3 research outputs found
Premigratory increase in circulating triiodothyronine/thyroxine ratio in the red-headed bunting (Emberiza bruniceps)
No full textThe circulating triiodothyronine/thyroxine () ratio in the red-headed bunting significantly increased prior to migration. Marked extrathyroidal conversion of T4 to T3 also occurred. The possibility that migratory disposition in this bird may be related to an increase in serum concentration of T3 is, therefore, raised
Environmental correlates of the annual fattening cycle of Spotted munia,Lonchura punctulata(Aves, Estrildidae)
No full textSpotted munia exhibits a distinct annual periodicity in body weight, which does not coincide with the annual temperature and photoperiodic changes. A seasonal variation in daily feeding pattern could be associated with the cycle. An endogenous circannual oscillator with a periodicity of about 10 months may also be involved. This bird, therefore, may prove to be a suitable model for the studies of interaction of daily and annual events with respect to circannual rhythms
