Migration

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Migration

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I don't know if you got this unfinished blog, I pressed the wrong button...sorry.

  1. Why don't the chicks come back for 2/3 years?
  2. How do they 'know' when the 2/3years are up?
  3. How do they know which direction they are going?
  4. Will they come back to LG?

Thanks, in anticipation for answers!!!!

All Replies
  • Hello Maureen

    I rather suspect they don't know which direction they are going. Remember Deshar last year? (did I spell his name correctly?). South probably registers somewhere in their brain 'cos they will fly to 'warm' and birds will be very sensitive to a degree or two in temperature I'm sure. As they go south of the nest they must feel the air 'warm up' which maybe encourages them to keep going in the same direction.

    Like the 'chicks' finally felt it was time to just trust their wings and fledge - Mallachie had a hard time of it didn't she? - finally she was just 'ready' and left the nest.- I think they also just 'know'  'feel ready' to return north. They won';t be counting the months llike we will !

    All of this is 'maybe' or 'probably'  of course but nature is amazing. There is just 'something' in their brain boxes that says  'Go'.

  • Maureen, I'm no expert and have asked the same questions myself - over and over!! Try Roy Dennis for answers - he has an amazing book you can order from his website http://www.roydennis.org/  Another place I found a few answers is a US site where Ospreys have been tracked for a number of years and a huge amount has been learnt from their travels. http://www.bioweb.uncc.edu/bierregaard/Index.htm  It may take you some time to read all this but its perhaps something to bookmark for when the LG sisters have started their migration and we have dark winter days to fill.

  • Jacki, thanks very much for your answers I have bookmarked the pages for, as you say, the long dark nights.

    I am glad I'm not the only one to have these type of questions popping into my head. We could go on forever speculating and I am sure it purely instinct which helps the Ospreys on their way 'back home'. BUT I would like to know how they know that 2/3yrs have passed. LOL

  • Thanks Jane.....I will be counting the minutes, never mind the months 'til EJ and hopefully Odin come back.:o)

    Maureen x

  • Maureen all the evidence we have suggests that most of the juvenile ospreys that do come back, arrive about June in their second year. Of course that pre-supposes that they have been ringed and someone actually spots them.

    There is one case of a female from Rutland  called 06 (01) who was satellite tagged and she came back in her first year (2002) and actually nested and raised two chicks as a two year old (2003). Unfortunately she was not ever seen again as far as we know.

    06 (01) was strange in another way too. She overwintered in Portugal rather than go on to Africa. She clearly had not read any osprey books.

    There have been only 11 chicks fledged from Loch Garten since 2001. We know that Nethy and Deshar came to grief. As far as I know none of the 2004 or 2006 broods of three chicks each have been reported again.

    It seems that the males are likely to return to near their natal sites but the females wander near and far. The female chick raised in the Basenthwaite nest in 2004 was spotted in Norway and is presumably nesting there now.

    However males do not always come back to their natal sites. The first Welsh chick, Black 80,  ever known to make a return came back to Scotland rather than Wales and is raising his first family there right now.

     

  •  

    Hi Maureen,

    1. Many young birds will remain in wintering areas for their first summer or stop in the Mediterranean basin, some second year birds also stay in the south, and have given rise to persistent rumours of breeding in the African interior. for the vast majority of of second year birds do migrate north and attempt to attract a mate although sucessful breeding probably won't occur until the following year. Second year birds follow on average a month later than experienced breeders.    

    2. As the birds reach an age of breeding maturity they instinctively migrate to higher latitudes. An immature bird will even build a practice nest without securing a mate in thier second year. its simply a case of practice makes perfect. The urge to migrate can be demonstrated as an innate ability (best described as being determined at a genetic level and trickered by other environmental factors) - as is seen in cuckoos. Cuckoos for example never encounter thier parents yet thier behaviour is all naturally dictated as to where and when they migrate. 

    3. As a general rule bird migration movements are north-south and this has evolved as an evolutionary response to seasonal changes in the climate. So birds don't necessarily "know" where they're going, rather they move in a general north/south direction and use markers such as coast line to assit in thier navigation. 

    4. No, they probably won't return to LG, although it is possible.  Breeding age birds may settle close to or far from thier birth sites - the maximum recorded distance from orginal nest site was 950km! this promotes better genetic mixing and keeps the population healthier!  

    Lloyd

       

  • Osprey -  I'm in awe of your knowledge. Thank you for such an interesting, no, fascinating blog. I've really enjoyed the read. But am SO sad that  so many juvenile Ospreys do not mature.  I think that 06(01) was very sensible. Why go so far, anyway, if Portugal has the right temperature and lots of fish !! 


    Only 11 Chicks in 8 years. Gasp ! That's devastating.

  • Sorry Cirrus - clicked ''suggest an answer' to see what happens and a yellow tick appeared!! How do you get that box to appear in the first place.?

  • it seems to happen automatically if  'experts' do not answer the question LIbby. I'm agog waiting for a REAL expert to answer a question so I can see what happens. Until you said, I didn't even know a yellow  tick appeared when one clicked  on 'suggest an answer'.    ! !   :)

    I have had SUCH a frustrating time online with the forums today you woudn't believe. The highlight of today has been REAL LIVE OSPREYS in the nest . ! YES  !!!!!!!!!!!!!!!!!!!!!!!!!!!  That's what I'm talking about.

    And I do hope you've been nest watching and seen them too. Glorious views when 'cam man' zoomed and panned. Here's to CAM MAN !!!   Thank you sir, or maam.

     

     

  • Cirrus

    it seems to happen automatically if  'experts' do not answer the question LIbby. I'm agog waiting for a REAL expert to answer a question so I can see what happens. Until you said, I didn't even know a yellow  tick appeared when one clicked  on 'suggest an answer'.    ! !   :)

    I have had SUCH a frustrating time online with the forums today you woudn't believe. The highlight of today has been REAL LIVE OSPREYS in the nest . ! YES  !!!!!!!!!!!!!!!!!!!!!!!!!!!  That's what I'm talking about.

    And I do hope you've been nest watching and seen them too. Glorious views when 'cam man' zoomed and panned. Here's to CAM MAN !!!   Thank you sir, or maam.

     

     

    Glad it isn't just me! I find it really annoying and slow. I think I shall stay with the bloggers on facebook and just dip into this one. Watched Garten this pm for ages - she is my favourite - hate to think of her going and then knowing nothing for 2 years and then only maybe knowing what becomes of her.

  • Ah Libby, I've had an epiphany, or maybe just a clout across my head !! Anyway, I reckon the yellow TICK is for when someone (no idea who mind!) indicates that the 'suggested answer' is actually, the 'correct answer'. ......or not. But maybe.    :)

  • Watched Garten this pm for ages - she is my favourite - hate to think of her going and then knowing nothing for 2 years and then only maybe knowing what becomes of her.  (your quote)

     

    Mmmmm. Yes, I'm with you there, Libby. The awful chasm of not knowing about precious little Garten for two years - and just hoping that after that time someone spots her leg ring!  Shudder. It's all too much. I don't know that I'm going to do the GoogleEarth thing - I did last year, but Deshar just broke me up.

     

     

  • LLOYD....thank you so much for explaining migration. I can understand them using land marks etc. but what fascinates me is how do they  'know'  when the 2/3yrs are up and it is time to migrate and hopefully breed.

    I guess it is one of life's mysteries!!!!

    PS. I am an avid fan of Walt Disney LOL........wouldn't it be great if life for the wildlife were like that???

    Thanks again and I am sure I will have more questions for you!!!

  • Cirrus

    Watched Garten this pm for ages - she is my favourite - hate to think of her going and then knowing nothing for 2 years and then only maybe knowing what becomes of her.  (your quote)

     

    Mmmmm. Yes, I'm with you there, Libby. The awful chasm of not knowing about precious little Garten for two years - and just hoping that after that time someone spots her leg ring!  Shudder. It's all too much. I don't know that I'm going to do the GoogleEarth thing - I did last year, but Deshar just broke me up.

     

     

    This a second attempt!

    I maked the last known 'sightings' for Deshar and Nethy on Google so they are gone but not forgotten. I still upsets me to think of Deshar being exhausted and all alone in the Atlantic. 0% survival last year wasn't good - let's hope this year is better. Can I bear to watch?

     

  • No British juvenile osprey has to my knowledge ever carried a transmitter to Africa and back although two have successfully carried them to Portugal and back.

    I feel feel very hopeful that either Rothes or Mallachie will be the first British juveniles to carry a transmitter to Africa an back but then who knows they may elect to overwinter in Spain or Portugal.

    There is one juvenile osprey that has carried a tranmitter to Africa and back (a number of times) and that was a young Finnish osprey called Mirja. See http://www.fmnh.helsinki.fi/english/zoology/satelliteospreys/2002/mirja.htm