Most males of flies (Diptera) in the suborder Nematocera have plumose, i.e. featherlike, antennae. These have usually been interpreted as sound receptors, with the common claim that they resonate in response to the female's wing tone frequency. There is evidence for this in some species. As you wrote, the male swarm has the advantage of ease of location by females, even though each male will have only a 1 in xxx chance of mating with each arriving female. But his chances must still be higher than "going it alone." Male swarms locate themselves over landmarks, and these can be simply bright spots, as in the top video, or they can be lights, as you noted. Each male seems to locate himself independently of the others, as the figure of the looping flight track shows. It is still possible that this orientation is also modified by the position of other males--- hard to tell.
But here is a fun and possibly relevant observation. My father often saw midge swarms in the back yard, dancing over some landmark. He found that if he made a high pitch bzzzt sound, all the midges bounced (just like your top video). He could do it repeatedly. I got it to work for me sometimes, but not as reliably as he did. The implication is that the "bouncing" is in response to sound, and the sound perhaps (this is my hypothesis) resembles a very large female midge from a very general direction, so all the males move quickly in that general direction. Keep in mind that the female's wing tone would be much quieter and more local. My hypothesis implies that if the bzzzt came from different directions, the males should bounce accordingly. There should be a correlation between the sound source and the bounce direction, though not necessarily in the same direction. A research project looms....
So, next time you see a swarm, give it a try. It might work better after a gin and tonic, but who knows. Let us know how it goes.
For those not in the know, Walter is a recognized authority in the field of Myrmecology and his books on the stunning architectures of ant nests and on the fire ants combine scientific insight with witty and graceful writing. I own both and can highly recommend them. To have him as a commentator, means alot! Glad I found this place!
Updrafts and heat, perhaps? Insects love heat. Look at your yard early morning and then again afternoon. Many more insects aloft in the hot part of the day. That sets the stage for swarms. Perhaps swarms are attracted to areas of stronger heat convection. Usually stones cement etc. Where no gradients are to be found, perhaps they have some quorum aggregating behavior, where small groups attract larger groups. Now to group jumps. The low-tech explanation may be simple: just sudden updrafts taking all the swarm upwards as a block. Or downwards. Defeaters of these swarms and jumps would be the same atmospheric phenomena that defeats hurricanes- sheering winds. All this behavior is predicated on fairly still air conditioner. Q.E.D!
That's really cool, I loved the video of the mosquitoes jumping in sync. I also love seeing clouds of gnats, although I don't think I've ever seen a group jump.
Years ago, I used to work late in an office which gave me a good view of the starling flocks coming in to roost in the evenings, and it was spectacular watching them.
Most males of flies (Diptera) in the suborder Nematocera have plumose, i.e. featherlike, antennae. These have usually been interpreted as sound receptors, with the common claim that they resonate in response to the female's wing tone frequency. There is evidence for this in some species. As you wrote, the male swarm has the advantage of ease of location by females, even though each male will have only a 1 in xxx chance of mating with each arriving female. But his chances must still be higher than "going it alone." Male swarms locate themselves over landmarks, and these can be simply bright spots, as in the top video, or they can be lights, as you noted. Each male seems to locate himself independently of the others, as the figure of the looping flight track shows. It is still possible that this orientation is also modified by the position of other males--- hard to tell.
But here is a fun and possibly relevant observation. My father often saw midge swarms in the back yard, dancing over some landmark. He found that if he made a high pitch bzzzt sound, all the midges bounced (just like your top video). He could do it repeatedly. I got it to work for me sometimes, but not as reliably as he did. The implication is that the "bouncing" is in response to sound, and the sound perhaps (this is my hypothesis) resembles a very large female midge from a very general direction, so all the males move quickly in that general direction. Keep in mind that the female's wing tone would be much quieter and more local. My hypothesis implies that if the bzzzt came from different directions, the males should bounce accordingly. There should be a correlation between the sound source and the bounce direction, though not necessarily in the same direction. A research project looms....
So, next time you see a swarm, give it a try. It might work better after a gin and tonic, but who knows. Let us know how it goes.
For those not in the know, Walter is a recognized authority in the field of Myrmecology and his books on the stunning architectures of ant nests and on the fire ants combine scientific insight with witty and graceful writing. I own both and can highly recommend them. To have him as a commentator, means alot! Glad I found this place!
Updrafts and heat, perhaps? Insects love heat. Look at your yard early morning and then again afternoon. Many more insects aloft in the hot part of the day. That sets the stage for swarms. Perhaps swarms are attracted to areas of stronger heat convection. Usually stones cement etc. Where no gradients are to be found, perhaps they have some quorum aggregating behavior, where small groups attract larger groups. Now to group jumps. The low-tech explanation may be simple: just sudden updrafts taking all the swarm upwards as a block. Or downwards. Defeaters of these swarms and jumps would be the same atmospheric phenomena that defeats hurricanes- sheering winds. All this behavior is predicated on fairly still air conditioner. Q.E.D!
That's really cool, I loved the video of the mosquitoes jumping in sync. I also love seeing clouds of gnats, although I don't think I've ever seen a group jump.
Years ago, I used to work late in an office which gave me a good view of the starling flocks coming in to roost in the evenings, and it was spectacular watching them.