Code for: A century of wild bee sampling: historical data and neural network analysis reveal ecological traits associated with species loss

We analyzed the wild bee community sampled from 1921 to 2018 at a nature
preserve in southern Michigan, USA to study long-term community shifts in
a protected area. During an intensive survey in 1972 and 1973, F.C. Evans
detected 135 bee species. In the most recent intensive surveys conducted
in 2017 and 2018, we recorded 90 species. Only 58 species were recorded in
both sampling periods, indicating a significant shift in the bee
community. We found that the bee community diversity, species richness,
and evenness were all lower in recent samples. Additionally, 64% of the
more common species exhibited a more than 30% decline in relative
abundance. Neural network analysis of species traits revealed that
extirpation from the reserve was most likely for oligolectic
ground-nesting bees and kleptoparasitic bees, whereas polylectic
cavity-nesting bees were more likely to persist. Having longer
phenological ranges also increased the chance of persistence in polylectic
species. Further analysis suggests a climate response as bees in the
contemporary sampling period had a more southerly overall distribution
compared to the historic community. Results exhibit the utility of both
long-term data and machine learning in disentangling complex indicators of
bee population trajectories.