Avian navigation

Intro
This piece has been forwarded to me by one of our editors: Simon Raggett. He gives us the quantum twist. You will also find much written here on the subject of avian navigation based around gravity from our editor Antonio Nafarrate, who has been in communication with the authors of this piece. Please follow the link below.

Richard Nissen
Editor

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A curious finding is reported in the 15 November New Scientist. Trained homing pigeons became disorientated when flying over a crater where the force of gravity was lower than normal.

Gravity is the weakest force and the intermediating particles are undiscovered, the force usually being understood in terms of the curvature of spacetime. Our normal understanding of brains does not allow for detection of presumably very minor fluctuations in the gravitational field, but it can be speculated that the radical pair entanglement in avian brains might somehow be up to this. It might also be worth considering that water courses, mineral deposits etc might create fluctuations in the gravitational field.

The reference is Journal of Experimental Biology, DOI: 10.1242/jeb.108670

https://www.google.co.uk/?gws_rd=ssl#q=Journal+of+Experimental+Biology%2C+DOI:+10.1242%2Fjeb.108670

Simon Raggett

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Traditional Shepherding and Transumance in the Cevennes

Transumance  is the seasonal movement of animals from the lowlands to high pastures for the summer months.

This article and images come from witnessing Transumance in the Cevennes each year and talking to Annie Lashermes whose flock it is. The tradition of Transumance goes back millennia.

Richard Nissen
Editor
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Transumance routes

Transumance

A shepherd with his typical umbrella just starting off on his journey with the flock up to the high pastures in June

photo

The leading ewes, who are seen by the shepherd as the most responsible and have made the Transumance journeys before, are marked with pom-poms and are the leaders of the flock on journeyphoto

Transumance4I often visit a community in the Cevennes, which is in the South of the Massif Central in France. This is a little village called Saumane near St Jean du Gard,

The Cevennes is a very mountainous in that it has steep hills that are covered in snow in the winter but these are not rocky or barren and wherever possible the people have terraced the ground or hacked out small fields as they can.

Annie Lashermes inherited a large flock of sheep from her father and has over 200 sheep now.

She is a traditional shepherdess and tends her flocks by deciding on where they should eat each day and then goes off with her flock to that location. She or a friend is always with the flock. There are no stock proof enclosed fields in this region.

The flock sticks together, Annie stands with her stick besides the flock overseeing the sheep with her dogs beside her

She told me that she decides where the sheep are to go and they seem to know where she has chosen. She does not use her dogs as the British do: to chivvy and corral the sheep.

Annie looks over her flock and if a few ewes ere from their patch, which Annie has somehow willed out, she whistles and the erring sheep know exactly that they have overstepped the boundary and scuttle back to the main body of the flock.

Once, I was talking to her and she said we are just going to move to the next pasture on the other side of the road, nearby, and as she said that the first sheep moved over the road into exactly the place she had intended.

Sometimes Annie finds some sheep seem to have ignored the flock and she sends the dog off to “sort it out”. She talks so quietly I am certain that dog cannot hear her but her dog picks up a telepathic message and sets off. When I have seen her work her dog often the dog just approaches the errant sheep and glares at them. They immediately take fright and run back to join the others.

It is uncanny as Annie’s grazing areas are not bounded by anything more than her will. She grazes areas that are a portion of an open field sometimes half of which she does not have permission to use, yet this is not a problem.

As the weather changes she participates in what is called the Transhumance. This is the journey up from her village Saumane (300 metre altitude) where she and her flock live to the high pastures around Mont Aigoual (1567 metres altitude). Her flock join with thousands of other sheep of other flocks to take advantage of the pasturage at these higher elevations.

In order to do this journey they follow ancient Neolithic trails (the Draille). The Draille like all the ancient Palaeolithic tracks goes dead straight up and down the mountains just below the ridge line (so as not to be seen) on the lee side to the prevailing wind (for shelter). There are traditional stopping points on way.

The sheep that Annie thinks of as leaders, are decorated with coloured wool Pom Poms on their backs. The sheep go up at the end of May and come back down in September.

Annie tells me that the sheep know these ancient routes and follow them. She says that they somehow “feel” the track and keep on it. Another demonstration of this sort of behaviour are what is know as hefted sheep in the Uk. These flocks know their areas and live in them. The especially prevalent in the Lake District in the UK.

There is a bond between Annie and her sheep and the sheep know the ancient route of the transumance too.

See en.wikipedia.org/wiki/Transhumance

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Navigation Networks in the Brain

Professor Kate Jeffrey of University College London gave the annual address to the Royal Institute of Navigation (RIN) this year (2014). This article published in RIN’s Navigation News is, for me, a seminal step forward in describing the parameters of animal navigation and building a structure to delve deeper into how navigation might work.
Her idea that you need to know where North is in order to orientate your “map” makes sense of a whole lot of otherwise incomprehensible research. Knowing where North is without a map does not get you home.
Richard Nissen
Editor September 2014

Brain Feature

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The amazing navigation of Shearwaters

http://www.delanceyplace.com/view_sresults.php?2591

 

Shearwaters

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The hippocampus of rats

Prof Kate Jeffery has done some very interesting work on how the hippocampus of rats processes navigational information. Scientists are clear that the hippocampus is critical for navigation but believe that it is only one part of a larger system that has many functions including recognising landmarks, computing distances and directions etc. and forming memories. For instance, the homing pigeon needs a direction to fly from its unknown (to it) release site until it reaches its own neighbourhood where its loft is, where it needs familiar remembered landmarks to help it home in on its own loft. The navigation system is thus closely linked to memory. Please see this link to see her work: http://www.ucl.ac.uk/jefferylab/research

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Monarch Butterflies

Here is a link to Monarch Butterflies

http://phys.org/tags/monarch+butterflies/

Editor’s remark

I have difficulty understanding these results which  suggest that Cryptrochromes are involved which I am fairly clear is impossible as there is not enough time for the quantum coherence to take place.

Inclination compasses are very inaccurate as there can be huge changes locally due to magnetic anomalies in the ground.

I still have the problem that knowing where North is, is of no help, if you do not know the bearing of where you are going.  Ie You must  know where your destination is.

I look forward to any feedback on all of this.

I have heard that The Monarchs that set off on these migrations are not the same individuals as end at their destinations – another conundrum!

Richard Nissen
Editor

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Songbirds really do fly south for the winter

There has been a recent article in the New Scientist 9 August 2014 entitled:

“Songbirds really do fly south for the winter”

Scientists had postulated that intercontinental migratory songbirds flew north for the summer to breed in order to escape overcrowding and intense competition in the tropics. Most of us had always though that the flew south to avoid hard winters.

Ben Winger of the University of Chicago has now done some research.  He suggests that there is strong evidence that songbirds are actually driven to fly south to avoid harsh northern winters.  Winger’s team studied 800 species of North American sparrows, warblers and blackbirds and looked at the present distribution of each species and then inferred where the species had once lived and discovered that birds who carried out long distance migration were twice as likely to come from temperate ancestors than tropical ones.

This leads to the supposition that if Climate Change is leading to warmer winters we will see more birds staying put for the winter.  This indeed is what we already find with birds changing their strategies and becoming resident where the climate allows this.

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Editor’s comment

This piece of work just underlines what I think we all knew all along –birds migrate to avoid harsh winters.

Richard Nissen

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