The embryonic development of the California Gull

The California gull (Larus califomicus) is a summer resident in Utah nesting commonly on certain islands in Great Salt Lake as well as at man-made refuges on the east side of the lake. Many aspects of the biology of the species have been investigated (Beck, 1942; Behle, 1958; Behle and Goates, 1957; Behle and Woodbury, 1952; Greenhalgh, 1952; Johnston, 1956; Odin, 1957; Woodbury, Behle and Sugden, 1946) and it seemed that an opportunity was presented to study yet another feature, namely, the early embryonic development. This conviction was strengthened when it was noted in Romanoff's (1960) extensive work on the avian embryo that whereas there is mention of embryological studies on some species of gulls of the genus Larus, the California gull was not included. Furthermore, no study of the gross external anatomy of any gull seemed to have been made; rather the studies had been histological investigations of the internal anatomy.