Halfway down the east slope of the Andes in Ecuador, sightings of the luminous yellow beaks of the chestnut-mandibled toucan are abruptly replaced by the colorful beaks of the white-throated toucan.

We created experimental patches with one, two or three sizes of seeds, and recorded the number of species, and numbers of individuals of each species of birds exploiting the seeds in winter. Bird ...

1. Although competition for pollination is often invoked as a driver of broad-scale evolutionary and ecological patterns, we still lack a clear understanding of the mechanics of such competition. When ...

I AM glad that Drs. Andrewartha and Browning have been able to go some way with me. I hope that the following remarks will help them to travel further. The example of the car was used as an analogy, ...