Phenology refers to the periodic appearance of life-cycle events and currently receives
abundant attention as the effects of global change on phenology are so apparent …

Birdsong is controlled in part by a discrete network of interconnected brain nuclei regulated
in turn by steroid hormones and environmental stimuli. This complex interaction results in …

Physiological Adaptations for Breeding in Birds is the most current and comprehensive
account of research on avian reproduction. It develops two unique themes: the consideration …

Sex is ubiquitous and variable throughout the animal kingdom. Historically, scientists have
used reductionist methodologies that rely on a priori sex categorizations, in which two …

Organisms in a seasonal environment often schedule activities in a regular way over the
year. If we assume that such annual routines have been shaped by natural selection then …

Study of seasonal reproduction has focused on the brain. Here, we show that the inhibition
of sex steroid secretion can be seasonally mediated at the level of the gonad. We investigate …

Life of many organisms flows as a sequence of annual cycles. Timing of cyclical events is
shaped by natural selection also via the domino effects that any life history stage has on the …

Most animals in the temperate zone exhibit robust seasonal rhythms in neuroendocrine,
physiological and behavioral processes. The integration of predictive and supplementary …

1. Breeding at the right time of the year is crucial for many temperate zone organisms, as any
mismatch with their optimal breeding period leads to a reduction in fitness. The roles of the …

This paper reviews current knowledge of photoperiod control of GnRH-1 secretion and
proposes a model in which two processes act together to regulate GnRH1 secretion. Photo …