Global declines in pollinator populations have raised alarm in conservation and agricultural circles in recent decades. Pollinators face multiple synergistic threats, including habitat loss and fragmentation, pesticides, competition with and disease transmission from non-native species, and climate change. Pollinators not only enable gene flow and reproduction for the plants that depend on them, they also underlie a host of ecosystem services stemming from diverse plant communities, including carbon sequestration, erosion control, water regulation, and wildlife habitat provisioning. Because pollinators cross political boundaries, we set out to assess the state of knowledge of pollinators in Mexico, the US, and Canada, to examine spatial and temporal trends, and to identify knowledge gaps. We extracted data on pollinator genera from the Global Biodiversity Information Facility (GBIF), an international repository for species occurrence data. GBIF is a clearinghouse of information from a variety of sources, including museum specimens and geotagged photographs from citizen science projects. In all, GBIF curates over a trillion species observations. We queried the GBIF database using R statistical software. We extracted data on the spatial distribution, number of observations, observation time horizon, and species within a genus and used georeferenced data points to extract information on ecoregion and habitat type.
Results/Conclusions
Our database includes 3597 insect pollinator genera for North America. Extracted records account for 25062 species and 1815883 observations of pollinator taxa across the three countries. Major groups of genera queried in GBIF include Diptera (53.4% of queried taxa), Lepidoptera (39.2%), Hymenoptera (4.4%), and Coleoptera (2.6%), with other groups rarer in our database. The most recent occurrence records range from the year 1800 (for the Diptera Arctodiamesa appendiculate, Ernoneura argus, and Pleurochaetella simplicipes) to 2020. In all, 46.1% of the extracted invertebrate genera occur in Canada, 72.7% occur in the US, and 30.0% occur in Mexico. Urban and built-up areas were habitat for the highest number of records in all three countries, emphasizing the tendency for collectors to record species they encounter in the locations they frequent. Although bees are known to exhibit highest diversity in arid regions, other pollinators likely peak in diversity in the tropics, as do many other taxonomic groups. However, a general dearth of tropical detections in the GBIF database, as well as fewer detections in Mexico than in either Canada or the US, likely stems from unequal sampling across the three countries and across habitat types, pinpointing an important gap in our knowledge of pollinators.