H. Eaton, Jr. Volume 12, No. 12, pp. 521-551, 22 figs. Published October 25, 1963 University of Kansas Lawrence, Kansas PRINTED BY JEAN M. NEIBARGER, STATE PRINTER TOPEKA, KANSAS 1963 29-7865 BY ROBERT L. MERZ For some time many investigators have thought that the genus Zenaida , which includes the White-winged and Zenaida

In order to determine in each species the normal pattern of musculature of the jaws, heads of 13 specimens of doves were dissected (all material is in the Museum of Natural History of The University of Kansas): White-winged Doves ( Zenaida asiatica ), 40323, 40324, 40328, 40392, 40393; Zenaida Doves ( Z. aurita ), 40399, 40400; Mourning Doves ( Zenaidura macroura ), 40326, 40394, 40395, 40396, 40397, 40398. Thirty-seven skulls from the collection of the Museum of Natural History of The Universit

My appreciation is extended to Professor Richard F. Johnston, who advised me during the course of this study, and to Professors A. Byron Leonard and Theodore H. Eaton for critically reading the manuscript. I would like also to acknowledge the assistance of Dr. Robert M. Mengel and Mr. Jon C. Barlow for suggestions on procedure, and Mr. William C. Stanley, who contributed specimens of Mourning Doves for study. Mr. Thomas H. Swearingen offered considerable advice on production of drawings and Prof

The jaw musculature of doves is not an imposing system. The eating habits impose no considerable stress on the muscles; the mandibles are not used for crushing seeds, spearing, drilling, gaping, or probing as are the mandibles of many other kinds of birds. Doves use their mandibles to procure loose seeds and grains, which constitute the major part of their diet (Leopold, 1943; Kiel and Harris, 1956: 377; Knappen, 1938; Jackson, 1941), and to gather twigs for construction of nests. Both activitie

M. pterygoideus ventralis. —Contraction of this muscle retracts the upper mandible by moving the palatine posteriorly, and simultaneously adducts the lower mandible. M. pterygoideus dorsalis. —This muscle functions in essentially the same manner as M. pterygoideus ventralis . The result of having a part of its origin on the pterygoid as well as on the palatine is to facilitate retraction of the upper mandible. M. adductor mandibulae. —This is the chief adductor of the lower mandible and the musc

The ability of most birds to protract the upper mandible, and the structure of the skull which enables them to do so are responsible for common reference to the skull as "kinetic" (Beecher, 1951a:412; Fisher, 1955:175). The movement is effected by muscular action on a series of movable bones that exert their forward force on the upper mandible, which in turn swings on a horizontal hinge, the "naso-frontal hinge," at the base of the beak. The bone initiating the movement is the quadrate, which is

In the species dissected, the only variable muscle that I consider significant in revealing relationships is M. pseudotemporalis profundus . It is markedly enlarged in the White-winged Dove in relation to the homologous muscle in the Mourning Dove. The muscle is enlarged in such a manner that a lateral expansion of its mass is apparent in superficial or dorsal view (compare figures 15 and 16). This, of course, indicates a muscle with powerful contraction, which has been unable to enlarge its cir

An attempt will be made here to summarize all the available evidence, direct or indirect, which bears on the problem of relationship of these genera. The original dissections which are discussed in this report are only valuable as one more bit of evidence concerning one characteristic that aids in clarification of generic relationship, and it is only in conjunction with other evidence that any satisfactory conclusion may be forthcoming. My dissections demonstrated that, in relation to the size o

The avian genus Zenaida is currently considered to be distinct from the genus Zenaidura by most columbid taxonomists. The jaw muscles of six Mourning Doves ( Zenaidura ) and five White-winged Doves ( Zenaida ) were investigated as to differences and similarities that might clarify the relationships of the genera. The sizes and proportions of skulls were also considered in 37 Mourning and White-winged doves and two Eared Doves. Larger size of M. pseudotemporalis profundus , the muscle that functi

Adams, L. A. 1919. A memoir on the phylogeny of the jaw muscles in recent and fossil vertebrates. Annals New York Acad. Sci., 28:51-166. Audubon, J. J. 1834. Ornithological biography. Vol. II. Adam & Charles Black, Edinburgh, xxxii + 588 pp. Baird, S. F. , Brewer, T. M. , and Ridgway, R. 1905. The land birds of North America. Little, Brown, and Company, Boston, 560 + xxvii pp. Beecher, W. J. 1950. Convergent evolution in the American orioles. Wilson Bull. 62:51-86. 1951a. Adaptations for