Osprey Q & A

Sue C Do you know if the parents of EJ were ringed. Just wondering if there is a remote link to female near me. She was ringed in 1994 - right leg royal blue/XL white & is believed to have nested near Bridge of Cally since 1997.

I know its a long shot but worth a try!

Thanks

Val

Val The info about EJ hatching near Bridge of Cally was drawn from Roy Dennis' book "A Life of Ospreys" and it says no more than I've said above. The people who would know, would be Roy and Keith Brockie, who I believe still does the ringing in the area - I remember him posting on the LOTL blog last year.           

Keith Brockie posted just yesterday over at the LOTL Facebook group.

I'm using this thread to continue a discussion which started on this thread, around the following question:

What is known about the behaviour of sub-adult ospreys (age 2) and young adults (age 3 up to first breeding)?

• At what age do they first migrate north from their chosen wintering site?
• Where do they go, especially in relation to the place they hatched, or fledged?
• What are the criteria, for choosing nesting sites?

If you were taking part in the earlier discussion, please feel free to copy across relevant posts.

It's worth reading this page from Roy Dennis' website, which mentions some relevant points explained in greater detail in his book "A life of ospreys" 

In particular:

• Young male ospreys are philopatric - that is, they tend to return to the place they fledged from (usually the place they hatched, unless they were translocated by human intervention).
• Both sexes tend to gravitate towards existing osprey "colonies" when looking for a nest/mate. 

Both of these factors are obstacles to ospreys colonising new areas - though obviously there are real-life exceptions, or nests like the Welsh ones, Bassenthwaite and Kielder would not exist.     

1. How much time would it usually take for Rothes to get back to the LG area? Providing she doesn't have an extended stop over somewhere

2. How often has Roy or any ringer been wrong in guessing the sex of a Juvenile?  I ask this because I expect some one to see Garten and I still think he is a male. :) 

Unknown said:

1. How much time would it usually take for Rothes to get back to the LG area? Providing she doesn't have an extended stop over somewhere

2. How often has Roy or any ringer been wrong in guessing the sex of a Juvenile?  I ask this because I expect some one to see Garten and I still think he is a male. :) 

 

Hi Barbara Jean, 

1. If you look at the days Rothes was actually travelling on her way south, she took 6 days to fly from LG to the Gironde, a further 8 from there to the Senegal river, which she was nearing in Caroline's last report, and then 3 to reach the Bijagos Is. So in theory a fortnight from now, though there would probably be a stop at some point.  

2. As I understand it, juveniles are sexed on the basis of weight, wing length and other key dimensions in relation to their age - because females are heavier & bigger. Some mistakes have been made - for example I think I'm right in saying that Black 80, the male now breeding at Threave Castle, was thought to be female when he was ringed at Glaslyn as a chick. If you look at this report of the ringing and tagging of the 2009 chicks, Garten would have been pretty heavy if male - though she was known for her appetite!  

Unknown said:

1. How much time would it usually take for Rothes to get back to the LG area? Providing she doesn't have an extended stop over somewhere

2. How often has Roy or any ringer been wrong in guessing the sex of a Juvenile?  I ask this because I expect some one to see Garten and I still think he is a male. :)