Thursday night is a special night in our house at this time of year, it is the night of Autumnwatch.  We put extra logs in the stove, put up our feet and make sure the little man has been fed in time for our dose of mother nature.

This week we found out that the conker trees are dying and may face extinction!  Northern Ireland seems to be a bit away from this wave of horse chestnut death for the moment but the Atlantic weather buffer we hate love so much might not protect us for long.

On a cheerier note, the show revealed a new method for tracking bird migration that I can only describe as elegant.  Elegant is a phrase not to be used lightly in science but I think it is warranted here.


Sunrise on the Platte River during crane migration by jc-pics

Bird migration methods range from the classically widely used ringing to the use of gps navigation.  I imagine the use of gps navigation has the advantage of being accurate and giving details of the bird’s path.  However, gps is horrific in terms of weight and power consumption and therfore totally impractical.  The latest device is beautiful in its simplicity and yet is powerful in its ingenuity and accuracy, it is elegant.

The method if geolocation by light.  A sensor is placed on a bird that records the light levels every few minutes and records it.  It also has its own accurate clock and these two things combined seem to give it the ability to record the bird’s position on a day to within 50 miles.  And it consumes very little power.

source

The principal is that if you had your own clock with you as you voyaged around the planet, and if it could never be adjusted, you would find that the sunset and sunrise times, and length of day, would always seem to be not quite right compared to your home.  If your home was position A and you found yourself in position B then your clock would be telling you that sunset was very late,  hours late.

If your home was position A and you found yourself in position C then your clock would be telling you that the days were far too short and the nights much too long.

Someone somewhere had the revelation that this blindingly simple concept could be used to track bird migration. And, so the story is that it is we are on the crest of a new wave of research on the amazing long distance voyages across the planet.

On a more local view-point, Autumnwatch should be on for a couple of more weeks and on Thursday evening of this week it will be in Northern Ireland.  We can’t wait!

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