... gonadal activation are modified when food is scarce or temperatures are low by changing hypothalamic Tshβ, Kiss1 and Rfrp expression to adaptively adjust the timing of reproductive organ development. Seasonal reproduction Photoperiodism Ambient temperature Food scarcity Hypothalamic gene...

... modifies seasonal timer mechanisms. Summary: Svalbard ptarmigan show photoperiodic responses when transferred from constant darkness to constant light without circadian entrainment. Photoperiodism Circadian Seasonal reproduction Pars tuberalis Eyes absent Deiodinase Svalbard ptarmigan...

... breeding seasons at lower latitudes than at higher latitudes, leading to nearly year-round reproduction in the most southern stream populations. A review of recent progress in our understanding of the physiological mechanisms underlying seasonal reproduction in the three-spined stickleback indicates...

... and gonadal level. Luteinizing hormone Gonadal development Gonadotropin-releasing hormone Hypothalamic–pituitary–gonadal axis Seasonal reproduction Testosterone For many animals, the decision of when to breed is a critical one because timing reproduction to coincide with favorable...

.... * Author for correspondence (e-mail: [email protected] ) 8 4 2009 2009 energy expenditure respirometry gonadal cycles timing of reproduction seasonal reproduction phenology supplemental factors environmental cues captive experiments predictability day length In most...