scholarly journals Circadian versus circannual rhythm in the photoperiodic programming of seasonal responses in Eurasian tree sparrow (Passer montanus)

2020 ◽  
Vol 19 (3) ◽  
pp. 371-381 ◽  
Author(s):  
Anand S. Dixit ◽  
Namram S. Singh
Keyword(s):  
Circadian Rhythm ◽  
Day Length ◽  
Circannual Rhythm ◽  
Tree Sparrow ◽  
Passer Montanus ◽  
Eurasian Tree Sparrow ◽  
Proximate Factor ◽  
Seasonal Responses

Experiments were done on the subtropical tree sparrow to examine whether day length, as a proximate factor, involves circadian rhythm in timing seasonal responses or these events are programmed by the mediation of endogenous circannual rhythm.

scholarly journals Photoperiodic control of GnRH-I expression in seasonal reproduction of the Eurasian tree sparrow

2018 ◽  
Vol 17 (7) ◽  
pp. 934-945 ◽  
Author(s):  
Anand S. Dixit ◽  
Sanborlang Byrsat
Keyword(s):  
Temporal Information ◽  
Day Length ◽  
Seasonal Reproduction ◽  
Tree Sparrow ◽  
Photoperiodic Control ◽  
Passer Montanus ◽  
Eurasian Tree Sparrow

Day length has been shown to be a major source of temporal information regulating seasonal reproduction in the Eurasian tree sparrow (Passer montanus).

Environmental control of seasonal reproduction in the wild and captive Eurasian Tree Sparrow (Passer montanus) with respect to variations in gonadal mass, histology, and sex steroids

2013 ◽  
Vol 91 (5) ◽  
pp. 302-312 ◽  
Author(s):  
Anand S. Dixit ◽  
Namram S. Singh
Keyword(s):  
Environmental Control ◽  
Day Length ◽  
Seminiferous Tubules ◽  
Seasonal Cycles ◽  
Reproductive Seasonality ◽  
Tree Sparrow ◽  
Annual Cycles ◽  
Passer Montanus ◽  
Eurasian Tree Sparrow ◽  
In The Wild

The present study was undertaken on both sexes of the subtropical Eurasian Tree Sparrow (Passer montanus (L., 1758)) to investigate seasonal cycles of gonadal mass, histology, and hormones in relation to various environmental factors at Shillong, India. Attempts were also made to examine whether seasonal responses differ under wild and captivity and also between the sexes. Finally, reproductive seasonality of the sparrow under subtropical conditions was compared with the patterns found elsewhere in its distribution. Both sexes of the Tree Sparrow possess annual cycles of gonadal mass, histology, and steroids that follow the annual solar cycle. Increasing day length during spring stimulates gonadal growth with a corresponding increase in gonadal steroids followed by spontaneous gonadal regression leading to steroidal decline and photorefractoriness. Histomorphometric analyses of gonads revealed seasonal variations in the thickness of germinative epithelium and testicular wall, diameters of seminiferous tubules, and area of intertubular space in the males, and in the thickness of follicle wall and ratio of various follicles in the females. Although males responded in a similar fashion under wild and captivity, the responses of females deferred significantly. Thus, the Tree Sparrow exhibited sexual responses almost similar to their conspecifics at other latitudes.

Eurasian Tree Sparrow (Passer montanus)

2017 ◽  
Author(s):  
Jon C. Barlow ◽  
Sheridan N. Leckie ◽  
Peter Pyle ◽  
Michael A. Patten
Keyword(s):  
Tree Sparrow ◽  
Passer Montanus ◽  
Eurasian Tree Sparrow
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