Re: [beemonitoring] Are not tall flowers long distance bee signals?
- Dear Sam:You make a good point. The height of a flower on a stalk was of interest to Dr. Amots Dafni <amots.dafni@...> at the University of Haifa. I believe Dr Dafni was interested in relating the height of the flower to the height at which bees flew and the position and shape of the eyes on their heads. Peter Kevan may have more to say about this.Another way to look at it is based on the density and height of competing vegetation at the time certain plants bloom. Yes, Helianthus spp. are often tall and subject to wind throw but most evolved as summer-blooming, prairie plants... right? Have you seen a tall grass prairie in July-August? Tall grass species are rather... uh tall, with tillers reaching several meters in height (often taller than most people) by the time they bloom. Remember, tall grass species are the dominant vegetation in tall grass prairies in summer. Consequently, most (all) of the composites blooming at the same time must produce flowering heads higher than the dense grasses if they are to be located easily by pollinators.Look at the literature on the pollination ecology of insect-pollinated wildflowers on tall grass prairies. When I studied the pollination of Schrankia nuttalii and Oxalis violacea in early spring the grass tillers were only a centimeter or two in height and insects could easily find the prostrate Schrankia or the small, tufted oxalis.PeterOn Fri, Feb 17, 2012 at 8:15 PM, Sam Droege <sdroege@...> wrote:
It strikes me that many flowers are designed to be long distance signals to dispersing bees. Why, for example, would a plant make a flower so vulnerable to windthrow as a sunflower, particularly when the seeds are so heavy and are not windblown? I am particularly thinking that Melissodes uses color to detect flowers from very long distances. For example, I recall a study that Cathy Stragar did with blue vane traps .... they attracted moderate amounts of bees (2x the amount found in an individual bowl) but ungodly numbers of Melissodes. This makes sense to me in that flowers that love Melissodes and visa versa such as ironweed, sunflowers, boltonia, pickerelweed, daisies, and thistle are both bright in signal strength as well as height, whereas other flowers are usually more moderate in their presentation to the environment.
Sam Droege sdroege@...
w 301-497-5840 h 301-390-7759 fax 301-497-5624
USGS Patuxent Wildlife Research Center
BARC-EAST, BLDG 308, RM 124 10300 Balt. Ave., Beltsville, MD 20705
No one has planned
what grows in this ditch:
a couple of wild irises,
dark purple; and lighter
purple thistles whose leaves
imitate white rock; and then
the small, drooping blue flowers
whose leaves and stems are hairy
(I swear) and also
silvery; and wild mustard,
spindlier and higher than the rest,
with pale joints like Tinkertoys.
I'm leaving out the yellow
dandelion and the strange
colorless flowers with black
dots in the center of pale green
cups that the bees love so
that they make bee parties
and get unruly and make a racket.
(I swear, I had to stop
and figure it out!)
I say I saw a rock lizard, too,
flecked black and gray with bits
of what looked like rock
hanging from him.
I looked at him.
He became a rock.
So much seems to aspire
to be dry, white, and rocklike
in the pit of the ditch
and it isn't only
the failure I admire.
- Greg Miller
- Hi Josh,I had been researching the foraging distances of bees in general a few months back and ran across a good number of sources that related bee body size to foraging distance - in general, larger bees have larger foraging distances. I am sure that this must vary greatly across landscape types, but one particularly nice source I found was by Greenleaf et al. (2007) - Bee foraging ranges and their relationship to body size (can be downloaded at http://xa.yimg.com/kq/groups/17598545/383890861/name/Greenleaf+et+al+2007+Oecologia+foraging+ranges+.pdf ) . The reference list is also quite good for this topic.Cheers!Jessica
- Two other useful references with useful empirical results on foraging ranges are Guédot, C, J. Bosch and W. Kemp. 2008. Relationships between body size and homing ability in the genus Osmia (Hymenoptera, Megachilidae). Ecological Entomology 34:158-161l and Zurbuchen, A, L. Landert, J. Klaiber & A. Müller. 2010. Maximum foraging ranges in solitary bees: only few individuals have the capability to cover long distances. Biological Conservation 143: 669-676. The latter is particularly relevant and uses a very clever methodology.bestJackJohn L. Neff
Central Texas Melittological Institute
7307 Running Rope
Austin,TX 78731 USA
From: pollinator2001 <Pollinator@...>
Sent: Friday, February 17, 2012 5:18 PM
Subject: [beemonitoring] Re: foraging distances
--- In email@example.com, "Campbell, Joshua" <jcampbel@...> wrote:
> Hi all,
> I am involved in a project that is attempting to monitor flower visitors (abundances/species richness) in various biofuel crops (native grasses, Bermuda, switchgrass, etc.). I have been using various colored bowls to capture flower visitors. I am curious whether any information exists on how far a bee (in general) can see bowls (or flowers). My plots are about 20 acres...mostly square. Is there any legitimate chance that bowl traps could draw bees (or other potential pollinators) from long distances into habitat that they may not normally go? Or do most bees forage pretty close to their home? Any information (or opinions) will be gratefully appreciated. Thanks again.
I have had honeybees on some very large farms, and I've made observations aplenty over the years - mostly because some growers want the bees dropped two at a time, where it saves a lot of labor to drop them in much larger groups.
What I've found is that the effective pollination range (on cucurbits) is pretty consistantly at about .6 mile (1 kilometer). Beyond this bee density on the flowers drops off rapidly. Now they certainly can range farther, but only in lean times.
You also find that within a couple hours after they start working, there are almost no bees on flowers that are close to the hives. Apparently competition drives them farther and farther out.
I can't really relate this to other species, but my gut feeling is that honeybees likely have the longest range. Flying wears out their wings, but honeybees, with their large populations and more expendible individuals, can afford to fly more.
Retired pollination contractor