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6th Jun 2010
Creatures in Colonies
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The science of social species goes under the microscope this week. We hear what radio-tagging individual ants is revealing about the way they organise their nests to decide who goes hunting and who stays at home. Meera explores the growth of urban apiculture, including why city-made honey tastes superior to its countryside equivalent, we find out how bees encountering hostility use a stop signal to deter their fellow foragers from befalling the same fate, and in Kitchen Science we explore the physics of flight to see how bees stay airborne. Plus why not cleaning your teeth could cause a heart attack, how early humans eschewed vegetarianism, mongooses that teach each other nut-cracking tricks and how to give a reef a coral transplant!
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News
A large UK-based study has confirmed that not cleaning your teeth is a significant risk factor for having a heart attack...
New archaeological evidence suggests human ancestors gave up their vegetarian diet and began feasting on land and aquatic animals 2 million years ago, perhaps boosting their brain size in the process...
Animals pass-on practical knowledge and learning to their counterparts, researchers have proved this week...
Transplanting coral fragments broken off by storms could be a simple, cheap, and effective way of restoring small areas of damaged reef...
Kitchen Science
There is an urban myth that 'science' says that a bee can't fly - so we thought we should look into it. You can try too with just a pond and your hand...
QotW
Are memories encoded in our genes? Can past glories and bygone embarrassments be passed down to our children unknowingly?
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Interviews
It’s an incredibly complicated world inside an ant colony, with different types of ant doing lots of different jobs. But how does an ant know what role to take? Dr Elva Robinson explains more...
Increasingly, people are keeping bees in crowded urban environments - Meera Senthilingam caught up with Alison Benjamin, from UrbanBees.co.uk to find out how bees cope with living in the city...
We talk to James Nieh about the warning signals used by bees to stop their colonies from entering harmful areas...
Questions

Do animals really learn from one another?
Malc was referring to this news story, about an experiment where young Mongooses (Mongeese?) appeared to learn from their elders the technique for getting into fiddly food items.
Chris - It’s a good point. These animals obviously know how to pick things up and they know how to manipulate them in their paws, so that’s instinctive. But how they actually choose to break into the object is obviously something they pick up from an adult. The researchers did control for that instance that you've raised because by giving the escort animal the open egg, the young pups didn’t have to watch an adult breaking into it. So therefore, when they came to open one themselves, they either chose to smash it on something or to gnaw into it. And they showed equal numbers of them doing either, showing there was no bias. So they do it by instinct, but they choose to do one thing or the other based on what they're shown how to do in certain situations by an adult or an older animal.

Why do some species have thousands of sterile individuals?
We posed this question to Elva Robinson from the University of York...
Elva - In some species of ants, there are workers that are completely sterile although in many species of ants, bees and termites, the workers can actually reproduce a bit, but not as much as the queen. This posed a problem for Darwin when he was thinking about evolution by natural selection because usually, evolution should move individuals towards the best chance of passing on their own genes directly to the next generation. Obviously, sterile worker ants can't do that. But they are, of course, very closely related to the queen who is their mother, and actually, because of ant genetics, they're more closely related genetically to their mother than we are to our own mothers, because ant genetics work slightly differently. So, this means that their genes will be passed on to the next generation through their siblings, through their sisters, the future queens of other colonies, and through the males that that colony produces.
Chris - So it’s less "selfish gene", it’s more that the genes will go on, but you have to be there to help the genes flow from somebody else. But because you're closely related to them doesn’t matter?
Elva - Yes and we call it kin selection; acting in the interests of the family when it’s very closely related. There are also big efficiency benefits for these ant colonies because of the way they organise their division of labour. So they can very efficiently help their siblings to reproduce.

Could radio signals or mobile phone masts confuse bees?
We posed this question to James Nieh from the University of California at San Diego...
James - There was an original study in India that created these questions and interest, and what they did is they actually put a radio cell phone transmitter inside the hive, but it really wasn’t done with very many colonies and the results were ambiguous. They were not statistically significant. I actually have looked at this paper. In addition, the authors have said that their results were too broadly interpreted. So I would say, the answer is that there really is no scientific evidence that cell phone towers or other types of electromagnetic radiation from communications devices harm bees. In addition, there are many areas that are afflicted by colony collapse disorder that do not have cell phone towers that are nearby. So it’s not thought to be a good link.

What happens if a bee or ant gets lost from its colony?
We posed this question, with reference to bees, to James Nieh from the University of California at San Diego and, with reference to ants, to Elva Robinson from the University of York...
James - Bees do vary in their acceptance of bees by their colonies. In general though the guard bees smell bees that are coming in and if they detect a difference from their colony odour that’s significant, they will reject that bee or even try to kill it. So, very often, these bees will be rejected. However, the way that many beekeepers work is they take one colony and they divide it over subsequent years. So in fact, there is a kind of relatedness among these different colonies, and if they are sister colonies, there is a good chance that a lost worker bee will be accepted.
Elva - It does vary depending on how closely [the ant colonies] are related and most ants are very hostile to ants coming in from other colonies. So usually, they would fight and kill that ant. But there are some species of ants which form networks of connected colonies where the colonies bud off and produce new colonies which pretty much stay in contact, so they're colonies made up of lots of different connected nests. So then, an ant that got lost could go into any nest and it would be fine.

What is the cause of colony collapse disorder?
We posed this question to James Nieh from the University of California at San Diego...
James - It’s definitely a part of colony collapse, which we think of as having four features. One are parasites like Varroa destructor, the mite. Pesticides are thought to be involved, viral and bacterial diseases, and then finally, management practices which are not optimal. We’re actually moving bees around a lot. It’s startling that in one month, about 80% of all bee colonies in North America converged in Central California for agricultural pollination, and this can be very stressful because they're packing bees together and they're moving them around, and worker bees don't orient very well to a new location. They tend to get lost.
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