DCAs do exist

[Repwoc]

I didn't realise it was in doubt.

https://phys.org/news/2021-05-radar-tracking-uncovers-mystery-honeybee.html

 

[Murox]

Sometimes we have to wait for a new generation of "research" to tell us that we were correct all along - happens roughly every 20 years or so

 

[GuyNir]

Thanks for the link Paul. Very interesting.

 

[Antipodes]

I didn't realise it was in doubt.

https://phys.org/news/2021-05-radar-tracking-uncovers-mystery-honeybee.html

I guess they must have got data on how far apart the congregation areas are that the drones move between?

 

[Arfermo]

Sometimes we have to wait for a new generation of "research" to tell us that we were correct all along - happens roughly every 20 years or so

I'm 86 now so I am not holding my breath for anything at all really.

 

[jenkinsbrynmair]

I'm 86 now so I am not holding my breath

Just in case you forget to stop and take another?

 

[Arfermo]

There' maybe a tiny hint there?

 

[Repwoc]

I guess they must have got data on how far apart the congregation areas are that the drones move between?

There's a link to the paper in the linked article with heat maps showing where the drones went. They didn't seem to go far though:

 

[Antipodes]

There's a link to the paper in the linked article with heat maps showing where the drones went. They didn't seem to go far though:

Good stuff, thanks. They even managed to do a bit of tracking of the queens I see.

 

[pargyle]

"The researchers still don't understand how the drones find these congregation areas in the first place. Drones are born in Summer and their average lifespan is only around 20 days, so new generations can't find these areas by following older drones."

Perhaps I should send them a set of my hand made, yew handled, copper coated, dowsing rods. Then they would know ....

 

[Newbeeneil]

"The researchers still don't understand how the drones find these congregation areas in the first place. Drones are born in Summer and their average lifespan is only around 20 days, so new generations can't find these areas by following older drones."

Perhaps I should send them a set of my hand made, yew handled, copper coated, dowsing rods. Then they would know ....

With the appropriate invoice of course

 

[Murox]

There's a link to the paper in the linked article with heat maps showing where the drones went. They didn't seem to go far though:

An interesting read. The references to leks/lekking may bear more study along with the mentions of flightpaths and proximity of manmade/geographic features and time of day. It's only just scratched the surface of understanding really.

 

[pargyle]

With the appropriate invoice of course

In the interests of science I would give them a discount ! So much has always fascinated me about DCA's since I first read about Gilbert Whyte and his experience at Selborne in 1792 and the fact that the same DCA is still evident today. There's so much we don't know about this phenomena and this study does not add a great deal to what has already been discovered by earlier studies and beekeeper's observation but ... if they persist to the next level who knows what will emerge ?

This came mainly from research 20 or so years ago ...

https://www.valleybees.org.au/wp-content/uploads/2017/11/DRONE-congregation.pdf

 

[gmonag]

As any glider pilot will know, thermals (warm, rising air, heated by sunlight on the ground) tend to spring from the same place over a period, in the same way as drips of condensation from an Artex ceiling will always drip from the same place. These spots will vary according to the sun position and wind direction, because a thermal needs a "trigger" to start rising. This will often be a ridge, tree line, lake shore or even a change of surface (eg a ploughed field).

I have seen it suggested that the DCAs will form where the drones can fly for an extended period with minimal energy use. A thermal source would be perfect, as the bees could soar like a glider.

So, my point is that geographical features are most definitely important for locating a DCA, along with wind direction and time of day.

 

[pargyle]

So, my point is that geographical features are most definitely important for locating a DCA, along with wind direction and time of day.

Now ... the only things that concern me ...

1. There is no consistency in terms of topography between the DCA's that have been identified.

2. As drones are reared 'fresh' every year there can be no learned behaviour so how does the first drone in a DCA decide that this is the place it is going to be established and how do they find their way there ?

 

[gmonag]

If my theory is correct, the drones will find a thermal by feel (just as glider pilots do). Others will join the party and .... you have a DCA. The trigger features for thermals can help glider pilots by indicating where thermals may form but birds (and bees?) just search for the lift. Once one starts circling, others quickly join them.
The trigger features are not always obvious and vary a lot, but they are consistent once they start triggering thermals.

 

[pargyle]

If my theory is correct, the drones will find a thermal by feel (just as glider pilots do). Others will join the party and .... you have a DCA. The trigger features for thermals can help glider pilots by indicating where thermals may form but birds (and bees?) just search for the lift. Once one starts circling, others quickly join them.
The trigger features are not always obvious and vary a lot, but they are consistent once they start triggering thermals.

But .... there's no evidence that all DCA's are related to places where thermals occur and at 20m to a max of 50m where DCA's are active surely you are not going to see a lot of thermal activity .. I thought that thermals came into their own at much greater heights than these - but, I'm not a glider pilot.

 

[Newbeeneil]

So much has always fascinated me about DCA's since I first read about Gilbert Whyte and his experience at Selborne in 1792 and the fact that the same DCA is still evident today.

RP described seeing the DCA at Gilbert Whyte's house in a conversation a few years ago.

 

[gmonag]

.. I thought that thermals came into their own at much greater heights than these - but, I'm not a glider pilot.

Thermals clearly start at ground level, but you are correct, they do not really get going (to be useful for a glider anyway) until they rise to a thousnd feet or more. However you will see birds such as kites, gulls, buzzards etc soaring just above tree-top height. Also I have encountered flocks of swallows and martins at several thousand feet altitude feeding on insects that have been carried up. So I believe thermals are quite capable of supporting drones at 100-150ft.
Just my theory.

 

[pargyle]

Thermals clearly start at ground level, but you are correct, they do not really get going (to be useful for a glider anyway) until they rise to a thousnd feet or more. However you will see birds such as kites, gulls, buzzards etc soaring just above tree-top height. Also I have encountered flocks of swallows and martins at several thousand feet altitude feeding on insects that have been carried up. So I believe thermals are quite capable of supporting drones at 100-150ft.
Just my theory.

It's as plausible as anyone else's....