Endocrine Regulation of Body Weight in the Spotted Munia, Uroloncha Punctulata
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چکیده
Literature on the body-weight cycles of nonmigratory birds is meager (Nice 1937, 1938, 1946; Baldwin and Kendeigh 1938), and consequently the factors that regulate these cycles are only incompletely understood (Farner 1955). The mean body weight of a bird that has free access to food, it has been suggested, may change because of alteration in the level of the activity of the hypophysis (Wolfson 1952; Famer 1960; King and Farner 1963; Meier and Farner 1964) or of the gonads (Hijhn 1947; see also review by Famer 1955), or even of the thyroid (Schildmacher and Rautenberg 1952). However, experimental investigations of the body-weight cycles have been confined mostly to migratory birds. Recently Thapliyal ( 1966) and Thapliyal and Pandha (1966) have shown in the nonmigratory Spotted Munia, Urokmcha punctulata, that during the breeding phase the average weight of males is significantly higher than that of females (fig. 1). It has also been reported (Thapliyal1966) that, while orchiectomy had no influence, thyroidectomy induced a rapid increase in the body weight of the birds, and after some time the mean body weights of the two sexes overlapped. To explain, it was suggested that the mechanisms that control the body weight of a Spotted
منابع مشابه
Circadian rhythms are not involved in the regulation of circannual reproductive cycles in a sub-tropical bird, the spotted munia.
Circannual rhythms regulate seasonal reproduction in many vertebrates. The present study investigated whether circannual reproductive phenotypes (rhythms in growth of gonads and molt) were generated independently of the circadian clocks in the subtropical non-photoperiodic spotted munia (Lonchura punctulata). Birds were subjected to light:dark (LD) cycles with identical light but varying dark h...
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Seasonal changes in reproduction and other metabolic conditions may result from interaction of circadian neural oscillations and hormonal secretion that change seasonally. To test this hypothesis, the present study was designed to study the effect of melatonin and circadian neurotransmitter activity on reproductive and hormonal conditions in a subtropical finch, spotted munia (Lonchura punctula...
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A long term investigation was made on the importance of thyroxine and prolactin in the reproduction of a tropical wild bird, spotted munia, Lonchura punctulata. Different doses of thyroxine i.m. (0.5, 1.0 and 2.0 microg; 0.56, 1.12 and 2.24 n mol Sodium salt, Sigma) per day/bird were administered in 0.1 ml of 0.9% alkaline NaCl per day per bird. Similarly various doses of prolactin (1.0, 2.0,. ...
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تاریخ انتشار 2001