Annual gonadotropin and testosterone cycles in free-living male birds

✍ Scribed by Silverin, Bengt

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 627 KB
• Volume: 232
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402320326

✦ Synopsis

Seasonal changes in the activity of endocrine organs have been studied for decades using histological, histochemical, and enzymatic methods. The recent development of radioimmunoassays for measurements of hormone concentrations in very small quantities of plasma have provided a new dimension to endocrine studies in birds. Most studies within this field have, however, been performed on caged birds or birds living under seminatural conditions. As seen in Table 1, annual hormonal cycles in strictly freeliving birds have, to date, been studied in 18 bird species. In some free-living species, studies have been restricted to the breeding season; for example, western meadowlark, Strunella neglecta (Wingfield and Farner, '80); vesper sparrow, Pooecetes grammineus (Wingfield and Farner, '80); collared dove, Streptopelia decmto (Peczely and Pethes, '79); pied flycatcher, Ficedula hypoleuca (Silverin and Wingfield, '82; Silverin and Goldsmith,