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So something like every single bee in a couple hundred colonies flew out to a single pair of trees to be poisoned? Isn't that fairly odd behavior in and of its

by roc 13y ago

So something like every single bee in a couple hundred colonies flew out to a single pair of trees to be poisoned? Isn't that fairly odd behavior in and of itself? Wiki suggests bumble bees only range a few kilometers. Is it even normal to see that many colonies that close together?

Blahah 13y ago
I suspect the number is inflated - it's unlikely (but not impossible) that anyone counted all the bees. Estimating that number by eye could be off by an order of magnitude. Probably the tree and surrounding vegetation were flowering abundantly, attracting many insects from the area. I would say thousands of insects on a large tree is not unfeasible at all, perhaps even tens of thousands. Whether they were all bees, and whether the bees were really all bumble bees, is not clear. You're right that 25,000 bumble bees in one place does sound logistically difficult to arrange. We can back-of-the-envelope it... (edit: increased foraging distance with data from reference, which slightly changes the conclusion) It would be ~150 colonies within a several kilometer radius. If we assume mean foraging distance of 10km [1], thats (a rather beautiful) 314km^2 of source area. We should probably also assume that the vast majority of bees in the area are not visiting those two trees, as there are likely other good sources in the area too. If we assume 1-5% of the local bees might be visiting the trees, there would have to be a colony density of ~10-50 colonies per km^2. That is high, but not impossible. Previous measurements of bumble bee colony density have estimated in the region of 0.5 to 20 per km^2 [1]. So, one of the following is probable: the number of bumble bees is exaggerated in the story, or they weren't all bumble bees, or some of my estimates are wrong. I would arrogantly assert the first two are more likely :) 1. https://ir.library.oregonstate.edu/xmlui/handle/1957/35082 https://ir.library.oregonstate.edu/xmlui/handle/1957/35082
- whimsy 13y ago
  I know how ants stop going to a food source (e.g. the pheremone trail stops getting refreshed on the return trip) but how do bees stop? I know they transmit pathfinding information with dancing... do the bees just stop dancing on return or something? The reason I ask is the 1-5% figure you mention. I assume bees must have some mechanism to prevent sending bees to fatal sites. For ants, no one comes back, so no one keeps going. Ant traps short-circuit this by providing food with a slow-acting poison - the ants make it back with "food," causing more ants to be sent, and soon a significant portion of the stockpile is poison, drastically reducing numbers in the colony. Could that have happened here? It sounds like that's probably not the case, given that the bees appear to have died practically on contact with the linden trees. But I don't know how bee flow control works.
DougWebb 13y ago
only a few kilometers? That's something like 67 thousand times the length of a honeybee, which would be equivalent to a human ranging around 133km for food/work every day. That's a hell of a commute, especially for a creature that has to violate physics to fly :)
- Samuel_Michon 13y ago
  > only a few kilometers? That's something like 67 thousand times the length of a honeybee Which is what they do routinely. Bumblebees have been known to fly up to 8 miles (13 kilometers) from their nest. http://news.softpedia.com/news/Scientists-Map-the-Flight-of-the-Bumblebee-31005.shtml http://news.softpedia.com/news/Scientists-Map-the-Flight-of-... > a creature that has to violate physics to fly Nonsense. http://www.snopes.com/science/bumblebees.asp http://www.snopes.com/science/bumblebees.asp
  - mig39 13y ago
    He used a :) to indicate sarcasm. I'm sure he knows bees don't violate physics.
    - Samuel_Michon 13y ago
      Usually, in this context, one uses a wink face to indicate sarcasm and a smiley face to indicate you find something amusing. Also, I wasn't under the impression that he thought bumble-bees can’t fly, but that he is of the belief that at one point in time, scientists couldn't explain how it’s physically possible and that that is where this factoid came from.
- roc 13y ago
  > "only a few kilometers?" At 30 - 50km/h? Yeah, "Only". The hypothetical human in your example would have a car that traveled a couple thousand km/h. Given which, we'd be right to say "only" of his 133km commute as well.

by roc 13y ago

Blahah 13y ago

I suspect the number is inflated - it's unlikely (but not impossible) that anyone counted all the bees. Estimating that number by eye could be off by an order of magnitude. Probably the tree and surrounding vegetation were flowering abundantly, attracting many insects from the area. I would say thousands of insects on a large tree is not unfeasible at all, perhaps even tens of thousands. Whether they were all bees, and whether the bees were really all bumble bees, is not clear. You're right that 25,000 bumble bees in one place does sound logistically difficult to arrange. We can back-of-the-envelope it... (edit: increased foraging distance with data from reference, which slightly changes the conclusion) It would be ~150 colonies within a several kilometer radius. If we assume mean foraging distance of 10km [1], thats (a rather beautiful) 314km^2 of source area. We should probably also assume that the vast majority of bees in the area are not visiting those two trees, as there are likely other good sources in the area too. If we assume 1-5% of the local bees might be visiting the trees, there would have to be a colony density of ~10-50 colonies per km^2. That is high, but not impossible. Previous measurements of bumble bee colony density have estimated in the region of 0.5 to 20 per km^2 [1]. So, one of the following is probable: the number of bumble bees is exaggerated in the story, or they weren't all bumble bees, or some of my estimates are wrong. I would arrogantly assert the first two are more likely :) 1. https://ir.library.oregonstate.edu/xmlui/handle/1957/35082 https://ir.library.oregonstate.edu/xmlui/handle/1957/35082

whimsy 13y ago
I know how ants stop going to a food source (e.g. the pheremone trail stops getting refreshed on the return trip) but how do bees stop? I know they transmit pathfinding information with dancing... do the bees just stop dancing on return or something? The reason I ask is the 1-5% figure you mention. I assume bees must have some mechanism to prevent sending bees to fatal sites. For ants, no one comes back, so no one keeps going. Ant traps short-circuit this by providing food with a slow-acting poison - the ants make it back with "food," causing more ants to be sent, and soon a significant portion of the stockpile is poison, drastically reducing numbers in the colony. Could that have happened here? It sounds like that's probably not the case, given that the bees appear to have died practically on contact with the linden trees. But I don't know how bee flow control works.

DougWebb 13y ago

only a few kilometers? That's something like 67 thousand times the length of a honeybee, which would be equivalent to a human ranging around 133km for food/work every day. That's a hell of a commute, especially for a creature that has to violate physics to fly :)

Samuel_Michon 13y ago
> only a few kilometers? That's something like 67 thousand times the length of a honeybee Which is what they do routinely. Bumblebees have been known to fly up to 8 miles (13 kilometers) from their nest. http://news.softpedia.com/news/Scientists-Map-the-Flight-of-the-Bumblebee-31005.shtml http://news.softpedia.com/news/Scientists-Map-the-Flight-of-... > a creature that has to violate physics to fly Nonsense. http://www.snopes.com/science/bumblebees.asp http://www.snopes.com/science/bumblebees.asp
- mig39 13y ago
  He used a :) to indicate sarcasm. I'm sure he knows bees don't violate physics.
  - Samuel_Michon 13y ago
    Usually, in this context, one uses a wink face to indicate sarcasm and a smiley face to indicate you find something amusing. Also, I wasn't under the impression that he thought bumble-bees can’t fly, but that he is of the belief that at one point in time, scientists couldn't explain how it’s physically possible and that that is where this factoid came from.
roc 13y ago
> "only a few kilometers?" At 30 - 50km/h? Yeah, "Only". The hypothetical human in your example would have a car that traveled a couple thousand km/h. Given which, we'd be right to say "only" of his 133km commute as well.