convergence

The texture of a plant community, i.e. the range of values in functional characters across the species present, integrates the ecological and evolutionary processes that have led to that communityÕs present species composition. The idealistic prediction of ecological theory is that selection for co-adaptation and competitive sorting will lead to convergence in texture between different patches of vegetation with the same environment. This concept has previously been applied at the continental scale; here it is applied for the first time at a within community scale.

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.