The development of photorefractoriness in termination of the breeding season in the tropical brahminy myna: role of photoperiod

Kumar, Vinod; Kumar, BS

doi:10.1051/rnd:19910102

Cited by 10 publications

(6 citation statements)

References 11 publications

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“…This suggested that there was a seasonality in loss and gain of photoresponsiveness in sparrows. A comparable situation exists in several photoperiodic species including temperate zone grey partridge [ Perdix perdix , [ 46 ]] and subtropical Indian weaver bird ( Ploceus philippinus [ 47 ]) and brahminy myna ( Sturnus pagodarum [ 48 ]). A study of Dawson [ 27 ] on house sparrows at 52°N, nevertheless, provided slightly different results.…”

Section: Discussionmentioning

confidence: 99%

Control of annual reproductive cycle in the subtropical house sparrow (Passer domesticus): evidence for conservation of photoperiodic control mechanisms in birds

2006

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BackgroundIn many birds, day length (=photoperiod) regulates reproductive cycle. The photoperiodic environment varies between different seasons and latitudes. As a consequence, species at different latitudes may have evolved separate photoperiodic strategies or modified them as per their adaptive need. We studied this using house sparrow as a model since it is found worldwide and is widely investigated. In particular, we examined whether photoperiodism in house sparrows (Passer domesticus) at 27°N, 81°E shared features with those exhibited by its conspecifics at high latitudes.ResultsInitial experiment described in the wild and captive conditions the gonad development and molt (only in captives) cycles over a 12-month period. Both male and female sparrows had similar seasonal cycles, linked with annual variations in day length; this suggested that seasonal reproduction in house sparrows was under the photoperiodic control. However, a slower testis and attenuated follicular growth among captives indicated that other (supplementary) factors are also involved in controlling the reproductive cycle. Next experiment examined if sparrows underwent seasonal variations in their response to stimulatory effects of long day lengths. When birds were transferred every month over a period of 1 year to 16 hours light:8 hours darkness (16L:8D) for 17–26 weeks, there was indeed a time-of-year effect on the growth-regression cycle of gonads. The final experiment investigated response of house sparrows to a variety of light-dark (LD) cycles. In the first set, sparrows were exposed for 31 weeks to photoperiods that were close to what they receive in between the period from sunrise to sunset at this latitude: 9L:15D (close to shortest day length in December), 12L:12D (equinox, in March and September) 15L:9D (close to longest day length in June). They underwent testicular growth and regression and molt in 12L and 15L photoperiods, but not in 9L photoperiod. In the second set, sparrows were exposed for 17 weeks to photoperiods with light periods extending to different duration of the daily photosensitivity rhythm (e.g. 2L:22D, 6L:18D, 10L:14D, 14L:10D, 18L:6D and 22L:2D). Interestingly, a slow and small testicular response occurred under 2L and 10L photoperiods; 6L:18D was non-inductive. On the other hand, 14L, 18L and 22L photoperiods produced testicular growth and subsequent regression response as is typical of a long day photostimulation.ConclusionSubtropical house sparrows exhibit photoperiodic responses similar to that is reported for its population living at high latitudes. This may suggest the conservation of the photoperiodic control mechanisms in birds evolved over a long period of time, as a physiological strategy in a temporally changing environment ensuring reproduction at the best suited time of the year.

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Section: Discussionmentioning

confidence: 99%

Control of annual reproductive cycle in the subtropical house sparrow (Passer domesticus): evidence for conservation of photoperiodic control mechanisms in birds

2006

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“…Photoperiodic responses of the tree sparrow are comparable to those of many temperate and subtropical photoperiodic avian species in which increasing day lengths in spring induce gonadal growth but fail to prevent regression of large gonads or to induce recrudescence of regressed gonads in summer months (Deviche and Small, ; Dawson, ; Singh et al, ). Seasonal changes in photosensitivity in the tree sparrow, thus, resemble to those of temperate zone gray partridge ( Perdix perdix ; Sharp et al, ), house sparrow ( Passer domesticus ; Dawson, ), subtropical weaver bird ( Ploceus philippinus ; Singh and Chandola, ), and brahminy myna ( Sturnus pagodarum ; Kumar and Kumar, ).…”

Section: Discussionmentioning

confidence: 94%

Seasonal Variation in Sensitivity of the Photoperiodic Response System in the Subtropical Tree Sparrow (Passer montanus)

Dixit

Singh

2012

J. Exp. Zool.

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We investigated seasonal variations in response to photoperiods in subtropical tree sparrow (Passer montanus), by examining the effects of long and short days on stimulation of response and termination of refractoriness, respectively. We also assessed whether photoperiodic effects were sex dependent. In one study, wild sparrows were transferred in each month of the year to artificial long days (14L/10D) for 12 weeks. Birds transferred from November to March (female) or April (male) showed gradual increase in gonadal growth and darkening of bill color, while those transferred from April (female) or May (male) to July underwent gradual regression in the above responses. Moult in the wing primaries and body feathers progressed with gonadal regression and the birds transferred from April/May to October exhibited gradual increase and decrease in feathers moult. In another study, 6 weeks of short day (9L/15D) exposure could recover responsivity to long days in refractory birds. Male and female birds responded almost in similar fashion with some variations. Overall, our results show a gradual change over seasons in responsiveness of the endogenous response system to stimulatory effects of long day length. They suggest roles of both long and short day lengths in regulation of seasonal cycles in subtropical tree sparrows.

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“…These life-history stages under natural conditions are controlled by two mechanisms: environmental light-dark cycle and circannual rhythm generation (Misra et al 2004). Seasonal and photoperiodic response on Indian weaver bird resemble with some other species, temperate zone gray partridge (Perdix perdix: Sharp et al 1986), house sparrow (P. domesticus: Dawson 1991;Trivedi et al 2006), tree sparrow (P. montanus: Dixit & Singh 2011, 2012 subtropical weaver bird (Ploceus philippinus : Singh & Chandola 1981), and brahminy myna (Sturnus pagodarum: Kumar & Kumar 1991). Finding of Singh & Chandola (1982) suggested that the transferring of birds under long day length and continuous light, decline the photoperiodic response, after attaining the peak response of gonads.…”

Section: Discussionmentioning

confidence: 99%

“…Also, day length acts as important proximate factor for life-history stages of some sub-tropical species including Indian weaver bird (Singh & Chandola 1981, 1982Pandey & Bhardwaj 2011;Bhardwaj & Pandey 2015), brahminy myna (Kumar & Kumar 1991), house sparrow (Trivedi et al 2006) and tree sparrow (Dixit & Singh 2011). Photoperiod is the important factor for the regulation of seasonal responses in a number of avian species inhabiting both mid-and high latitudes (Jain & Kumar 1995;Kumar 1997;Rani et al 2005;Dawson & Sharp 2007;Hahn & MacDougall-Shackleton 2008).…”

Section: Introductionmentioning

confidence: 99%

Photoperiodic regulation of seasonal responses in Indian weaver bird (Ploceus philippinus)

Pandey

Bhardwaj

2015

Biological Rhythm Research

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Photoperiod (=day length) is the vital factor for the regulation of behavioral and physiological activities in many avian species. This study investigated the seasonal cycles of testicular growth and secondary sexual characteristics of Indian weaver bird under natural day length (NDL) and the effects of duration and intensity of light on photoperiodic induction. In the first experiment, groups of birds (n = 7 each) were exposed to under NDL in April 2008 and May 2009 for 8 and 12 months, respectively. In second and third experiment, birds (n = 6 each group) were exposed to different photoperiods (11.5L:12.5D, 12L:12D, 13L:11D, and 15L:9D) at the same (500 lux) light intensity, and to 13L:11D at different light intensities (10-, 50-, 500-, and 800-lux). Observations on testis size, molt, and plumage score were recorded 2-week (molt and plumage) or at 4-week intervals (testes). Both the NDL groups showed similar seasonal cycles of testicular growth-regression and secondary sexual characteristics. Second and third experiments suggest that the photoperiodic induction was depending upon duration and intensity of the light. Birds showed testicular growth-regression cycle followed by molt and plumage color change only under 13L:11D and 15L:9D and only 500-and 800-lux under 13L:11D photoperiod but not under 11.5L:12.5D and 12L:12D and 10-and 50-lux light intensities. Pre-and postnuptial molting on body feathers were progressed with gonadal stimulation-maturation and regression cycle under 13L:11D and 15L:9D. Results under different lightdark cycles suggest that day length of about 12 h or more and above the threshold level of light intensity are essential for the induction of photoperiodic responses.

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The development of photorefractoriness in termination of the breeding season in the tropical brahminy myna: role of photoperiod

Cited by 10 publications

References 11 publications

Control of annual reproductive cycle in the subtropical house sparrow (Passer domesticus): evidence for conservation of photoperiodic control mechanisms in birds

Control of annual reproductive cycle in the subtropical house sparrow (Passer domesticus): evidence for conservation of photoperiodic control mechanisms in birds

Seasonal Variation in Sensitivity of the Photoperiodic Response System in the Subtropical Tree Sparrow (Passer montanus)

Photoperiodic regulation of seasonal responses in Indian weaver bird (Ploceus philippinus)

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