Climate change and seasonal reproduction in mammals

摘要

Seasonal reproduction is common among mammals at all latitudes, even in the deep tropics. Thispaper (i) discusses the neuroendocrine pathways via which foraging conditions and predictive cuessuch as photoperiod enforce seasonality, (ii) considers the kinds of seasonal challenges mammalsactually face in natural habitats, and (iii) uses the information thus generated to suggest how seaso-nal reproduction might be influenced by global climate change. Food availability and ambienttemperature determine energy balance, and variation in energy balance is the ultimate cause of sea-sonal breeding in all mammals and the proximate cause in many. Photoperiodic cueing is commonamong long-lived mammals from the highest latitudes down to the mid-tropics. It is much lesscommon in shorter lived mammals at all latitudes. An unknown predictive cue triggers reproductionin some desert and dry grassland species when it rains. The available information suggests that asour climate changes the small rodents of the world may adapt rather easily but the longer livedmammals whose reproduction is regulated by photoperiod may not do so well. A major gap inour knowledge concerns the tropics; that is where most species live and where we have the leastunderstanding of how reproduction is regulated by environmental factors.