Where are DCA?s?

[Aroc]

I understand they are 20-50 feet up.  I understand they are generally around an acre in size.  My question is where are they?

Do they have to be a certain distance from the hive, or can they be right in front of the hive?

[BeeMaster2]

From studies done by Ashley at UF, a DCA is an area that has a clearing and a tall wall like a vertical cliff or very tall trees next to an open field. She was able to look at satellite pictures and select the best possible candidates and then go out and find the DCA.
Your queen will not use a DCA near her hive. She will fly 2 kilometers or more to find one her brothers normally only fly 1 kilometer.
Jim

[eltalia]

From studies done by Ashley at UF, a DCA is an area that has a clearing and a tall wall like a vertical cliff

Jim would you kindly add to "Ashley"(Who)?
I am very interested in these claims of "DCA" so would seek that
information available from professional studies.

At this time I remain a nonBeliever, perhaps change is appropriate?

Bill

[BeeMaster2]

Ashley Mortensen
Profile:
Doctoral candidate at the University of Florida Honey Bee Research and Extension Lab. Mortenson?s current research focuses on the behavior effects of in vitro rearing on adult honey bees. She also completed her master?s degree in the HBREL, during which time she studied drones at Drone Congregation Areas to assess the prevalence of African genetics in the Florida honey bee population.

[BeeMaster2]

Ashley taught several classes at the bee colleges here in FL and she also was a speaker for our bee clubs. She is a very good speaker and very knowledgeable about bees and their mating behavior.
Jim

[BeeMaster2]

Here is her complete paper on what she learned.
http://ufdcimages.uflib.ufl.edu/UF/E0/04/60/44/00001/MORTENSEN_A.pdf
Jim

[beepro]

I don't have scientific evidence to prove.  From my experience using the Cordovan bees to study bee genetics, my local DCAs are full of the
carnis drones about 95% of them, especially in the Fall than early Spring.   Less than 1% are the Italians drones.   Within my hives, closer to my bee yard there are
the Italians kept bees from another beekeeper nearby or the wild hive nearby.   So every time a Cordovan virgin is laying the
carnis hybrid workers I know she had made it outside of the Italians DCAs (closer to home.)   When she is laying the Italians worker bees then her
mating whelm is still within the local Italians DCAs.    My estimate for the carnis DCAs is within 12 minutes driving time from my
bee yard and the Italians only within 5 minutes of driving time.   Because of geographical and local bee environment differences, it is
really hard to say how far they are from your bee yard.   I say within 2-3 miles minimum.   
So far the Cordovan queens are pretty consistent with their worker genetics.  Rarely mixing the carnis and the Italians together.  And in the early Spring
the likely of mating with Italians drones increased by 80% versus the Fall mating where the carnis drones will dominate 95% of the DCAs.   Which direction
the virgin fly to, depending on what type of drones are there, will increase her change of mating with that type of bee.  Using the Cordovan bees I have learn a lot about my bee environment and bee genetics in general.  In this area I'm totally satisfied with my learning and findings so far.   

[little john]

Using the Cordovan bees I have learn a lot about my bee environment and bee genetics in general.  In this area I'm totally satisfied with my learning and findings so far. 

... and yet you make no mention of the time of day when the matings have taken place ?
LJ

[AR Beekeeper]

In my location the virgins usually fly from 2 to 5pm.  This spring is a bust for mating returns, depending on the yard, the success rate is 25 to 50%.  Cold, high winds, rain, and a large King Bird population.

[Bush_84]

I?ll be honest I have not given much thought to this.  How does one even get started if they were looking for one. If drones from my hive stay closer than a queen would, will my drones stay close to my house or prefer somewhere else?

[Van, Arkansas, USA]

I have seen a DCA, one could through a rock up into the DCA.  The drones would fly down chasing the falling rock.  The size was about 2 feet by 3 feet.  The mass of drones moved slowly, united and stayed clustered as a group about 20 feet up in an open area, sunny, calm wind, mid day.

Due to the fact I have only witnessed one DCA, I would not draw conclusions from this.

I saw where Jim, posted reference, to a scholar on DCA, Jim(s) info I would recommend over my one observation.

[Van, Arkansas, USA]

AR, I usually have many mated queens, this time of year.  To date, I have not even set up my cloak board for queen rearing, mid April and I have not even a start, too cold, mornings in the thirties F,,, to cold for queen rearing.

i was successful in forcing a split to raise a queen, she is now mated and laying very well.  So, one mated queen going into 3rd week of April.  Regarding queen rearing,,,  I believe I am about 3-4 weeks behind due to cold weather.  No complaints, May will be beautiful.

[Van, Arkansas, USA]

{DCA.  The drones would fly down chasing the falling rock.  The size was about 2 feet by 3 feet.  The mass of drones moved slowly, united and stayed clustered as a group about 20 feet up in an open area, sunny, calm wind, mid day.}

This is called a drone congregation area COMET as described by
Ashley Mortensen, the link provided by Jim.  The DCA would have been a much larger area.  Apparently when a queen is targeted in a DCA, the drones from a {comet}, a dense mass of drones to chase the queen.

The drones will defend this comet from intruders, such as the rock I threw that was chased by the drones.  Ashley Mortensen described this drone COMET well.

Thanks again, Jim for the link to the Mortensen paper.  This paper is packed full of valuable information regarding African Honey Bees.
Blessings

[BeeMaster2]

Van,
Glad you enjoyed it.
Jim

[eltalia]

Van,
Glad you enjoyed it.
Jim

I am still wading through that tome, Jim.
I read initially a lot about scutella and will look to see if that colours the whole work. For the moment I am struggling with the statements quoted below. Some references I may have read and largely forgotten, others I have yet to discover.

"Drone congregation areas were first observed in 1958 (Jean-Prost 1958), and
comparatively little is known about the determination of DCA locations considering our
advances in knowledge of other aspects of honey bee biology since that time. It
generally is believed that drones leave their colony flying towards a depression in the
horizon (Ruttner 1966) until they reach a vertical relief such as a tree line or building
(Zmarlicki and Morse 1963, Strang 1970). Tribe (1982) suggested the locations of DCAs
are based primarily on wind, stating that drones typically fly upwind until encountering a
turbulent area that could be caused by buildings or trees. Thus, DCAs typically occur at
breaks in the horizon like openings in forest areas, and along tree lines in fields (Ruttner
1985).
"

"1958" - yet it has to be a state secret, at least in this Country.
"comparitively"
"generally"
"suggested"
"could be"

There was talk here lately around archelogical dating of attifacts.
I got from it much the same I put here on this topic, show me verifiable facts
and I get interested. I have seen too many psuedoscience(sp?) declarations
around ancient times past - and the Universe -  to form an understanding some
('science') individuals are very good at selling their imagination on a world stage.
In my paranoia the quoted extracted keywords above are early warning signs of
what is about to be presented. Suddenly under those 'caveats' all that follows
becomes "facts".

I shall pull on the wellies to wade through the 73 pages :-)))

Bill

[beepro]

This year taking a family member advice I did not go into the hives that much.  So finally I got this impatience habit put
away.   Just let nature take its course! So the virgin get out around 10am and come back around 4pm in my
area.   Last year I spotted a virgin with a white thingy sticking out of her end around 4pm during the hive inspection.  I feel I've learn enough in this area to not bother the hives that much this year.   The chance of a successful mating will increase when I leave them alone after spotting the virgin that I do keep track of.

[Ben Framed]

I am bumping this for the benefit of newer beekeepers here at beemaster. It is almost that time of year in North America

[Michael Bush]

At a conference once we had a presentation by a graduate student on finding DCAs.  She had a fishing pole, a weather balloon and a queen cage with a cotton ball soaked in queen juice. (retired queen in alcohol)  We trolled for them and soon got a comet of drones following it.  The where was covered by the presentation which is they tend to be at the intersection of two or more lines.  Lines are roads, tree rows, etc.  Usually in an open area, like a meadow etc.

[BeeMaster2]

Michael,
Was the Ashley Mortensen that did that presitation?
Here is a picture of Ashley.

[Michael Bush]

Probably.  It was some time ago.  If she was at UNL then I'm pretty sure it was.