How climate change influences the dynamics of plant populations is not well understood, as few plant studies have measured responses of vital rates to climatic variables and modeled the impact on population growth. I used 25 years of demographic data to analyze how survival, growth, and fecundity re

PREMISE OF THE STUDY: Optimal Defense Theory predicts that selection should drive plants to differentially allocate resources for herbivore defense to tissues with high fitness values. As pollen’s primary role is the transport of gametes, plants may be expected to defend it from herbivory. However,

Hummingbirds foraging for nectar in mountains of the western USA encounter spatially-variable rewards under energetically-demanding environmental conditions. Previous workers have found that hummingbirds respond quickly to the average quantity and quality of reward; in addition, one might expect a r

It is concluded that bees prefer to visit magenta-coloured flowers with a sparkling surface, which has implications for the idea of ‘pollination syndromes’, whereby certain plants are thought to be adapted to attract particular pollinators.

The potential for a trade-offs between these two components of pollinator service exists when visit duration depends on reward quantity; whether the trade-off is realized will depend on variation in nectar production and on whether pollinators forage systematically.

Two different mechanisms can result in multiple paternity within fruits: deposition of a mixed pollen load due to carryover of pollen from flower to flower and multiple pollinator visits in close succession. I investigated the extent of multiple paternity within fruits of Ipompsis aggregata containi