Seasonal and Taxonomic Differences in the Size and Activity of the Thyroid Glands in Birds
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Citation:The Ohio Journal of Science. v66 n4 (July, 1966), 369-379
The thyroid glands of the house sparrow and other small birds in the Cleveland region have greater secretory activity during late autumn and winter than during late spring and summer. Evidence for this is the presence, during the winter, of high epithelial cells surrounding the follicles, of smaller follicles, and of lesser volumes and weights of the whole thyroid. Large-sized species have larger thyroids, both absolute and relative to body weight, than do small species. With certain precautions, changes in the size of the thyroids serve as a useful index of inverse variations in secretory activity intra-specifically, but not inter-specifically.
Author Institution: University of Illinois, Champaign, and Metropolitan Park District, Cleveland, Ohio
Rights:Reproduction of articles for non-commercial educational or research use granted without request if credit to The Ohio State University and The Ohio Academy of Science is given.
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