Undergraduate University of Wisconsin Westby, Wisconsin, United States
In the face of environmental change, including climate change, many organisms’ biological and ecological processes are being altered. Adult sex ratios are directly related to an organisms’ reproductive success and long-term viability. Understanding what influences sex ratios in the face of these changes may help us to predict the success of an organism. Here we investigated how climate variation influences the adult sex ratios of twelve species of solitary bees present in what is now the Gothic, Colorado area. We looked at how climate variation, specifically snowmelt timing, may influence their adult sex ratios. We also explored how nesting traits may provide protection or susceptibility to climatic influence. Using long-term data collected by Dr. Rebecca Irwin’s lab and billy barr, we ran generalized linear models to understand the relationship between snowmelt timing and the sex ratios of each of the twelve selected bee species. Across all species, we found that in years with early snowmelt, the following year had a smaller proportion of females. The same trend was seen significantly with below-ground nesters. Above ground nesters exhibited the same pattern but the pattern lacked significance. We hypothesize that snowmelt does not have a direct effect on the sex ratios of solitary bees, but rather that it influences floral abundance which affects the ability of females to provision female vs. male offspring. Future studies should further explore this as it may have a direct influence on the long-term viability of solitary bees.
