Queen pheremones and DCAs

[Thymallus]

From reading Dave Goulson, it seems to me bumble bees do the same. The drones wait for a virgin queen to fly by.

It depends very much on which species of bumblebee. In some species the males fly regular routes and "scent" mark specific areas at the ends of their routes, which virgin queens find and wait there for the male to return. Some males ambush females as they leave the nest....it's not straightforward. Bit like Goulson

One thing I found interesting about DCA's is they can't seem to find them in flat country. Koeniger's mention this in their book, whereby tethered queens/artificial queens ( experiments in East Anglia and some German marshes) attract drones almost randomly as they "walk their queens". Suggesting that with no obvious depletions in the horizon the drones are more randomly spread.

[Mellifera Crofter]

It depends very much on which species of bumblebee. ...

... Suggesting that with no obvious depletions in the horizon the drones are more randomly spread.

That's interesting - so, these bees don't have a local to head for.

Thanks also for the information about the bumble bee habits.

Kitta

[gavin]

Was reading that section earlier. Yes, the lack of DCAs in flat monotonous landscapes was interesting. Also that DCAs seem to need drones to become stable - too few in the air and they don't accumulate. It isn't clear what it is that holds them together - sight/sound of other drones or maybe even a pheromone, to return to Kitta's question.

[The Drone Ranger]

Like hang gliders there may be a micro version of rising thermals caused by the local geography ?

[Thymallus]

There has to be something, the impression I got from their work in hilly areas was that they could pinpoint direction by "depletions of horizon" but couldn't explain why they stopped and congregated where they did.

[madasafish]

Like hang gliders there may be a micro version of rising thermals caused by the local geography ?

Rocks or any bare dark ground help generate thermals with some sunlight.

(I used to fly radio control gliders)