How Do Homing Pigeons Home


With the barn swallows back this Spring and being quarrelsome for about 45 minutes prior to day break, I am reminded that many birds fly long distances and come back to the place they started.

Pigeons are a little different in that they are definitely “home birds” and we have regular competitions where we take them somewhere that they haven’t been before and tell them to go home. Big money can change hands for the best birds.

It has long been a question as to how do homing pigeons home? The favorite idea is that they have a compass stashed away, but exactly where has been the subject of speculation. No more!  Dickman and Wu of Baylor have cracked it. The BBC has a full report (1) on their recent paper in Science (2) in which they report that the bird brains have room for a very sophisticated magnetic field sensor.

Apparently, each pigeon has 53 neurons that fire up in response to magnetic field changes. They measured the electrical signals from the individual neurons as the bird was held in a magnetic field that was varied in direction and magnitude.

Sharks, whales and bats also use the earth’s magnetic field to navigate by, so this ability seems to be fairly widespread and leads one to wonder if many men think that they also can do this, and that is why real men don’t stop driving and ask for directions. Their success is clearly the reason that their female passengers demanded that the GPS for automobiles be invented.

  1. http://www.bbc.co.uk/news/science-environment-17855194
  2. http://www.sciencemag.org/content/early/2012/04/25/science.1216567   



Physical Education Grades – More Important Than You Think


 For many of us who have been enjoying our developed world Western diet, albeit with care, the annual physical is not something we look forward to. You need to get more exercise is mentioned in surgeries all over.

While we make up our minds to do better, we look with envy at those amongst us going out, rain or shine, to train for their next marathon. A couple of miles down the road and we’re looking out for the next bus stop. But now it turns out we should have been trying much earlier.

How much earlier? According to Timpka et al in PLoS ONE this week, we should have been hard at it in school physical ed. class, especially if we happen to be female. This is a study from Sweden of 1712 people who were 16 in 1974 – 1976. Their health records from 2003 to 2007 were put under the microscope along with their grades in PE.

The stark result of the study was that poor health in the mid-forties for women correlated with poor physical education grades at school. There wasn’t such a correlation for men, though.

The authors of the study have to do some mental gymnastics. They suggest that there is a “bio-psycho-social” model that explains their findings, tying up poor PE grades with habits like smoking, low fiber diet and putting on too much weight.

Why not with boys? Well, it is suggested that the have a higher habitual activity level. I guess they have playing soccer in mind rather than running after girls.

I think that they should revisit the cohort in another 30 years to ensure that the data don’t change.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0035718  



Mirror Neurons Win Out


On my walk yesterday morning I found that at one stage my mirror neurons took over as I approached a woman hurrying towards me with a camera and pointing it up in the air. Then I saw another couple 25 yards away stopped and looking up as well. My mirror neurons would not be silent and I stopped and looked up.

Now, I knew we weren’t far from our osprey’s nest and the tree I was looking up at probably had her mate in, but I had to join in and stand and stare. This of course is a well-known effect and has just had another quantitative check by Gallup et al who have published in this week’s Proceedings of the National Academy of Science (1).

The new experiments were done in the busy streets of Oxford at lunchtime and at a commuter station. Over 3,000 pedestrians were tracked and the first type of experiment just entailed some plants stopping and looking up at a roof-top camera. The second type of experiment had a couple acting as though they were trying to discretely video people while one of them was taking copious notes – good conspiracy theory stuff.

The results showed that lunch ideas were tending to damp down mirror neuron activity. The bigger the group of planted starers, the more people tended to spend time also looking and about a dozen seemed to saturate the interest of the hungry crowd. However, the starers didn’t cause the crowd to crystalize so that they all stopped to stare.

Being English, the people in the crowd were more likely to look if the others who were looking would be unable to see that they were also looking. And as for staring at people doing suspicious things in a commuter station, that would be really bad form. Nobody would want a “and what are you looking at?” response which is a standard precursor to a Donny Brook.
  
  1. Gallup et al, http://www.pnas.org/content/early/2012/04/18/1116141109.full.pdf



Meerkat Challenge


Photo: Ashleigh Thompson
 (Creative Commons posted to Flickr.com by Snowmanradio)


Meerkats make some of the most appealing animal pictures. They cluster together to give wonderful group photos. They clearly form well knit groups with shared division of labor on such things as watching out for trouble while the rest go looking for food.

In their wild breeding colonies they have a clear hierarchy and like any successful group of animals, the colony doesn’t stay static. Some of the feisty young males disperse looking for excitement elsewhere. They have to do this because of the usual group dynamic of the older dominant males hogging the females.

These young guys can be innovative in many ways. Thornton and Samson have written up their study of meerkat innovation and this was featured in a BBC report (1) after appearing in J Animal Behaviour (2). The authors of the study took the meerkats favorite food (that is scorpions) and placed them in a container which was a puzzle to get into.

Young juvenile meerkats all rushed to try their luck but failed. The old guys were too busy with affairs of status, leaving the feisty young blades to solve the problem. Given multiple opportunities to puzzle out how to get a scorpion dinner, they managed to succeed many times.

However, their success didn’t come from learning about the complicated set up of the experimenters, but from dogged persistence. Maybe they had more time on their paws or maybe they were not quite ready to relax and enjoy the good life as they weren’t seeing too much of it thus far. Whatever, they appear to be the future of the meerkat groups as problem solvers for the next meerkat challenge.



Perky Pond Life


 The past few days here have been unseasonably nice weather and the wildlife in and around the Ponds is definitely perky. The plant life too is enjoying the sun.

On my walk this morning, I noticed that most of the trees have new leaves showing and the cherries are magnificent, but the magnolias hereabouts are looking a little blousy. The heaps of scarlet petals beneath the large rhododendron reminded me that it has been offering its wares to the insect world for over a week now. Bluebells are flowering too.

Several pairs of Canada geese have little troupes of goslings. They swim in line astern with the little ones paddling as hard as they can to keep up. Too early for ducklings yet, though.

The ospreys are back to serious nesting. The female is getting pretty raucous calling to her mate when she spots him coming back from the river. He clearly hadn’t brought anything back this morning as she kept giving him a piece of her mind for several minutes after he arrived.

The turtles are out in force keeping the cormorants off their logs. They were out very early today with their shells turned towards the sun. On my way back they had all shuffled round to follow the sun. With dark shells, it must get pretty hot inside. Perhaps the least perky pond life on show.


Entomophagy, A Mealworm Meal


The US is very keen on pets, exotic or otherwise, and as a result every year it imports approximately 110M wild animals (see refs in (1)). But the even more surprising figure is that of the importation of non-live wildlife – that is a staggering 25M kg/annum (see also ref 1 sources). Some of this comes in cooked, smoked or raw.

These imports are monitored and legal, but underlying this is a significant trade in smuggled bushmeat from the African continent. Some of these are primates (non-human of course) such as chimpanzees, mangabeys and baboons, while others are rodents like rats including cane rats.

Of course these are only a minute fraction of the US diet and not to be found on your average supermarket shelves, but the problem is that they can be hosts to viruses. A USFWS study, reported on by Smith et al in PLoS one found things like simian foamy virus and some herpesviruses in some of the samples confiscated from smugglers (1). The viruses were identified by genomic analysis.

To put the problem in perspective simian foamy virus is a relative of SIV and then HIV, so that’s not a good thing to be washing down with a fine wine at dinner. Also, you’ll recall that the SARS outbreak of a few years ago was traced back to munching on palm civets caught in the wild.

Perhaps its time to go with the new trend in the Netherlands of moving over to eating insects (2). I understand that there is at least one restaurant in Amsterdam catering for insectivores instead of carnivores.

I should note that for those enthusiasts of correct English, insectivores are normally reserved for animal insect eaters, for human insect eating the preferred term (little used so far) is entomophagy. Entomophagy is not widely practiced yet as part of the standard Western diet, although about 80% of the nations of the world indulge quite happily (ref Wikipedia).


  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0029505#pone.0029505-Smith1
  2. http://www.dutchdailynews.com/eating-insects/

Being Sensitive To Our Robots


As our technological achievements rush forward, more and more groups are working on robots that need to interact closely with us. The HRI (human-robot interaction) is an ongoing problem as most of us are keen to have likeable robot assistants even if it’s only a vacuum cleaner.

A new trick in the game has been written up by Sciutti et al in the International Journal of Social Robotics where they are proposing a technique that they call motor resonance (1). Now motor resonance was new to me and I was relieved to discover that it referred to the way mirror neurons work where we get fired up just watching an action taken by somebody else. Thus humans tend to do the same thing as other humans.

Apparently our EEG activity is modulated by noticing a robot action just as much as a human action. Hence, it seems that we should respond to our robot friend and take our cues in a similar manner to how we would respond to a person.

Thus as we spot the robot starting to take action, our mirror neuron system fires up and we respond in kind. So now we know how to behave around our humanoid robot, but how is it going to pick up the cues from us?

 I doubt if we’ll be happy to leave the robot entirely in charge, but maybe I’m wrong. As long as it responds to an imperious command from us, I suppose we’ll be content with being sensitive to our robots.

  1. Sciutti et al, Int. J. Soc. Robot, (2012), DOI 10.1007/s12369-012-0143-1