Weighted interaction networks and bird/plant traits.
Weighted plant-bird interaction networks at eight sites in the Andes; two in Colombia, two in Ecuador, two in Peru, one in Bolivia and one in Argentina. At each site, networks were sampled by direct observation of true seed-dispersal events (fruit swallowing or carrying-away). Sampling effort was high in all networks (range of sampling hours: 300960, mean=606, standard deviation=224). For all bird species we collected the following morphological traits: bill length and width (mm), body mass (g) and Kipps index (Kipps distance/wing length). For all plants species we collected the following morphological traits: fruit length and diameter (mm), crop mass (g, fruit mass * number of fruits per plant), and plant height (m). Plant traits were sampled in the field.