Pollination network studies are based on pollinator surveys conducted on focal plants.This plant-centred approach provides insufficient information on flower visitation habitsof rare pollinator species, which are the majority in pollinator communities. As a result,pollination networks contain very high proportions of pollinator species linked to asingle plant species (extreme specialists), a pattern that contrasts with the widely acceptedview that plant–pollinator interactions are mostly generalized. In this study of aMediterranean scrubland community in NE Spain we supplement data from an intensivefield survey with the analysis of pollen loads carried by pollinators. We observed 4265contacts corresponding to 19 plant and 122 pollinator species. The addition of pollendata unveiled a very significant number of interactions, resulting in important networkstructural changes. Connectance increased 1.43-fold, mean plant connectivity went from18.5 to 26.4, and mean pollinator connectivity from 2.9 to 4.1. Extreme specialistpollinator species decreased 0.6-fold, suggesting that ecological specialization is oftenoverestimated in plant–pollinator networks. We expected a greater connectivity increasein rare species, and consequently a decrease in the level of asymmetric specialization.However, new links preferentially attached to already highly connected nodes and, as aresult, both nestedness and centralization increased. The addition of pollen data revealedthe existence of four clearly defined modules that were not apparent when only fieldsurvey data were used. Three of these modules had a strong phenological component. Incomparison to other pollination webs, our network had a high proportion of connectorlinks and species. That is, although significant, the four modules were far from isolated.
