The frequency of bee sightings has slowed down in the past couple of days, but in the mean time we have been typing up our updated protocols, and begun looking at the data that we've collected. Read on for detailed protocols, the musings of this year's Bee Team, and tips for next year's Bee Team.
After we had painted a sufficiently large number of bees, we transitioned to tracking their flight paths between Echinacea heads. Our goal with this project was to obtain data that would allow us to determine average flight path distance of the pollinators between heads and therefore get a better idea of gene flow within the garden, and also to see if we could estimate the home range size for individual bees.
Our protocol for tracking bees didn't undergo too many changes from the initial version. The biggest challenge that we ran into was keeping up with the bees both visually and in terms of taking data. We updated the visor form several times to increase the efficiency of the data taker. The current form seems to work well, although we've considered the idea of taking data on paper. It would also streamline data processing if the visor/paper form could assign and group each flight series by an ID number.
We found that it was most effective to work in groups of at least three, and up to five. One person would be data taking on the visor, and the others would be visually following the bee. It was best for the trackers to stay back a couple of meters from the bee so as not to scare it, and for the trackers to be spread in a circle around the bee, so that it could be tracked in any direction. When the bee left the flower, the trackers would call to the data taker that the bee had left the head, so that they could prepare a new data point in the visor, and would then call out the new plant coordinates and twist-tie color. If the bee visited multiple heads on one plant, the second, third, etc. twist-tie colors were recorded in the notes instead of calling up a new form every time. If the bee was lost for more than ten seconds, we marked lost track, and then would resume with a new flight ID for the next bee, even if it was the same bee that we had previously been tracking.
Because we got all the details of this protocol worked out after the peak flowering, there weren't many bees still in the garden when we were searching for them. As a result, we tended to concentrate our searching for bees in the '96 garden where the flowering plant density was the highest. This made the most efficient use of our time, since we weren't randomly walking rows with few or no flowering plants, but resulted in a data set that is concentrated in one place. Therefore, our data, especially when it comes to home range estimates, may be inaccurate, as we concentrated our time in the one area.
We the members of the Bee Team (formerly Team Binocular) have done our best to track, mark, and record the position of bees in the common garden for the last several weeks. Our first suggestion is that you start early. This year we got a late start compared to the Echinacea flowering. We also had to figure out all the protocol from scratch as well so in the future this project can get organized shortly before flowering starts to be ready when flowering starts. Pollen set and bee activity are closely related and are both tied to weather.
After trial and error, we found that the best time for finding bees in the common garden was right around 7:30. Agapostemon virescens tended to be out earlier in the morning while the Melissodes were out later. We hoped that by getting out early we would be able to find A. virescens to track, but because of the late start of our project, we were unable to find any. Cold weather and windy weather both diminished the number of bees visiting flower heads. Wind also made it difficult to track bees because when the bees took off from the flower head they were caught by the wind and blown away.