Pollen Quantification
Pollen loads were assessed by comparing non-bee insect visitors to the genus of bee with the largest pollen loads, Halictus , using a generalized linear model (GLM) using quasi-poisson distribution. A GLM was used in place of a linear model to account for the non-normal distribution of data. As the data were also overdispersed, a quasi-poisson distribution was chosen (Ver Hoef and Boveng 2007). The pollen counts for each respective genus were used as response variable. Each non-bee genus was treated as a factor and included as explanatory variables. Visualizations of pollen loads, and insect abundance were presented using TreeMaps generated in R (version 2.5-5). To assess total available pollen contribution, data from observations were combined with pollen counts from collected specimens, total pollen = observed abundance x average pollen count. The percentage of total pollen was calculated by taking the average pollen load for each insect taxon and dividing it by the absolute sum of total pollen counts.