The Urban Bee Project's Protocol
For Data Collection
of our work in the wild and urban areas of northern California is
based on what we call “Bee Frequency Counts.” These
counts are used to assess bee-flower relationships – that
is, to get a picture of which bees like what flowers when. By carefully
observing flowers and the bees that visit them, we can begin to
determine what bees and flowers are present during different times
of the year, which bees visit which kinds of flowers, and how attractive
different flower species are to bees.
Best Procedures For Monitoring
1.) Take a look outside and make sure it’s
nice day! Sunny, warm days of 70°F or higher, with little to
no wind are optimal for bees. Generally, bees are out and about
between 10:30am and 3pm. However, it is fun (and important) to experiment
with monitoring at different times of day. We may be surprised to
find that some flowers offer nectar much earlier or later than the
set time, coaxing the bees out of bed.
Survey the garden for those patches of flowers that are in full
bloom – these are the patches on which you will be monitoring.
Sometimes, patches of flowers will not quite be in full flower,
or may be starting to go out of season. These patches can also offer
good information, and you will have to use your judgment to determine
whether the patches are good enough to monitor.
3.) In order to assess the bee-attractiveness of
a flower species, it is important to know what flower species you
are monitoring! Hopefully, the flower patch will be labeled with
the flower’s scientific name. If it has only a common name,
you may be able to look it up in an ornamental plant guide such
as Sunset Western Garden Book. If the patch is not labeled, your
best bet is to pick a branch or two with flowers and leaves and
bring it to a nursery for identification.
4.) Choose your first flower patch (1.5m X 1.5m
or the equivalent in case of linear plantings) and begin by filling
out the Bee Frequency Data Sheet
(PDF format). You will need to include information about the weather,
your monitoring site, the flower patch, and nearby flowering plants.
You will need a Data Sheet for every flower patch you monitor.
Then, without getting too close to the flowers (so as not to scare
away the bees) begin your counts. Each count should take 3 minutes.
You will need to check your watch often to make sure you are counting
for the right amount of time. Be sure to count every bee that lands
on the reproductive parts of the flower (usually the pollen or nectar
center), distinguishing between honey bees, bumble bees, large bees,
and small bees. You can write these down as you see them, but you
must be careful to keep watching the flowers even as you write so
as not to miss a bee. It may be easiest to make a little chart (see
below), simply putting a mark under the appropriate category when
you count a bee:
Finally, you must make sure to count each bee only
once. It is not accurate to count the same bee landing on the same
flower over and over again. With a little practice you will be able
to keep track, in your peripheral vision, of all the bees you have
already counted. If they fly outside the patch area and then return
for more nectar, they can be counted again. Otherwise, you can leave
their repeated visits out of your counts.
6.) Repeat these counts 4-5 times. It is best to
step away from the flower patch for a few minutes between each repetition
so that bees that were frightened off will return. During this time,
you can continue filling out the “Counts” section of
your Data Sheet. If possible, do each count on a different section
of the same flower patch. If the flower patch is larger than 1.5m
X 1.5m, you can divide the patch up into several sections for counting.
If not, you can try to do counts from different angles (sides, back,
and front). In the second case it is especially important to let
the patch “rest” for a few minutes between each count.
7.) Take note of anything unusual or interesting
you saw, such as descriptions of bee types, bee behaviors (like
bees chasing each other around flowers), and different types of
flower visitors (wasps, butterflies, flies). Enter these notes into
your field journal, including a description of the weather, the
time, what flowers you monitored, and anything else that caught
your eye. You may even want to include sketches of the bees and
flowers you monitored. Be creative!
8.) Sometimes flower patches of the same species can attract different
frequencies of bees depending on whether they are surrounded by
other attractive bee flowers or are isolated in a yard. It also
may be that one particular patch may be producing more or less pollen
and/or nectar treats for their bee visitors. In order to get an
overall picture of a flower species’ attractiveness, you should
try to locate other patches of this flower species in your area
and repeat the frequency counts on at least three different patches.
The overall attraction of the species can be categorized as follows:
The plant is highly attractive (Common) if it averages more than
5 bees per 3 minutes; it is moderately attractive (Occasional) if
it averages between 1 and less than 5 bees per 3 minutes; it has
a low attraction if it averages between 0.5 and 1.0 bee every
9.) Once averages are determined for bee frequency counts
on a particular plant, and the visiting bees are categorized into groups,
predictive information begins to emerge as to what relationships can
be expected for a given plant. This information is very useful from an
academic standpoint, as well as for planning residential bee gardens.