Seasonally breeding birds detect environmental signals, such as light, temperature, food availability, and presence of mates to time reproduction. Hypothalamic neurons integrate external and internal signals, and regulate reproduction by releasing neurohormones to the pituitary gland. The pituitary gland synthesizes and releases gonadotropins which in turn act on the gonads to stimulate gametog...

The Arctic halocline stratification is an important barrier to the transport of deep ocean heat to the underside of sea ice. Surface water in the Chukchi Sea, warmed in summer by solar radiation, ventilates the Canada Basin halocline to create a warm layer below the mixed-layer base. The year-round persistence of this layer is shown to be consistent with the seasonal cycle of halocline ventilat...

Seasonal polyphenisms are widespread in nature, yet the selective pressures responsible for their evolution remain poorly understood. Previous work has largely focussed either on the developmental regulation of seasonal polyphenisms or putative 'top-down' selective pressures such as predation that may have acted to drive phenotypic divergence. Much less is known about the influence of seasonal ...

Major volcanic events with a high loading of stratospheric aerosol have long been known to cause cooling, but their impact on precipitation has only recently been emphasized, especially as an analog for potential geoengineering of climate. Here, the authors use a coupled atmosphere–ocean–land–vegetation model in conjunction with observations to study the effects of volcanic aerosol on the tropi...

Residential gardens in urban areas offer substantial opportunities for biodiversity conservation. To realize this opportunity, a comprehensive understanding of which species prosper gardens, mechanisms promote their use these green spaces and how can be manipulated by residents to achieve conservation outcomes, is needed. While progress has been made evaluating the that influence diversity, pre...