Many types of birds regularly consume fleshy fruits and, as seed dispersers, perform important mutualistic services for plants. Some frugivorous birds have recently been introduced to geographic locales beyond their native range. Are non-native birds important frugivores in their introduced range? To answer this question, I observed native and introduced birds foraging for fruits in a New Zealand forest at approximately 5-day intervals for 5 years.
If deterministic processes consistently structure ecological communities, similar patterns in species interactions should be observed in different geographic areas that experience similar environmental conditions. I tested for convergent patterns in dietary diversity of fruit-eating birds inhabiting similar latitude forests in the Northern and Southern hemispheres. I observed birds foraging for fruits over two fruiting seasons in both Nelson Lakes National Park, South Island, New Zealand, and the Pacific Rim National Park, Vancouver Island, Canada.