Thread subject: Fidelity in Ospreys
||07/01/04 07:10 pm
||I know ospreys pair for life etc. However it is often fascinating to watch what goes on if say the female osprey returns to the nest first.
It seems to be the case that they seem to pair off with whatever male turns up.
There was a fascinating case of this at Loch Garten earlier this year. Last autumn are two failed years it was felt that there was a stable couple in residence viz. Henry and White EJ.
Now EJ returned rather early on March 25th and so we anxiously awaited Henry's return. Now a different male turned up on March 30th and EJ and him got together quickly quickly.
It was noted that the pair seemed to know each other. Indeed they should because they had been a pair two years before!
Henry finally arrived on Arpril 4 and claimed EJ as his and then another fascinating story began.
Mind you when Henry had EJ safely with eggs on the nest it was alleged that he was on the look out for "a bit on the side" as his absences from the nest were very much greater than during the pre incubation phase.
So do you have any infidelity in ospreys stories?
||07/01/04 07:59 pm
||Tiger...I had posted something similar on the message board earlier, perhaps 6 wks ago for I too had read about Fidelity in Ospreys and it wasn't all positive. As you mentioned that once the female is on the eggs then what is to stop the MALE from trying a little 'on the siide'. It could be believed too that any femle already on an egg( who wasn't guarded) might welcome the attentions of yet another male who comes a calling. Can't put all the blame on the Males NOW CAN WE?????A confident/strong male would want to spread as many of his genes around now wouldn't he.
||07/01/04 08:29 pm
||I think the thing that is wrong with the idea that the male looks for a "bit on the side" is that he is very limited in the time window that it is possible.
Initially he is too busy guarding his own female from the attentions of any other ospreys and by the time she is "with eggs" most of the other female ospreys are brooding too.
||07/02/04 01:16 am
||This is my THIRD attempt to reply to this thread! Hopefully it will get posted this time.
I was wondering if DR. Tiger you had viewed the video clip on COPULATION from April this year? If you hadn't it is worth a peek. This clip is less than a minute in length. I have determined that it doesn't really take long to get into an ospreys nest, and for the male to do his thing. I do believe that there is a window of opportunity for any male to sneak in while the resident male is off 'Fishing' for his hen who remains back at the nest. After all he can't be every where at the same time... :-)) Anyway that is my theory.
More energy is spent selecting and securing a mate for, it is written, that the male may indulge in a series of short dives about(30ft) for as long as nine minutes without a pause:and pairs may be seen soaring and chasing one another
So...even though the experts say they mate for life who knows if this assumption can be challenged. Guess we need to Band all the young ospreys to really prove a point.
||07/02/04 05:00 am
||Poole's book also mentions that a male will be
"dropped" by the female if he is not a good provider of fish. The successful nest is one where the male has the experience,(as little as one year), even if the female has none. Though this is not about osprey, this year the storknest in Germany returning male was "waiting" for the "returning female" of last year. She was a bit late, so he hooked up with a new female who even got so far as to lay eggs. When the "late" migrating female stork arrived, she destroyed the eggs and chased the female away during the night, and currently is raising 3 baby stork of her own with her mate of previous years.
||07/02/04 05:02 am
||I have had a look and that is an interesting piece of video.
I know of a fascinating story from 2001 involving an adult called S18 and a young sub adult called S09 which were both satellite tracked.
I was particularly interested in S09 because although it was caught in Scotland it was a Norwegian not a Scottish osprey. I was very interested as to whether it would go back to Scotland or Norway.
Well in the spring of 2001 not only did S09 return to Scotland but it set up home with the mate of S18. Now poor S18 had lost its way and was late in arriving and of course since it was satellite tracked we could see where it was.
When S18 arrived home it was to find the wife sitting on eggs which presumably had been fertilised by S09.
Interestingly S09 was evicted and S18 took over the duties of being a good parent raising a kid that almost certainly was not his!
I think that S18 and his wife got back to normal in 2002.
S09 on the other hand has not been seen again as far as I know.
Anyway more details of this can be seen at:
||07/02/04 05:16 am
It is absolutely amazing that we should have been tying those two posts at the same time contrasting the behaviour of storks and ospreys.
Young storks seem to have a much more hazardous existance particularly if you are chick #4 or #5 where you are very likely to be murdered by mum or dad.
As for the ability to fish. One of the young female tranlocated ospreys went back to Scotland and paired up with an osprey with a missing toe. Now up to then this osprey had not successfully raised any chicks presumably because it had difficulties fishing.
However the pair are currently raising their third brood.
There was also an example last year of a young male who did not seem to understand that he had to provide fish for the female. Imagine the shock for the female as her previous partner was a legendary fiherman. Eventually she gave up.
Mind you that particular males was not much good at mating either! :)
||07/02/04 07:05 am
||Sounds like prime time soap operas, to me!! Thanks, all of you, for all the behind-the-scenes looks, it is really all so fascinating.
Now, if only THEY would write a tell-all book..... ;-)