Think of the foods you eat during the course of a day. For those of us fortunate enough to have access to good food, it’s an incredibly diverse selection of delicious & nutritious foods including grains, fruits, vegetables, nuts, and much more. How is that food produced? Where does it come from? What are the challenges in growing it? As it turns out, a large portion of food, just about 30%, is available to us thanks to some kind of insect. An insect? Aren’t those just annoying critters that scurry about and gross me out? Certainly not!
Insects are essential to helping to produce a majority of the food we eat. The most important are pollinators – insects, especially bees, that help plants to reproduce and create the delicious and nutritious fruits, vegetables, nuts, and seeds we love. Despite their importance, many bee species are declining. Increased intensity of farming, newly emerging diseases and parasites, increased use of pesticides, and climate change are all struggles bees face in many regions, especially in the US. So what can we do to help ensure their survival and well-being?
The first step in helping bees is trying to figure out which environments they do best in. Do bees only thrive in native grasslands? Can they do well in a more mixed landscape including grasslands and agriculture? Can they thrive in urban environments? Knowing areas where bees do well will highlight areas we should protect, or try to emulate elsewhere in the landscape. While we are well aware of how necessary bees are for our survival, we still don’t know a lot about their biology and ecology. Most of our knowledge is about the honey bee, Apis mellifera. This single species is the work-horse of the agricultural industry and provides us with a nice, tasty treat. However, the honey bee is just one of over 20,000 species of wild bees, worldwide. All of these species are capable of pollinating plants, but our focus on only one has let many of these species fall to the wayside.
So, one of the first step in helping wild bees is to figure out what types of environments are best for them. Easy enough, right? We’ll just ask them where they prefer to live. Unfortunately, we can’t do that, so we have to figure out something else…
How we get there: RFID Radio Tagging
Because we can’t just talk to bees and figure out where they like to live, we have to look at some other aspect of the bee to get the information we need – perhaps how many bees are in a certain area and how many kinds are there. While this tells us about the biodiversity of an area, it doesn’t do a great job of telling us exactly what aspects of the environment are promoting the bee abundance and diversity that we observe. There are two other ways that we can determine how bees perceive their habitat: how healthy individuals or colonies are, and how individuals or colonies behave. The health one is easy: we can see how many bees a colony has, how big they get, and how reproductively active they are. How they behave is a bit different…
Bumble bees must gather food for their offspring, just like any other animal. To do this, they fly around gathering pollen, a protein source for developing larvae, and nectar, a sugar-rich carbohydrate for themselves and their offspring. Both of these food sources come from flowers. Bumble bees will take off from their nest and search for these resources. If there aren’t many flowers around, we might expect that it would take them longer to find what or enough of what they need. In contrast, if there are a lot of flowers in the vicinity, we might expect them to find what they need quickly – returning to the nest sooner than bees in landscapes with fewer flowers present. So, that’s something that we can measure to evaluate a given landscape: their time away from the nest, also known as their foraging time.
But how can we do that? The easiest way would be just sit at the colony entrance and stop-watch bees that leave and return. While that would work, it’s extremely laborious, and doesn’t allow us to
track multiple colonies or landscapes simultaneously. To get around that limitation, we turn to a really cool technology that most of use regularly: RFID.
RFID stands for radio frequency identification, and it’s the same technology used in parking garages, keycard access, and the Illinois I-PASS toll system. The process of using this technology is quite simple: we place a small radio-tag onto bumble bees, each of which has a unique ID associated with it. We then set up an antennae system on the colony entrance, basically little loops the bees fly through, which log when they leave the nest, when they return, and what direction they were headed (in or out). From recording their entrance and exit, we can easily calculate a bumble bee’s foraging time, how often they forage, and a variety of other responses. We can deploy many RFID systems on bumble bee colonies all over the place and get continuous, simultaneous tracking of foraging times. We can then compare the foraging time and colony performance across all of the different places we put the bees, allowing us to say with data about the bees themselves, which places are likely better than others for bumble bees.
This process can then be repeated across a range of different landscapes that vary in their resources (flowers), how they’re constructed and laid out, and how much human activity they have. With all of this, we can slowly begin to build a map of the best and worst places for bumble bees, and by association, other wild bees.